Why I upgraded to a digital SLR

Its a lot of stuff to capture in rational behind moving from G5 to 20D. I'll break it down into two posts.

1. Why I upgraded to digital SLR
2. Why I chose Canon EOS 20D

Here we go with the first part.

Why I upgraded to a digital SLR

I got G5 in November 2003. Had great time learning basics of photographic exposure with it. My primary goals was to learn basics of photography and G5 helped me solve that purpose.

But for all its features, G5 is still a prosumer camera with its limitations. Read on...

Limitations of Canon Powershot G5
It has been a few months since I had started feeling "the one year itch". I started feeling that I can not do more with G5 and started facing its limitations. No doubt its a great camera, but it can not scale with your skill for sure.

• Focusing Difficulties
  When I bought G5 I thought, "I am not going to take pictures of fast moving objects in low light that often". But when my new born daughter started moving, It was becoming more and more difficult to focus properly. Remember, with G5 you have to do focusing with LCD screen. And it is really not that efficient or reliable. This is applicable to any camera where you have to do focusing using LCD (read LCD - Looks Can be Deceiving). Also, autofous is slow, especially in low light. Due to day job, I found myself trying to take pictures of my daughter in the evening at home in low light, more then expected. And focusing difficulties was becoming the main issue.
  
• Noise at Higher ISO speeds
  G5 allows ISO sensitivities of 50, 100, 200 and 400. But higher ISO means more noise in the image. I could always use software like Neat Image. But nothing compares to an original picture with minimal noise.
  
• Lot of motion blur
  Due to bad noise levels above ISO100, I was forced to use lower ISO and hence slower shutter speed (need more light as the sensor is slow at capturing it). This caused motion blur in low light pictures.
  
• Depth of Field Issues
  Another thing I could do to get more light in was open the aperture to the maximum. In case of G5, that would be F2.0 (read The F Number - Demystified). This will help increasing the shutter speed to avoid motion blur, but then, you start losing Depth of Field because your aperture is wide open (read Depth of Field - the Third Dimension). Narrow depth of field causes parts of the subject to be blurred (e.g. eyes will be OK but hair or hand will be blurred). Such effect was not always desirable.

As you can see above, all of these problems were somehow related to Photography in low light coditions without using any flash. However that's not it.

• Aperture limits
  Smallest aperture for G5 is F 8.0. So if you want to take long exposures with wide depth of field, you can only go upto the point where your picture won't be over exposed at F8.0. Imagine that you are trying to take a picture of water falls and you want to expose it for long time to get really smooth water effect. Eventhough G5 allows upto 15 seconds max shutter speed, you will be limited to a second or so at ISO 50, because beyond that your picture will be overexposed. If aperture smaller then F 8.0 was available, you can set it to smaller size and go for longer exposure. On my 4th of July Fireworks pictures, I had to use Neutral Density filter on top of at F8.0 to get decent 15 second exposures even at night. Even then the grand finale shot came out overexposed !
  
• Depth of field
  If you want to choose a certain depth of field by setting proper aperture on G5, It is very difficult. You take a trial snap, get the picture on LCD, zoom in and verify that the depth of field covers all that you want. Problem is once you zoom in on LCD, you quickly lose perspective. The guide box on the corner tells you where you are on the picture but I always found it to be very inconvenient this way. A better way would be to be able to see depth of field optically (through viewfinder, not on LCD) and verify, and of course you can not see depth of field in a viewfinder in a non-SLR camera.
  
• 3:4 Aspect Ratio
  The pictures generated by your G5 fit perfectly well on your TV. But if you get 4X6 print from a consumer lab, your picture will be trimmed from top and bottom. This may be a killer for your composition. This is because G5 images are with 3:4 aspect ratio, which fits perfect on your TV, but not in a 4X6 print. Workaround is to manually crop all the images to 4:6 aspect ratio before sending for print.
  
• Filters
  I also wanted to start trying out different filters (especially Circular Polarizer). But faced by other limitations, it was clear that I wanted an SLR, so I just didn't feel like doing any investment in buying good filters etc for G5. This was bothering me because I was delaying learning new techniques!
  
• Scalability
  Being a non-SLR camera, G5 does not have capability to change lenses. You are limited to the built in lens. There are two adapters available, one for wide angle and other for telephoto. But that is it. Contrast this with the SLR world where there is a plethora of choices depending on what is it that you want to shoot.

Faced with this Limitations I started looking for an SLR. I did not see a point in upgrading to G6 or Pro 1 from Canon or any prosumer camera for that matter. It would have been just like G5 with few more features and few more mega pixel.

So why did I think an SLR would fix many of these problems ?

SLR features

• Interchangeable Lenses
  This is the Defining Feature of an SLR camera. You can choose any lens that you want that is compatible with your camera's lens mount and just replace it. Your ability to zoom in, set very small apertures, shoot a very wide angle of the scene etc. are limited only by the lens that you mount. You can have one general purpose zoom lens or you can go for a different lens for every different type of picture. Want to take pictures in low light? Get a lens that can open aperture upto F1.4 ! Want to shoot very wide angle landscape photograph? Get a lens with small focal length like 10 mm to 22 mm. Want to get into wildlife photography ? Get a long focal length lens like 200+ mm.
  
• Composing with a ViewFinder
  In a point and shoot, you have some limited zoom and the view finder will have a mechanism which will show the same view. Still it is not through your camera's main lens. When you zoom in and out, the viewfinder also moves its small elements back and forth just like the main lens to mimic the same amount of zoom. This is OK as long as it shows correct zoom.
  
  However in a camera with interchangeable lens, it is impossible to have a viewfinder with it's own independent lens. If you shoot extreme telephoto and the viewfinder does not show extreme telephoto view, how are you going to compose your picture ? It just doesn't make sense. For Point and shoot, this was OK because the lens is fixed and its capabilities are imitated by viewfinder also. But similar mechanism in a camera with interchangeable lens will be impossible.
  
  That's why in camera's with interchangeable lens, optical mechanisms like penta prism and a mirror are implemented that show the view finder's view thorough the main lens. Due to this mechanism, they are called Single Lens Reflex Camera or SLR Camera! This is required because the lens is interchangeable. That is why I call the Interchangeable lens the Defining Feature for SLR. You will never have a separate lens for view finder in a cameras with interchangeable lens.
  
  What are the advantages ? Well, when you are composing, you look through the view finder. You can very accurately verify if you have achieved proper focus as you are not limited by the resolution of an LCD.
  
• Higher ISOs and lower Noise
  dSLR offer better ISOs. 20D offer 100,200,400,800,1600, 3200. Higher ISO speeds allow you to take the picture faster. Also at similar ISOs the noise levels are way too low compared to a G5. Primary reason for this is a better sensor. A dSLR is usually a bigger and more expensive camera, it employs a larger sensor compared to a point and shoot with the same mega pixels. Larger Sensors have larger individual pixels which produce less Image noise.
  
• Better control over Aperture and Shutter speed
  An SLR supports very small aperture settings. These are limited to what lens you put on it of course. Also shutter speeds can vary from a few thousandth of a fraction to as long as you want(called bulb setting). With the combination of wider range of ISOs, shutter speeds and apertures, you can get the same exposure level in the way most suitable to your situation. Trying to avoid motion blur ? Trying to cover enough depth of field ? Trying to do both together but in low light ? No problem ! Your playing fields is a little bigger.
  
• Depth of Field
  Most SLR cameras come with this neat feature. Your composition is done with aperture wide open. But then after you have selected your desired aperture, you want to verify if it covers enough depth of field or not. Press a little button, and camera instructs the lens to give you a preview by setting the aperture to the desired level. You can verify everything from the viewfinder and change aperture if you wish.
  
• Faster Camera
  Prosumer cameras typically have a couple of second startup time for it to get initialized. It's an electronic device just like your DVD player. However, this delay can make you miss a very valuable photo moment if your camera was not on. dSLRs are built to professional quality where you can't afford to miss a moment. So typically they have startup time of a very small fraction of a second. They also capture multiple frames per second (for those shots of kids jumping in the pool or running in the garden). You don't need to be the luckiest guy to capture the exact moment. Shoot continuous whenever you want to captue fast action. Just make sure that you have enough room on your compact flash card.

"How many megapixels is it?"
I still get asked this as the first question. As you can see in the list above, higher megapixel was not the reason for upgrade at all . Beyond 5 MP, I dont think MPs are that relavent for point and shoot. May be in SLR world, it matter a bit because the expectation is that the images might be printed at anything larger then 4 x 6. Well, I've not done that yet. But MP was definately not a criteria. I had lots of other things to complain about before any lack of resolution. FYI, 20D is an 8.2 MP and I think it will provide more room to crop. But again, one needs to get better at composition and rely less and less on cropping.

Oh one more thing...

What happens to G5 ?
Nothing, G5 still stays as my second camera and I am sure I'll be using it for many occasions like..

• Places where "professional photography" is not allowed (They typically think of anything SLR as professional).
• When I don't want to carry a rather big camera with me. (Formal party)
• Just as a backup if I spill my coffee on 20D (I hope not!).
• Where an SLR camera might look overwhelming.

Enough said, the true measure of success of a decision is the results. And so far it looks good. I have not had that many chances to take pictures outdoors this last few days after I got my 20D, because sometimes California weather really Sucks. But I am looking forward to a great summer with the new toy.