I have spent a little time tonight looking at the artifacting problem again in DPP and C1. Here is what I am seeing with my 7D:
1. Problem occurs in both C1 and DPP.
2. Artifacting increases as ISO increases.
3. Artifacting is present to some degree in ISO 100 images and all images above this level. Although it is at it\'s lowest point at ISO 100.
4. Noise reduction seems to reduce the effect. But, the artifacts that you see after NR were there in the final form before NR.
5. Artifacts create rectangular patterns that are visible at 100% view. They give the image a rougher, more textured look than it should have ... even at normal viewing sizes.
6. Artifacts seem to be the most noticeable when they align either horizontally or vertically in the image. There seems to be a tendency to this pattern.
7. I wouldn\'t call it mazing as it is presented in DPP or C1. But, it may be the remnants of that patterning. I have no expertise or special insight into mazing.
8. If you bring conversions by DPP and C1 into Photoshop and place them on separate layers, then move the opacity from 0 to 100 you can study the differences between the two conversions. The same artifacts are in both images in the same spot. So the software is not making them up. But, there are differences in how noticeable a given pixel in the artifact might be.
9. Careful exposure seems to really pay off big. If you under expose and bring exposure up in PP, then it appears like you end up generating many more artifacts and they will be significantly more noticeable. This was the last area I was analyzing and I feel that there is more to this story. This may explain one thing I noticed when shooting: that the degree of artifacting was not constant and could vary from image to image. It is possible that I was adjusting exposure in PP and this was impacting the amount and degree of artifacting in the images. Also, the images I was using for evaluation initially were shot under tougher lighting conditions. Using a careful expose to the right strategy seems like (with a few more tests) a way to get the best results here.
10. After spending more time on this problem than I really wanted to, I am left with a general feeling that this artifacting problem is somehow tied into the ability to get better ISO performance.
I would consider it a new class of digital noise. One that I don\'t really understand or like. Perhaps Canon is using some new approaches in processing the data going into the RAW file and the mathematics of processing these files is still not optimized.
It seems that some of the 7D buyers are not seeing this artifacting. I don\'t know what to make of that (outside of the expose to the right comments above). The only explanations that I can think of is that our cameras are performing differently, our personal expectations are different or maybe people have not spent enough time working with images to start to see the problems.
I don\'t really know what I am going to do. I can\'t return my camera at this point in time. I guess my options are:
1. Buy another 7D to compare to mine and see if I get different results.
2. Sell my 7D and use my 5DII exclusively. Prior to the introduction of the 7D, I had been leaning toward just selling all of my crop stuff and going completely FF anyway.
3. Wait and hope Adobe pulls off a miracle with ACR 5.6 ... or that Phase One or Canon tweaks their software further. I feel that the current release of DPP and C1 are production releases. My own analysis seems to indicate that Adobe has some chance of creating a conversion that is better than DPP or C1. This could reduce the problem further.
4. Wait and give this problem a little time to be better understood. Maybe call CPS in December or January and see if they have any insights after the dust settles down. Send in camera for repair.
I will say that outside of this IQ problem, the 7D is my favorite Canon body that I have owned since I started shooting Canon in 1987.
Anyway, just sharing my observations.
Nov 08, 2009 at 03:20 AM
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