Finder Scope Questions

1. Is a "Straight Through" finder the same as a "Correct Image" finder? correct image I understand: It ain't updside down and backwards.

2. How is a finder used when it is too large of a diameter to be able to see with the unaided eye what you are zeroing in on? I can't find a thig if I can't see both images.

3. Uh, based on #2, how in the world is a right angle finder used?

4. On Telrads....I love mine. Our club has one that the red circles move around based on what angle you view from, so it is impossible to find anything, because anything is in the field can be centered by simply moving your head....Mine does not do this. What could be wrong with theirs?

Randy

Randy
Having struggled through the use of straight through finders, erect image finders and right angle correct image finders, my choice is to have a telrad type finder to place me in the sky, then a correct image right angle finder to precisely locate my target.

The correct image finder provides a view that matches my star charts, whereas the erect image finder provides a mirror image which I find very difficult to use. Others seem to have mastered this problem since their scope may also be mirror image. My dob on the other hand provides an image rotated 180 degrees, which only requires me to rotate my star chart.

I could print my star charts mirror image then use an erect image finder, but that would cause me to reinvent my process.

A straight through finder on my dob is very difficult for me to use since it requires placing my head next to the tube, which can be very difficult at certain viewing angles. In addition, I have opted for a larger finder aperture (70mm) since a lot of my viewing is done in light polluted skies at home. Really comes in handy when the seeing is mag 4.

Hi,

I think there are many good answers here already, and if it's any help here is my rather long review of the SV50 right angle correct image finder, and why I like it.

http://www.astromart.com/articles/article.asp?article_id=585

Timm