Hello, Al
For evenly illuminated, brighter regions of the moon, I have recently discovered that I can get good results with the following settings:
- Capture rate: 5fps
- Capture time: 360 secs (=1800 frames)
- Brightness: 50%
- Gamma: 25 to 50%
- Gain: 25 to 50%
- Shutter: 1/33 or 1/50sec
25% and 50% are rough guesses of where the slider is positioned. The Clavius image was a stack of approx 200 from the 1800, with the Quality in Registax set to 95% on the Align page.
I also try to keep the K3CCDTools histogram bar to between 210 and 230 to avoid burnt out whites in the avi capture.
For the moon, I discovered the use of the “Gamma” slider. Previously, I always had this hard left which seemed to work for Jupiter and Saturn. When imaging the moon, where there is so much more light available, as well as a tremendous brightness range to cope with. I have found that the Gamma setting can compensate for these factors, helping avoid the extremes of “coal blacks” and “whiter than white whites”.
By sliding the Gammas slider towards the right, I have observed the following:
- Whites become toned down, i.e. they move towards light grey.
- Blacks become less black, i.e. they move towards dark grey
This means that the overall image can appear “flattened” as the extremes of illumination are removed or modified.
I think this has something to do with how many shades of grey a monitor can display, or the ccd camera can handle. I believe that the ToUcam is an 8 bit device, which means that it can differentiate between 2 to the power of 8 (256) shades of grey, where pure black =0 and white =256.
The Gamma slider appears to try to keep the brightness range between 0 and 256, so that you do not lose any information.
Hope that helps.
Cheers
Dennis
PS - I noticed that the Clavius image looked a lot darker, too dark for my liking, when I viewed it indoors this morning, on the desktop PC LCD monitor, whereas last night in the garden where I processed it on the notebook computer, it looked okay.
I normally include equipment details, but posting from the back garden last night whilst still acquiring images via K3CCDTools as well as processing in Registax whilst reading IIS, must have addled my brain.
