RAW vs JPG

PhotosGuy wrote in post #5727316
I haven't tested an untweaked image, so maybe if you get the jpg dead on in the camera, you won't see a difference. But there are some examples on page 2, post #58,that illustrate easily seen information loss in a web jpeg derived from a RAW file & one shot in the camera if you make a small white balance change.

I think you're missing the point that was made. gcogger was talking about comparing two JPEG images which both used relatively low compression levels. You are talking about making adjustments to a JPEG and to a RAW file and comparing the end results. Non sequitur.

e-k

well actually after just conducting a test i've found that the JPG is the larger when saving as 16bit TIFF

Bobster wrote in post #5727733
IMHO, i think those who shoot JPG, don't have the knowledge to shoot RAW

All generalizations are wrong.

Bobster wrote in post #5727867
well actually after just conducting a test i've found that the JPG is the larger when saving as 16bit TIFF

Well I hope not by much as it really should be down to the meta data it contains . The actual size of the image data would be the same and would be the same for a completely black or white image with the same dimensions.

e-k

PhotosGuy wrote in post #5727316
I haven't tested an untweaked image, so maybe if you get the jpg dead on in the camera, you won't see a difference. But there are some examples on page 2, post #58, that illustrate easily seen information loss in a web jpeg derived from a RAW file & one shot in the camera if you make a small white balance change.

I'm not arguing in favour of shooting JPEGs - I've posted comparison shots myself that demonstrate good reasons to use RAW.

You appear to be discussing a different topic now, however. None of this has anything to do with JPEG file sizes.

the way i see it is you can always get a Jpeg from a raw image...you cant go back and get the benefits of raw from a jpeg image.

apart from high shutter counts and buffer fill, the only other thing i can see in jpegs favour is lower memory overheads, but memory is cheap.

It refers to your statement, "I was arguing against the implication, made a couple of times in this thread (and many times elsewhere!) that the fact that a RAW converter produces bigger JPEG files than the camera means that the RAW converted image contains more information..."

If you make equal adjustments to each file & one looks better than the other, then I think the original larger file size contained more information, referring to my statement, which you disputed, "A max jpg from my 20D is about 2,754 KB. The exact same shot with the jpg extracted from the 12-bit RAW "negative" is 4,315 KB which is 1.57X larger.
Think of it as a free upgrade to your camera."

My eyes show a difference & bigger is better. I'm done. Measurebate this:
RAW vs. JPEG - the real story

PhotosGuy wrote in post #5730123
If you make equal adjustments to each file & one looks better than the other, then I think the original larger file size contained more information, referring to my statement, which you disputed, "A max jpg from my 20D is about 2,754 KB. The exact same shot with the jpg extracted from the 12-bit RAW "negative" is 4,315 KB which is 1.57X larger.
Think of it as a free upgrade to your camera."

My eyes show a difference & bigger is better. I'm done. Measurebate this:
RAW vs. JPEG - the real story

Let's say the photographer got it "right" in the camera (i.e. there is no WB adjustment or exposure adjustment - meets your same adjustments requirement). Let's also say they use Zoom browser EX for their raw converter.

Now let's say they converted a RAW image that had been shot with RAW+JPEG using the highest quality JPEG setting when saving (remember no adjustments were made).

The camera JPEG is 2,457,354 bytes, the converted RAW is 5,069,412 bytes. The converted RAW is more than double in size!

Now let's load both images as layers into an editor and difference them. Oddly, there are only differences around some severe contrast areas. When clicking the top layer on and off, this difference isn't even noticeable at 100%.

This is a true story . If you don't believe me try it yourself.

e-k

gcogger wrote in post #5727132
If you take the same image and save it at 2 different compression levels then the larger file is theoretically better. There comes a point, however, when increasing the file size makes no visible difference. The size of images produced by a Canon camera in max quality JPEG mode is almost certainly beyond that point, so the fact that you can make a larger JPEG from a RAW file is meaningless. If you're worried about that sort of thing, then save as TIFF.

You've often tried to suggest that the fact that your JPEGs from RAW files are bigger than the ones from the camera means that they must contain more data. This is absolutely not true. I can take a blurred photo with poor contrast (in RAW) and save it as a larger file than a sharp, high contrast JPEG from the camera. JPEG file size is almost completely irrelevant to the RAW vs JPEG discussion.

By the way - I shoot RAW pretty much 100% of the time and would hate to be forced to shoot JPEGs. The compression level of the in-camera JPEGs, however, has nothing to do with it.

Now you are comparing two separate photos! How is that going to work in this discussion? We were talking about having larger file size between an in-camera JPEG and one converted from RAW of the SAME file, not different ones.

While I do agree that at some point a larger file size won't show a better image file, but can you honestly tell me that a person could not discern the difference in an image, say 1800x1200 pixels @ 100KB vs 2MB? Now how much difference can you see in a full res, 3000+ x 2400+ pixel image at 3MB vs 5MB? Probably not much, if any, at 100%, or in small prints, not sure about larger prints as I haven't tested it.

E-K wrote in post #5730433
Let's say the photographer got it "right" in the camera e-k

So your whole scenario is based on "Let's say...". I surely wouldn't want to take some shots, get home and as I load them think "Let's say I got this right, cause I shot JPEG. Glad I didn't "waste" the time or space on RAW."

E-K wrote in post #5728053
Well I hope not by much as it really should be down to the meta data it contains . The actual size of the image data would be the same and would be the same for a completely black or white image with the same dimensions.

e-k

was nearly a Kb! i was quite surprised at the result..

In2Photos wrote in post #5731098
So your whole scenario is based on "Let's say...". I surely wouldn't want to take some shots, get home and as I load them think "Let's say I got this right, cause I shot JPEG. Glad I didn't "waste" the time or space on RAW."

Take it in the context that it was given . PhotosGuy and others take the file size as proof that RAW is better. What I'm saying is that file size is not a very good indicator of image quality - there are just too many variables. The hypothetical test (which in fact was a real test) was used to eliminate a number of the variables and to demonstrate that file size has little bearing on image quality when comparing a large HQ from the JPEG to a HQ from a RAW converter.

Did I ever say RAW doesn't have more latitude? Did I ever say RAW doesn't have more information? Did I ever say I don't shoot RAW? No I haven't.

e-k

Bobster wrote in post #5731224
was nearly a Kb! i was quite surprised at the result..

Might have been differences in the embedded JPEG thumbnails.

e-k

PhotosGuy wrote in post #5730123
It refers to your statement, "I was arguing against the implication, made a couple of times in this thread (and many times elsewhere!) that the fact that a RAW converter produces bigger JPEG files than the camera means that the RAW converted image contains more information..."

If you make equal adjustments to each file & one looks better than the other, then I think the original larger file size contained more information, referring to my statement, which you disputed, "A max jpg from my 20D is about 2,754 KB. The exact same shot with the jpg extracted from the 12-bit RAW "negative" is 4,315 KB which is 1.57X larger.
Think of it as a free upgrade to your camera."

My eyes show a difference & bigger is better. I'm done. Measurebate this:
RAW vs. JPEG - the real story

You're now saying that a RAW file contains more information than a JPEG, which I'm sure no-one disputes. That's also what the article you linked to is discussing.

Your statement that "The exact same shot with the jpg extracted from the 12-bit RAW "negative" is 4,315 KB which is 1.57X larger." proves nothing except that the JPEG from the RAW was saved at a different JPEG compression level. I'm not disputing that the file is 57% larger - I'm just saying that it's irrelevant to the discussion.

In2Photos wrote in post #5731084
Now you are comparing two separate photos! How is that going to work in this discussion? We were talking about having larger file size between an in-camera JPEG and one converted from RAW of the SAME file, not different ones.

Because you appear to be convinced that a larger JPEG inherently means that you have a higher quality image. It doesn't.

In2Photos wrote in post #5731084
While I do agree that at some point a larger file size won't show a better image file, but can you honestly tell me that a person could not discern the difference in an image, say 1800x1200 pixels @ 100KB vs 2MB? Now how much difference can you see in a full res, 3000+ x 2400+ pixel image at 3MB vs 5MB? Probably not much, if any, at 100%, or in small prints, not sure about larger prints as I haven't tested it.

The size of a max quality in-camera JPEG is enough that you won't notice a difference from a larger file at any viewing size. If you think it makes a difference, why are you outputting JPEGs from your RAW converter? Why not use TIFFs instead? They're even bigger files, so surely that means that RAW is even better than you thought?

gcogger wrote in post #5732300
Because you appear to be convinced that a larger JPEG inherently means that you have a higher quality image. It doesn't.

No, I said that up to a certain point a larger JPEG will have a higher image quality. I did not make a blanket statement that ALL larger JPEGs will have a higher image quality.

The size of a max quality in-camera JPEG is enough that you won't notice a difference from a larger file at any viewing size. If you think it makes a difference, why are you outputting JPEGs from your RAW converter? Why not use TIFFs instead? They're even bigger files, so surely that means that RAW is even better than you thought?

Is that not what I said? At some point the difference in file size is unjustified. I even said I didn't know where that point is. And who says I output JPEGs? If I print from LR I don't output to JPEG, I print directly from RAW. Most of the labs I use also accept TIFFs. Now, do I always use TIFFs? NO! Why? File size mostly. I don't see the need to send a 40MB TIFF when a 3MB JPEG will work for the 4x6s, 5x7s and 8x10s my clients order (young kids playing sports).

Of course all this assumes that we are dealing with a perfect shot captured. If I could do that every time I would likely use JPEG, simply because of the speed increase in workflow. But I prefer to have the latitude associated with RAW and the larger files that RAW file produces.