SharpCap Forums

Hi there,

I have an Altair 26M (yayy, been waiting for this camera for ever!). SharpCap sees it fine with the native driver, but it doesn't seem to have an option to enable ultra mode. I believe with the 26C an option should appear in the capture format box, but I can't find anything for the 26M. I'm keen to try the sensor analysis with ultra mode enabled. Am I missing something?

Analysis works fine otherwise (nice sensor!).

-simon

Sorry should have said I'm using v3.2.6480 64-bit.

As a delta comparison, I ran a sensor analysis using the ASCOM driver in HCG mode. The ASCOM driver enables Ultra mode. As you can see performance is significantly improved:
The 100 gain entry with HCG ultra is equivalent to the 200 gain entry on the "standard" chart -- so we can see that enabling ultra mode drops the read noise from 1.45e to 0.95e and improves dynamic range from 13.5 stops to 14.1 stops, while maintaining an almost identical full well depth (16710 vs 16751). I'd say it would be worth letting people enable Ultra mode in SharpCap

Hi,

I'm not sure that what you are seeing is the effects of Ultra mode – SharpCap and the Ascom driver both have the same way of detecting it and enabling it, so if SharpCap isn't seeing ultra mode is being available then the Ascom driver won't be seeing it either. The Ascom driver enables it by default if it's available on the grounds that if you are using Ascom then you're doing long exposure imaging... Another reason I'm not convinced is that my experience of enabling ultra mode was that it drops the read noise by about 10% – the reduction you're seeing from 1.452 0.95 doesn't seem quite right for that (although I don't quite understand where that reduction is coming from).

I'll have a chat with with Nick at Altair on Monday to see if we need an update of the SDK.

Cheers, Robin

The ASCOM driver doesn’t see ultra mode on the 26M either (or at least it doesn’t offer a switch to turn it off). However Nick told me that the ASCOM driver will enable ultra by default, even if the switch does not appear. I look forward to reaping the benefit of your investigations

Hi Robin, any update on this? Would be great to be able to turn on Ultra mode in SharpCap. I did a little more testing with the ASCOM driver in LCG and it shows a much smaller read noise drop -- 10% as you mentioned sounds about right (don't have the numbers to hand, am building a new mount PC currently). From the numbers it seems that it has a more dramatic effect when in HCG. (Personally I'd love the ability to also be able to manually enable HCG/LCG in SharpCap native drivers for testing purposes, but I understand you're not a big fan of that!).

Hi,

I had an update from Altair, but unfortunately it had another issue in it that means it has to get more fixes... Hopefully next week.

Robin