Has anyone come up with a clever solution how to reduce the amount of dust coming into the tube, some of it eventually landing on the lens? I guess it comes in through the gap in the focuser. Would some sort of felt filling the gap help?
The thing is - while the lens on the SW80 is easy to clean, the TS102 is not. The lens cannot be unmounted without having to adjust the collimation, and is difficult to wipe from the inside due to the length of the tube. Maybe vacuum cleaner...?You are right, I forgot about the gap caused by the long track on the focuser tube...
If I may, I would suggest you stay away from electrical tape because, after some time, it will leave sticky glue on the contact surface. I use masking tape to lock the IS switch on my 100-300mm lens and it performs well without leaving any residue.
Personnaly, I'm not too worried about small dust particules on a lens because they can't be seen on the photo most of the time. Also, they are quite easy to remove if they bother me. Same for the scope, both inside out.
The thing is - while the lens on the SW80 is easy to clean, the TS102 is not. The lens cannot be unmounted without having to adjust the collimation, and is difficult to wipe from the inside due to the length of the tube. Maybe vacuum cleaner...?
Jules,Tord
I didn't know that. Now I understand your concern. I hope you will find a fix.
If it were mine, I would try this:
- Use camo tape over the fixed joints. The type that extends and sticks only to itself.
- Try a rubber balloon cut as a cylinder over the moving joint of the focuser. It may just work...
Good Luck
Jules
Jules,
I tried the balloon thing and it does not work, the material is too weak and will not resist scratches.
What I did instead was to cut a cylinder from a discarded neoprene glove, secured it with duct tape and wrapped the duct tape in camo tape. Looks quite OK and seems to to the job. Had it on during a full day session and as far as I can see no dust entered the scope (I had the lens blowed and cleaned prior start). So I will leave it on for some time and run a long term field test. "Spring force" is however increasing when focusing towards full contracted focuser (which contracts the cylinder) and when reaching the last cm or two the spring force is higher than the focuser friction will withstand. However on my TLAPO804 + CNC prime focus adapter + 80mm extension tube I reach infinity with the focuser extracted about 2 cm so it is not an issue as such.
Possibly a dish washing glove would work, should be more resistant to scratches than thin ballons. Will try that on the TS102 (it has a 3" focuser so need a larger diameter). Or maybe use a cylinder cut out from a discarded neoprene wet suit or something like that.