Hi James, welcome to the list. I'd agree with Erik that cost certainly figures into the lack of choice on commercial right-angle finders. However, neck-pains aside, there is another reason that they aren't more widespread in use. Straight finders inherently have you looking in the direction the telescope is pointing. Referencing the telescope against the target area on the sky is an intuitive operation. Think of trying to aim a rifle with a right-angle scope. Not as easy as it was when you were sighting down the barrel before you put your eye to the scope. You are already in the general neighborhood of the target. I use both straight-through and right-angle finders, depending on the main scope I'm using at the moment. I generally prefer straight-through for the sake of expediency, even though one must do a bit of contortion at times. I find it very easy, keeping both eyes open, to superimpose the cross-hairs in the finder with the spot in the sky I think the target is at. After all these years, I'm almost always dead-on. You can't do that with a right-angle finder. I suppose what I do with both eyes open is a sort of mental reflex sight. When using a right-angle finder, I still must sometimes sight along the main tube just to get the scope in the neighborhood of the target, before going to the finder eyepiece. A mirror-reversed image is much harder to mentally flip than a simple inverted image, at least for me. YMMV. A correct-image right-angle finder helps this problem. Red-dot reflex sights still have you putting your head in the same positions as a straight through finder. Probably the easiest finder I have ever used, regardless of scope or mount type, is a green laser mounted as a finder, in an adjustable bracket. I have a momentary switch on a long cord so you don't have to push on the laser button itself while using it, which may disturb the telescope's aim. It essentially gives you an infinitely long pointer. You just place the end of the pointer (laser beam) on the spot on the sky where your target is. No head contortions at all. Hope this helps. C. On Sat, Jun 23, 2012 at 7:08 AM, James Harvey <wyominggeezer@gmail.com>wrote:
My questions are:
1. It seems that there are few right-angle finders on the market. Why? 2. Could one use a "standard" finder scope and mount it at right anges with the use of a mirror? In other words, mount a mirror on the scope to direct the sky image away from the scope at a ninety degree angle and use a finder scope to look into that mirror. Could this not be a $10 solution to a $90 problem?
This is my first post here so, if there is a FAQ somewhere on this topic, please let me know.