Atik OSC Histogram Help

[Stephen]

Last night I was out getting familiar with my new 314 OSC and shot off some 60 and 120s subs of M92. (Brain still in DSLR mode, I'm reasonably sure I can go much longer than this!)

Along the way it occurred to me that Artemis Capture doesn't have a histogram so I couldn't judge max exposure length!

That point aside (will be installing Paint.NET before I go out tonight to get histogram) a thought occurred to me...

If you take a sub that has not been debayered, is its histogram accurate : ie is it the same histogram that you would get looking at the debayered output?

Thanks in advance!

[ollypenrice]

Good question. I've never given this a thought but I think it will be accurate. I just look at the black point value with regard to exposure times, though the values I get from this very dark site won't be any use to you I don't think.

I may also open a single sub in Astro Art to see if I have any saturation in very bright areas but I'm constantly amazed by how hard it is to saturate a CCD camera.

Olly

[ianaiken]

Olly, when your looking at the black point values what exactly are you looking for?

[Jessun]

I agree, good question. The histograms are clearly different. Below left is RAW and right is debayered.

[martin_h]

Ive just had a look at mine, and to be fair there is not a lot in it.

The Pixel Stats for the Whole Image have hardly changed at all.

If you ignore the histogram spread and just look at the left edge(black point) there is not much in it.

Fits on left, debayerd on the right.

[terrym2002uk]

I dont know if fits liberator can read osc fits, but it can also give you some useful stats regards the image levels. Like you Im just getting to grips with a ccd, so would be interested in a good reliable method.

[swag72]

When I moved from DSLR imaging, I got really hung up on the histogram and how to determine an ideal exposure length. I decided that the histogram was no longer a good indicator, as I found I struggled with the .fits format as you could basically make it what you wanted! So, now I just take a sub then look at it in Maxim. I look at the brightest stars and ensure that I don't have too many fully saturated (more than 65500K) and I also chack the main part of the image to see that I haven't oversaturated the galaxy core etc.

Hope that helps.