I have an STX 16803 camera and just changed my FW5-STX filter wheel for FW7-STX with STX-guider, so to have more filters and also to hopefully get more light in for guiding. In the STX-guider manual it says to point the telescope to a nearby light source and take some images to see if there is a shadow on one side of the image. I did this with a light panel I placed on the dome and with the pick-off mirror knob turned fully counter-clockwise, there is certainly a vertical shadowing on the left side of the image taking up about 20% of the image. I then kept turning the knob clockwise, expecting the shadow to go away but it didn't. I tried with varying exposures and binning but nothing made a difference to the shadow. I made sure the lock knob was fully counter-clockwise and that I was also turning the pick-off mirror knob and not the focuser. Have included the image that comes up and doesn't change with changing the pick-off mirror knob. Am using an F8 scope 18RCT so thought fully counterclockwise would've been the correct setting. I am using MaxIm DL 6.1.4 Any suggestions? The only thing in the manual I wasn't sure about is that it says to take the image in 'focus mode'. Unsure what this means exactly or if this would change anything
I don't think you have a lot of illumination in that image, and I don't think that's the shadow of the pick-off mirror. Best to post a FITS image if you want to discuss. Also you can bin it.