Unknown Differences in Capture Area

[john_robertson1953]

Hi Robin,

See attached settings text docs for both light & dark frames for asi533MC camera. (Im using latest SC & asi drivers)

Couple of issues:

See first doc, light frame: shows binning= 3, capture area= 3000X3006?, yet default for this camera is 3008X3008? Also shows Exposure = 2s?, yet these were 180s exposures, see bottom of doc showing Total Exposure = 10800s (correct). When I try and change capture area in Capture Format and Area, from 3000X3006 to 3008X3008, it doesn't allow me.

See second doc, dark frame: shows binning = 3, capture area= 3008X3008. Appears correct.

This inconsistency, how to correct?

Thank you,
John

[admin]

Hi John,

there are various rules for the size of image that you are allowed when using ZWO cameras, including that the horizontal and vertical resolutions have to be multiples of various values. These rules change with different binning levels and also vary depending on whether the 'Hardware Binning' option is on or off.

Up until very recently, SharpCap would display the resolution that you had requested, but change the value behind the scenes to make it one that obeyed the ZWO rules. In the last few weeks I changed that to make SharpCap show the changed resolution.

I'm fairly sure that these rules are behind the effects you are seeing. For instance, you cannot have 3008x3008 in bin3 as 3008 is not a multiple of 3. 3000x3006 will be the nearest image size that obeys all the relevant rules.

On the incorrect exposure in the capture settings file, it looks like you have dithering enabled, so I think that maybe if you saved during dithering, it would have taken the camera settings from a dithering frame of 2s, even though that is not typical of the frames actually going into the stack.

cheers,

Robin

[john_robertson1953]

Hi Robin,

Thank you for info.

I just changed from Bin3, 3000X3006, to Bin1. The resolution stayed the same: 3000X3006. Shouldn't it change by default back to 3008X3008?

[admin]

Hi,

I suppose in theory it should, but once you have changed to bin3 and the resolution is at 3006x3000 bin3, there isn't really anything storing the original target resolution (and you could end in a similar place in ROI mode too).

cheers,

Robin