SharpCap Forums

I've just run the smart histogram and it's giving me setting up of 895 using a dual narrowband filter, normally the gain for my Hypercam is just under 400, is this normal as I assumed unity gain didn't change, or has something gone wrong? I'm still getting 900 MDR which is what it normally is. TIA

Hi,

basically what has happened is that the sky brightness is lower with the filter, so you need to take longer subs - so long that optimum settings can't be found in your normal exposure range (you have a min/max exposure you can choose - say 5s to 5min - in the brain window).

When this happens, SharpCap will pick a higher gain than usual to compensate. Note that the gain option is 'aim for unity gain' not 'use unity gain' - that means that SharpCap tries to get as close to unity gain as possible given the other constraints.

cheers,

Robin

Thanks very much for your prompt reply.

I think something went wrong when I measured the sky as I got a gain of 895 and exposure of 502s, this was aiming for unity gain and seems much higher/longer than what I was expecting.

Hi,

did you happen to note down the sky background measurement value? Would that value it's possible to re-run the calculation and see if the results makes sense in terms of the measured value. If that value was unusually low then a longer exposure and higher gain would be recommended.

Cheers, Robin

I didn't unfortunately, if I get results I'm not expecting I shall make a note next time. I was wondering if the sensor data that is pre-installed on Sharpcap is kept if a sensor analysis is run or does the new sensor analysis overwrite the data that came pre-installed.
If it does overwrite it can the original data that came with the download be reinstalled somehow?

Hi,

the data that is pre-installed was SharpCap is never deleted, but if you do your own sensor analysis then a separate file is created with those results in it. SharpCap will use the data from your own analysis in preference to the pre-installed data. To go back to using the pre-installed data, find and delete the file containing your own measurements which will be in the folder
Once you've done that, restart SharpCap and you will you back on the default data.

Cheers, Robin

Thank you very much.