Sunday, November 29, 2009

Small Pixels = More Noise

These last few weeks I have barely had a camera in my hands. Instead I have been doing a ton of post processing work (my least favourite activity), taking courses, workshops and other pursuits. I miss taking pictures. Oh well, I am anticipating many more shooting opportunities in December.

I may not have been shooting but I have been reading many blogs and web sites about the new Canon gear. The 7D and the 1D Mark IV. I was lucky enough to attend the Canon 7D launch event about a month back and man, I tell you, it was everything I could do to keep my wallet in my pocket. But experience has taught me not to jump at every new product that comes down the pipeline. When the 50D was introduced I could not wait to hand Canon my money but in the end I chose the 40D as my replacement for my well used Rebel XTi. A year later I could not be happier with my decision. Lately though I have been getting eager to relegate the 40D to backup and bring home a new Canon. I thought for sure the 7D was going to be the one but now I'm not so positive.

Small Pixels Equals More Noise

My 40D has a resolution of 10 megapixels on an APS-C size sensor, which translates in to each light gathering pixel being 5.7 microns in size - same size as my Rebel Xti. One would expect the picture quality to be roughly the same, and, yes it is. When the 50D first came out I tried one out for about a week before settling on the 40D. Why? A couple of reasons. The images were really noisy above ISO 1600 and using DPP (Canon's Digital Photo Professional software) to remove the noise made the images too soft. If I switched on in-camera noise reduction the images also came out too soft. Secondly, I found the 50D images lacking the sharpness of my Rebel XTi. I played around with in-camera settings and post processing techniques but I could not find the sweet spot. Was the 50D, with its increased pixel density, harder to hand hold? Or did the increased pixel density of the sensor inherently produce softer, noisier images? I don't know. But I do know I was not satisfied with the quality so I passed and chose the 40D instead.

One year later and the 7D arrives on the scene. Oh boy was I excited!! As soon as the specifications were out I read all about it. Eight frames per second - awesome! 100% viewfinder - incredible at that price point! All new autofocus system - yah! And then.... 18 megapixels on an APS-C size sensor. Woah! What?!?!? Are you kidding me?!?! Yup. It's true. The Canon engineers found a way to squish even more pixels on that tiny sensor pushing the pixel size to a miniscule 4.3 microns - the smallest of any camera in the EOS line. I was stunned and saddened.

I had to read more about it. Turns out Canon performed some amazing engineering tricks to make 18 megapixels on an APS-C sensor produce high-quality images. But let us skip all the fancy explanations of how and why because I failed grade 11 physics. OK, full disclosure, I didn't try too hard in high school. Clowning around proved to be more fun. Seriously though the general consensus is that smaller pixels have less light gathering ability and thus produce softer images with more noise. I know Canon has truly outdone themselves with the engineering on this sensor but I am still skeptical, especially after my experience with the 50D.

I have read some pretty positive reviews of the camera from The Digital Picture and Rob Gilbraith but there are questions of image quality. However, gave it a "highly recommended" review and had no qualms about the image quality. Personally, for the short time I got to play with it I must admit that the thing feels and handles like a dream and has an incredible feature set, especially at that price. I did a quick cursory check of the image quality and I did find it very similar to the 50D. Similar not in a good way.

As much as I would like to run out and buy one, the most prudent course of action for me will be to rent one for a day, put it through the paces and see if it meets my needs and my tastes. There really is no better way to do it.

One Last Thought...

I cannot help to wonder what if Canon stopped the megapixel madness and capped the 7D at 15 megapixels (same as the 50D) and applied the same engineering techniques to the sensor. Would we be seeing stunning low-light images? Less noise? More sharpness and more dynamic range? Sigh. I can only imagine.

Although I was not impressed with the 50D images on the screen I was quite impressed with the prints. The level of detail was simply amazing. I expect the 7D, with 80% more pixels than my 40D, to produce some pretty amazing output as well. But will it take a bunch of post processing effort to produce stunning prints or screen output?

I am one person who would rather be taking pictures than making them on my computer.

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