post

Deciphering The Camera Jargon – Part 3 – Loose Ends

This is the third and the final part of the Camera Jargon series. Hopefully, I explained most of the popular terms in such a way that a beginner can understand. I left out some of the technical details when I felt that they are not necessary to understand the concept. Some of these terms are only explained briefly and has much more to it. As I keep writing this blog, I intend to go in to details in depth.

Depth of Field

Depth of Field or DoF for short is the area of an image that appears reasonably sharp or in focus. I discussed about DoF in the previous article in brief and I mentioned how the aperture affects the DoF. There are couple of other factors contributing to the DoF. However, I think I’m going to leave out most of the technical details out in this discussion.

Aperture – No point in repeating myself. See the previous post.

Sensor Size – Have you ever noticed when you’re taking pictures with your phone or your pocket camera, everything seems to be in focus no matter what you do? Hence the increased popularity in the Instagram and its blur feature. But when you’re using a DSLR, it’s much easier to achieve a blurred background and a sharply focused subject. FYI the blurred out background is called bokeh and nobody knows how to pronounce it (or to spell it). Anyway, the DSLRs have a much larger image sensor compared to mobile phones or pocket cameras. Larger image sensors allow shallower DoFs.

Camera to Subject Distance – When you’re up close and personal to the subject, you get a shallower DoF and if you step back couple of feet, you get a deeper DoF.

Subject to Background Distance – If the distance between your subject and the background is greater, you will get a much blurred background. If the said distance is smaller, you will get a deeper DoF. Just think of a person standing right next to a wall. The wall will almost always will be in focus. But if your subject is standing out in an open field, the far away mountains will almost always will be out of focus.

Focal Length – This gets a little tricky to explain without going into technical details. Contrary to the popular belief, focal length does not contribute to DoF. But there’s a reason why I included it here. It APPEARS to have a significant impact on DoF. There is an apparent change in DoF with a long lens vs. a short lens because the length of the lens changes the perspective in the scene – longer lenses render the background larger in relationship to the subject making it seem more blurry thus creating the impression of less depth of field. This is because when you’re shooting at a very wide focal length (say 16mm), your field of view is much greater. But when you’re shooting at a telephoto length (300mm or so), you field of view gets narrower. Thus your subject occupies different fractions of your image. Tele lenses magnifies the subject and therefore, they occupy a greater portion of your image whereas in wide angles, the subject appears smaller and they only occupy a smaller portion of the image. If the subject occupies the same fraction in both scenarios, the DoF will be the same. In order to do this, you have to step back a lot when you’re shooting with the telephoto lens. But that kind of defeats the purpose of a telephoto lens, doesn’t it? So the take home message is that technically, focal length does not have an effect on DoF. However, artistically it does. Since photography is an artistic medium, I will leave it up to you to interpret this one. It has been raining in Sri Lanka like crazy for the last couple of days. I will demonstrate this with an example the first chance I get and post it here. Bare with me until then.

White Balance

I think it would be fair to say that white balancing is a way to reproduce the colors as accurately as possible. Each light source has a different temperature (or a color) associated with it. Day light, tungsten lights, candle light, fluorescent etc. has different colors. However, modern DSLRs are more than capable of doing a decent job when the available light is uniform, or you have one type of light source. When you’re using couple of different types of light sources, it gets a little tricky. Imagine you’re shooting inside a room that is lit by fluorescent bulbs and tungsten bulbs. Your pictures are likely to have an unnatural color cast on them.

White Balance_1

Left – White Balanced. Right – Not White Balanced.

Have you ever taken pictures, specially with a compact digital camera, inside a room and all of your pictures had an amber color to them and you wondered why? This is because your camera gets confused under these conditions unlike human eye, which does a fantastic white balancing job. Simply put, white balancing is telling your camera what white looks like, hence the name white balancing. When you tell your camera what white looks like, it automatically puts all the other colors in to their proper places and thus produces an accurate image. If you’re mathematically inclined, you can think of this as a circle centered at origin (0,0) on a XY plane. The radius is irrelevant here. Imagine that inside the circle is all the colors you need. When the camera is not properly white balanced, the circle shifts its position. So what’s supposed to look like white, does not look like white anymore. When you white balance your camera, the circle shifts back to its proper place, and you have all the natural colors again.

White Balance

If those red straight lines are our X and Y axis, the one on the left is when you have your camera properly white balanced for the situation and one on the right is when you don’t have your camera properly white balanced. Note: This does not represent all the colors your camera can produce. This image is only used to illustrate my point. I grabbed the color wheel from PemaMendez in DeviantART. Kudos to him for making it.

There are several methods to white balance properly. You can shoot RAW format and adjust your white balance later during post processing. This is what I personally do. If you shoot JPEGs, you limit your ability to properly white balance during post processing because you burn your white balancing profile into the image and doesn’t collect enough data to do it later. You can adjust it a little bit but not as much as shooting RAW. If you want to get it right in the camera, you can use something called an 18% grey card. As the name suggests, it’s simply a card that is grey. What so important about the color grey? Well grey has equal amounts of each primary color and reflects natural light and the camera can use it as a reference point. What you do is, you place the grey card against the subject you want to shoot and take a picture of the card, properly exposed, filling the entire scene. Then use this image as a reference custom white balance image. Refer to your camera manual on how to achieve this on your camera. When you do this, your camera will produce accurate colors.

Aspect Ratio

Aspect ratio describes the ration between the width and the height of an image. This is something often ignored by many people because the aspect ratio is something that is fixed. This ratio reflects the width to height ratio of your camera’s image sensor. Canon, Nikon, and Pentax have a 3 : 2 ratio whereas Olympus and Panasonic have a 4 : 3 ratio. The 3 : 2 ratio comes from the 35 mm film where the area that records the image is 36 mm wide and 24 mm tall. This becomes a very important subject when you’re going to print your pictures. If your camera’s aspect ratio is 3 : 2, you can make 2 x 3, 4 x 6, 10 x 15, 16 x 24, 20 x 30 prints or anything that matches the 3 : 2 ratio without cropping out your image. However, the problem is that most of the popular print sizes, like 5 x 7, 8 x 10, 11 x 17 don’t match with this ratio. There are some places that will make prints that matches with your ratio, so don’t fret. I don’t like to throw away pixels but most importantly, when you crop your picture, it changes the composition of the image. So when you’re out there taking pictures, and if you plan to print these pictures with anything other than the native ratio of your camera, you need to take into account the fact that you have to crop this image later. Personally, I always stick with  3 : 2 ratio because that’s what my camera gives me.

FPS

In photography, fps stands for frames per second, not first person shooters. When you look at a camera’s specifications, this number is often under continuous mode or burst mode. This mode allows you to take a series of shots by holding the shutter button. This is mainly used when taking action shots, like sports or birds in flight. This increases the chance of getting a sharp shot and later you can discard the rest of the images if you want to. Thank goodness we’re shooting digital. The fps depends on several things. Buffer, the temporary memory where the images are stored before they are transferred into the memory card. Higher the buffer, high the fps. Image processor is another factor. If your camera has a faster image processor, the fps is higher too. The megapixel count has an indirect impact on fps. Since more megapixels mean bigger file sizes, it fills up the buffer really fast and thus results in a lower fps. This is why the Nikon’s the D800, fully equipped with all the other modern features, still shoots at a very low 4 fps because it has a unnecessarily large 36.8 megapixel count.

Image Stabilization

Remember I mentioned the one over focal length rule? Now that I have discussed the effective focal length, I should say that it’s actually one over effective focal length. This rule gives you a rough idea of how much your minimum shutter speed should be to handhold your camera in order to obtain a sharp image. This is of course not a rule written in the stone and it varies from person to person. However, the Image Stabilization (IS) technology gives you the option to handhold the camera at lower shutter speeds. Usually a lens would say that it has 2 stop IS or 4 stop IS. What this means is that you can shoot either 2 or 4 stops of shutter speed lower than the regular shutter speed when handholding the camera with an image stabilized lens. There are two main ways of stabilizing images.

Lens – Based

This is accomplished by introducing gyroscopic sensors. It would move the lens elements to counter the movement of the camera due to hand shake and direct the light into the sensor. There are two gyroscopic sensors, one to detect horizontal movement and the other to detect vertical movement. Some high end lenses come with a secondary mode of image stabilizing which allows you to turn off the horizontal gyroscopic sensor. This is useful when you are panning your camera to follow a subject, like a moving car.

Sensor – Shift

In this method, the sensor is shifted to compensate for the movement of the camera. The advantage of this method is that the image is stabilized irrespective of what lens is used. The disadvantage is that the effectiveness of stabilization is limited to the movement of the sensor and that if your camera has an optical view finder (most DSLRs do) the view finder won’t be stabilized. Sensor Shift IS is also called the in body image stabilization.

IS

Effect of Image Stabilization. The left one was taken with the IS on and the right one was taken with the IS off. Both were taken using the same camera, lens, and settings. The shutter speed was 1/50th of a second at 300mm (480mm effective focal length). As you can see, the IS makes a huge difference specially when shooting in such slow shutter speeds at higher focal lengths.

Different lens manufactures like to call this feature different names.

  • Canon – Image Stabilization (IS)
  • Nikon – Vibration Reduction (VR)
  • Olympus – In Body Image Stabilization (IBIS)
  • Sony Cyber Shot – Optical Steady Shot (OSS)
  • Leica and Panasonic – MegaOIS
  • Sony – Super Steady Shot (SSS)
  • Sigma – Optical Stabilization (OS)
  • Tamron – Vibration Compensation (VC)
  • Pentax – Shake Reduction (SR)

Olympus, Sony, and Pentax uses sensor shift stabilization whereas the others use lens-based stabilization. Image stabilization only works to compensate for the camera movement. If your subject is moving, you will still get a blurry image if you don’t use a fast enough shutter speed. IS is specially useful when shooting in low light conditions where handholding the camera is necessary.  

This does not obviously conclude all of technical terms used in the wonderful world of photography but some of the most important ones. Other terms will be explained as they come along in our discussions.

post

Deciphering The Camera Jargon – Part 2 (Focal Length and Lens Choices)

This is the 2nd part of the camera jargon series. Once you finally pick out your first DSLR then you are faced with another challenge. How can you possibly pick out a lens from all those lenses available to you? Which lens is right for you and what are some of the limitations that you may face? This article aims to answer some of those questions.

Focal Length

Focal length is probably the most basic description of any given lens and is usually represented in millimeters. It is horrifying to hear that some people think this is the actual length of the lens. If it was, imagine the size of a 10mm lens. While it would be so nice to have such tiny lenses, that is not the case. So what is it then? The focal length of a lens is the distance from the optical center of the lens (where light rays converges to form a sharp image when focused at infinity) to the image sensor of the camera. Without discussing physics behind this, it is easier to think of the ways certain focal length ranges affect the image. Note that the focal lengths described here are in terms of full frame cameras. The sensor size of the camera determines the effective focal length of a lens as mentioned in a previous article.

Sorry about the crappy scene. I'll update this as soon as I get the chance.

Sorry about the crappy scene. I’ll update this as soon as I get the chance. Click on the picture for a better view.

As seen in the picture, short focal lengths allow a wider viewing angle whereas longer focal lengths gives you a narrower viewing angle (Field of View – FOV) and magnifies the subject. So the focal length and FOV are inversely proportional. If you really want to know, FOV = 2 arctan (x/2f) where x is the diagonal length of the image sensor and f is the focal length. But that’s just bonus information. Strictly technically speaking, anything lower than a 50mm is considered wide angle and anything higher than 50mm is considered telephoto. However, in popular culture, this is not the case. We put lenses into several categories.

Normal Lenses – If the focal length of the lens is equal to the diagonal length of the image sensor, it is said to be a normal lens for that particular camera. For instance, a full frame sensor has a diagonal length of 43.3mm but there are no such lenses. So on full frame cameras we consider 50mm (or between 35mm – 70mm) lenses as normal lenses. Normal lens roughly gives you the same field of view as your eyes. Thus everything looks normal. These lenses are used for documentary, journalism, and street photography.

Extreme Wide Angle Lenses – Lenses with focal length less than 21mm is considered extreme wide angle. These lenses have a very large field of view. Mainly used in architecture photography, although I use a 10mm (16mm effective focal length) for landscapes.

Wide Angle Lenses – Focal length between 21mm – 35mm are considered wide angle and are used in landscape photography.

Medium Telephoto Lenses – Lenses with focal lengths between 70mm – 135mm belong to this category. Specially used for portraiture.

Telephoto and Super Telephoto Lenses – Anything between 135mm – 300mm and above are considered telephoto lenses. These are mainly for sports, birds, and wildlife photography.

Macro Lenses – This is an entirely different domain on its own. These lenses come in various focal lengths. In a very technical sense, a true macro lens has a 1:1 magnification. This means, the reflection that is created on your image sensor has the same dimensions as the actual object. For instance, if you’re focusing on a penny that has a, say 10mm, diameter. The reflection of this penny will also have a 10mm diameter. But some lenses are designated as macro lenses using a less strict definition if they achieve a reasonable magnification. The Sigma AF 70-300mm f/4.0-5.6 APO DG Macro is such an example. It’s not a true macro lens but it achieves a 1:2 magnification. Meaning, the diameter of the reflection of that penny would be 5mm instead 10mm if you use this lens. Macro lenses generally have a very small nearest focusing distance. So you can get very close to the subject and still focus fine. Macro photography opens up a whole new world for photographers. You can see amazing details on tiny little things. However, this requires an advanced understanding of the medium, proper equipment, patience, and adequate technical knowledge. Taking close ups and taking true macro photos are two entirely different things. Perhaps I will cover this subject in depth in a future article.

This was taken with the Sigma AF 70-300mm f/4.0-5.6 APO DG Macro. It's not a true macro lens. But these types of lenses are not too bad either.

This was taken with the Sigma AF 70-300mm f/4.0-5.6 APO DG Macro. It’s not a true macro lens. But these types of lenses are not too bad either.

Now, I should also mention that these categories are just to get an idea. This does not mean that you cannot use a 50mm lens to take portraits. In fact one of the most popular portrait lenses is the 50mm f/1.8 AKA the nifty fifty. Perhaps the reason is that it’s available for almost any brand of camera, it’s fast, light weight, considerably cheap (probably the cheapest, I know it is with Canon not sure about other brands), and still delivers amazingly high quality pictures. A must have lens for anyone, beginner and professional alike.

To illustrate the point, here are three portraits I took using three different lenses. Experiment with different focal lengths to get your desired result.

Taken with the Canon EF 50mm f/1.8, the nifty fifty.

Taken with the Canon EF 50mm f/1.8, the nifty fifty.

Taken with the Canon EF-S 10-22mm f/3.5-4.5 USM at 15mm. This is a self portrait, well a combination of 3 self portraits taken in my room. I had little space. So I had to use a wide angle lens to get a large field of view.

Taken with the Canon EF-S 10-22mm f/3.5-4.5 USM at 15mm. This is a self portrait, well a combination of 3 self portraits taken in my room. I had little space. So I had to use a wide angle lens to get a large field of view.

Taken with the Canon EF 70-300mm f/4.0-5.6 L IS USM at 200mm

Taken with the Canon EF 70-300mm f/4.0-5.6 L IS USM at 200mm

Inside The Lens

A lens is constructed using several lens elements, apart from the lens barrel. The main role of these lens elements is to focus the ray of light on the image sensor as accurately as possible and recreate the image in front while minimizing any distortions and aberrations. This determines the optical quality of a lens and ultimately dictates its price tag. Lens manufacturers are constantly trying to build high quality lenses using least expensive elements.

Light, however, does not behave exactly the way we want. Visible light is a very small fraction of the electromagnetic spectrum. The wavelength of visible light ranges from about 390nm to 700nm. Each wavelength refracts differently when going through different medium. This is why we see rainbows. Due to this phenomenon, when light travels through the lens, each lens element refracts each wavelength (different color) differently. This leads to false alignment of colors and results in chromatic aberration.

A ray of light being refracted in a plastic block. Image courtesy - Wikipedia

A ray of light being refracted in a plastic block. Image courtesy – Wikipedia

Chromatic aberration is just one measure of optical quality. There’s also vignetting (darkening of edges), loss of contrast, blurring, and distortion. This is why your lens is more important than your camera body. If you’re to exploit your camera to its full potential, it’s vital that you have a good piece of glass in front of it. Otherwise your high end professional DSLR won’t deliver the results you would expect. High quality lenses have various techniques to battle these problems. Therefore, they are more expensive. That is why you see lens manufacturers have several lenses covering the same focal length range. One is either optically better or faster or both than the other and is more expensive. However, it should be mentioned that lenses have come a long way since the beginning. Even the consumer grade lenses now deliver decent results. You wouldn’t notice a quality difference until you make a side by side comparison  with a professional grade lens.

See that purple line along side the tree branch? That's chromatic aberration. Click on the image for a better view.

See that purple line along side the tree branch? You’re going to have to click on the picture to see this. That’s chromatic aberration. Also note that this is a 400% crop. This picture was taken with an L grade lens. So the chromatic aberration is minimal. I had to hunt for an example.

Different lens manufacturers have their own methods to designate or identify their top quality lenses. Canon has their “L” series (luxury) with a red ring at the end of the lens barrel. Nikon has a gold ring at the end of the lens barrel. Sigma designates them as “EX” for excellence. Tokina has AT-X Pro so on and so forth. From my experience, the most noticeable difference between consumer grade and pro grade lenses is the frequency of getting sharp images. Consumer grade lenses will still give you sharp results, but not as often as a pro grade lens would. But this is just one side of the story.

Zoom vs Prime Lenses

In the good old days, there were only prime lenses. These lenses have fixed focal lengths. Therefore, the only way you can change the composition or the perspective of a picture is by moving in or out. Zoom lenses on the other hand offers a predefined focal length range. This allows you to change your composition or perspective without physically moving. Thus zoom lenses are very versatile. But there are many reasons why prime lenses are still around.

Advantages of Prime Lenses

  • Cheap – Prime lenses generally tend to be cheaper due to the fact that it has less lens elements. This does not mean that there aren’t any expensive prime lenses though.
  • Faster – I mentioned the speed several times already. So what does it mean that a lens is fast? It refers to the maximum aperture of the lens. As you already know, if a lens can open up more, it lets in more light. Thus you can use faster shutter speeds. Prime lenses are almost always faster than their zoom counterparts. Very handy in low light situations. This also makes your view finder a little brighter.
  • Weight – Prime lenses are smaller and light weight compared to many zoom lenses, again due to less lens elements.
  • Sharp Images – While cost, speed, and weight are the three main advantages of prime lenses, they tend to produce sharper images. There are less moving parts inside a prime lens (less lens elements). Therefore, it’s easier to accurately focus light which results in sharper images.
  • Bonus – Prime lenses have the potential to make you a better photographer. This is because you’re limited to one focal length and you’re forced to move around a lot to get the shot you want. This teaches you how to compose properly and forces you to think a little bit harder. Zoom lenses are likely to make people a little lazy but that’s just what I think.

Advantages of Zoom Lenses

  • Versatility – Like I said before, these give you the option to change the composition and perspective without moving. This doesn’t mean you shouldn’t move though.
  • Keeping up with the subject – If you’re shooting dynamic subjects, a zoom lens is the way to go, so you can follow your subject without too much of a hassle.
  • Bang for the buck – I know I said that the prime lenses are cheaper. But if you want to constantly use several different focal lengths, you’re going to need several different prime lenses or one zoom lens. So it depends on your needs.

When zoom lenses first came into play, the optical quality was far inferior than prime lenses. However, with the advancement of technology, the gap has been narrowed significantly. Now they make remarkable zoom lenses that deliver high quality pictures to a point that an untrained eye is unable to say the difference between the two.

So, zoom or prime?

Well I think by now, you already know the answer I’m going to give. It’s up to you. I will say this though, I think everyone should have the 50mm prime. It’s inexpensive and extraordinary. That is the only prime lens I’m carrying at the moment. Give this lens a try. Then you get to experience the mesmerizing qualities of a prime lens. If you think primes are not for you, you can always sell it with very little loss.

I hope I answered some of the questions you may have had. If you still have questions or need a little more help, leave a comment and I will get back to you. Stay tuned for the next part of this series.

post

Deciphering the Camera Jargon – Part 1 (Sensors and Megapixels)

When you’re going to buy your first DSLR, it’s so easy to get lost within the technical terms. Without knowing what they mean, it’s difficult to make a choice. Even when you read reviews online, they often don’t make any sense if you don’t know what they are talking about. In an effort to explain some of these terms that tend to appear over and over again, I’ve decided to write a series of posts. I’m going to publish this in several parts to keep each post relatively short. It’s near impossible to explain one term without relying on other terms as they are inter-connected with one another. So if you run into something unfamiliar here, it’s very likely that it will be covered in a future post.

DSLR

This goes without saying but I thought I’d add this here anyway. DSLR stands for Digital Single Lens Reflex. The reflex mechanism is the main difference between a DSLR and a compact digital camera. The light travels through the lens and hits a mirror, which reflects it to the view finder through either a pentamirror or a pentaprism. When you click the shutter button, the mirror flips up, allowing the light to hit the image sensor. The term “single lens” here can be a bit confusing because DSLRs use many different lenses. However, the term refers to the fact that the light travels to both the viewfinder and the image sensor via a single lens as opposed to having a different lens for the viewfinder.

Full Frame vs Crop Sensor

Different Sensor Sizes. Image courtesy - Wikipedia

Different Sensor Sizes. Image courtesy – Wikipedia

In photography, we use the 35mm standard film SLR camera as the reference point. Of course the digital cameras don’t use film but instead full frame cameras have an image sensor with the same dimensions as the 35mm film, which is 36mm x 24mm. Now, why on earth is this called 35mm if the width of the film is actually 36mm? It’s because it actually refers to the full height of the film which is 35mm, including those tiny little holes on the sides. And if you think this is bad enough, it is also called the 135 photographic film format. Why? Because Mr Kodak said so and ain’t nobody’s messing with him. All in all, any DSLR with a 36mm x 24mm image sensor is considered a full frame DSLR. But there are so many different sizes of sensors out there. Technically speaking, a crop sensor is anything smaller than a full frame. But we don’t hear people referring to their pocket cameras as crop sensors even though the image sensor in those cameras are significantly smaller than full frame sensors. This language is mainly used to describe DSLRs.

The size of the image sensor is directly related to the effective focal length of a lens. What is the effective focal length you ask? The advertised focal length of a lens is always in terms of a full frame camera because it is our reference point. But if you put that same lens on a crop sensor body, the lens does not behave the same way it does on a full frame body. Since the crop sensor bodies only capture a portion of the image a full frame body would, it narrows the viewing angle and thus it has a magnifying (zoom) effect. While there are so many crop sensors out in the market, there are several popular ones. Canon APS-C (22.3mm x 14.8mm), Nikon DX, Pentax K, Sony (23.6mm x 15.6mm), Canon APS-H (27.9mm x 18.6mm), Olympus and Panasonic Four Thirds System (17.3mm x 13.0mm). There’s an awesome table in Wikipedia which includes all these numbers and the associated crop factor. Crop factor, or the focal length multiplier, as the name suggests is the factor by which you multiply your focal length to get the effective focal length (full frame equivalent focal length). For instance, the Canon APS-C system has a crop factor of 1.6 which means if you put a 50mm lens on a Canon APS-C body, you have to multiply 50mm by 1.6 to get the effective focal length. 50mm x 1.6 = 80mm and therefore this 50mm lens would behave like an 80mm lens on a full frame body. Thus the effective focal length of a 50mm lens on a Canon APS-C body is 80mm. As you might have already guessed, the full frame sensors have a crop factor of 1.0 just for book keeping purposes. Now that I mentioned APS-C, it stands for Advanced Photo System type C (Classic), in which the sensor size is approximately 60% of the size of a full frame sensor. APS-H stands for  Advanced Photo System type H (High Definition), in which the sensor size is approximately 75% of the size of a full frame sensor. There’s also an APS-P (Panoramic) albeit not very common.

So it all comes down to choices again. Which one is best for you? Well, that I cannot tell. What I can do is to tell you some advantages and disadvantages of each system. I’m going to limit this comparison to full frames and classic crop sensors because they are the most popular out there.

Full Frame Advantages

  • Improved dynamic range and better low light performance leads to higher quality pictures (larger pixels compared to a crop sensor with the same megapixel count).
  • Lenses behave the way they are supposed to. Although this is not a huge advantage due to the large range of available lenses.
  • Easier to achieve a shallower depth of field. If you keep all the other factors the same and shoot the same scene using a full frame and a crop sensor camera, the full frame camera will have a shallower depth of field. The sensor size is a factor determining the depth of field. This is why it’s near impossible to achieve a shallow depth of field with your point and shoot camera despite the fact that it has a f/1.8 lens.
  • Brighter view finder. Comes in very handy when focusing manually.
  • Larger field of view. If you use a 14mm lens on a full frame, you would capture a wider view than using a crop sensor body. Especially useful in landscape and architecture photography.

Full Frame Disadvantages

  • Expensive. That large sensor is sure going to cost you a lot more.
  • Generally heavier and bulkier than crop sensor bodies.
  • Shallower depth of field. I wouldn’t say it’s difficult to achieve a deep depth of field with a full frame because that would be a lie. There are many ways around this. But like I mentioned before, if you use the same settings, a crop sensor body will give you a greater depth of field. There are many occasions where you would want a deeper depth of field.
  • To fully exploit the advantage of a full frame camera, you need those expensive lenses. Mind you, I’m talking about the image quality here, not the photographic quality.
  • Higher quality pictures mean bigger file sizes. But this is hardly a problem now that storage options are dime a dozen.

 Crop Sensor Advantages

  • Cheaper. Most of the entry-level and mid-level DSLRs are crop sensor cameras. They are more affordable than those expensive full frame bodies. This was a reason why photography opened up for so many people, including me. Heck, I still can’t afford a full frame camera.
  • Light weight and less bulky.
  • Extra reach. While crop sensor bodies have a disadvantage on the wide end, they have an advantage on the tele end. This comes very handy especially in wild life, bird, sports photography due to the focal length multiplier. Crop sensor bodies magnifies the subject like I mentioned before.
  • Smaller file size.
  • Specially designed lens series. Canon has EF-S lenses and Nikon has their DX lenses specially designed for their crop sensor bodies. These lenses tend to be cheaper than their full frame counterparts while delivering amazing results at the same time. Crop sensor bodies can also use the lenses you put on a full frame (Canon EF and Nikon FX) but the reverse is not true. The full frame bodies cannot use EF-S or DX lenses. So there’s a wide variety of lenses available for crop sensor bodies.
  • Vignetting and soft focus at the edges are less likely due to the cropped field of view.

Crop Sensor Disadvantages

  • Well this section should be pretty obvious by now after you read everything else I said. So I will refrain from stating the obvious.

It should be pointed out that over the years camera manufacturers have closed the gap between full frame cameras and crop sensor cameras. For instance, there are specially designed lenses to battle the wide angle problem in crop sensor bodies now. Both systems deliver amazing results. There are good enough reasons to pick either one. While most professionals stick to high end full frame cameras, there’s a good amount of professionals who still prefer crop sensor bodies and they are in no way inferior. It’s just a personal choice and depends on what kind of work you do with your camera. For photography enthusiasts like myself, it makes much more sense to use a cheaper crop sensor system because I don’t earn any money from my camera. 99% of the time, each system would deliver similar results. But sometimes you have to push your camera to its limits and then the advantages one system offer over the other becomes important. A professional bird photographer would have to use a $20,000 system to get the results just because anything less wouldn’t deliver exactly what he needs. If you’re still unsure what you need, I suggest that you rent out some equipment and try it out for yourself. If you’re just starting out photography, I would suggest you just get an entry to mid level camera and some decent lenses. But that’s just me.

Megapixels

Where do I even begin? I think in the digital camera world, megapixels have the highest number of myths associated with it. I’ll try to keep it short. The smallest element of a picture is called a pixel (PICture ELement –> pixel, get it?). I’m not gonna go into sub-pixels because it’s not very relevant here. Just so you know, there is something called sub-pixel as well. If you zoom in on a picture, you’ll start seeing individual pixels. Remember the late 90s and early 2000s when digital cameras were gaining popularity? I’m sure you’ve heard a conversation somewhere along the lines of “hey, my camera is 3 megapixels. how many megapixels does yours have?” “five” “woah!”

Now, let us back up here for a moment. Does the number of megapixels really matter? Not really! Let me put it this way. Imagine a 2 cm x 2 cm square (note: most DSLR image sensors have an aspect ratio of 3 : 2 but for the sake of this argument, we’ll consider a square). This square has an area of 4 cm2. If we are to fill this square with 1 cm2 little squares, we need 4 of those. We’ll call each of these 1 cm2 squares a pixel. However, if we are to fill this 4 cm2 square with 0.25 cm2 little squares, we’re going to need 16 of those. Now imagine that the bigger square is the image sensor. This is exactly what happens when they cram in more pixels into the same sized sensor. Simply the size of a pixel goes down. Mega stands for 1 million (106). So a 10 megapixel camera has 10 million pixels. So why does the size of a pixel matter? Larger pixels have more light gathering capabilities, which means at a given time interval, the larger pixel will collect more light compared to a smaller pixel. This results in less noise (little grainy stuff you see when you take a picture, especially under low light. See ISO) and sharper, more detailed images. Hence, what determines the image quality of a camera is not its pixel count but the size of a pixel. This is one of the distinguishing factors between DSLRs and compact digital cameras (and one of the reasons why DSLRs are expensive) because DSLRs have larger image sensors and thus larger pixels when comparing the same number of megapixels.

So why all the hype? It’s one big marketing strategy! The megapixel count was used by camera manufacturers as a primary way of competing with other brands. Don’t you love it when a salesman keeps exaggerating this? If they feel like you don’t know what pixels are, almost always they are going to push this. Sometimes they just don’t have any idea what it actually does either. Once I was on the phone with AT&T and I wanted to get an upgrade. When I asked about different phones, he kept coming back to the number of megapixels. I told him I’m looking for a phone, not a camera. Funny how that works.

Does the number of megapixels matter at all? Very little. If you want to crop out an image and still print it big, a higher pixel count would come in handy. This leads to another discussion on print resolutions. I promise I’ll keep it short this time. Two terms keep popping up. PPI (Pixels Per Inch) and DPI (Dots Per Inch). These are two different terms, although some people use them interchangeably. This page explains the difference in great detail. I promised I’d keep this short 🙂 Anyway, back to the matter at hand, a 15 megapixel camera will allow you to print 10 x 15 images at 300ppi without artificially enlarging (using algorithms) the image. If you want larger prints, you simply reduce the ppi and when you do, it appears pixelated, you know like when you really zoom in on a picture. However, it doesn’t really matter because the larger your print is, greater the normal viewing distance. For instance, you’re not going to make a print 2 meters tall and stand right next to it. You step back. This is how large bill boards work. They are printed at very low resolutions but since you’re viewing them from a greater distance, you don’t notice the pixelation. Of course, if you stand very close, it would look horrible but then you don’t see the bigger picture, do you?

I think I’ve covered most of the important facts about megapixels. Now repeat after me, “I’m not going to be fooled by megapixel count again!”

post

The Very Basics of Photography

Exposure Trianlge

The exposure triangle consists of three (I know you wouldn’t have guessed that) main components – ISO, Shutter Speed, and Aperture. With all the other technical details apart, these three dominate how you are going to make the picture. Understanding the exposure triangle is critical for anyone who wants to master the art of photography. I mean really, there is no other way around it. These concepts should be second nature to you. Do not worry though, they are not too difficult to comprehend. I’ll explain what each of these does and then how they are related to each other.

ISO

ISO stands for International Standards Organization. It’s an organization which sets standards. Who would’ve thought, right? In photography, ISO is an indication of how sensitive your image sensor to light. When you have very little light available, you have to increase the light sensitivity of the sensor to achieve a reasonable shutter speed to capture the image without causing blur. Seems simple enough. But here’s the catch. When you increase the ISO, the image sensor tends to heat up and produces grainy images (image noise). This is the place where bigger pixels trumps the pixel count. So when possible, shoot at the lowest ISO that allows a reasonable shutter speed for the occasion.

Here’s an example of what ISO does to your images.

f/4.0, 70 mm, 1/60, ISO 100

f/4.0, 70 mm, 1/60, ISO 100

f/4.0, 70 mm, 1/4000, ISO 6400

f/4.0, 70 mm, 1/4000, ISO 6400

Notice that the top image is sharper and much cleaner and the bottom image appears very grainy and not as sharp. These are the two extremes that my camera will go. Any ISO between 100 and 6400 will produce an image in between these two extremes. Also note that I kept the aperture (f number) and the subject distance a constant to achieve the same depth of field. So I had to change the shutter speed to get a properly exposed image. Keep these things in mind because it all comes together to form a good image. I will address the focal length and the depth of field in a future post, to learn more about aperture, shutter speed, and the exposure triangle, keep on reading.

Shutter Speed

Seems a little obvious but here goes. Shutter speed is the time the film or the digital sensor is exposed to incoming light. A higher shutter speed is required to freeze the motion, especially comes in handy in sports photography, bird photography etc. A lower shutter speed allows to capture the motion. One of the most popular use of low shutter speed, but not limited to, is taking pictures of waterfalls. It gives the picture a silky feeling. Shooting at lower shutter speeds can produce very creative results. In fact, there are specially designed filters called natural density filters (ND filters, my personal favorite) to cut back a portion of incoming light to achieve very low shutter speeds without over exposing the image. A tripod is essential when using lower shutter speeds to avoid blur caused by camera shake. There’s a rule of thumb called the 1/focal length rule. It means, if you’re shooting at 50mm, your shutter speed should at least be 1/50th of a second to handhold the camera. Anything slower will cause camera blur. Most entry level DSLRs have a maximum shutter speed of 1/4000th of a second whereas high end professional cameras have a maximum shutter speed 1/8000th of second. To achieve these speeds, DSLRs employ a mechanism called shutter curtains. There are two shutter curtains and at higher speeds, as one curtain opens up the other one is already closing. So there is a small slit that allows the light to pass through the curtains into the image sensor.

f/1.8, 50mm, 1/4000, ISO 100

f/1.8, 50 mm, 1/4000, ISO 100

This was taken at 1/4000th of a second and since the shutter speed is very fast, it froze the motion of the droplets.

f/11, 10 mm, 75 sec, ISO 100

f/11, 10 mm, 75 sec, ISO 100

This one on the other hand was taken over a period of 75 seconds. I had to use a 10 stop ND filter to cut back the incoming light to capture the motion of the waterfall. If it wasn’t for the ND filter I would never be able to achieve this shutter speed because it was a bright sunny day and it would have over exposed the picture.

Aperture

Aperture refers to the opening of the lens and is represented by f/number. When the f number is low, for instance f/1.4, the lens has a larger opening. When the f number is high, for instance f/22, the lens has a smaller opening. This greatly affects the depth of field.

Different apertures. Image courtesy – Wikimedia

f/4.0, 70mm, 1/200, ISO 400 - Shallow Depth Of Field (DOF)

f/4.0, 70mm, 1/200, ISO 400 – Shallow Depth Of Field (DOF)

Here the background is out of focus where as the foreground or the subject is in focus. This is what we call a shallow depth of field. I will be referring to depth of field as DOF from now on. DOF, in a nutshell, is the area in focus. Aperture is a key factor when it comes to achieving the desired DOF but not the only factor.

f/22, 70mm, 1/30, ISO 1600 - Deep Depth Of Field (DOF)

f/22, 70mm, 1/30, ISO 1600 – Deep Depth Of Field (DOF)

Compared to the above picture, this one has a cluttered background and the background is in more focus. Notice the apertures used in the two pictures. This one has a deep DOF than the other. Usually a deep DOF is used in landscapes to capture sceneries with both the background and the foreground in focus. At best, this is a crappy DOF but enough to demonstrate the effect of aperture has on DOF. Like I said before, aperture is not the only thing deciding the DOF. Also take note of the different shutter speeds and ISO values I’ve used.

When the lens is at its lowest possible f number, it is said that the lens is wide open. When you look at the name of a lens, the f number mentioned there is the widest aperture (lowest f number) the lens can go. In other words Canon EF 50mm f/1.8 lens can open up to f/1.8. If there’s a range of apertures given, for instance Canon EF 70-300mm f/4.0-5.6 L IS USM, it means at 70 mm the widest aperture the lens can achieve is f/4.0 and as you zoom in the f number will increase too. At 300 mm the widest aperture the lens can achieve is f/5.6. You can of course control the aperture using a small dial on your camera or on older lenses using an aperture ring. Increasing the f number is called stopping down the lens because it stops portions of light as you increase.

The Triangle

Exposure Triangle

Exposure Triangle

Now, you saw the effects of ISO, Shutter Speed, and Aperture. You need to combine all three of these to achieve your desired goal. Each one of these can throw out the balance of your picture if they are not in correct proportions. you would either get an over exposed image or an under exposed image. 

f/14, 10 mm, 1/160, ISO 100 - Properly Exposed

f/14, 10 mm, 1/160, ISO 100 – Properly Exposed

f/14, 10 mm, 1/40, ISO 100 - Overexposed

f/14, 10 mm, 1/40, ISO 100 – Overexposed

f/14, 10mm, 1/640, ISO 100 - Underexposed

f/14, 10mm, 1/640, ISO 100 – Underexposed

There are several popular analogies to explain the relationship between these three. I will mention a few.

Equilateral Triangle – Imagine that the perfect combination of ISO, Shutter Speed, and Aperture (perfect exposure) is similar to an equilateral triangle. If you change an angle or a side of the triangle, it’s no longer an equilateral triangle. So you have to adjust the other two accordingly to get it back into an equilateral triangle. Bottom line is that the perfect exposure can be achieved in many different ways. The combination you want to use depends on the result you need. Once you find the perfect combination (cameras have built in light meters to help you with this, although not always very accurate it does a pretty decent job), you can play around with the values. You can lower the f number and increase the shutter speed. You can use a slower shutter speed with a lower ISO etc.

The Window – In this analogy, the camera is similar to a window with shutters. Size of the window is your aperture. Bigger the window, the more light gets in. The time frame you have the window open is like your shutter speed. The longer you have it open, you let more light in. Now, there isn’t exactly an easy way to include the ISO here but imagine that you’re inside the room with your sunglasses on (douchebag alert!). The sunglasses decreases the sensitivity of your eyes to light much like ISO does. Taking off your sunglasses is like boosting the ISO, increasing the sensitivity to light.

Rain Bucket – Unless you do the rain dance, I’m assuming you can’t control the rate of rainfall. This is similar to available light. While there are many ways to manipulate the natural light, let’s just think of a scenario where you’re just shooting as it is. But you can control several other factors to collect just enough (proper exposure) rain water. You can control the diameter of the rain bucket. A wider bucket will collect more rain water in less time whereas a narrower bucket will take much more time to collect the same amount of water. You can also control the amount of time you leave it out there to collect water. Now do you see where I’m going with this? ISO, Shutter Speed, and Aperture are completely under your control to get a properly exposed image.

Here’s the take home message. Lower f numbers (higher apertures) let in more light whereas the higher f numbers (lower apertures) let in less light. This might take some time to get used to because it’s kind of counter intuitive. You can also think of the f/number as a fraction. When the number in the denominator is bigger, the overall value is smaller. This is true for shutter speeds as well. Faster shutter speeds allow less light in and slower shutter speeds allow more light in. Again, think of the number in the denominator. ISO on the other hand is straight forward. Higher the ISO, more sensitive the image sensor is.

Sometimes, you have to intentionally underexpose or overexpose images because the cameras are not just yet advanced enough to capture everything we see in one go. Then you have to combine the best of each image and come up something new.

Combination of the above three images

Combination of the above three images

When you do, it’s called a High Dynamic Range (HDR) image. More on this later though. I’ve dragged this post long enough for now! 

post

On Cameras and Choices – What is the Best Camera?

Imagine that you want to build a dog house. Then you find out that you don’t have a hammer. Naturally, you start looking for one. Then you hear stories, legends, and ballads about this great hammer. You embark on a quest to find this legendary artifact. For years you travel through jungles, rivers, oceans, conquer mountains, volcanoes, blizzards and finally you find this supposedly mythical hammer. You take it, go home, and build your dog house. Then it turns out to be crappy. Why? Because you have no experience in carpentry what-so-ever.

Now imagine the outcome if you spent all those years you wasted finding this mythical hammer, honing your skills and carefully designing what you were planning to build. You would end up with a beautifully finished work of art. When you want to make something, do you focus on the product you’re making or the tools you use to get the job done? When you see a beautiful painting, do you ask the artist about his paint brush? When you enjoy a nice meal, do you ask the cook about his stove? Then why do most people end up asking a photographer about his camera?

With the introduction of entry-level DSLRs to the market several years ago, digital photography has become one of the most popular hobbies. Yet one question keeps appearing all over the internet. What is the best camera? It’s very simple. It does not exist. When you post a picture somewhere, there is always that one guy who inquires about the camera you used. The best camera is what you have. You cannot take pictures with a camera that you don’t have. Stop chasing around something that does not exist and learn to use what you have.

Now, a perfectly legitimate question that you can ask a photographer is how he planned the shot and what settings he used. If EXIF data is available to you (in most cases it is) you can easily look at all the settings that were used to make the shot. You can learn a lot from that. But all those famous camera brands have yet to release a camera that takes no bad pictures.

I think the question “what is the best camera?” originated from the misconception that the camera does all the work. But it is a tool just like a paint brush or a hammer. Perhaps the fact that there are so many brands and models is confusing. Why are some cameras more expensive than the others? It’s simply because some offer features that others don’t. Is it absolutely necessary have all these features? Not at all. At the end of the day, a camera just take pictures.

When it comes to buying a camera, you really are spoiled with choices. The range is incredibly large, going from cheap compact point and shoot cameras to high end professional DSLRs that cost as much as a used car. I know I said that the tool you’re using does not matter. But now I’m going to tell you why it would be advantageous to have a decent DSLR. This is a little tricky. Does it matter or not? Well, yes and no. If you can snatch a priceless moment with your cheap pocket camera, that would be much better than a regular snap shot captured by a very expensive DSLR any day. Let me put it this way, it’s something like 75% the photographer and 25% the camera. So it does matter a little. I know, I lied.

So what is the advantage of having a DSLR? First and foremost, it’s electronics vs. mechanics. Compact digital cameras use an electronic shutter system whereas DSLRs use a mechanical shutter system. So the shutter lag in DSLRs is minimal, allowing you to freeze the moment. A DSLR is as fast as you are. Unlike point and shoots that takes couple of seconds to turn on and couple more seconds to take a picture, a DSLR is always ready. Then there is RAW capability of DSLRs, although some compact cameras now offer this feature. But shooting RAW is a story on its own, which I’m hoping to cover in a future post.

DSLRs have larger image sensors than compact cameras. Which means, if you look at a 12MP compact camera and a 12MP DSLR, the DSLR will have larger pixels. Thus it performs way better (higher quality) than the compact camera, especially under low light conditions. High quality and speed, these are the two main advantages of having a DSLR. There’s more but there’s always a catch, isn’t it? The catch is that they are big, heavy, and annoying to lug around. Please do the world a favor and don’t buy a DSLR if you’re just going to keep it on your shelf. You’ve been warned. Now you know it’s heavy and not many people are ready to make the commitment.

Here’s the best and the worst part of having a DSLR. Interchangeable lenses. Why is it the best? Because the quality of the pictures mostly depend on the optics and with specially designed lenses for specific jobs, the performance is fantastic. Worst part? They are going to cost you an arm, a leg, and a liver. Soon you will find out that you’re going to need more than one lens and they cost way more than what you paid for the camera, which is already a hefty sum of cash. Remember, it’s much better to have a cheap camera body and a decent lens than a very expensive body and a crappy lens.

When you buy your first DSLR, it’s easy to get frustrated real fast because you probably only have the kit lens that came with it. The kit lens performs far better than its reputation but it has a lot of limitations. There’s no alternative other than slowly building up your lens arsenal. Until then, stay strong folks!

“Having a camera makes you no more a photographer than having a hammer and some nails makes you a carpenter” – Claude Adams.

DSLR

 

post

On Photography

I’m sure that you’ve heard the saying “it’s not the camera. it’s the person behind.” It’s true. the world’s most expensive camera is useless in the hands of a person who doesn’t know how to use it or someone who knows nothing about the basics of photography. That expensive camera will take high quality snap shots but wouldn’t make brilliant photographs. Well, that being said, high quality gear (expensive stuff) does help. It improves the quality of the picture but to make it a memorable photograph is the job of a photographer.

If you’re just getting your first DSLR, read your manual. There’s a lot of information available in there and some of them will be specific to your camera. You need to know your camera like the back of your hand so you won’t miss an opportunity when it presents itself. Look at a lot of photographs. See what you like about them and what you don’t like about them. It’ a subjective field. Think of what you would’ve done differently. Accept constructive criticism. That’s one of the best methods to learn IMO. There are a lot of websites that teach you a lot of different things, different kinds of photography. Read them regularly. Some of them will start to make more sense when you read it for a second time. Be a part of a photography forum. Go on field trips with friends with similar interests. Talk to professionals/experienced photographers. Figure out what type of photography you’re most interested in. Sooner or later you will find out that you tend to take certain types of pictures (landscapes, portraits, street photography, macro, wild life etc.)

There are several stages an upcoming photographer goes through. When you first get your DSLR, it’s like ohh look I took a close up of a flower. My pictures are amazing stage. Unfortunately many don’t get over this stage. Next is my photos are crap stage. You compare your shots with everything else you see and then get disappointed. You see pictures on flashy travel magazines, all over the internet, art galleries etc. and then think to yourself that you’re not good enough. This is where you need inspiration. Instead of thinking that you’re not good enough, learn from all the pictures you see. There’s always a take home message. You will always learn new tricks, from how to compose a good shot to how to manage your pictures to how to process your pictures. Given enough time, anybody can master photoshop. But make no mistake, no amount of photoshopping will turn a snap shot into a brilliant photograph. After this stage, your skill level gradually increases. You will feel satisfied with some of your shots. Good photographs are hard to come by. Even Ansel Adams only expected one good photograph every month. Soon you will have a collection of your favorites. Upload your pictures to somewhere like flickr or 500px. They are great places to share your pictures. Facebook is not as good. It’s good if you want to share your pictures with friends and family but flickr and 500px are mostly for photographer and if offers a whole lot that facebook doesn’t. And I can’t stress this enough, print your favorite pictures. If you think your pictures look good on a monitor, it will blow your mind when you print them. It is a great feeling. This is what helps you feel good about what you’re doing. It’s like “wow, I made that”.

If it’s ever possible, forget digital and get a film camera and use a prime lens (fixed focal length, no zooms) for a little while. It will drastically improve your photographs because you have a limited number of exposures and you have to do the leg work to compose a pictures properly. At the same time, you will be thinking of aperture and shutter speed depending on your film ISO and available light. You need to understand the basics before you try this.

There’s a lot more I can tell but it already turned out to be longer than I expected. I’m sure you can find most of them all over the internet. However, as an end note, I’ll share this.

Ira Glass