Problems focusing Nexstar 5

[tom33pr]

Folks,

My s/h Nexstar 5 has just arrived.

I took it outside to do the alignment and when pointing at a very remote tree (noon time) I noticed that I can focus the scope on the tip of it fine, except the image it produced wasn't as sharp as I would expect.

I had done that previously with different scopes and I was able to resolve much more detail than in this case.

I mean the detail is there - it's just a bit too hazy...

My guess is it is out of collimation... I tried to adjust the screws ever so slightly but it didn't help. I gave up after a few minutes - it is probably not the best idea to mess around with the screws using the tree as the point of reference.

Any suggestions?

Thanks in advance.

[DirkSteele]

If collimation is the issue, you will need a point source to bring it back into alignment. A simple device known as a Duncan Mask is quite helpful for collimation of an SCT. The link below provides the template and instructions of use.

http://www.astrovox.gr/forum/download.php?id=17658&sid=646453d99bbd6eef6845f3d3254b6ff9

Clear skies,

[tom33pr]

Thanks dirk.

Had it out for a quick test and star-collimated it.

It was a bit off, but after a few tweaks the offset appeared perfectly round.

I'm pretty confident it is fine collimation-wise; however, the lack of sharpness on detail when looking at a remote tree this afternoon, still concerns me... Needs more investigation

Anyway,thanks again.

[Sobel]

Perhaps it was the atmosphere?

I too tried aligning my 8SE on a distant tree the other day, even at low magnification in the strong sunlight the seeing conditions terrestrially were very poor.

I too found that collimation was fine when I took it out later that night.

[mikehab]

I get exactly the same effect on my 4SE when focussing on a distant tree - exactly as you describe.... yet when testing on a star it seems to be perfectly collimated. Weird isn't it...?

[tom33pr]

It is weird...

I must say I was a bit worried until I took it out last night.. As I mentioned I ended up with perfectly round offset pattern plus the stunning views of Jupiter and a few Messiers kind of convinced me that everything is ok.

Out tonight again...