QHY gain and offset

[FenderGreg]

Hi,

I have a QHY 168c which is still fairly new to me. I want to make sure I’m setting or at least understanding how to set the gain and offset.

Where do I do this? I use APT, am I just typing in the gain and offset on my plans? Do I edit the settings outside of APT beforehand?

 

Thanks

[FenderGreg]

My histogram in APT is looking severely far left

[Stuart1971]

Just make sure you have a very small gap between the histogram peak, and the left side, this means you are not clipping ant pixels, then all will be good, try different offset settings until you get this small gap, as for gain, look up the  camera online and see what the unity gain is, this is a good place to start…For your camera unity gain is 10, and maybe a good idea to read this too…

https://www.qhyccd.com/uploadfile/2018/1106/20181106030334403.pdf

Edited March 3 by Stuart1971

[FenderGreg]

12 minutes ago, Stuart1971 said:

Just make sure you have a very small gap between the histogram peak, and the left side, this means you are not clipping ant pixels, then all will be good, try different offset settings until you get this small gap, as for gain, look up the  camera online and see what the unity gain is, this is a good place to start…For your camera unity gain is 10, and maybe a good idea to read this too…

https://www.qhyccd.com/uploadfile/2018/1106/20181106030334403.pdf

Here is the histogram even after raising the offset

[Stuart1971]

53 minutes ago, FenderGreg said:

Here is the histogram even after raising the offset

It’s because the scale on the graph is so small, I don’t use APT are there any numbers to go with the graph, mean or median numbers…?

[Stuart1971]

What does it look like with an offset of 50…? As that is the recommended 

[FenderGreg]

On 03/03/2024 at 22:06, Stuart1971 said:

What does it look like with an offset of 50…? As that is the recommended 

It’s really what I have seen mentioned online from someone. The cameras default is gain 4 offset 30 which is quite a bit lower than ‘unity’ gain but I don’t know what it really means in terms of function

[Stuart1971]

2 hours ago, FenderGreg said:

It’s really what I have seen mentioned online from someone. The cameras default is gain 4 offset 30 which is quite a bit lower than ‘unity’ gain but I don’t know what it really means in terms of function

You should try offset 50 that is recommended for that camera…and also unity gain is what you should use if not sure which is 10

[FenderGreg]

On 05/03/2024 at 09:02, Stuart1971 said:

You should try offset 50 that is recommended for that camera…and also unity gain is what you should use if not sure which is 10

Thanks for the replies Stuart. Histogram is actually looking better now.

If only we had two clear nights in a row then I could do I night on one setting then the other to see the difference!