p.1 #1 · Sony compression creates artifacts in A7r ?
I had nothing but good things to say about the A7r until I took my first field tests and started to see what Lloyd had documented earlier in the week.
Here's the scenario - Zeiss 135 APO - shooting RAW 36mp - sRGB -> LR5.3 -> no post -> Export into JPEG 3 variants -> It appears that ProPhoto RGB export creates the strongest artifacts. sRGB the least and Adobe in between.
The issue doesn't show up much in a 200mp TIFF or RAW but there is a hint of it and it is greatly exacerbated by any post work for the JPEGs in addition to JPEG itself.
It appears that clipping the values in Sony's Lossless Compression sets the stage for those values to be rounded further to create the artifacts seen here -
p.1 #3 · Sony compression creates artifacts in A7r ?
Exporting to jpeg will always create artifacts.
Why are you checking your files at 8:1 magnification for flaws? Even if you print really big, between 50 to 100% should be a good magnification range for potential IQ issues that may translate to your print.
Fred
p.1 #4 · Sony compression creates artifacts in A7r ?
Fred, If you look through the photos there are artifacts in the RAW and TIFFs as well. There's been an ongoing discussion of whether the 'lossless compression' Sony uses is the cause.
I never noticed these in NEX7 JPEGs and with some post. Even subtle or no post is creating this with the A7r.
There are several photos in the flickr page where the artifacts are visible at 1x
p.1 #5 · Sony compression creates artifacts in A7r ?
Fred Miranda wrote:
Exporting to jpeg will always create artifacts.
Why are you checking your files at 8:1 magnification for flaws? Even if you print really big, between 50 to 100% should be a good magnification range for potential IQ issues that may translate to your print.
Fred
Fred,
I was wondering the same thing. 8X is excessive magnification and certainly well beyond what anyone should ever consider printing. If you want to stitch images for huge files that is fine for immense prints; that way you could keep the magnification down even more.
p.1 #6 · Sony compression creates artifacts in A7r ?
What does a 24x36 print look like?
This is what Lloyd had to say which seems quite reserved....
"...published a discussion of an “orange peel” texture to the Sony A7R image quality, a not unpleasant but also not endearing effect I have not seen with Nikon D800E images.
Overall image quality is really spectacular, but it’s something that caught my eye and worth knowing about the camera"
p.1 #7 · Sony compression creates artifacts in A7r ?
Max, is the coca-cola image yours? If so, what is the jpeg compression you used? The background tonal transitions look awful.
Can you provide a link to a TIFF or RAW file that shows compression artifacts?
"Over" sharpening will introduce artifacts/halos to any file from any camera. Perhaps A7R files do not need the level of sharpening needed for other files from different cameras.
p.1 #8 · Sony compression creates artifacts in A7r ?
I just took a look at my D800e files and saw the exact same pattern. This whole discussion is ridiculous and mostly designed to make Loyd more money and drive people to his site. If you over magnify and over sharpen this is what happens. Both the D800's have a anti-aliasing filter whereas the A7r doesn't, making it more susceptible to seeing this pattern at lower sharping. Diglloyd says he wants to apply the same amount of sharpening to his A7r as the D800, this is way to much as far as I'm concerned .
p.1 #10 · Sony compression creates artifacts in A7r ?
Max, Can you make the raws available? I would like to have a look (as I'm sure would others). You can upload it to https://www.transferbigfiles.com/ and then post the resulting link here. No registration is required and the upload limit is 100MB per file set. Also the links are only good for 5 days.
p.1 #14 · Sony compression creates artifacts in A7r ?
I want to be clear about what I think is happening.
1. I didn't go looking for this. I was very happy with the MTFs and started to field test the camera.
2. I did ETTR 1 stop and this may not be needed with the A7r.
3. I cleaned up the files I shot today and uploaded to Flickr expecting great photos.
4. I noticed the processed ones had garbage of all types so I started testing no post uploads and various exports (as seen in the Flickr page)
5. Even at 1X these defective areas can be seen. This is unacceptable to me as IQ is primary and I could give a ratsass about wifi and scene modes.
6. From participation in other threads and discussions on 'lossy' and 'lossless' I believe that the first compression of data within the camera results in some missing values and that those rounded values are rounded even further and become more apparent in the second iteration of compression. (aka assumptions on assumptions)
7. As I have never noticed this with the NEX7, I believe that Sony in an effort to capture the XMAS season rushed this camera (algorithm) to market with these flaws.
8. I would be willing to accept 2 or even a single frame a second for true 'lossless RAW images' as this camera is not a sports or AF or high speed camera by any means. Perhaps this is a fix Sony can make in firmware.
I made a few test photos tonight with the NEX7 and the A7r and will share those RAW images as well.
p.1 #16 · Sony compression creates artifacts in A7r ?
jcolwell wrote:
Me too.
Or a least options for compressed or uncompressed files available for the D800/E.
Nikon offers uncompressed files at 76MB and 14-bit lossless compression at 41MB. Sony's files maxes out at around 37.4MB.
Sony's A7/R compressed RAW (cRAW) can be described as a "visual" lossless compression but technically it is nearly lossless. It seems to be a sophisticated algorithm and I haven't seeing evidence that the compression impacts IQ including dynamic range so far. The benefit is getting 40-50% smaller files when compared to full uncompressed RAWs.
For many, shooting uncompressed RAW is like having an insurance that we are getting the best out of our camera and therefore, it would be great if Sony offered that option in a future firmware.
That's just a test render based on my standard processing (the preset is based on Phillip Reeve's default settings, with some tweaks for my preferences). A slight bit of NR was applied for the shadows and CA removal for the CA on the coke bottle. This is the native output from LR (I normally create 2048xXXXX JPEG's on export), not resized by Flickr
I think it's pretty clear that the tonal transitions are getting pushed either in the processing or in the JPEG's when Max is processing.
0-800 contains 801 unique values (ie is continuous)
801-1424 contains 320 unique values (skips 1 out of every 2)
1424-1427 contains one unique value (skips 2 of 3)
1428-2023 contains 149 unique values (skips 3 of 4)
2024-2029 contains one unique value (skips 5 of 6)
2030-4093 contains 258 unique values (skips of 8)
That's just a test render based on my standard processing (the preset is based on Phillip Reeve's default settings, with some tweaks for my preferences). A slight bit of NR was applied for the shadows and CA removal for the CA on the coke bottle. This is the native output from LR (I normally create 2048xXXXX JPEG's on export), not resized by Flickr
I think it's pretty clear that the tonal transitions are getting pushed either in the processing or in the JPEG's when Max is processing.
Mawz - can you post an open link to the full size you made ? Thanks.
Everything else is zero's, this is my default preset with NR and CA removal tweaked (in an actual render I'd add a curve to drop the mid shadows a bit, but that would wipe out much of the tones in the background so I didn't add it).
Archive 2013 · Sony compression creates artifacts in A7r ?
