MaxIM 3D plots

LewisM · #1 21-10-2015, 06:21 PM

I am not sure what I am expecting to see in MaxIM regarding the 3D plot of star focus - is ANY degree of flat top "acceptable" or is the aim to get a pointed top showing a perfectly focused star image?

I am still hand-focusing, and am getting some pretty tight 3D plots, but do I need to aim for the pointed spire? (probably nigh on impossible hand focusing in the CFZ with an f/5 scope).

My Sharpsky will be up and running later this week.

Atmos (Colin) · #2 21-10-2015, 06:35 PM

You think that's bad, I am trying to focus a F/3.76 guide scope

Peter.M · #3 21-10-2015, 06:47 PM

Flat tops do not indicate lack of focus. Generally it is the star saturating at the center.

LewisM · #4 21-10-2015, 07:00 PM

Thanks Peter. I wouldn't have thought that they would saturate that much in a 10 sec exposure on medium magnitude stars, even at f/5.

LewisM · #5 21-10-2015, 07:02 PM

Quote:

Originally Posted by Atmos

You think that's bad, I am trying to focus a F/3.76 guide scope

One word -helical focuser. You can get one for around $70 and retrofit it to an 50mm tube finder etc. (old image, but same guidescope conversion)

Image below. makes life a breeze!

Atmos (Colin) · #6 21-10-2015, 07:29 PM

Quote:

Originally Posted by LewisM

One word -helical focuser. You can get one for around $70 and retrofit it to an 50mm tube finder etc. (old image, but same guidescope conversion)

Image below. makes life a breeze!

Already got one

Only properly figured out how to use it yesterday afternoon so I haven't actually had a decent focus out in the field yet :/