SharpCap Forums

Hi all,

Please, I have an ASI 533 mc pro:

I want to know how to set OFFSET.

I suppose it is in "Image Controls" then setting "Brightness". Is it right?

thanks in advance
Paolo

Hi Paolo

That is correct. Zwo calls it Brightness which indeed is Offset.

Menno

Thanks Menno!

Please,
which is "default" offset(brightness) value for ASI533 mc pro camera? In Sharpcap it goes from 0 to 100.
I don't want to move it... I want just set exposure time and gain

thanks

You can set brightness to 10 and leave it there. It's the "default" setting for that camera.
For Gain I should go for 100 to begin with.

Menno

I also just want the default set and go from there but in ASCOM it appears the default is 70 - any thoughts as I would think 10 would be better for well depth...

I know there are differences between Ascom and Zwo. I don't know why though.
When using the Zwo capturing software for some testing, my camera too had different value. Id did choose the Zwo offset value which was the lower one.
When looking at the 533 on Cloudynights for example, the 10 value seems to be most mentioned and recommended.

Menno

Yep I think I am going to light, Flat and dark for Brightness 10 again and compare to higher recent results...

Hi,

the simple trick for setting the offset is to set up the camera to capture dark frames at the gain and exposure you intend to use, then adjust the offset/brightness/black level control until the histogram peak is at least slightly separated from the left hand side of the graph (ie you can see both sides of the peak and the left side tails down to zero or near zero by the time it gets to the left hand side of the graph). From then on, leave the control at that value for all captures. You only might need to change it again if you start using higher gains (as that makes the dark frame peak wider).

cheers,

Robin

Greetings Robin, with the ASI533MC Pro the only gain I set is 105 and I never touch Brightness so my only variable is exposure. You just made that now an extremely easy decision to decide where to land on Brightness (Offset). I took your advice and sure enough Brightness 10 (G105) and any exposure I choose kept the histogram exactly where you described it should be.

This forum and your availability on it, has been an astrophotography lifesaver in cutting down on so much of the misunderstood information in this hobby.

Thanks to your input I feel great about my Brightness, Darks, Flats, livestacks, etc., etc.

Thank you for being right here for all of us.

Randall

Hi Randall,

good to hear that you are all set now - hope you get some clear skies soon!

Thanks for your kind comments too

cheers,

Robin