Yes, I am in danger of becoming a "pixel peeper". A pixel peeper is someone who magnifies photographs on a computer screen to critically evaluate image resolution at the pixel level. However, it is commonly used as a derogatory remark as explained in the Urban Dictionary.
Late in April, shortly after receiving my new Olympus OM-D E-M10, I was doing some comparison of image quality and came up with the following shocking sample. Note that the sharpest image seems to be from an old Canon SX50 with a 1/2.3" sensor, not the APS-C Sony A55 or the new Micro Four Thirds Oly. (SX50 on the left, then E-M10 and A55 - you may have to click on the image to see the difference) A fluke, you might say. I might agree. Unfortunately I didn't have time at the time to pursue the issue (closing up in Florida and heading back to KC), and now the SX50 is gone (took an unfortunate dip in the lake) and the A55 is also gone (upgraded to an A77 M2). So, back to the drawing boards
It is just too weird to think that a super small sensor could yield images comparable to APS-C or MFT, so I decided to concentrate on a comparison between the E-M10 and the brand spanking new A77 M2. Results have been different from my first attempt, but are still puzzling. Even though having a smaller sensor than A77 (MFT is 61% the size of APS-C), the E-M10 appears to have significantly better sharpness. What the heck?
I started by setting both cameras up to what I considered to be a typical configuration for sailing or birding shots: shutter preferred and fairly fast (1/1000 or faster), medium ISO (greater than 200 but less than 1,000), which would probably mean shooting most of the time wide open, maximum aperture. I ended up using a shutter speed of 1/1600, ISO 400 and max aperture on a Sigma 70-400mm (f/5.6) and the Olympus 150-300mm f/6.7. And, this is what I got:
Again, you may have to click on the image to see the difference, but just look at the window frames and I think you'll agree that the E-M10 images are sharper. So, thinks I, lenses typically aren't at their best wide open, let's stop down a couple stops. And this is what I got (f/11):
Not much difference, is there? Note that I cranked the ISO up to 1600 in order to stop down and from a noise standpoint there isn't much difference compared to the original ISO 400 shots.
Oh, dear. What can the matter be? Well, we all know that zoom lenses are not at their best at maximum zoom, so I backed both lenses down to the 35mm equivalent of 300mm (instead of 600mm). Results? Not that much different:
What is left to explain this phenomenon? A 300mm vs a 400mm lens? Brand name lens vs independent?
My plan is to clamp these babies on a tripod even though I probably won't do that very often in reality. Any insight into this dilemma will be greatly appreciated...
Update: I failed to mention that the images above were 100% crops of these windows.
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