Sharpcap Sensor Analysis not completing

[admin]

Hi Julian,

Really you should leave it in the same position - the initial phases of the measurements work out how wide a range of gains the measurement can handle without the exposure getting either too long or too short. If you start adjusting the brightness then those calculations will be wrong and you will likely be in trouble later.

For that particular camera, a good starting exposure is somewhere in the 0.5 to 0.7s range. If you have the camera on a telescope and are having a problem getting an exposure that long then partially cover the aperture of the telescope with a piece of paper or card.

I just ran the analysis on the Altair 294MC from a starting exposure of 700ms with no light level changes and it all ran through cleanly, so that should be sufficient hopefully.

Robin

[julian489289]

Thanks Robin

Thank you, I will try with the camera off of the scope and see what happens then.

When I start the run, do I just leave the rectangle in the middle of the screen when it suggests to find a point of brightness and do I adjust the size of the rectangle at all?

I am not sure what I am doing wrong as you state that the initial phases of measurements work out the range of gains, yet for some reason my resulting range doesn't work with the later gain settings hence the failure message??

Thank you

Julian

[admin]

Hi,

if you have different brightness is across the camera field-of-view then you can certainly move the selection area if that helps you achieve the target exposure time. Remember to try not to move the camera when covering/uncovering the sensor if you take this approach as that could change the brightness of the selected area.

If you still have problems with a run without trying to adjust the brightness partway through then hopefully the log will point me in the right direction to solving the problem. With brightness changes going on, that kind of makes it hard to spot anything else going wrong in the log.

Cheers, Robin

[julian489289]

Hi Robin

Well, I removed the camera from the scope and ran the analysis again at 770ms and the analysis finished without failing .

However, the analysis looks a little strange, I have enclosed the results in a pdf and the log for this run too.

Does this analysis look right? I thought the graph started high and then fell at around 900 to lower values yet my graph seems to be low all of the time?

Thank you for your continued support

Regards

Julian

[julian489289]

The pdf wouldn't load with an error message ...

Error

Sorry, the board attachment quota has been reached.

The jpeg images are too large also??

[julian489289]

Can I email the sensor analysis graph to you Robin??

[admin]

Hi Julian,

I've received your email thanks – it looks as though some of the read noise values are odd, particularly the one at the lowest gain which is much too high. Additionally I would have expected higher read noise values up to 900 gain where SharpCap operates the camera in LCG mode.

There is some indication in the log that the computer may be struggling to keep up with the frames coming from the camera, so it may be worth running the analysis with the camera in ROI mode to reduce the load.

Robin

[julian489289]

Thanks Robin.

I have copied the json file into SC sensor analysis file and NINA found the directory automatically.

Thank you for your support. The Eagle is an Intel I3 processor so I would have thought was fast enough for the frames coming from the camera. I will try to run it again though in ROI mode.

To that end, how would I set that up please?

Thanks again

Julian

[admin]

Hi Julian,

you just need to choose a smaller capture area in the top right of the control panel – maybe 50% of the full number of pixels in each direction would be a good starting point.

Cheers, Robin