Converting ARW to DNG good idea?

[IvankoPetro]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

• ARW 47 MBytes
• DNG 22 MB (lose-less JPG compression)
• RAR archive 23 MB

To save space i need to decide which option to use, obviously using RAR is not very convenient as i have to extract every time before viewing them and with DNG i can see right away.

ChatGPT saying there's nothing i loose in terms of dynamic range etc when converting to DNG still same quality, just want to double check what you think?

 

[ajscullard]

It's very much a personal choice, although I never consider disk space a valid reason to make file format decisions.

When DNG first appeared, many, many years ago, I thought it was a great idea and started converting all raw files to dng. Then I saw that I was spending a lot of time doing this and not gaining anything. In my case Canon raw and dng files were about the same size anyway. So for a while I did the conversion but kept the original raw files as well. Then I found that my new raw conversion software would not convert Adobe dng files.

Game changer. Now I couldn't go back and re-process any of the files that I had converted even though newer software produced much better results than the old stuff. I kept all the dng files that did not have duplicate cr2 files and deleted all the ones where I did.

It's up to you, but consider all aspects of the post-processing workflow when making your decision, not just disk space.

 

[Digital Nigel]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

• ARW 47 MBytes
• DNG 22 MB (lose-less JPG compression)
• RAR archive 23 MB

To save space i need to decide which option to use, obviously using RAR is not very convenient as i have to extract every time before viewing them and with DNG i can see right away.

ChatGPT saying there's nothing i loose in terms of dynamic range etc when converting to DNG still same quality, just want to double check what you think?

 

[IvankoPetro]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

Not ideal scenario for me because according to Sony, A7 III saves only 12-bit raw's when using Compressed RAW in Continuous Shooting mode which i sometimes use, besides i have lack of trust about Sony's lossy compression in general rather stay with uncompressed.

 

[Digital Nigel]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

Not ideal scenario for me because according to Sony, A7 III saves only 12-bit raw's when using Compressed RAW in Continuous Shooting mode which i sometimes use, besides i have lack of trust about Sony's lossy compression in general rather stay with uncompressed.

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

 

[tbcass]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

• ARW 47 MBytes
• DNG 22 MB (lose-less JPG compression)
• RAR archive 23 MB

To save space i need to decide which option to use, obviously using RAR is not very convenient as i have to extract every time before viewing them and with DNG i can see right away.

ChatGPT saying there's nothing i loose in terms of dynamic range etc when converting to DNG still same quality, just want to double check what you think?

There's a free program called Adobe DNG converter if you want to try out and compare results. It will batch convert but it takes quite a while if you have a lot of them.

 

[Erik Baumgartner]

Once you've converted to DNG and chucked the RAW you can never reconstitute the RAW, it's gone for good.

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I. demosaicking and noise reduction processes that requires the original unmolested file to operate. There is also proprietary maker metadata that is often stripped for good when converting to DNG, and some software (like Capture One uses) the file type to enable camera-specific film simulations etc. (not available with a DNG). It's just a generally bad idea, IMO. Shoot lossless RAW and call it a day.

 

[ishwanu]

Once you've converted to DNG and chucked the RAW you can never reconstitute the RAW, it's gone for good.

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I.

Adobe DNG converter does not do demosaicing unless you override the default and tell it to create linear files.

There are other reasons why it could be better to preserve the original RAW files, though.

 

[IvankoPetro]

Once you've converted to DNG and chucked the RAW you can never reconstitute the RAW, it's gone for good.

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I.

Adobe DNG converter does not do demosaicing unless you override the default and tell it to create linear files.

There are other reasons why it could be better to preserve the original RAW files, though.

Never seen option to de-mosaic raw when converting to DNG, which one is that?

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I. demosaicking and noise reduction processes that requires the original unmolested file to operate.

Just tried RawDigger shows DNG still has all channels independently and AI Denoise works as well.

There is also proprietary maker metadata that is often stripped for good when converting to DNG, and some software (like Capture One uses) the file type to enable camera-specific film simulations etc. (not available with a DNG).

Whats the use of that metadata exactly?

 

[ishwanu]

Once you've converted to DNG and chucked the RAW you can never reconstitute the RAW, it's gone for good.

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I.

Adobe DNG converter does not do demosaicing unless you override the default and tell it to create linear files.

There are other reasons why it could be better to preserve the original RAW files, though.

Never seen option to de-mosaic raw when converting to DNG, which one is that?

Click on Compatibility and select Custom.

 

[ishwanu]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

Not ideal scenario for me because according to Sony, A7 III saves only 12-bit raw's when using Compressed RAW in Continuous Shooting mode which i sometimes use, besides i have lack of trust about Sony's lossy compression in general rather stay with uncompressed.

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

There have been many confirmations in the past that Sony lossy compression can produce pixel-level anomalies along high contrast borders, which can matter to some people. Just one example:

https://stephenbayphotography.com/blog/sony-raw-compression-artifacts-real-examples/

 

[Lan]

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

I can, but only in certain circumstances - unfortunately they're circumstances I like to shoot in.

Basically any shots where you have very hard edge contrast. Again probably won't be noticeable if you leave everything at default, but as soon as you lift the shadows these edges look bleurgh.

I love shooting in blue hour with artificial lights in the shot, and I also like shooting contra jour sunsets. Both tend to exacerbate the issue.

If you always shoot with the sun behind you, it'll be fine. If you don't lift the shadows, it's fine. If you shoot the things I like to shoot - then Sony's lossy compression can be problematic.

 

[Digital Nigel]

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

I can, but only in certain circumstances - unfortunately they're circumstances I like to shoot in.

Basically any shots where you have very hard edge contrast. Again probably won't be noticeable if you leave everything at default, but as soon as you lift the shadows these edges look bleurgh.

I love shooting in blue hour with artificial lights in the shot, and I also like shooting contra jour sunsets. Both tend to exacerbate the issue.

If you always shoot with the sun behind you, it'll be fine. If you don't lift the shadows, it's fine. If you shoot the things I like to shoot - then Sony's lossy compression can be problematic.

OK, you obviously know exactly when lossless raws are needed. I suspect many others shoot uncompressed huge files unnecessarily.

 

[Tony Hall]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

Not ideal scenario for me because according to Sony, A7 III saves only 12-bit raw's when using Compressed RAW in Continuous Shooting mode which i sometimes use, besides i have lack of trust about Sony's lossy compression in general rather stay with uncompressed.

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

There have been many confirmations in the past that Sony lossy compression can produce pixel-level anomalies along high contrast borders, which can matter to some people. Just one example:

https://stephenbayphotography.com/blog/sony-raw-compression-artifacts-real-examples/

Ewe, no thanks.

 

[Digital Nigel]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

Can’t you use lossless compressed raw files?

Not ideal scenario for me because according to Sony, A7 III saves only 12-bit raw's when using Compressed RAW in Continuous Shooting mode which i sometimes use, besides i have lack of trust about Sony's lossy compression in general rather stay with uncompressed.

Can’t you see any difference in quality at all between the uncompressed 14-bit and lossy compressed files? I just use lossy compressed files from all my Sony cameras.

There have been many confirmations in the past that Sony lossy compression can produce pixel-level anomalies along high contrast borders, which can matter to some people. Just one example:

https://stephenbayphotography.com/blog/sony-raw-compression-artifacts-real-examples/

Ewe, no thanks.

Note that that article is from six years ago. Modern Sony cameras do (finally!) offer lossless compression, as well as lower resolution options (which not all raw converters will handle):

https://helpguide.sony.net/ilc/2230/v1/en/contents/TP0003057049.html

 

[IvankoPetro]

I suspect many others shoot uncompressed huge files unnecessarily.

They not huge anymore after converting to DNG size becomes almost same as compressed ARW's, but has whole 14-bit data.

 

[ThomasNorway]

I am not a fan of DNG format, however Sony uncompressed 14 bit ARW files weight too much.

• ARW 47 MBytes
• DNG 22 MB (lose-less JPG compression)
• RAR archive 23 MB

To save space i need to decide which option to use, obviously using RAR is not very convenient as i have to extract every time before viewing them and with DNG i can see right away.

ChatGPT saying there's nothing i loose in terms of dynamic range etc when converting to DNG still same quality, just want to double check what you think?

After much research and experimentation, I shoot Lossless RAW (large) as the default on my A7IV.

With difficult subjects, I use (ISO) auto bracketing, typically +-3 stops. Either with spot metering or highlight metering.

You should watch

btw.

In some situations I might switch to Uncompressed RAW, but that's probably less than 1% of my images.

On my GFX100RF I use LOSSLESS 14bit (16bit adds noise), and might switch to UNCOMPRESSED on special subjects.

 

[IvankoPetro]

After much research and experimentation, I shoot Lossless RAW (large) as the default on my A7IV.

I'd explore Loseless RAW compression option however its not available in A7III so i resort to Uncompressed.

Lossless compressed RAW available only on:

• a7 IV
• a7 R V
• a7 CR
• a7C II
• ILX-LR1
• a6700 (APS-C)

What's the size difference between Lossless compressed RAW vs Uncompressed in A7III?

 

[TimoKoo]

Once you've converted to DNG and chucked the RAW you can never reconstitute the RAW, it's gone for good.

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I.

Adobe DNG converter does not do demosaicing unless you override the default and tell it to create linear files.

There are other reasons why it could be better to preserve the original RAW files, though.

Never seen option to de-mosaic raw when converting to DNG, which one is that?

Problem? Yes, the DNG file has been irreversibly demosaicked which no longer allows you to make use of constantly improving A.I. demosaicking and noise reduction processes that requires the original unmolested file to operate.

Just tried RawDigger shows DNG still has all channels independently and AI Denoise works as well.

Do you see four channels in RawDigger? RGGB?

There is also proprietary maker metadata that is often stripped for good when converting to DNG, and some software (like Capture One uses) the file type to enable camera-specific film simulations etc. (not available with a DNG).

Whats the use of that metadata exactly?

 

[tbcass]

I suspect many others shoot uncompressed huge files unnecessarily.

They not huge anymore after converting to DNG size becomes almost same as compressed ARW's, but has whole 14-bit data.

Here's the problem with converting to DNG. As an experiment after a cross country shoot I converted the 673 photos I took to DNG with the Adobe DNG converter. It took an outrageous amount of time, over an hour, to convert all those files. That makes it impractical for me to use it.