Failed Sensor Analysis of QSI 726

[richard_]

Hi Robin,

Ah, sorry if it wasn't clear in the last screenshot. The white box with "ASCOM.QSI v1.1.06" in the heading is not embedded in NINA, this is a floating dialog box for the ASCOM driver separate from NINA (I would get the same thing if I connect via Sharpcap). I just overlaid it with NINA in the background to make a convenient screenshot.

Thanks for the prompt responses and updates so far, they're much appreciated. Let me know when the new version per your second paragraph is up on your website and I'll give it a try

Cheers,
Richard

[richard_]

Hi Robin,

In the background, I've been in touch with QSI/Atik regarding the ASCOM drivers who have confirmed they were able to recreate the issues I was seeing and have since updated the software (QSIInstaller-2025.05.30) and driver (ASCOM.QSI 1.1.0.7). They also updated the SDK which is of no use to me, but may be useful for you? I installed the new driver and started up Sharpcap (version 4.1.13343.0 - 26/05/2025) to rety the sensor analysis.

Straight away, Sharpcap now sees the custom readout mode as I can change the Gain and Offset in the "Camera Control" panel on the right hand side. I performed a Sensor Analysis, but with some additional Gain values via the console to verify when the High Gain mode kicks in (QSI manual v1.4 states this happens at 60, so I tested some additional values around this part):

Code: Select all

SharpCap.SelectedCamera.SetGainsOfInterestForSensorAnalysis([60,61,65,70])

The sensor analysis was able to fully complete without any hang ups like I saw before, although it did take over an hour to complete. At full resolution, I was achieving 0.3fps and after the analysis was complete, I reduced the resolution to 320x240 which did increase frame rate to 1.0fps which in theory should triple the speed of the analysis? I'm using a short length USB3 connected directly to the laptop so I'm unsure how else this would be increased as there's no USB traffic options available. Any suggestions?

The results shown in the picture below look similar to what I see in my QHY268M (which is to be expected of an IMX571) and gives me confidence that the test was performed correctly. I can confirm that the HCG mode kicks in at 61 and not 60, as evidenced by the significant drop in read noise in the table of results below.

So I think the update performed by QSI/Atik has done the trick regarding the issues I was having, so unless you have any concerns about the results or the frame rate with the camera, I think we can put this issue to bed Thanks for your support with this!

Sharpcap sensor analysis QSI726 31-May-2025.PNG (101.26 KiB) Viewed 2244 times

[admin]

Hi Richard,

good to hear that you got an update from QSI, and I have to say that those results look fine for an IMX571 sensor. It looks like the gain value number is fairly closely related to the gain in dB being provided by the camera (with a factor of 10 thrown in), which is reasonable and similar to the way that ZWO, Player One and others implement their gain adjustments.

Using an ROI to get a faster frame rate would increase the speed of the analysis, you can sometimes speed things up a bit by increasing the illumination level which pushes the routines to use shorter exposures, but if you are maxing out at 1fps then this isn't going to help much.

Hopefully you will now get some nice clear skies (even if not properly dark at this time of year) to get some use from the camera

cheers,

Robin