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Using a Canon camera, I took an image in black & white, and saved it as RAW. When I'm opening the image on my PC with, it displays in black & white as expected, and 2 seconds after in colors, and when I zoom in, the image is really "grained", it looks very bad.

From what I could read and understand - In the 2 first seconds, I can see the "thumbnail" image that is "attached" to that raw data image, while it's being interpreted, and then I see the Interpreted image when it's ready.

I was expecting Lightroom software to display the image at its best, and not a "bad" interpretation of it. Why does the CR3 format exist, if not to have the best quality and most precise and uniquely interpreted? How can I work with it?

wp42
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    What does "really 'grained'" mean? Can you put a snip of the picture in your question? – Solomon Slow Apr 19 '22 at 21:45
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    Try opening it in Canon's own software. That should apply the same settings as your camera used. 3rd party software will guess, & usually guess wrongly. – Tetsujin Apr 20 '22 at 07:07
  • The reason it's called raw is because it is raw image data. Of course it doesn't look its best - but it allows you to get the best out of the image. Even if I don't think analogies always help, think of it like raw cooking ingredients - by using your software recipe of choice you can make a much better meal than your camera's automated systems can. But without doing anything, of course all you have is a raw image, with some kind of basic interpretation shown to you. – osullic Apr 20 '22 at 14:13
  • @osullic Those answers written 12 years ago are so naive with regard to what information a raw image file actually contains, and how that information is stored, as to make that question/answer nowhere near the best possible duplicate from among existing questions here. – Michael C Apr 21 '22 at 06:51
  • What's the deal, @MichaelC? You know how this site works. If that question requires an updated answer, please add/edit one. – osullic Apr 21 '22 at 07:45
  • @osullic You know quite well that any answer written today by anyone, no matter how much better it might be, would remain buried at the bottom of those answers that garnered more upvotes when the community was new and had much higher participation than will even see the newly created answer. (This isn't unique to PhotoSE, it's true of many "mature" SE sites where pretty much all of the questions have already been asked and answered multiple times.) – Michael C Apr 21 '22 at 07:51
  • Related: Why do RAW images look worse than JPEGs in editing programs? and What does an unprocessed RAW file look like? and While shooting in RAW, do you have to post-process it to make the picture look good? and How does shooting on dedicated monochrome digital cameras compare to shooting in monochrome mode on full-colour digital cameras? – Michael C Apr 21 '22 at 08:00
  • @osullic Not to mention that's an awful general "duplicate" of a very specific question about why a raw file shot with the camera set to B&W opened in color in a raw convertor app. None of the answers to that suggested dupe come remotely close to answering why LR would open a raw image shot with the camera set to B&W and display it in color. – Michael C Apr 21 '22 at 08:26
  • @MichaelC sorry for the personal comment but I've noticed you becoming more abrasive in your comments recently. Jaded a bit by this mature SE site with the constant duplicate questions? Let's keep it civil – osullic Apr 21 '22 at 08:46
  • @osullic Please point out what part of any comments I've made above are not civil. I've not attacked anyone personally, nor accused anyone of poor character. I've only discussed why I don't think the duplicate suggested was the best choice from the multitude of choices among existing questions. From Code of Conduct "Be clear and constructive when giving feedback, and be open when receiving it. Edits, comments, and suggestions are healthy parts of our community." – Michael C Apr 22 '22 at 00:08
  • Maybe I misinterpreted your comments. Multiple directly aimed at me, simply for pointing out a potential duplicate - but which you call out as "awful" (cf. "lazy" in the CoC). Then you unnecessarily spell out the "very specific question" here, like I can't read it myself? Well, I can read it. Indeed - if you read the entire body of the question, you can see that there are 3 question marks asking 3 different questions. Not specific at all. More like an X/Y problem. This question is clearly rooted in a fundamental misunderstanding of what a raw file actually is. – osullic Apr 22 '22 at 07:41
  • Again, if my suggested dupe is out of date, everyone is free to add/edit answers there. – osullic Apr 22 '22 at 07:41
  • @osullic Just for the record in case you thought differently, the comment I made that starts with "Related" was not directed at you. It was directed at anyone who is interested in other questions/answers here at Photo SE that cover related topics to this question. It's not a list of suggested duplicates. It's a list of Q&A that cover related subjects that are not duplicates. – Michael C Apr 22 '22 at 08:12
  • @osullic I made one comment in response to an autogenerated comment that resulted from your vote to close as a duplicate of a question that doesn't even mention B&W anywhere in the question and answers. I made no other comments until you responded with a comment directed at me that some might consider not keeping it civil. The comment began with, "What's the deal...?" If you then say, "You know how this site works..." then please do not get bent out of shape when someone responds to that comment with, "You know quite well..." Geese≡Gander and all. – Michael C Apr 22 '22 at 08:21
  • Points are made, I think. – osullic Apr 22 '22 at 08:22

4 Answers4

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I don't know your camera in particular, but the whole point of RAW files is to save exactly what the sensor saw, without any special effects. "Black and White" is a special effect. The sensor in your camera always sees in color.

Solomon Slow
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  • The sensor in digital cameras always sees in monochrome. Color is derived by comparing the monochrome values recorded by each photosite filtered by one of three colors (that are not the same three colors as those emitted by our RGB displays) with the monochrome luminance values recorded by adjoining photosites filtered for the other two colors used in the Bayer mask. – Michael C Apr 21 '22 at 05:45
  • @MichaelC, OP asked a simple question, so I gave a simple answer. I am a software developer with some experience in digital image processing. I know what a Bayer mask is, and I know somewhat about human color perception. But, I didn't think the OP was asking for a lecture on those topics. – Solomon Slow Apr 21 '22 at 12:46
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First of all: Welcome :-)

When you shoot in RAW, your camera collects all the information from the image sensor and saves it in a RAW file. This means that all the color information as well. When you set your Canon camera to e.g. the Picture Style "Monochrome", then what really happens is that the image in the LiveView (or Electronic Viewfinder, if your camera has this) is represented as black and white. But the sensor still collects every thing.

Then when the file is saved, a "preview" image is stored in the RAW file along with the raw data.

Now, what happens when you view the image in e.g. Windows is that the Preview is shown (provided Windows can read the CR3 file).

In Lightroom it is, as you say, the preview that is displayed at first. Then Lightroom shows the raw data from the RAW file. Depending on your settings in Lightroom, this can look weird because of color temperature etc. This is because you feed it with a RAW file containing exactly what information that was hitting the sensor when you took the picture. Lightroom does not, by ways of magic represent the image in the best possible way. You do, by adjusting the image using the various sliders, adding noise reduction and so on.

If your image looks grainy in Lighroom, there are most likely two possible explanations:

  1. You shot at a high ISO. In this case you must apply noise reduction to clean up the image.
  2. You don't really mean noise, but rather pixelation. This can happen if Lightroom does not build a Smart Preview of the image. You can check in the top left corner, next to the histogram (as I recall), to see if it says "Smart Preview". Perhaps you have accidentally disabled this, or the smart previews are set to be very small?

I think that most likely #1 is the cause, but as others have mentioned, we will need an example of the noise to say for sure.

John Sørensen
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When you take picture in RAW you should "forget" about these camera settings:

  • white balance
  • styles (like black and white)
  • aspect ratio
  • sharpen
  • colour space
  • noise reduction
  • highlight tone priority
    (and probably few other)

All these things should be "created" in post or by taking photo in JPEG.

P.S. And one clarification, your sensor see only in black and white, thanks to Bayer filter and demosaic process you get colour image

Romeo Ninov
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    Re, "your sensor see only in black and white..." Most things in this world can be understood on multiple levels. Yes. Each individual sensor element records only the intensity of the light that falls on it. But thanks to the Bayer filter, different sensor elements record different colors. When we talk about it at a higher level, it makes sense to say that the whole hardware assembly records a picture with color information. That level is especially meaningful because it's right at the dividing line between camera hardware and camera firmware. – Solomon Slow Apr 20 '22 at 12:33
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    @SolomonSlow, no, different sensor elements record different luminance levels. Which levels are interpreted by demosaic algorithm and make colour image. In RAW you do not have colour information. – Romeo Ninov Apr 20 '22 at 12:36
  • Most things in this world can be understood on many levels. Yes. The data in a RAW file is in a form that cannot not be trivially sent to a computer monitor. A monitor needs to know what color to make each pixel, and that information is not directly available from the file. But when we talk about it at a higher level, the RAW file must contain color information. When lightroom displays a full-color image on the screen, where do the colors come from if not from information that is in the file? – Solomon Slow Apr 20 '22 at 12:44
  • @SolomonSlow, RAW do not contain colour info. WHat is displayed on your screen is result of work of demosaic algorithm which combine RAW data and information about Bayer, X-Trans or Foveon sensor filter. – Romeo Ninov Apr 20 '22 at 12:51
  • Suppose I photograph a girl who's wearing a pink dress, and playing with a blue ball. How does lightroom know to color dress pink and the ball blue? Is it magic? or is there something in the RAW file that yields those colors? If it's from the file, then that's what I'd call "color information." It's information about the colors in the picture. Note! I'm saying picture. You are talking about pixels. Those are different levels of understanding. The RAW file does not tell the color of each individual pixel, but it does provide information from which pixel colors can be reconstructed. – Solomon Slow Apr 20 '22 at 13:06
  • @Shlomo, there is no info in RAW about the colour of dress/ball. And demosaic algorithm get info from luminance info of group of cells, map them to Bayer mask (for example), do some math and as result get the "colour" of this cell (based on luminance of neighbor cells and the colour of filter in front of them) – Romeo Ninov Apr 20 '22 at 13:11
  • OK, so the TLDR version is, it reconstructs the colors from information in the file, But that is in no way, shape or form to be called "color information." Got it. Thanks. – Solomon Slow Apr 20 '22 at 13:14
  • @SolomonSlow, again no. The file DO NOT HAVE colour information. Think about the situation when you change Bayer with X-Trans mask and use the same values from RAW. And get totally different image. – Romeo Ninov Apr 20 '22 at 13:17
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    While you are correct that each sensel only contains a single luminance value, @SolomonSlow is also correct that because light passes through the bayer filter before hitting the sensel, each raw pixel does contain color data. Demosaic algorithms do not "combine" raw data with a filter to create color, rather the known pattern of the filter is used to extract the red, green and blue filtered pixels to separate channels and interpolate the missing pixels. As stated, especially in context of the question, you have (unintentionally) implied that the raw image is simple black and white. – LightBender Apr 21 '22 at 04:39
  • @LightBender Except the colors used in the Bayer mask do not correspond to the same colors emitted by the Red, Green, and Blue channels of our RGB emitting displays. "Green" is pretty close, "blue" is about halfway between Blue and Violet, but "red" is closer to Yellow than to Orange, much less to Red on the other side of orange from yellow. The color of all three channels is interpolated for every monochromatic luminance value contained in the raw image file. The strength of each of those channels is determined by the color temperature and white balance compensation settings. – Michael C Apr 21 '22 at 05:52
  • @SolomonSlow Look at it this way: "red" filtered sensels do not just record red wavelengths of light. They absorb the energy of all of the photons that make it to the bottom of the photosite. Some photons vibrating at frequencies along the entire visible spectrum will make it past each filter color, just as using a red filter with B&W film does not make everything in the scene that is not red appear to be featureless black. It just makes non-red things darker shades of grey than they would be without the red filter in place. No digital camera actually records specific colors/wavelengths... – Michael C Apr 21 '22 at 06:08
  • ... it's all synthetically interpolated from monochrome luminance values. This isn't that much different that the way the human vision system works. There's no such thing as "color" in various wavelengths of electromagnetic radiation. Color is created by the system that perceives it. We call a certain range of the EMR spectrum "visible light" because it is the range of EMR that our retinas chemically respond to, not because there is any unique property of the wavelengths contained in the "visible spectrum" compared to other wavelengths such as UV or IR or even radio waves or X-rays. – Michael C Apr 21 '22 at 06:11
  • @MichaelC, all very true, chalk it up to oversimplification due to the character limit. – LightBender Apr 21 '22 at 12:14
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First, let's remind ourselves of what a raw file is. It is a set of single luminance values for each photosite (a/k/a pixel well or sensel) on the sensor. As such there is no color information to a raw file. Color is derived by comparing adjoining pixels that are filtered for one of three colors with a Bayer mask.¹ But just like putting a red filter in front of the lens when shooting black and white film didn't result in a monochromatic red photo, the Bayer mask in front of monochromatic pixels doesn't create color either. What it does is change the tonal value (how bright or how dark the luminance value of a particular color is recorded) of various colors by differing amounts. When the tonal values (gray intensities) of adjoining pixels filtered for the three different colors used in the Bayer mask are compared then colors may be interpolated from that information. This is the process we refer to as demosaicing. How much bias is given to red, green, and blue in the demosaicing process is what sets white/color balance.¹ The gamma correction and any additional shaping of the light response curves is what sets contrast.

¹ Just for the record, the three colors used in Bayer masks are not the same three colors emitted by our RGB displays, notwithstanding all of the cute little red-blue-green checkerboard diagrams on the internet. They're each, respectively, closer to being most transmissive to the wavelengths to which the three types of cones in the human retina are most responsive. Please see Why are Red, Green, and Blue the primary colors of light?

The B&W image you see on the back of the LCD screen of your camera is not "THE raw image". It is a preview image generated by the camera by applying the in camera settings to the raw data that results in the B&W jpeg preview image you view on the LCD. This preview image is appended to the raw file along with the data from the sensor and the EXIF information that contains the in-camera settings at the time the photo was shot. This is also what you are seeing for those first few seconds when you open the image file on your computer.

Any depiction of the data in a raw image file that you see on your screen is not "THE raw image", either. It's one of a near countless number of possible interpretations of the raw data contained in the raw file. What set of instructions are applied to convert the raw data to the JPEG-like image you see on your screen determines how it will look on your screen. This is why opening the same raw image file in one specific raw convertor produces an image that looks different from the same raw file opened with a different raw conversion application.

I was expecting Lightroom software to display the image at its best, and not a "bad" interpretation of it. Why does the CR3 format exist, if not to have the best quality and most precise and uniquely interpreted? How can I work with it?

If you are saving your pictures in raw format when you shoot, when you do post processing you'll have the exact same information to work with no matter what Picture Style is selected at the time you shoot. Some applications may initially open the file using either the JPEG preview or by applying the in-camera settings active at the time the image was shot to the raw data. But you are free to change those settings, without any destructive data loss, to whatever else you want in post. Most third party raw image processing applications will apply their own default settings that affects how their interpretation of the raw data will look on your screen when you open the image. In general, they ignore many of the in camera settings and apply a generic group of settings that produce a color image with the saturation and contrast "punched up" a bit, just as most in-camera JPEG engines do when set to "Standard" or "Auto" picture styles.

Option A: Use a raw conversion application that automatically applies the in-camera settings at the time the photo was taken to the raw data in the .cr3 file.

Canon EOS cameras since mid-2005 incorporate Canon's "Picture Style" selection of various ways of processing a scene to produce a photo with certain general characteristics. Which Picture Style is selected does not affect the luminance values from each pixel in the raw data at all. Which picture style is selected does affect the way the raw data is interpreted to produce the preview image embedded in the raw image file.

When you select the Monochrome Picture Style you will see a B&W preview image on an EOS camera's LCD. The raw data saved to the memory card will still include the necessary information to process the images in color later with a raw editing application. WARNING - Be sure you are saving the raw data. If you only save the pictures as B&W JPEG images all color information will be discarded!

Canon's Digital Photo Professional will, by default, open an image in the same Picture Style as was selected when shot. All you have to do to change it is use the drop-down menu and select another Picture Style. You can even create a "recipe" for one image and then batch apply it to all of the images before beginning to work with them. (Note: there is a setting in the preferences menu of DPP that can be set to either show original image which uses the in-camera settings or show image with recipe applied which will apply any changes you have made using DPP when viewing images with the Quick Preview module. If you shoot using the Monochrome Picture Style but want to preview the images in color then select the later and batch apply a recipe preset that includes a color Picture Style before opening them in the Quick Preview module.)

Option B: Simulate the in-camera settings as closely as possible with Lightroom or other third party raw conversion applications.

With third party raw processing applications such a Adobe's Lightroom or Camera Raw, Apple's Aperture or Photos, PhaseOne's Capture One Pro, DxO Lab's OpticsPro, etc. getting images to display according to the in camera settings can be a bit trickier. Adobe products, for instance, totally ignore the maker notes section of a raw file's EXIF data where Canon stores information about the Picture Style selected at the time the photo was taken. Just how convoluted of a workaround is needed to accomplish such is outlined in the accepted answer to How to automatically apply a Lightroom Preset based on appropriate (Canon) Picture Style on import? In the present case of wanting to see the images in monochrome, you must select a different default profile with which to open the images from within LR's profile list that will allow you to develop those raw files from a B&W starting point.

For related questions here at Photography SE for further reading, please see:

RAW files store 3 colors per pixel, or only one?
Why are my RAW images already in colour if debayering is not done yet?
How to automatically apply a Lightroom Preset based on appropriate (Canon) Picture Style on import
Why can software correct white balance more accurately for RAW files than it can with JPEGs?
Why do RAW images look worse than JPEGs in editing programs?

The following is an excerpt from my answer to Why can software correct white balance more accurately for RAW files than it can with JPEGs? which you may find helpful:

Anytime you open a raw file and look at it on your screen, you are not viewing "THE raw file." ² You are viewing one among a near-countless number of possible interpretations of the data in the raw file. The raw data itself contains a single (monochrome) brightness value measure by each pixel well. With Bayer masked camera sensors (the vast majority of color digital cameras use Bayer filters) each pixel well has a color filter in front of it that is either 'red', 'green', or 'blue' (the actual 'colors' of the filters in most Bayer Masks are anywhere from a slightly yellowish-green to an orange-yellow for 'red", a slightly yellow green for 'green' and a bluish-violet for 'blue' - these colors more or less correspond to the center of sensitivity for the three types of cones in our retinas). For a more complete discussion of how we get color information out of the single brightness values measured at each pixel well, please see RAW files store 3 colors per pixel, or only one?

² Please see: Why are my RAW images already in colour if debayering is not done yet?

Michael C
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