secondary question

[bmitchell82]

Picking the brains of the greater community. Vingenetting! nasty stuff it is, my understanding of it is that the CCD/Cmos sensor is not being fully illuminated.

Would replacing the secondary with a slightly larger one be of benifit? I do have a 10" scope so loosing a touch more on the clear aperature shouldn't be a big issue.

[DavidU]

Give me the FL and specs on the focuser and the OTA dia and cam sensor size and I will work it out for ya.

[DavidU]

Something like this to get 100% illum through a 2" focuser
* 250. mm f 4.7

250. primary mirror diameter
4.7 f ratio
305. tube inside diameter
1.5 tube thickness
25. extra focus height
0. camera focus height
55. diagonal minor axis*************
70. focuser height
50. focuser diameter
150. focuser to front of tube
40. mirror to back of tube
0. fixed baffles (1 or 0)
mm unit of measure

[DavidU]

Limit mag of 13.8
Central obstruction 22%
Angular FOV at 100% illumination .1257Deg @ 2.56 inch

Any good?

[Starkler]

Yes it would.

[bmitchell82]

wow is there a program that does this so i can fiddle around with the specs a bit?

Its good to know that i can maybe enhance the scope to proform better. every day i do something else to tune it better and better for this dark art i do :)

[DavidU]

I use this
http://www.dalekeller.net/ATM/newtonians/newtsoft/newtsoft.htm