Accessing RGB histogram on 20d

[Oatman]

Hiya! been lurking around for a while, and finally after 2 years of lusting plunked down the dough for a 20d.

My first project was to practice some basics of expure and exposure compensation in various light and playing with variouse combinations of ISO, aperture, and shutter speed.. So I'b been playing with the histogram and white ballance settings a lot learning about how they work...

Now according to the Magic Lanturn Guide to the 20d there is an RGB histogram that gives color saturation info... This sounds like a useful thing, but I can't figure out how to access it. The guide book vaguely mentions a setting in the playback menu, but darned if I can find it. Nothing at all in the manual.

Anyone have a clue about this Mythical feature?

Thanks!

[picture-this]

While previewing a photo, press the Info button twice to toggle the historigram/blowout warning. If your asking for indiviual R G B historigrams you have the wrong camera only the 1 series do that.

[Oatman]

Thats a pritty big mistake in the magic Lanturn guide then, but I think your right because a feature like that wouldn't be left out of the owners manual.

Thanks!

[robertwgross]

Once you get the image over to your computer, then most of the editors and RAW converters will allow you to see the luminance histogram or the RGB histogram. However, just in the camera you have to make due with luminance only. Pity.

---Bob Gross---

[Oatman]

"Pity"

lol.

Yeah what a sacrifice:)

As a total newbie Its probably more information than I know what to do with anyway. It was just a matter of seeing a feature listed in a guide book and not knowing why I couldn't find it.

Just a mistake in the book. I'm not sure how much I'll be shooting RAW anyway. I figure for the next several months I'm going to be so far down the learning curve and mostly experimenting to really say what kind of shooting I'll be doing. At this point I only have a 256MB card, so RAW isn't an option until I get around to ordering a larger card.

Thanks again.

[DocFrankenstein]

"Pity"

lol.

Yeah what a sacrifice:)
Trust me, it is. Especially with the current "expose to the right" trend from the tip of luminance landscape.

Sure, the guy who wrote it has a 1D of some sort, with histograms for every channel. He can expose to the right all he wants.

Us, average joes are guaranteed to blow out a channel or two if we follow his advice with the luminance histogram.

[drisley]

http://www.adobe.com/digitalimag/pdfs/highlight_recovery.pdf

The kewl thing about the new Adobe Camera Raw (v2.2 and up) is that it can recover highlight information using information from any of the RGB channels that aren't blown out. This is something that no other Raw program can do, and really makes not having an RGB histogram almost a moot point. If one channel is blown, ACR can use the remaining two. If two channels are blown, ACR can use the remaining one channel.

[DocFrankenstein]

http://www.adobe.com/digitalimag/pdfs/highlight_recovery.pdf

The kewl thing about the new Adobe Camera Raw (v2.2 and up) is that it can recover highlight information using information from any of the RGB channels that aren't blown out. This is something that no other Raw program can do, and really makes not having an RGB histogram almost a moot point. If one channel is blown, ACR can use the remaining two. If two channels are blown, ACR can use the remaining one channel.

Intresting, I should try that thing sometime.

[topaz]

http://www.adobe.com/digitalimag/pdfs/highlight_recovery.pdf

The kewl thing about the new Adobe Camera Raw (v2.2 and up) is that it can recover highlight information using information from any of the RGB channels that aren't blown out. This is something that no other Raw program can do, and really makes not having an RGB histogram almost a moot point. If one channel is blown, ACR can use the remaining two. If two channels are blown, ACR can use the remaining one channel.


I think it was this feature that saved some shots for me today. Took a shot of some purple flowers that were getting hit by direct sunlight. My 20D's histogram looked beautiful - no spike on the right side. And not a blinking pixel to be seen (ok, I admit there was one, in an unimportant area). I assumed: good exposure.

Back at home with ACR, I found the red channel blown out badly all over the flowers (but green and blue fine). Pulling down EC and playing with other settings, I ended up with a very nice image that showed great detail in the areas ACR initially said were blown.

I normally shoot RAW only, but I was actually shooting in RAW+JPEG today for the first time, just for curiosity's sake. I couldn't, for the life of me, get things fixed up in the JPEG version. Don't know if this is a case of "RAW rules", or if ACR just has a nice algorithm, or if it just means I'm lousy at processing JPEGs. It does have me more firmly convinced, though, that based on my current skill set, and based on the luminance-only 20D histogram, I better stick to shooting RAW.

[drisley]

Good to hear! This is definately a prime example of the benefits of Raw, especially when using ACR.

[Tshoe]

Drisley, I can't get the pdf file you posted on recovery.

Does PS CS use the 2.2 version?

Terry

[drisley]

I think it comes with v2.0, but I could be wrong.
However, you can update to the latest v2.4 from Adobe for free.