I was finally able to set up the WO flt-132mm the other night for a couple of quick snapshots. I took a 3 second shot of Aldebaran on a modified dslr. I cropped the star image so we could see it clearly. I am wondering what is causing the dark lanes at 120 degree angles? Is the normal, I checked optical aberations on the net and I do not beleive it is pinched optics? But would love this group to offer insights.
This is an air spaced lens, yes? When you look through the front of the lens can you see three little spacers at 120 degrees? That could easily cause what you saw. If so, nothing at all to worry about.
Yes those are the lens spacers. But perhaps a bigger question is why there is so much light out there to make a dark spike. I might suspect the lens has some turn-edge or roll-off right at the edge.
If you can make two more images of a star like that. But set 5mm inside best focus, and another image 5mm outside best focus, it would be very instructive. Some of us over at http://tech.groups.yahoo.com/group/roddier have been doing this Roddier test on our telescopes. You would probably need a tracking mount (drive) to do it -- maybe you are using one already.
Another approach would be to somehow mask off the outer 2mm of the lens, and see if the spikes go away, and whether images suddenly seem much sharper. Maybe get a cardboard and cut a 125mm hole in the middle.