phd 2 pixel setting slightly out would it make much difference

[iwols]

hi guys always struggled a bit with phd 2,sometimes ok sometimes poor,so while weather bad checked a few settings and found that the pixel size for my qhy5l ii guide camera was set to 3.45 instead of 3.75 would this made much difference in reality thanks

[Tim]

Won't make a fat lot of difference, but doesn't hurt to be accurate. PHD2 picks up my Lodestar as 8.3, in fact they are 8.2 x 8.4, so I guess it chose a happy medium.

[newbie alert]

I thought my camera was 3.75 but is 2.8um..dont make a drastic difference but my guiding had got slightly better..due to this or my PA is better I don't know

[vlaiv]

It will not make any difference in regards to guiding accuracy - it will just have an impact on numbers it displays converted to arc-seconds.

Guide RMS in arc-seconds will change and so on, but your images will look exactly the same.

[drjolo]

Another thing it affects is calculation of calibration step that is derived from given pixel scale. But at this 10% mismatch it should not affect guiding accuracy at all. 

[alacant]

On 4/3/2018 at 22:00, iwols said:

would this made much difference in reality

Assuming you've the correct numbers and you've dismantled and reassembled your mount enough times, I find the guiding depends exclusively on seeing. If it's steady, you can go for long focal lengths. If you've turbulence there's nothing you can do to improve it. Be sure to run the GA for 5 minutes before you take your first frame to minimise effects. HTH.