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

First off, your camera ONLY shoots RAW. When you select JPG, the camera takes the RAW data and pipes it into its on-board JPG processor to generate the JPG "image" to save to the card.

When you shoot RAW, the RAW "data" goes directly to the card and is not an image.

To generate an image, you use a RAW processor (software on your PC) which turns the data into a viewable image, much like the camera's JPG processor. The difference is that YOU have complete control over the image generation process. You can change the white balance, adjust the contrast/brightness/bl​ack point/etc....

So you can leave these decisions up to the camera's little processor (and hope it makes the right decisions since they are irreversible), or save the decisions for later where YOU have complete control over it.

I just want to comment that I LOVE the smilie!!!!!!!!!!! Is it possible that we can have that added to our smilies box?!?!?!

Several posters have mentioned that TIFF images aren't compressed. Not so - they can be uncompressed or LZW compressed (which is lossless).

I notice that Photoshop CS4 also allows TIFF images to be saved compressed as ZIP files (also lossless).

-js

number six wrote in post #10155494
Several posters have mentioned that TIFF images aren't compressed. Not so - they can be uncompressed or LZW compressed (which is lossless).

I notice that Photoshop CS4 also allows TIFF images to be saved compressed as ZIP files (also lossless).

-js

Yes, they can be compressed, but it's not quick. As has been mentioned, they turn out to be the worst of both worlds as far as camera output is concerned.

A point that you've made subtly is that the JPEG processing application (firmware) in the camera is optimized for speed (most importantly), small size, and lower power...not for image quality.

As anyone who has worked with several different RAW processor has learned, the application matters. It can matter a great deal.

The processing application in the computer (software) has relatively a severaly magnitudes more time, space, and power--it's optimized for image quality. I can set my camera to RAW+JPEG, let DPP convert to JPEG with no changes whatsoever from the "as shot" setting, and I will see better dynamic range from the DPP-produced JPEGs as from the camera-produced JPEGs.

egordon99 wrote in post #10154849
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.

Heh! That's an interesting question. I've never delved into the details of the de-mosaic algorithms, but just knowing that it invoves taking separate discreet R, G and B values at different pixel locations and combining them into unique RGB values for each location would lead me to believe that doing that backwards would be a nightmare of legendary proportions that only someone who was extrememly nerdy and had no life would even attempt to take that up!

No offence, of course, to those here who might be extremely nerdy and lacking in better things to do who may be inclined...

RDKirk wrote in post #10155969
A point that you've made subtly is that the JPEG processing application (firmware) in the camera is optimized for speed (most importantly), small size, and lower power...not for image quality.

Not quite true.

JPEG files can use any of ten standard JPEG compression levels, "1" through "10", where "1" is optimized for maximum compression and lowest quality and "10" for minimum compression and highest quality.

With the current 1D and 1Ds cameras, you can select any JPEG compression level you desire.

In the other (lesser) current cameras, the choice is between "Fine" and "Normal," where "Fine" is JPEG compression level "8" and "Normal" is JPEG compression level "3".

Do not confuse the JPEG compression level with the JPEG resolution (number of pixels), which is another thing altogether. In the current 1D and 1Ds series cameras, there are four JPEG resolutions: large, medium 1, medium 2, and small. In the other current cameras, there are three rsolutions: large, medium, and small.

The file size for a given image is a composite of the JPEG resolution, the JPEG compression level, the ISO value, and the overall image detail.

Note that all JPEG compression algorithms create loss, how much loss is a function of the compression level and the image detail.

A TIFF file, on the other hand, may be uncompressed, or compressed using a lossless algorithm. This makes for huge files, massively bigger than JPEG files with the same resolution.

Like JPEGs, however, TIFF files are "processed." This means that certain parameters are locked or hard-coded into the file. Processing the file invariably introduces some loss.

Also, no processed file, JPEG or TIFF, can be reprocessed without loss, sometimes severe loss.

RAW files are compressed using a lossless algorithm (different from the one used for TIFFs). Additionally, RAW files are unprocessed. They are, effectively, the data straight from the sensor. This means that RAW files start out with no loss of any kind. Processing a RAW file into a JPEG or a TIFF introduces only those losses required of the specific JPEG or TIFF final image. The same RAW file can be processed into any number of different JPEG or TIFF files without incurring any unnecessary loss.

As an aside, each RAW file also contains a small JPEG embedded within itself. This small JPEG is used by the Canon CODEC and other utilities to view a thumbnail of the RAW file. This thumbnail will often have settings nowhere near what your final images will have. Therefore, you should use such a thumbnail only to identify the image, never to analyze it. You need a full RAW processing program (like DPP) to do that.

tonylong wrote in post #10156216
No offence, of course, to those here who might be extremely nerdy and lacking in better things to do who may be inclined...

"No offense" my Aunt Fanny!

Just remember that nerds rule the world. Jocks and other "beautiful people" can make millions and have big businesses, beautiful homes, fancy cars, etc., all of which are financed by (and in reality owned by) the purest of nerds, the bankers.

And just take a look at the bank statements of "The Bill" if you think nerds aren't at the top of the food chain.

Point is, TIFF after conversion is a lot bigger in size than RAW

400dabuser wrote in post #10156796
Point is, TIFF after conversion is a lot bigger in size than RAW

That depends upon the TIFF resolution. A small resolution TIFF may well be smaller than a RAW file.

However, a TIFF is not only massive in size for a given resolution, it is processed, and cannot be altered without incurring additional, unnecessary losses.

20droger wrote in post #10156819
That depends upon the TIFF resolution. A small resolution TIFF may well be smaller than a RAW file.

However, a TIFF is not only massive in size for a given resolution, it is processed, and cannot be altered without incurring additional, unnecessary losses.

Well, do you want a crummy resolution for your photos?

400dabuser wrote in post #10156827
Well, do you want a crummy resolution for your photos?

Sometimes, yes. That's why Canon provides multiple JPEG resolutions.

20droger wrote in post #10156730
Not quite true.

JPEG files can use any of ten standard JPEG compression levels, "1" through "10", where "1" is optimized for maximum compression and lowest quality and "10" for minimum compression and highest quality.

I did my tests with "large" JPEGs. I'm not talking about the effects of compression. I'm talking about the quality of the application. DPP, ACR, and Capture 1 are better processors than the camera firmware and do a better job, over and beyond compression. I see it most clearly in increased dynamic range.

RDKirk wrote in post #10156909
I did my tests with "large" JPEGs. I'm not talking about the effects of compression. I'm talking about the quality of the application. DPP, ACR, and Capture 1 are better processors than the camera firmware and do a better job, over and beyond compression. I see it most clearly in increased dynamic range.

As I clearly said above, "large" is a resolution thing, not a compression thing. With modern cameras, large JPEGS have the same resolution as RAW.

And I agree. DPP has much more power and flexibility than the camera's internal software.

And as I said clearly: I see it most clearly in increased dynamic range.