Can the finderscope of a telescope be mounted on the tube box rather than the tube itself?
farmgirl asked:
I built a dobsonian telescope and I want to attach a finderscope to it. I know that usually finderscopes are attached to the tube, but I was wondering if I could attach it to the top of the tube box instead as I want to avoid drilling holes into the telescope tube. Everything is in great alignment and precision, so there’s nothing to worry about there. I would just like opinion on where to mount the finderscope. Thanks!
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I built a dobsonian telescope and I want to attach a finderscope to it. I know that usually finderscopes are attached to the tube, but I was wondering if I could attach it to the top of the tube box instead as I want to avoid drilling holes into the telescope tube. Everything is in great alignment and precision, so there’s nothing to worry about there. I would just like opinion on where to mount the finderscope. Thanks!
January 23rd, 2009 at 10:20 am
Congratulations on building your scope. That is quite a nice accomplishment, If you mean the box down by the mirror? Sure, as long as it is convenient for you. BTW one of the very popular finders is the Telrad. You can attach it with double side tape that comes with it and it never will get unstuck. You dont have to worry about drilling a hole in the tube.
January 23rd, 2009 at 12:08 pm
As long as the finder moves with the main optical aaxis, it should be OK. But putting the finder down there will make it extremely inconvenient to use, since you need to place your eye behind the finder in order to aim it. For that reason I always recommend putting the finder as _high_ on the telescope tube as possible, to minimize the amount of movement needed to get to the finder’s eyepiece.
January 26th, 2009 at 3:13 am
Cool.
OK, so you have a box on the tube that is near the axis of rotation? Consider where your head is going to be, and how difficult it will be to keep it there. IMO, even the best designs often don’t get this right.
One home made Newtonian Dob has a longer than required tube. The finder is mounted in front of the main eyepiece so that the 90 degree finder eyepiece is right next to the main scope eyepiece. That way you can go back and forth easily. I wonder if the owner is left eye’d or right eye’d.
I’m left eye’d. My finder scope is clearly mounted for right eye’d people. How would I fix it? I’d put the focuser on the right side of the tube and put the finder above it and slightly behind.
Which eye’d are you? Which eye goes to the eyepiece? That’s all.