MAK Cullimation - Celestron 90SLT

[fatboy1271]

I've now had my Celestron 90SLT for just over a year. For the last couple months I've been taking lots of pictures using a Canon xsi. I have a bahtinov focus mask and that helps tremendously; however, I still have focusing problems because I believe that I have a cullimation issue:

The image is a star way out of alignment and it is clearly off center. Is this a cullimation issue? If so, I've seen how to fix that on every type of scope except a MAK... 

Thanks,

fat

[kalasinman]

http://stargazerslounge.com/topic/176741-collimating-maksutov-cassegrain/

[Dave In Vermont]

Before you start playing with collimation, try this: Remove the diagonal and insert the eyepiece directly into the draw-tube. Then see what you see. Quite often the diagonal will be the culprit in showing an off-alignment.

Worth a shot before you make a collimation adjustment.

Clear Skies,

Dave

[RT65CB-SWL]

Before you start playing with collimation, try this: Remove the diagonal and insert the eyepiece directly into the draw-tube. Then see what you see. Quite often the diagonal will be the culprit in showing an off-alignment.

Worth a shot before you make a collimation adjustment.

Clear Skies,

Dave

+1

I too have heard this one - The ETX Mak series, (ie 90, 105 & 125), are more problematic. Meade say they should not require collimation as they are collimated at the time of manufacture. This is what they told me several years ago.

If you do collimate an ETX Mak, it will involve removing the plastic flip mirror/counter weight housing from the OTA. Therefore you need to find a cap that will fit without the refitting and removal process as the baffle tube is not 1.25 inch. Once re-assembled, your ETX Mak visual port may not be lined up.

For further info on collimating an ETX, I would recommend a visit to Mike Weasners Mighty ETX site, www.weasner.com/etx

[fatboy1271]

http://stargazerslounge.com/topic/176741-collimating-maksutov-cassegrain/

Thanks kalasinman! I searched the forums before posting but didn't see that post.

[fatboy1271]

Before you start playing with collimation, try this: Remove the diagonal and insert the eyepiece directly into the draw-tube. Then see what you see. Quite often the diagonal will be the culprit in showing an off-alignment.

Worth a shot before you make a collimation adjustment.

Clear Skies,

Dave

Thanks Dave! That picture was taken with the diagonal removed and the camera inserted directly into the draw-tube...

[fatboy1271]

+1

I too have heard this one - The ETX Mak series, (ie 90, 105 & 125), are more problematic. Meade say they should not require collimation as they are collimated at the time of manufacture. This is what they told me several years ago.

If you do collimate an ETX Mak, it will involve removing the plastic flip mirror/counter weight housing from the OTA. Therefore you need to find a cap that will fit without the refitting and removal process as the baffle tube is not 1.25 inch. Once re-assembled, your ETX Mak visual port may not be lined up.

For further info on collimating an ETX, I would recommend a visit to Mike Weasners Mighty ETX site, www.weasner.com/etx

Thanks Philip! I will check out Mike's site.