When I was doing research for my review of the Canon EOS M50 some years ago, I came across the compressed cRAW files for the first time. The latest mirrorless cameras from Canon also support the cRAW file format. Because this raw file is compressed, you will be able to save even more photographs on the same memory card without any reduction in image quality.
In 2018, when I wrote my evaluation of the Canon EOS M50, I examined images captured in the cRAW file format. It is a modification of the standard raw file format, but the file size is approximately one-half of what it would be otherwise. If you convert your RAW files to the compressed cRAW format, you will be able to store almost twice as many photographs on your memory card.
Additionally, the new Canon EOS R5 and Canon EOS R6 both include the cRAW file format, which is a compressed version of the RAW format. This may come in quite helpful, particularly when dealing with the enormous files produced by the Canon EOS R5. Because the sensor in the Canon EOS R6 only has 20 megapixels, the resulting files are between 20 and 30 megabytes in size. This may make the issue less significant for the Canon EOS R6. When using the cRAW file format, the final files will be between 10 and 16 megabytes in size.
With the Canon EOS M50, I did a comparison between the raw file and the cRAW file; nevertheless, I thought it would be interesting to run the test a bit more fully. I didn’t just want to test whether there was a difference between different ISO settings; I also wanted to see if there was a difference when underexposure, overexposure, and excessive post-processing were taken into account.
I needed some fall leaves for this activity, so I went outside and grabbed some. I believed that it would be an interesting topic to include in this examination. I positioned an LED so that it would shine brightly through one of the oak leaves in order to achieve the desired effect.
Only the light coming in through the windows was on. There were no other sources of illumination. I used a Canon EOS R6 camera with an RF 24-105mm f/4L IS lens and a strong tripod to take these pictures. I utilized the manual exposure setting and the manual focus, despite the fact that the latter is of less significance for this examination.
It has come to my attention that Canon does not provide users the option to save a raw file on one memory card and a cRAW file on another. The unfortunate reality is that you can’t have both of those things at the same time. It would be fantastic if Canon enabled users to save raw files to one card while simultaneously writing cRAW backups to the second card.
Find an image with the proper exposure and compare it
The initial test consisted of nothing more than a straightforward comparison with the right exposure, and it was carried out in raw as well as cRAW. I made the decision to take a series of photographs with ISO settings ranging from 100 to 102,400. Because I don’t want to be a nuisance to you with the entire series, I decided to merely compare the photographs taken at ISO 100 and ISO 1,600 next to each other.
On the left, you’ll see the raw photographs, and on the right, you’ll see the cRAW images.
Analyzing Images That Are Underexposed by Three Stops
I repeated the process, but this time I purposefully underexposed the photo by three stops. This was fixed in Lightroom Classic by dragging the exposure slider farther to the right, which produced an effect that was more accurate than the original exposure. I performed this with the ISO 100 photographs as well as the ISO 1600 images to determine whether or not this exposure adjustment had an influence on the quality of the cRAW file in comparison to the raw file.
Analyzing Images That Are Overexposed by Two Stops
After exposing the photo two stops too much, I opened it in Lightroom Classic and attempted to make the necessary adjustments there. As can be seen, the LED light has caused the leaf that it is shining on to be trimmed. The post-processing stage will not be able to save this component. First, let’s take a look at the output with the ISO set to 100, and then again with the ISO set to 1,600.
Analyzing and Contrasting a Heavily Post-Processed Image
I couldn’t help but wonder how these pictures might turn out if I applied a more severe level of post-processing to them. In order to do this comparison, I went back into Lightroom Classic and adjusted the exposure of the photographs such that they had a three-stop underexposure. In addition to that, I adjusted the settings such that the shadows were at +100 and the highlights were at -100. I also adjusted the black point and the white point, along with the texture, clarity, and vibrance settings, and I removed some of the haze. This was accomplished using the raw and cRAW photos captured at an ISO of 1,600.
In Relation to an Extremely High ISO
Despite the fact that I have only shown the photographs that we have shot up to ISO 102,400, which, under normal conditions, I do not believe are suitable for use in commercial endeavors If you’re using a Canon EOS R6, I wouldn’t go any higher than ISO 12,800.
During the post-processing stage, I worked to bring the exposure up by 1.25 stops, brought the highlights down by 100, and brought the shadows up by 100. I adjusted the white point and black point, as well as the texture, clarity, and vibrance, and I removed some of the haze. In addition to that, I adjusted the white balance.
This leads me to the following conclusion:
Due to the fact that this experiment was carried out, I was able to determine that cRAW suffers very little to no loss in quality while having a reduced file size. It’s possible that a more in-depth examination will reveal some distinction, particularly if something like a color checker is shot.
On the other hand, I found that this experiment was a more realistic comparison, as it was similar to a circumstance that may occur in real life. It is probably reasonable to claim that the quality of the cRAW file is only slightly diminished. Even with extensive post-processing, I believe that it is perfectly acceptable to utilize the cRAW file format while photographing significant occasions such as weddings.
Another thing that stood out to me as I was looking at the pictures was how good the image with the ISO 12,800 setting was. In my opinion, the Canon EOS R6 is highly useful even at this extremely high ISO.
Check out the pictures for yourself and draw your own conclusions based on what you see. Please share your thoughts with me. Is working with cRAW just as practical as working with conventional raw files? In the comments box below, I would appreciate it if you could share your thoughts. I really anticipate hearing from you in answer to this.