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Old 12-06-2016, 03:33 PM
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codemonkey (Lee)
Lee "Wormsy" Borsboom

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Join Date: Jul 2013
Location: Kilcoy, QLD
Posts: 2,055
Quote:
Originally Posted by Shiraz View Post
Used a diffuser in front of the scope - same as your panel will give. Testing in the open under the diffuse light in a room will allow light from a very wide range of angles to affect the result - the scope will limit the range of angles that the light can come from. Suspect that will make a significance difference (of course it might not as well)

I am still using Nebulosity - I am getting only occasional bursts of clear sky and cannot bear the thought that the software will let me down.
Cheers Ray, that's a good point. I'll see how I go when it's actually on the scope (which is allllll the way "up there" in the paddock). I was briefly trying to confirm e-/adu for a given gain and noticed that it appears to vignette even with nothing on the camera than the black adapter that is screwed on by default (male to female M48 maybe?) and it was then that your comment fully made sense to me.

Quote:
Originally Posted by glend View Post
Jon Rista, writing in the CN beta test thread, has put up some graphic data on stacking effectiveness (SNR) with this camera.

Link here:
http://www.cloudynights.com/topic/53...9#entry7269131

And he has also suggested a Gain 75 "Sweet Spot" giving almost exactly 12 stops of dynamic range, with 2.05e-/ADU gain and 2.05e- RN, with a 8402e- FWC.

Link here, with data:

http://www.cloudynights.com/topic/53...0#entry7269537
Seems reasonable and maps pretty well to the graphs ZWO have provided.

I've captured bias (200) & darks (100 ea @ 300s and 120s) for a gain of 99 and offset 40. I'm now doing the same for gain of 74 & offset 35, although I'll probably only bother grabbing 50 darks this time, after seeing the diminishing returns from the previous set.

How annoying are those sliders in the ASCOM driver interface? I can never get gain to be exactly what I want.
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