RAW vs compressed RAW

I am looking for comparisons of Canon's RAW vs compressed RAW image quality. I am interested in getting sharp bird photos.

Thanks,

This might be helpful or at least give at bit more information, Bryan over at The-Digital-Picture.com has done some comparison:
www.the-digital-picture.com/Canon-Cameras/Canon-C-RAW-Image-File-Format.aspx

For birds, when the light is good, I see no reason not to use CRAW. But if the bird is backlit and there is no time to change exposure then it seems to me that RAW is slightly better than CRAW with the cost of needing more storage and taking longer to empty the camera buffer to storage.

It seems to me that the noise in dark areas looks more natural with RAW than with CRAW.

I did lots and lots of comparisons and never saw an improvement in image quality with raw vs craw. We are programmed to think the larger file should be better. To avoid that bias, the best way to do a comparison is to have a partner who can randomize the comparison images for a blinded study. If you want the absolute best results give up on ACR and use the Canon DPP4 software to open your raw or craw files. I will bet you will be able to see the difference between ACR and DPP4 files.

Brian's comparison at +3EV from under exposure quite striking here - with quote

*"Here again, I can see only minute differences in all except the strongly-underexposed comparison. And in the latter case, picking a winner is harder than noticing a difference. The detail in the underexposed C-RAW sample is not quite as finely rendered as in the RAW file, but it is still going to be hard to notice a difference in real life image output. Shoot the same comparison again and the random noise will look similar in quantity, but still different." *

I've found the bonus in CRAW is never hitting buffer now - even on my R10. The R5 with a fast SD card on RAW + LJPEG sometimes locked me out at critical moments - I know answer is CExpress but not gone there yet.

It's not really a bias because craw uses lossy compression, so it just can't be better than lossless compression in raw. Whether or not the difference is significant for your purposes is a different question. But the quality loss is visible.

The cRAW could be better if its noise pattern is more pleasant. All RAW files need some degree of sharpening and almost always get output eventually into a lower gamut like jpeg, HEIF or a print. All of these will change the noise patterns.

Heck, even the process of rendering the RAW to screen throws away a lot of data.

For my purpose, I’m studying something very different. I shoot concerts, and often, the light is absolutely terrible. What I’m trying to figure out is whether cRAW is worse under these poor conditions, when I dramatically push shadows and apply method such as DxO DeepPRIME to enhance the photos.

My thinking now is that I’ll shoot my next show saving RAW to one card and cRAW to the other, if possible, so that I can compare extreme conditions.

Is this the same post as DPReview?
If so I will add to it here, if not let me know and I'll copy the same reply over.

Do you have a reason to shoot compressed?

Test it for yourself and see if there is a meaningful difference for you. That said, bird photography often involves cropping and sometimes significant cropping. With significant cropping, you want the best possible image at the start. CRAW is not quite as sharp as RAW. So, I use RAW for bird photography.

Unfortunately, you cannot shoot RAW to one card and cRAW to another, so a side-by-side concert photography comparison isn't possible.

All CR3 files are compressed ;)

Yes you are correct, as you usually are Iliah.
But it might have been more helpful if you would have said that CR3 is in fact a compressed but lossless format. Whereas C-RAW is a compressed but lossy format which is why it results in a smaller file size.

CR3 isn't a format, it's a container allowing for multiple raw codings ;)
C-RAW is a subset of CR3 specification, a lossy option.
I can't help but notice that shorthand writing results in confusion ;)

Glad you can confirm that one is lossy and the other lossless.
Perhaps your first post might have been more helpful if you had mentioned that before. ;
The shorthand was your comment that "All CR3 files are compressed" Very true and a good example of your exemplary knowledge but not too helpful to those wanting to learn IMHO. ;)

There is no "one and the other". Both are CR3. Sigh... :))))

That's the truth of the matter.

а вот и не подеретесь (c)

Jekyll: As there’s a difference that can be seen (even though often subtle)…

Hyde: And because I do shoot in a lot of marginal lighting conditions

Jekyll: I’m going to take my “IQ hit” elsewhere.

Hyde: For instance when I’m using the (12-bit) electronic shutter., which I love.

Jekyll: I’ve got the fastest cards

Hyde: And plenty of storage capacity.

Jekyll: So I don’t have to worry about those factors at least.

Hyde: Continuing to shoot full RAW makes sense in my own case. So I’m happy with it. 😊

J&H