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Is There Any Quality Difference Between Raw and cRAW on the New Canon Mirrorless Cameras?

I first came across the compressed cRAW files when I reviewed the Canon EOS M50 a few years ago. The new Canon mirrorless cameras also have cRAW available. This compressed raw file will enable you to save even more images on one memory card without loss of quality.

When I reviewed the Canon EOS M50 back in 2018, I used the cRAW file format. It is a variation of the regular raw file format, but it’s about half the file size. Using this compressed cRAW file format, you can store about twice as much images on your memory card.

Also, the new Canon EOS R5 and Canon EOS R6 have the compressed cRAW file format. This can be very handy, especially for the large files of the Canon EOS R5. For the Canon EOS R6, it might be less important, because the sensor has only 20 megapixels, producing files that are between 20 MB and 30 MB. With the cRAW file format, you end up with files between 10 MB and 16 MB.

Although I made a comparison between the raw and cRAW file with the Canon EOS M50, I thought it would be interesting to do the test a bit more thoroughly. I not only wanted to see if there was a difference between ISO levels, but also by correcting underexposure, overexposure, and with extreme post-processing.

For this test, I went outside and gathered some autumn leaves. I thought it would be a nice subject for this test. In order to have a highlight in the setup, I placed a LED underneath one oak leaf. There were no additional lights, just the natural window lights. I used the Canon EOS R6 with the RF 24-105mm f/4L IS lens placed on a sturdy tripod. I used the manual exposure setting and manual focus, although the latter is of lesser importance for this test.

I noticed Canon doesn’t allow you to save a raw file on one memory card and a cRAW on another. You have to choose one or the other, which is a pity. It would be great if Canon allowed saving a raw to one card and cRAW for backup to the other one.

1. Compare a Correct Exposed Image

The first test was a simple comparison with the correct exposure, both in raw and cRAW. I decided to shoot a series of images ranging from ISO 100 up to ISO 102,400. I don’t want to bother you with the whole series; thus, I chose to compare only the ISO 100 and ISO 1,600 images next to each other.

The raw images are on the left, the cRAW images are on the right.

First are the ISO 100 images with and without the crop. 

Next are the ISO 1,600 images with and without the crop. 

The images are straight from the camera, and I used Lightroom to produce JPEG images from both the raw and cRAW files without post-processing. Even with a large magnification, which resembles approximately 100%, the images from the compressed raw show no visible decrease in quality.

2. Comparing Three-Stop Underexposed Images

I made the same image with a deliberate three-stop underexposure. This has been corrected in Lightroom Classic by increasing the exposure slider to resemble a correct exposure. I did this with both the ISO 100 and the ISO 1,600 images to see if this exposure correction had an effect on the quality of the cRAW file compared to the raw file.

Again, the raw images are on the left, the cRAW images are on the right.

First are the ISO 100 images with and without the crop. 

Next are the ISO 1,600 images with and without the crop. 

3. Comparing Two-Stop Overexposed Images

After I had overexposed two stops, I have tried to correct this in Lightroom Classic. As you can see, the leave that is lit by the LED light is clipped. This part cannot be rescued in post-processing. Let’s have a look at the result, both at ISO 100 and ISO 1,600.

The raw images are on the left, the cRAW images are on the right.

First are the ISO 100 images with and without the crop. 

Next are the ISO 1,600 images with and without the crop. 

4.Comparing an Extremely Post-Processed Image

I wondered how the quality would hold if I did a more extreme post-processing on these images. For this comparison, I took the images that had a three-stop underexposure and corrected this in Lightroom Classic again. Besides that, I set the shadows to +100 and the highlights to -100. I also changed the black point and white point and increased texture, clarity, dehaze, and vibrance. This was done at the ISO 1,600 raw and cRAW images.

The raw images are on the left, the cRAW images are on the right. I only placed the cropped versions for this comparison.

5. Comparing a Very High ISO

Although I have showed only the ISO 100 and ISO 1,600 images so far, images weare shot up to ISO 102,400, which under normal circumstances, I find not usable for commercial purposes. With the Canon EOS R6, I wouldn’t go beyond ISO 12,800.

In post-processing, I increased exposure by 1.25 stops, decreased highlights by 100, and increased shadows by 100. I set the white point and black point, increased texture, clarity, dehaze, and vibrance. I also changed the white balance.

The raw images are on the left, the cRAW images are on the right. I have only shown the cropped versions. Remember, these are shot at ISO 12,800.

My Conclusion After This Test

By conducting this experiment, I have found cRAW to have little to no decrease in quality, despite the smaller file size. Perhaps a closer look will show some difference, especially if something like a color checker is photographed.

But I found this experiment a more realistic comparison, resembling a real-life situation. I think it is safe to say cRAW shows a negligible decrease in quality. I feel it is very safe to use the cRAW file format when shooting important events like weddings, even with extreme post-processing.

Another thing I noticed while looking at the images is the quality of the ISO 12,800 image. I think the Canon EOS R6 is very usable at this high-ISO level.

Please check the images in this article yourself and make your own conclusion. Tell me what you think. Is cRAW as usable as the regular raw files? Please share your opinion in the comments section down below. I am looking forward to your response.


Source
FStoppers.Com

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