What exactly is a RAW converter?

There are many threads on this forum about RAW converters and which one is better than the other, but it occurs to me that I'm not absolutely sure what is being converted. What I mean is - is RAW conversion to do with converting the information on the CF card into a RAW format, or is it to do with converting the RAW file into, say, jpeg or tiff etc?

Another way of asking it is - is the information on the CF card already in RAW format or is it just a mass of information that has to be converted to RAW?

If you set your camera to take RAW, the files on your CF card are already in RAW format. The RAW conversion software takes those files, which are the raw data from the sensor, and converts them into something usable like JPG or TIFF. It also allows you to adjust white balance, exposure, color saturation, etc.

doctorgonzo wrote in post #6196805
If you set your camera to take RAW, the files on your CF card are already in RAW format. The RAW conversion software takes those files, which are the raw data from the sensor, and converts them into something usable like JPG or TIFF. It also allows you to adjust white balance, exposure, color saturation, etc.

If this is the case, if you are only ever going to work in RAW (including print), you don't need a RAW converter as such?

If you're working in raw you will most definitely need a raw converter. You can't send out a raw workfile to be printed. Although there are some labs out there that provide a conversion service for you but that kind of negates the advantage of working with a raw file.

People who work with their raw files are looking to have the most control over their finished product. With that added controls and color profiles you can do more with the image, even save some images that otherwise might be tossed.

A RAW file is not a color image file. It can't be viewed on a monitor without conversion nor can it be printed wihout being converted to a color image format. That is because each pixel on your camera's sensor sees light of only one color; either red or blue or green and that is what is recorded in the RAW. But in order to have a color image each pixel must contain data about all three primary colors. That additional data is invented by the computer or camera processor and that process is the core of the conversion. At the same time the original data (which will be 1/3 of the image) can either be retained as it was recorded or also changed (i.e., edited). Either way you have to create a jpg or a tif.

For a fuller (and better) explanation, see this:
http://www.ronbigelow.​com/articles/raw/raw.h​tm

Windows and OS X will allow you to view raw files, you just won't be able to do anything with them outside of a converter.

goTigers wrote in post #6197524
Windows and OS X will allow you to view raw files, you just won't be able to do anything with them outside of a converter.

But it is still applying its "own" conversion before it is displayed. As Tzalman states... it not an image file baked like a .jpg that should appear the same to everyone... it must be decoded and demosaiced first.

Every RAW converter will display the same exact RAW file differently based on its default algorithms.

What I'm trying to get at is - theoretically, if I import a RAW file from my CF card and only view it from my own own computer - and then print it - I don't really need a RAW converter. This, obviously, is in theory, but I'd like to get to the bottom of it.

No, you need the RAW converter in order to import and view the RAW files on your computer. A RAW file is just the, well, raw numbers from the sensors, plus some EXIF data. The only program that can understand those numbers, and form an image from them, is a RAW converter/viewer. True, I believe that Windows Vista will allow you to view RAW files, but I'm not sure about printing them. Don't know anything about Macs, if that is what you have.

It's also important to note that a RAW viewer, like the codecs in Windows Vista, will just allow you to view one interpretation of the RAW data, without being able to change things like the white balance, exposure, or levels, nor will it allow you to do things like apply USM to sharpen it up, so printing an image from a RAW viewer would not necessarily give you good quality at all.

I'll go out on a limb here but I don't really think you'd want to print the raw file with out at least some processing done to it. Even the processor in the camera does some minor enhancement to it to make it a little better.

I don't think you can directly print the raw file from the OS even though you can view. I'll agree that the OS needs to convert the file to view, on my Mac when I go to print the file from the finder it opens photoshop and ACR. I can't open the raw file in the preview program like I can a jpeg file.

goTigers wrote in post #6198147
I'll go out on a limb here but I don't really think you'd want to print the raw file with out at least some processing done to it. Even the processor in the camera does some minor enhancement to it to make it a little better.

Agreed.

Any viewer that will let you see a normal color image when you click on a raw file, will have to do either one of these two things:

- it will perform the demosaicing on the fly in order to render a color image on the screen, a demosaicing that will be in effect for the time the image is being displayed and not recorded anywhere;

- or, it will simply send to screen the low resolution jpg file that's embedded in every raw file for this purpose and for checking the picture on the camera LCD display when shooting raw.

In both instances, the raw file remains as it was before, i.e. not a proper color picture file.

Actually, even after conversion in a raw converter program, the raw file itself remains unchanged and as unusable for direct viewing or printing as before the conversion. Only the "derived" jpg/tif is a true picture file that's usable directly, without any further transformation.

doctorgonzo wrote in post #6198084
No, you need the RAW converter in order to import and view the RAW files on your computer. A RAW file is just the, well, raw numbers from the sensors, plus some EXIF data. The only program that can understand those numbers, and form an image from them, is a RAW converter/viewer.

Thank you. I think you're the first person who has actually answered my question.

goTigers wrote in post #6198147
I'll go out on a limb here but I don't really think you'd want to print the raw file with out at least some processing done to it. Even the processor in the camera does some minor enhancement to it to make it a little better.

I don't think you can directly print the raw file from the OS even though you can view. I'll agree that the OS needs to convert the file to view, on my Mac when I go to print the file from the finder it opens photoshop and ACR. I can't open the raw file in the preview program like I can a jpeg file.

I did say it was theoretical! I believe you can print RAW files in Lightroom, however, although I may be wrong

That's because Lightroom is a RAW converter!

Roy Mathers wrote in post #6198636
I did say it was theoretical! I believe you can print RAW files in Lightroom, however, although I may be wrong

Yes, I now know the answer - it was answered by doctorgonzo.