Good reason to shoot RAW...

It's just amazing how far you can push your images when you do...

My flash didn't fire, so the JPEG image looked like this:

HTTP response: NOT FOUND | MIME changed to 'image/png'

HTTP response: NOT FOUND | MIME changed to 'image/png'

Wow, its amazing you got that from blackness

lol, yes, a real advertisement for RAW.

In fact, if you have a good pile of bias frame, and average them, you can then subtract that from the un-demossiaced raw and reduce the fixed pattern noise! Even better is to also correct for dark current, and then multiply it all by a flat.

prep wrote in post #2407307
In fact, if you have a good pile of bias frame, and average them, you can then subtract that from the un-demossiaced raw and reduce the fixed pattern noise! Even better is to also correct for dark current, and then multiply it all by a flat.

Who's-a-jigga-what?

prep wrote in post #2407307
In fact, if you have a good pile of bias frame, and average them, you can then subtract that from the un-demossiaced raw and reduce the fixed pattern noise! Even better is to also correct for dark current, and then multiply it all by a flat.

Pardon

But it's still not a useable image for even printing 4x6 with those vertical lines. That shot was just too dark to begin with.

This is a better example of a recovered RAW file.

Flash went off by at maybe 1/8 power, iso200, 1/50, f6.3, pushed 3.15 stops in PSE3, no NR, and the one is as-shot settings, the other is a 100% crop of my subject's eyes, 6MP Drebel with Sigma 24-135.

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A bias frame is a `zero exposure' dark frame. Set your speed right up, and shoot with the body capped and the viewfinder covered. By doing several of them, you can average them and have an image of the fixed patern noise in YOUR camera. Most of the vertical and horizontal streaking can be removed this way.

When your exposure gets longer, dark current adds to the noise, and this can also be corrected if you have dark frames of the correct time taken at the same temp. Again, for your specific body.

A flat is a blank iluminated field with no detail or variation. Thus, and change in value is a result of lens vigneting etc, or uneven sensitivity of each pixel. So by making up a master flat from many flat averaged out, you can use that to `flattern' the gain across the entire chip.

You don't want a lens on, because that has been shown to generate noise of its own from the focus and f stop controll, and also from IS. It is an idea to check for this though. Some lenses have new main PCBs that cut noise injected into the body via the power lines.

There are a couple of astronomy SW packages that will do most of this, but documtation is less than wonderfull.

Also Roger Clark's web site a a treasure trove that EVERYONE should go right through.

Hellashot wrote in post #2407510
But it's still not a useable image for even printing 4x6 with those vertical lines. That shot was just too dark to begin with.

Unuseable is kinda in the eyes of the beholder... I have it printed 11x14, and in a black frame, and I love it. It is a VERY extreme example, and for most shots, it wouldn't do, but for this one I love the effect that came naturally. I've even taken this approach intentionally for a few shots where I wanted a lot of grain.

All of the technical jargon aside...RAW=safety net! This thread is proving once again that by shooting RAW, when we make the mistake of shooting before switching out of previous settings and having it all wrong, we still just may capture something useable!

RAW is the savour of cock-ups.

My photography would be VERY expensive if I shot on film

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO | PHOTOBUCKET ERROR IMAGE

HTTP response: 404 | MIME changed to 'image/gif' | Byte size: ZERO | PHOTOBUCKET ERROR IMAGE

^ amazing, im going to have to get more memory cards :\

Wow, pretty neat results from pitch black.

I too shoot exclusively RAW for the safety net and for the control over my final product.

If only I could take the time to figure out how to successfully use raw, this would have helped A LOT in the volleyball game I shot the other night. I just shoot JPEG, even though I know I should be shooting raw (I have 3gb, and rarely come close to filling). I honestly don't have a good reason for not trying :P

Personally I love the way brads shot looks because it has the feel that it is taken through canvas or something to give it an old rough texture