Focusing...

EzyStyles (Eric) · #1 13-08-2006, 12:29 AM

Hi guys,

After taking out my secondary and primary mirror for centering, can't seem to reach focus? I have to move the 2" to 1.25" adapter out abit to get focus. Any help would be appreciated. Thaks.

Eric.

gbeal · #2 13-08-2006, 07:18 AM

Eric. It came to focus before you did this work? I can only assume so.
The only thing that has changed is the distance between the focuser, and the primary, if one assumes you have everything lined up correctly.
If all is lined up, and if you haven't placed the focuser closer to the tube, then really the only thing that has changed is the primary mirror. It is obviously closer to the secondary and focuser. Try adjusting the collimation screws, to have it move away from the secondary/focuser. On some scope cells there is provision to move the mirror about 1 inch or more, so this could be your problem. From your post it seems it is only "out" by a small ammount as well. Different eyepieces have differing focus points as well.
Lotsa variables huh?

bojan · #3 13-08-2006, 08:59 AM

Another piont: if this is the case, you may consider moving mirror as far as it goes.
First, you will have focuser useable for more eyepieces ( I assume that the focus can not be reached with only one.. or is it the problem with all of them?) and vignetting of the secondary will be reduced.

EzyStyles (Eric) · #4 13-08-2006, 10:38 AM

thanks for the reply guys. I was actually taking a few snaps last night with the DSI not using any eyepeices at all. The DSI doesnt come into focus now unless i extend it out abit by adjusting the 2" adapter. Before removing the primary mirror, i can reach focus. I'll try first to adjust the primary mirror collimation screws.