SharpCap Forums

Hello to each other,

I have a problem with my new QHY410C. Yesterday I did a sensor analysis with SharpCap, but I only reached a full well capacity of 70 ke (see picture). Indicate with this camera is 120 ke. Either I made a mistake or something is wrong with the camera. What surprises me and I don't understand, the QHY410C works with 14 bit (output 8 or 16 bit), why does the sensor analysis say in the 15 bit? I apparently didn't do anything wrong with the methodology, because I did the sensor analysis for comparison with 2 other cameras and they fit.

Hopefully you can help me and maybe explain the whole thing. Thank you for your answers.

Greetings, Jonas

Hi Jonas,

looking at the results being about half the expected full well depth and the bit depth of 15 bits, I suspect that some setting is doubling the pixel values from the camera before they get to SharpCap - that would explain both problems.

The first thing to guess at is the colour balance controls for the camera - unfortunately the 'default' colour balance values vary from model to model with QHY cameras, so it is not always easy to know what values should be used to make sure that the colour balance is having no effect (for ZWO the default is always 50 - so much easier!).

I would put the camera into 8 bit mode, show the histogram and adjust the colour balance to see what effect it has on the histogram. Typically the 'neutral' value can be found by looking for a value where there are no unsual peaks or valleys in the histogram graph - as you change the values you will see these peaks and valleys appear at various positions in the graph - if you can make them all vanish then that's a good candidate for the right value. Often for QHY cameras the neutral values are powers of 2 - 16, 32, etc. Finally, if you have found the right value and turn down the control a bit then you will see the histogram for that colour channel not getting quite to the 100% level on the right.

I think that once you have found the right defaults for the white balance controls, you will get correct sensor analysis results.

cheers,

Robin