Why RAW (.CR2) and not just record in TIFF?

I suppose this is a question mostly for "Canon" But whatever. I'm bored and ranting. This is not a RAW vs JPG thread, leave comments about that to other threads please. This is a RAW vs TIFF debate. I can't narrow the search enough to see if this has been discussed before. The only thing I see when I search is the RAW vs JPG debate, and the fact that you need to convert to TIFF, so if this has been discussed before, then let the dead horse beating begin.

Think of Tiff as being the same as JPEG, just with loss less compression.
So while it contains more Data than a JPEG, it not be as easily or widely manipulated as a RAW.

Remember RAW is not an image format, it is simply a dump of data from the sensor, you need to convert it into an image format. Tiff is simply another image format.

Yes but the camera can record in JPG so why not TIFF?

Not sure what you mean by that, when you cant do anything with RAW besides view it.... or am I wrong?

I guess what I'm trying to understand is; theoretically If the camera was able to record both .CR2 (RAW) and Tiff would there be any difference? and how, since you cant even print CR2's?

Think of it like the RAW image is a bounch of information... when you convert it you loose most of it.

Yes, you can see the a picture from the RAW when you use DPP, but on a RAW you have ALOT more information in the picture than what you see. When you edit you just choose the information you want to see, or create a picture out of. When you then convert it to Jpeg or Tiff you keep the visible part but loose the invisible part of the picture.

Basicly this means, you can do more with a RAW picture. But when you are sending all the information to a printer (or online), the printer just get to much information. You need Tiff or Jpeg to get the picture viewable.

Crimzon wrote in post #10143183
Yes but the camera can record in JPG so why not TIFF?

Some cameras can, but image sizes end up being huge.
Go and compare some RAW, JPEG and Tiff file sizes from your camera.
Remember, RAW and JPEG are both compressed, Tiff generally isn't, or if so, not very much.

Crimzon wrote in post #10143183
Not sure what you mean by that, when you cant do anything with RAW besides view it.... or am I wrong?

I guess what I'm trying to understand is; theoretically If the camera was able to record both .CR2 (RAW) and Tiff would there be any difference? and how, since you cant even print CR2's?

Since a RAW file isn't an image you use a RAW conversion program to convert it into an image by selecting how the information from the sensor will be displayed. This gives you a far, far wider range of adjustments than you would get form trying to manipulate a Tiff or JPEG.
You also get to set somethings that can not be adjusted after conversion to an image file, White Balance being the best example.

Crimzon wrote in post #10143183
Yes but the camera can record in JPG so why not TIFF?




Not sure what you mean by that, when you cant do anything with RAW besides view it.... or am I wrong?

I guess what I'm trying to understand is; theoretically If the camera was able to record both .CR2 (RAW) and Tiff would there be any difference? and how, since you cant even print CR2's?

You can convert it to .jpg or tiff endlessly each with minor changes if so desired until you get exact conversion you want. Think of it as your digital negative. If you shot in tiff as you suggest, you wouldn't be able to revisit and reinterpret the information because tiff doesn't retain all of the information as raw does.

Moppie wrote in post #10143240
Some cameras can, but image sizes end up being huge.
Go and compare some RAW, JPEG and Tiff file sizes from your camera.
Remember, RAW and JPEG are both compressed, Tiff generally isn't, or if so, not very much.





Since a RAW file isn't an image you use a RAW conversion program to convert it into an image by selecting how the information from the sensor will be displayed. This gives you a far, far wider range of adjustments than you would get form trying to manipulate a Tiff or JPEG.
You also get to set somethings that can not be adjusted after conversion to an image file, White Balance being the best example.

Aaah, I get it now. Thank you Moppie I usually hate quoting an entire long post, but in this instance It explains everything

Great idea. Of course, in order to get all the data in a RAW you will want a 16 bit tif. 16 bit tifs from the 5D2 are 123 MB apiece. How many will fit on a card? How many will fill the camera's buffer? How long will it take to convert and save one?

The first and primary reason for RAW is to take control of your image, instead of letting some firmware designer in Tokyo decide what you probably want, or should want. The same guy who designs the jpgs would design the tifs also.

Google "Bayer sensor" and "demosaicing"

Crimzon wrote in post #10143183
Yes but the camera can record in JPG so why not TIFF?




Not sure what you mean by that, when you cant do anything with RAW besides view it.... or am I wrong?

I guess what I'm trying to understand is; theoretically If the camera was able to record both .CR2 (RAW) and Tiff would there be any difference? and how, since you cant even print CR2's?

Well, it doesn't record in JPEG. It records the data in RAW and then converts it to JPEG, which it then saves. Decisions made at the time of conversion are irreversible. You'd have the same irreversible decision-making happening with saving to a TIFF (even with 16-bit). Look, for instance, at the differences you can see in a .CR2 by applying the different picture styles via DPP. Those options aren't available in JPEG because the separate R, G, and B sensor site values have already been homogenized during the conversion process.

Crimzon wrote in post #10143183
Yes but the camera can record in JPG so why not TIFF?

The camera does not directly record in JPEG. The captured data is in RAW and it then processes the image to JPEG and records the JPEG. The major time-consuming component is recording the processed image. JPEGs are highly compressed (from 16-bit to 8-bit) and record very quickly. The RAW data is not really compressed, but it's not processed (nothing removed, but nothing added).

A TIFF image, however, would be the RAW plus added data without compression. I had a camera that output TIFF. It took forever to write and the resulting files were huge. TIFF output can be three or four times the size of the RAW file.

Actually, you don't even view the RAW. You view a temporary JPEG created by the processor. The point is that you get the captured data virtually untouched from which you can create as many different variations as possible.

Crimzon wrote in post #10143106
You can't print in RAW, you can't edit RAW, anything you want to do with RAW, you have to convert to TIFF first...

I print and edit RAW files, and never ever convert to TIFF. I suppose it would be more accurate to say that I'm probably not printing the RAW files directly, nor am I precisely editing them, but all of that is being handled by my RAW processing software (Aperture), without me ever having to deal with it, so the net result for me is that I am doing everything I want to do without ever converting my RAW files into TIFFs or JPEGs. Oh, and I can fit a whole lot more RAW files on a memory card than I could TIFFs.

Aaron Peabody wrote in post #10152152
I print and edit RAW files, and never ever convert to TIFF. I suppose it would be more accurate to say that I'm probably not printing the RAW files directly, nor am I precisely editing them, but all of that is being handled by my RAW processing software (Aperture), without me ever having to deal with it, so the net result for me is that I am doing everything I want to do without ever converting my RAW files into TIFFs or JPEGs. Oh, and I can fit a whole lot more RAW files on a memory card than I could TIFFs.

Your not saving the files as a JPEG or TIFF, but Aperture is converting them to an image format before printing.

Correct me if I'm wrong, but RAW has more information in it then a jpg. This includes all the information to set white balance after the shot is taken and also has more headroom in it from an exposure standpoint.
Does a TIFF also contain all the above extra info that a RAW does? If it does not, then that is a large difference between RAW and TIFF.

Raw data is the data directly off the sensor. The camera's image processor will "render" (google "demosaicing" and "Bayer Sensor" for more details) the data into a image. At this point, it's essentially a TIFF "file". TIFF files are HUGE, so the image processor will convert it to a JPG prior to saving it to the card.

Recording a TIFF file is the WORST of both worlds. It's demosaiced already, so you're locking in a white balance/contrast/sharp​ening/etc..., AND you're not compressing it. So you're wasting space on the card, and making decisions that are best saved for later in your raw editor on your PC. At least with the JPG, after you "lock in" your image settings, you're making the file smaller and more manageable.

Here's a question for the Image Processing/Math gurus - Given a demosaiced TIFF image, can you go back an "un-demosaic" it? I'm guessing "no", hence my argument above.