histogram question

Qarik

when I am shoting in raw, the RGB histogram that is generated in my LCD preview is based on jpeg out put of that raw file correct (because RAW has no color space right?)

So if I blow my red channel becasue I am shooting santa claus, this may be recoverable to some degree in post by adjusting saturation over all or reducing the luminence of the red channel correct?

Also (I don't have camera with em right now) if I change my jpeg conversion to vivid for example, will I get more red clipping in my jpg preview even though I am shooting in RAW only?

adbsgicom

Yes, it is off the jpg. There was a thread about making sure you set your camera to natural settings for the jpg even when shooting RAW to prevent erroneous data in the histogram.

I don't know how much headroom you have past the right side for bringing anything back. Based on a little experiment (using flash at a box of tissues), I could come back a full stop over the histogram saying it was saturated and get my image back in raw. Once re-adjusted for the over exposure, the images ended up looking pretty much the same (even at the blacks).

Both shot at f2.8 1/100 400ISO
FEC +2 (bounced):

Original Histogram:


+3 FEC (bounced and over exposed) and adjusted -1.0 in LR

Adjusted Histogram:


Original Image (over exposed)

Original Histogram:

Nikolai

Recent cameras are typically flexible enough and give you a room for error. One stop is a kid's play. I had cases when I had to pull exposure by two stops (tough lighting situation), and it was still acceptable.
I'm not trying to advocate a careless shooting, I'm only saying that if worst comes to worst, RAW can provide some leniency.
Naturally, if you're shooting JPEG only and you misexpose, you're screwed up for good.

kdog

Qarik wrote:

when I am shoting in raw, the RGB histogram that is generated in my LCD preview is based on jpeg out put of that raw file correct (because RAW has no color space right?)

Yes.

So if I blow my red channel becasue I am shooting santa claus, this may be recoverable to some degree in post by adjusting saturation over all or reducing the luminence of the red channel correct?

Yes. Saturation, brightness, vibrancy, exposure, recover, any/all of those can affect recovery.

Also (I don't have camera with em right now) if I change my jpeg conversion to vivid for example, will I get more red clipping in my jpg preview even though I am shooting in RAW only?

Yes it will and will cause you to miss some of your available headroom if you go by the the histogram or blinkies. That's why a lot of us shoot with the JPG settings at neutral, or even negative. Scott Quier posted an interesting article that explained a technique for setting a custom white balance that reports to make your histogram and blinkies a lot more in line with the RAW dynamic range. The downside to it was that it made your JPG shots on the LCD look awful, all green or something.

Regards,
-joel