SharpCam Crash on Wrong with Binning using ASCOM Camera
Posted: Thu Dec 11, 2025 10:26 pm
Hi, I will describe the issue that can be reproduce with a ZVO ASI662MC Camera,
SharpCap Pro v4.1.1300 64 bits,
ASCOM Plateforme6.6 SP2 6.6.2.4294.
Windows 10 Pro
ASCOM for ASI Cameras v6.5.40
ZVO ASI662MC
Start ScharCap
Select ASI Camera (1)
Setting are RAW 16 Exp: 1000 ms Gain 5
ROI 1920x1080 (Full sensor Area)
Pan:0 , Tilt : 0
The UI change as usual and Preview start.
Select Binning 2
The UI changes:
ROI is set to 960x540
but the list of available sizes is still the same from 1920x1080 to 320x240. It would start at 960x640 witch is the maximun in bin 2x mode
The ROI Zone shows a dark grey rectangle in the midle of a larger light one.
Pan is 240 and Tilt 134.
SharpCap then displays no preview and the crash report windows appears immediatly.
It seems that SharpCap ask the camera to take a frame starting at position 240,134 with a width of 960 and height of 640 !
This outside of the sensor area.
It is as if Sharpcap believe that the sensor is still 1920x1080 size.
ShapCap don't crash if you don't close the report windows.
You can select binning 1x and the you get a preview picture 960x640 starting at position 240,134.
If you set again bin 2x selecteted size switch to 480x270 and Pan=360, Tilt=202
No image in preview.
In SharpCap Log we can read :
Warning 23:16:04.014200 #33 Dropping frame due to pixel count mismatch - 2d source array (270x480), source had 129600 pixels, dest 32400 in bool SharpCap.Cameras.ASCOM.NewCameraProxy.ValidateDataSize(Array source, BufferFrame target)
This message repeated many times.
I understand that SharpCap received 270x480 frame (why not 480x270) that is excactly 129600 pixels but have alocated space for 4 time less pixels !!!
I describe this issue using tests I do with an ASI662 Camera.
I'm writing an Alpaca/Ascom interface for a Raspberry Pi Camera.
Every things works perfectly but the binning 2X mode do the same.
I test the Binning 2x mode with APT NINA and PHD2 and all these apllications work fine with my Raspberry Camera.
As I can see both logs (SharpCap and my Camera) SharpCap ask for a wrong sized area.
When starting from a full size frame (1920x1080) at bin 1x, when switching to 2x it would set Pan and Tilt to 0 and ask for a 960x540 area and allocate enought room for tha amount of pixels.
I know that few people use Bin 2x with an ASCOM Camera Interface but for my project it the only solution.
Thanks for your attention.
Best regards
Eric H.
SharpCap Pro v4.1.1300 64 bits,
ASCOM Plateforme6.6 SP2 6.6.2.4294.
Windows 10 Pro
ASCOM for ASI Cameras v6.5.40
ZVO ASI662MC
Start ScharCap
Select ASI Camera (1)
Setting are RAW 16 Exp: 1000 ms Gain 5
ROI 1920x1080 (Full sensor Area)
Pan:0 , Tilt : 0
The UI change as usual and Preview start.
Select Binning 2
The UI changes:
ROI is set to 960x540
but the list of available sizes is still the same from 1920x1080 to 320x240. It would start at 960x640 witch is the maximun in bin 2x mode
The ROI Zone shows a dark grey rectangle in the midle of a larger light one.
Pan is 240 and Tilt 134.
SharpCap then displays no preview and the crash report windows appears immediatly.
It seems that SharpCap ask the camera to take a frame starting at position 240,134 with a width of 960 and height of 640 !
This outside of the sensor area.
It is as if Sharpcap believe that the sensor is still 1920x1080 size.
ShapCap don't crash if you don't close the report windows.
You can select binning 1x and the you get a preview picture 960x640 starting at position 240,134.
If you set again bin 2x selecteted size switch to 480x270 and Pan=360, Tilt=202
No image in preview.
In SharpCap Log we can read :
Warning 23:16:04.014200 #33 Dropping frame due to pixel count mismatch - 2d source array (270x480), source had 129600 pixels, dest 32400 in bool SharpCap.Cameras.ASCOM.NewCameraProxy.ValidateDataSize(Array source, BufferFrame target)
This message repeated many times.
I understand that SharpCap received 270x480 frame (why not 480x270) that is excactly 129600 pixels but have alocated space for 4 time less pixels !!!
I describe this issue using tests I do with an ASI662 Camera.
I'm writing an Alpaca/Ascom interface for a Raspberry Pi Camera.
Every things works perfectly but the binning 2X mode do the same.
I test the Binning 2x mode with APT NINA and PHD2 and all these apllications work fine with my Raspberry Camera.
As I can see both logs (SharpCap and my Camera) SharpCap ask for a wrong sized area.
When starting from a full size frame (1920x1080) at bin 1x, when switching to 2x it would set Pan and Tilt to 0 and ask for a 960x540 area and allocate enought room for tha amount of pixels.
I know that few people use Bin 2x with an ASCOM Camera Interface but for my project it the only solution.
Thanks for your attention.
Best regards
Eric H.