SharpCap Forums

I think, the Analysis of my ASI 178MC-Sensor is incorrect, because:
Almost all lightning-Sources are too bright (including very dark/cloudy daylight-measuring with a mounted Canon-EF-Lense at an Aparture of 22!). SharpCap reports „Expusore too short“ (Exposure almost always 234ms). The Measurement can only start, if the ASI 178MC with an Canon-Lense at Aparture 22 is putting on a part of the very low lightened Display of my Notebook. Also the ASI 178MC without a Lense is putting on the white Display of my unlightened (turned off)!! Raleno video light.
So, if the Measurement was successful, the table of result begins at Gain=0 and e/ADU=0.91, next Gain=50 and e/ADU=0.50. There is no e/ADU > 0.91 (see the complete table in the attachment). It seems to be incorrect.
My SharpCap-Pro-adjustments (v3.2.6383): See attachment.
There are nearly the same results with a Windows 7-Notebook and USB 2 or a Windows 10-Notebook with USB 3.
Are the results correct? If not, what can be the reason for the incorrect measurement?

Hi,

apart from the values for gain 450 and gain 500, which look a little suspicious, your measurements look correct for the 178 sensor. Oddly this sensor does only have e/ADU values that are less than one - see the separate analysis that ZWO have on their webpage (https://astronomy-imaging-camera.com/pr ... 78mc-color), which matches the SharpCap one fairly closely.

The reason that the analysis wants to work with a low light level is to ensure that all of the measurements can be completed without needing to set exposures too near to the minimum that the camera supports, as some cameras have inaccurate exposure control or misbehave very close to their minimum exposures. SharpCap's goal is to allow for a factor of 1000 between the starting exposure (which is captured at minimum gain) and the potential shortest exposure which will be captured at maximum gain.

Cheers, Robin

Hi Robin,
thank you very much for your answer!