My DiY 2. Non-tilting Eyepieces

[DragosN]

For many years I was looking to a solution for a simple problem, which is usually not very disturbing, but can degrade the image quality of our telescopes, both visual, but especially in astrophotography.

When we are tightening the locking screw of the barrel which hold the eyepiece or the accessories, these  tilted, and worse, are decentered from the optical axis. The tilt is not big, as you can see in the photos attached, maybe half a degree, but, especially is there is a chain of accesories, can do damage.

Obviously, in recent years, there have been some solutions, but not all are good, and others are somehow expensive. For example, barrels with a compresion ring inside have very small efect to correct the tilting, especially for 1,25'' eyepieces, and none to correct the decentering. I used one of this for making the photos, and the tilt can be clearly seen in the second photo, like a gap on the left side.  I must say that the Vizen eyepiece has received his ''treatment'' only after it served as a model for the first two pictures.

The solution is simple. For those eyepieces, or accessories, which have a groove on the barrel, put in that trench a layer of  adhesive velvet. The eyepiece will stay centered, the heavy 2'' diagonals will not rotate itself when are not very well locked. Unfortunately, depending on the groove position and size, tilt does not always disappear. Sometimes are disappear altogether, sometimes only be reduced. But even so, I think that is a plus, especially for astrofoto. The downside, mostly visually, is that eyepieces and accessories equipped in this way, go in and come out of the barrel  with a little effort. But can't fall down.

And another thing. We all have problems with missing caps for our eyepieces. A good replacement for the 2'' eyepieces are photo lens caps for lenses with 49m  filter thread.

[DragosN]

I had to add something. This could be very useful for collimators. But I don't have a collimator with groove on the barrel. I've seen the Hotech laser collimators which has rubber rings, but none other.

By the way. I don't know how to edit a post here. Can someone help me?