Some color differences between sraw and full raw?

[SteveF]

A friend of mine has been comparing his sraw,mraw and full raw colours after we spoke about my 'interesting' situation with the cerise pink dresses at a recent wedding.

Here's an article some might find interesting and in particular 3.2.1

http://lclevy.free.fr/cr2/#sraw

This started out when he found differences between raw convertors and the more he experimented the more confused he became! Apparently shooting a colour swatch with the different sizes of raw gave him slightly different colours in the .tiff conversion.

Any views? I did hear that this was a 'slight' problem with 5D from another source.

[Polar01]

Steve: as far as I know there is only one size for raw files for your camera, you cannot adjust your camera's raw size to s,m, or l (full), you can set your jpeg file size to s, m, and l as to quality. I think some of the others will also comment on this, I would strongly suggest that you have your friend re-read their manual as to camera capture settings.

Cheers:

Allan

[SteveF]

Allan,

http://www.dpreview.com/reviews/canoneos7d/11

Canon have been providing some variations since the 40D, probably even earlier but I don't have this on the old 10D in the cupboard.

Cheers,

[rpcrowe]

The question is somewhat moot for me! I see no reason to shoot in any other that the full RAW size. It may take a bit more memory but, heck, memory is cheap these days! I can always reduce the full RAW image to a smaller JPEG but if I shoot sRAW or any other modified RAW size, that is what I am stuck with! Why limit myself?

[Donald]

The question is somewhat moot for me!

I have to agree with Richard on this. I'm not the most experienced photographer in the world, or the most read or informed, but I've never understood why sRAW exists. If you're into photography to the extent that you're shooting RAW, then you want to go fro the options that offers the greatest range of options. But maybe someone can explain to me.

[Polar01]

I learned something today I did not know that this was a feature that Canon has as I shoot with a Nikon, I have to agree with Richard and Donald with what they say. Now back in 2007 when the 40D came out as memory was costly maybe a selling feature, but not with the cost of today's memory those setting are just taking up space on the menu.

Cheers:

Allan

[SteveF]

Sraw is an extremely handy feature for the sports shooter shooting under mixed stadium lights. A Canon mark 4 will shoot a burst of about 26 raws before it fills the buffer and 43 sraw before filling the buffer. Speed of capture is of the essence here.

I rarely shoot raw, preferring to 'wing it' with a preset in jpeg so I hadn't come across this strange situation myself.

[SteveF]

Allan,

You might be interested in this - file formats - the D800 has several options here:

http://www.dpreview.com/reviews/nikon-d800-d800e/2

Works slightly different to Canon. Haven't looked into the details.

[rpcrowe]

When I was shooting with the 40D and memory was more costly than it is now; I never used sRAW. Even when it was more expensive, memory was but a tiny portion of a DSLR photographer's investment in equipment! I always thought that being stingy in buying memory was being penny-wise and pound-foolish!

As far as speed of capture in burst mode...

My Canon 7D with the latest firmware upgrade will shoot 26 full size RAW frames at high speed burst before stopping. I don't know what the specifications say but, I just tested this with my 7D using an 800x UDMA-7 Lexar Compact Flash Card

I seldom need 26 frames in one burst. The most I ever shot was when I was covering the demolition of a building. I shot in slow burst speed and cranked out 63 frames which covered from initial explosion to a pile of debris. I chose the slow burst speed to enable me to shoot the burst over a longer period of time. I stopped shooting because I opted to, not because the 7D forced me to...

As far as sports goes, I almost never shoot more than 10 frames in any burst and usually a lot fewer than that!

[Polar01]

Steve yes the Nikon D800 can shoot FX format, DX format, a further 1.2 crop, along with being able to shoot instead of the usual 2 x3 format it can shoot 4 x 5 format along with L, M, and S jpegs quality files for both. This also includes as most newer camera being able to record the files in both Raw and jpeg at the same time. I know that the D600 and D7000 can not shoot in a 4 x 5 format only 2 x 3 format as I own both.

Cheers:

Allan

[SteveF]

Richard, even if you never envisage shooting 26 or 43 frames in one burst, the explanation I was not making too well is that sports shooters don't need a 16mb file for reportage and 4mp from sraw is adequate. Also if they are shooting to the wire, so to speak, they're often now not even shooting to card at all but, to the wire straight to the image desk back in the stadium press office or even direct to the news desk back at headquarters. So the smaller files which can be colour corrected and on the web before you've even picked up your handset to change channels is all what it's about now.

The competition to be first is massive. In a shared press room different outlets want different perspectives for their publications and I'm sure if they could get a raw file down to 1mb they would be happier still

I don't get involved with this stuff but, I often come across a sports shooter at a national event and his wi-fi on his camera is pinging images back to the press centre/laptop in the car or assistant and they're up on the web before I can even change cards.

Fun to watch but not fun to be part of, thankyou!

[rpcrowe]

Steve, I would expect that in this case, as you allude to, the sports shooter would be shooting JPEG images processed in-camera and of smaller file sizes. The sRAW seems to me to be of a capability like the Canon "print from camera" which very few serious shooters use.

[Glenn NK]

When I was shooting with the 40D and memory was more costly than it is now; I never used sRAW. Even when it was more expensive, memory was but a tiny portion of a DSLR photographer's investment in equipment! I always thought that being stingy in buying memory was being penny-wise and pound-foolish!

Precisely.

I've only talked to a few sports shooters, but all three of them shoot JPEG, not any type of modified RAW.

At an event where they sell most of their images, they don't have time to develop any type/size of RAW file. I've witnessed this at a national BMX races; they shot exclusively JPEG. Within minutes of the end of a race, they have prints up on display. This is where JPEG is preferable to RAW. Any type of RAW file simply takes too long.

So the use of various quality RAW files does seem to be academic; you either have the time for RAW, or you don't.

And yes, Canon finally got rid of the print from camera button - after quite a few years of ridicule.

Glenn

[Manfred M]

The only time I ever used lossy compressed RAW on my D800 was when I stupidly left my spare memory cards at home and had to economize storage space because I was running out. Just like the rest of photography, I had to make a compromise and that was the best one that was available at the time. The quality loss was imperceptible.

[rpcrowe]

And yes, Canon finally got rid of the print from camera button - after quite a few years of ridicule.

Glenn

Yep, but they added the JPEG when shooting RAW and RAW when shooting JPEG button. It seems like the Canon Gurus just have to include a button that few folks will use!

[SteveF]

Steve, I would expect that in this case, as you allude to, the sports shooter would be shooting JPEG images processed in-camera and of smaller file sizes. The sRAW seems to me to be of a capability like the Canon "print from camera" which very few serious shooters use.

Depends who you ask I think Richard.

See a Seattle photographer, Jim Bryant here:

http://digital-photography-school.co...ng-sports.html

About half-way down.

[SteveF]

And I don't think all these guys are amateurs:

http://www.sportsshooter.com/message...html?tid=41120

Canon even state users have asked for this function at the very bottom here:

http://learn.usa.canon.com/resources..._article.htmlp

[revi]

To get back to Steve's question about colour differences:
From the link he posted I got the impression that the small RAW formats are stored as lossless jpeg in YCbCr format, and not as RGB.
That would mean a format conversion, and that can give rounding errors. If there's an additional scaling involved (I didn't quite understand how many bits were available for each component) that could mean another source of differences between the full RAW and the small raws. And if those differences change the ratios R:G:B, you get colour changes/differences.