Hello,
This is my first post here - I'd like to start with thanking you so much for this software. I upgraded to Pro because of the built in polar alignment tool that I absolutely love. Now on to my issue that I hope you can walk me through?
I'm attempting to do a sensor analysis of my ZWO camera (ASI071 Pro Color) I'm pretty sure the camera is 14bit Raw, however it's not an option in the settings, so I've chosen RAW16. I can't tell you how many times of attempted to run sensor analysis today - with every different setting, following endless of others responses on other forums but without success.
I am currently at Sensor Linearity section, which seems like part two of step one. Then it asks me to cover up my telescope which I do to make it dark, it passes this with charm, then on to the final stage where it asks me to remove and add light back. I've attempted every brightness I could think of to barely lit, so it would let me continue to fully bright and every time it says, reduce your brightness.
I know this has come up so figured I'd share it, I also attached a log file, as this was asked for regularly.
My gain on camera ranges from 0 - 600.
I also have the latest software update 64Bit.
Please help,
Casey
Sensor Analysis Doesn't Complete
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Sensor Analysis Doesn't Complete
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Re: Sensor Analysis Doesn't Complete
Hi,
That's actually quite interesting – I just tried this with my 071C camera and I had trouble too. Eventually I got the analysis to run through by setting up the brightness so that at maximum gain and exposure of just under 0.5 ms gets you a histogram level of about 60% in the green channel. You do get the warnings that the exposure is getting too close to the minimum and you might need to restart with less light at that level, but remember that's just a warning that can be ignored if everything continues working as it should.
What turns out to be critical is making sure that the camera never uses exposures of more than one second during the analysis procedure. It looks like the ZWO cameras (or at least this one) are now only setting exposures accurately to within 0.1 second when the exposure is above one second. That means you get the same brightness from setting exposures of 1300 ms, 1310 ms, 1350 ms all the way up to 1399 ms and then the image brightness jumps when you set the exposure to 1400 ms. I haven't had a chance yet to go back to an older version of the ZWO SDK to see if this has always happened or if this is a new problem. Anyway those step changes in the image brightness are not good for the sensor analysis code – it will tend to get stuck if it ends up on exposure range where that is happening.
Last couple of points, firstly the analysis for that particular camera has already been done and ships in the install pack for SharpCap, so there should be any need for you to run it except out of interest. Secondly, as you noted the camera is a 14 bit camera but the mode shows up as raw 16. This is because there is no reliable way to ask the ZWO camera what bit depth it uses. There is a way to ask but it often gives the wrong results, so the only way to find out for sure is by doing the sort of measurements that the sensor analysis does. This means that SharpCap servers raw 16 for all ZWO cameras regardless of whether they have 12, 14 or 16 bit ADCs.
Hope this helps, Robin
That's actually quite interesting – I just tried this with my 071C camera and I had trouble too. Eventually I got the analysis to run through by setting up the brightness so that at maximum gain and exposure of just under 0.5 ms gets you a histogram level of about 60% in the green channel. You do get the warnings that the exposure is getting too close to the minimum and you might need to restart with less light at that level, but remember that's just a warning that can be ignored if everything continues working as it should.
What turns out to be critical is making sure that the camera never uses exposures of more than one second during the analysis procedure. It looks like the ZWO cameras (or at least this one) are now only setting exposures accurately to within 0.1 second when the exposure is above one second. That means you get the same brightness from setting exposures of 1300 ms, 1310 ms, 1350 ms all the way up to 1399 ms and then the image brightness jumps when you set the exposure to 1400 ms. I haven't had a chance yet to go back to an older version of the ZWO SDK to see if this has always happened or if this is a new problem. Anyway those step changes in the image brightness are not good for the sensor analysis code – it will tend to get stuck if it ends up on exposure range where that is happening.
Last couple of points, firstly the analysis for that particular camera has already been done and ships in the install pack for SharpCap, so there should be any need for you to run it except out of interest. Secondly, as you noted the camera is a 14 bit camera but the mode shows up as raw 16. This is because there is no reliable way to ask the ZWO camera what bit depth it uses. There is a way to ask but it often gives the wrong results, so the only way to find out for sure is by doing the sort of measurements that the sensor analysis does. This means that SharpCap servers raw 16 for all ZWO cameras regardless of whether they have 12, 14 or 16 bit ADCs.
Hope this helps, Robin