Quote:
Originally Posted by Legin
Hello,
I was wondering what is the actual limit on how wide you can go with a scope. I currently have a nice 28mm, 2 inch eyepiece and love the nice wide field views it gives. The scope itself is a 12 inch Newtonian that has a focal length of 1500mm, f/4.9.
I have heard that the widest you should go is approximately 1/5th your focal length. Then you may get interference, I am not sure what you call it but basically the reflection of the primary mirror begins to appear in the eyepiece and can really ruin to wide a view.
I am still relatively new to the eyepiece game so any advice will be great. I get the basics eye relief, focal length, magnification etc. Just checking out my limitations   |
I should have mentioned 5 time the F/stop not the focal length. So my scope being f/4.9 would be about 25 mm.
It should be noted I have tried a 42mm in this scope and it works great for visual work. I have no luck for eyepiece projection though. I suspect it is just luck that I see anything other than the primary mirror, as nice and shiny as it looks.