Bloated Stars

[hobsey]

Last night I had my first proper go with the Star Adventure.

Looking at my subs this morning I was not impressed with the bloated stars in the images.

Is it down to my settings which were 2 minutes unguided, ISO 200, f4 at 200mm or is it the lens causing it?

Here is a dirty JPEG as I can't figure out how to up load a high-res verison.

[hobsey]

Hopefully this will work, a higher res verison.

http://astrob.in/141616/0/

[johnrt]

This is caused by the poor colour correction in the lens which you used. The optics cannot bring all colours to focus at the same point so you get bloated stars.

[hobsey]

Cheers for that, thought it may have been the lens.

I will try out a better lens next time, just glad I managed 2 minutes unguided without trailing.

[lensman57]

Cheers for that, thought it may have been the lens.

I will try out a better lens next time, just glad I managed 2 minutes unguided without trailing.

It is a combination of CA and probably poor focusing I regret to say. Some of the CA can be removed during post processing but there is little that can be done about the focus.

Regards,

A.G

[hobsey]

It is a combination of CA and probably poor focusing I regret to say.

I wouldn't be surprised to be honest as its a vintage lens using an adapter.

Think I may just try using proper canon fitment lens as I also couldn't get my vintage 135mm M42 focused properly.

[wxsatuser]

I wouldn't be surprised to be honest as its a vintage lens using an adapter.

Think I may just try using proper canon fitment lens as I also couldn't get my vintage 135mm M42 focused properly.

I have several vintage lenses and they all are similar.

I don't now bother with them as imaging time is precious.

I know others have the same lenses and get good results but mine just don't cut it.

[hobsey]

Wish I had tried out the 70-200mm f4 now as I it could be a while until I try again.

[lensman57]

Wish I had tried out the 70-200mm f4 now as I it could be a while until I try again.

It is supposed to be a decent lens for AP. I have yet to try mine. Make sure that the lens is properly cooled down and that you refocus after zooming in or out .

A.G