Wayne76

After checking, CPC without a wedge the you should keep exposures to maximum of 20 seconds. Otherwise field rotation will occur, f/2 (HyperStar) is 25X faster than imaging at f/10 (at cassegrain focus).

Thank you Ian i will take long and short exposure, and shorten to exposure time ?

Hi Ian, How are you, The main reason I brought the CPC unit is due to it mobility, but still it is heavy.......... It is still a mission to move in and out, And I brought the HyperStar is due to it short exposure advantage, For example the photo below it taken with 60 X 25s light frams, but only manage to keep 45 of them, 30 darks and 30 Bias, no flate, According to the Starizona, on the C11 with HyperStar, it reduce the focal length of f10 to f2, 1s = 30s exposure on standard equipment, Which means 30s X 25s X 45 = 33750 / 60 / 60 = 9 hour 37.5 minutues exposure, ( I hope my calculation is correct...) Issue I have now, 1 - Due to the mount issue, need to short the exposure time to 20s -15s to avoid flying stars..... Need to find out from other forum the recommend time for exposure 2 - Can only 10 -15 pic a time, then I need to move the object back to center of the screen 3 - Can't do to long exposure, other wise the whole pic will go over exposure, could also be my QHY10, Thank you for liking Cape Town !! Wayne 20-Dec-2017

Yes wedge is available on the CPC, but it really required lots of time just to do the set up, that is why I brought the HyperStar system....? i will start another topic in the equipment section Thank you Carastro !!

I am so sorry, Carastro, My CPC 1100 is on its own, no guide cam or wedge I did brought Celestron Nexguider, but still haven’t got it to work... what is the max exposure time do you suggest on just normal CPC mount, thank you so much for all your advices

Thank you, White Dwarf, donut effect is gone now !! Some of the star is not round, it is due to the tracking issue, since my mount is still unguided, Should have brought the CGEM not the CPC mount in the first place.... I will shorten the exposure time to 15s next time I try,

Forgot to ask you, which program did you use use to check