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Comparing A7R2 compressed and uncompressed raw files

Jim DE

New member
Problems arising from the lossy compression used by Sony do not show up in every shot, this is well known, so the fact that you have not seen any substantial advantage using the uncompressed option, proves nearly nothing. For my shots I prefer to stay on the safe side, I have plenty of SD's and storage space. BTW the issue was not just BS.
Ario, I have been shooting Minolta/Sony digital cameras since they got into this game back in the A1-2 days....... Shot RAW once it was available and continued shooting that format with DSLR's, DSLT's, NEX and now the A7FF line(I have only wandered outside of Sony with a Sigma DP2m for pano's)..... the cRAW has been their primary RAW format since the a900 and you know what? I cannot recall even one thread in the SLT/SLR Sony forums nor the NEX forums TILL the introduction of the A7x line and interest came from users of other camera lines...... not one stinking thread!!!!!!

I guess us ole dumb Minolta/Sony guy's just don't know what a good image looks like..... Funny I make a mighty good living shooting cRAW for a dumb ole ignorant A or E mount shooting Pro.

Thousands upon thousands of images have run through my post processing and printing and I have not once seen the issues all the BS was about on the web nor have my customers made mention of these....... I guess one needs to shoot for proper exposure and do what we get paid to do to make this a non issue in real life imaging. So for those who don't shoot and process properly I guess it is a issue for them but nothing a lesson or two in photography won't fix. My bet is after 6 months less than .05% of Sony using photographers will continue to use uncompressed RAW files....... Lossless Compression (which sounds like the best of both worlds though I have never used it)when made available in future Sony lines will replace the current cRAW and then uncompressed will die on the vine as it did with the a900 and once again disappear.

Vivek, I shoot what works for me and pays my bills..... I picked Minolta when Nikon wasn't even in the digital game and stuck with Sony because of the volume of gear I have and it still works very well for me...... if that is being a Sony Superfan in your eye's then so be it. I call it calling it as I see it........ from the eye's of a longtime Minolta/Sony gear user. This whole cRaw/Raw issue I guess might have relevance to someone shooting specific subjects like star trails or maybe even highly backlit stain glass windows but you know what?...... I have never made one single cent shooting either of these and never will as there isn't much demand or earnings available for such images and if there ever comes a time I need such shots there and many very easily achieved workarounds with cRAW that will get the job done as well or better than a lossless compression/ or uncompressed formats. But, Vivek you and I have seen each other on web forums for many years... I know your perspectives and you know mine............. We are very different in our thoughts and our likes but that is what makes the world go round as it would be boring if we all liked the same things...... It truthfully makes absolutely no difference to me what anyone else shoots or floats their boat... I don't care what other brands have or don't have as I am too old to change brands now...... what bothers me is people coming from other brands complaining that Sony cameras are not like the camera's they are leaving. If they like the other brands features so much go back and shoot them..... but they should not make up absurd criteria to visualize a defect that is outside the design intent of the product's intended purpose or any similar products design intent.
 
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dmward

Member
I downloaded C1 8.3.4 and reprocessed the previews for the uncompressed files.
It works as expected.

Regarding the discussion about whether or not one can see a difference between uncompressed and lossy compressed Sony raw files;
I went to the images I used for my initial comparison and looked at them in C1 8.3.4.

When looking at the highlight area (clouds in sky with sun behind) I found that using the C1 film curve the shoulder of the curve compresses the uncompressed file similarly to the why it does the compressed.

When using the linear curve there is a substantial difference. When using the highlight slider to further pull detail it becomes more apparent that the uncompressed has finer gradation. I suggest taking a file with detail in highlights that one want to bring down gradually from 255 to about 235 and experiment with linear tone curve and highlight slider.

At 100% there is a difference between the compressed and uncompressed files. For me, keeping this detail granularity in clouds etc. is important and not an uncommon requirement.
 

Knorp

Well-known member
After successfully installing C1 8.3.4 you may switch OpenCL back on to Auto ...

 
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Jim DE

New member
I can see with the past two posts I have much to learn in C1 :banghead:......... thankfully I can still use my Aperture 3 ;) I have no idea what film curve or linear curve controls are......... maybe it is just a verbiage issue but I think it is just something I have not dealt with in C1 as yet
 

dmward

Member
I can see with the past two posts I have much to learn in C1 :banghead:......... thankfully I can still use my Aperture 3 ;) I have no idea what film curve or linear curve controls are......... maybe it is just a verbiage issue but I think it is just something I have not dealt with in C1 as yet

I don't have C1 on this computer so I won't be able to accurately title the panels.

When in the first or second modules, (the icons at the top from the left), there is a drop down menu that includes the tone curve options. One option is film, another option is linear. There are two other options that have steeper mid-tone curve which means a stronger shoulder and toe curve which compresses highlight and shadow detail even more.

I think the C1 default is film. I prefer using linear because, if it is truly linear, means there is no compression in either the highlight or shadow extremes since a linear tone curve is a straight line from 0 to 255.
 
I don't have C1 on this computer so I won't be able to accurately title the panels.

When in the first or second modules, (the icons at the top from the left), there is a drop down menu that includes the tone curve options. One option is film, another option is linear. There are two other options that have steeper mid-tone curve which means a stronger shoulder and toe curve which compresses highlight and shadow detail even more.

I think the C1 default is film. I prefer using linear because, if it is truly linear, means there is no compression in either the highlight or shadow extremes since a linear tone curve is a straight line from 0 to 255.
Actually in the most recent releases the default curve is Auto which is the one used to prepare the corresponding camera profile (yes, mostly Film).
 
First of all, 'scuse me, but could you guys who are fretting over C1 please start a thread on that topic, so we can talk here about compressed & uncompressed files?

I've tried the recommended technique of converting the uncompressed ARW files into DNGs, which are supposedly lossless compressed – and 1/2 the size. This provides the option of lossless compression that Sony left out.

https://photographylife.com/sony-a7r-ii-uncompressed-raw-with-adobe-dng-converter

And after converting the ARWs to DNGs I opened both versions with identical settings in LR/ACR, and then saved the files. I checked the highest highlights in PS, and I don't seem to be losing any detail there because of the allegedly lossless comprssion. Good news!

But the PS files from ARW and DNG looked the tiniest bit different. With all settings the same in LR/ACR (Camera Neutral, Sharpening 0, Auto, etc.) I still get slightly different gamma readings in PS files for some tones. So while the DNG conversion is supposedly lossless, it's nevertheless not just the same as a Camera Neutral conversion from an uncompressed ARW file? The DNG converter, while apparently lossless, has its own very slightly different 'secret sauce'?

I should add that the differences I measured were very small compared the choices between different camera profiles (Adobe, Camera Standard, Camera Neutral, etc.). But seeing the ACR and DNG versions on the monitor, I had a hunch they weren't 100% the same, and that's what some 3-pixel point measurements seemed to verify.)

Kirk

PS, adding a little more: I'm quite happy with the uncompressed Sony files, but often I stitch 2 or more files. The stitching time is proportional to the file sizes. This and the resulting size was what made me interested in trying to retain the same detail via lossless compression.)
 
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dmward

Member
Kirk,
I think the best way to get maximum detail in the extremes is to use a linear tone curve.
It is interesting that the Adobe tone curves treat the dng and Sony proprietary files differently.

I wonder if it may have something to do with how the camera profile is applied. I use a camera profile I created using DNG Profile Editor rather than one of the Adobe profiles. Haven't looked critically at dng and camera raw to see if there's a difference.
 
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