Nice Idea for Planning Observing Sessions

[Darthdad8409]

http://www.skyandtelescope.com/astronomy-resources/using-a-map-at-the-telescope/

So I came across this article and I was thinking that it would be nice to make wire guides that I could put on my star chart to get an idea of what I should be seeing in my scope. The only problem is that I have read the article 20 times now and still can't figure out how to make the wire guides.

The first wire guide that I wanted to make was one for my 25 mm eyepiece. The focal length of my telescope is 1250 mm.  I am thinking that I just need to find the field diameter of my 26 mm eyepiece. Then figure out that translates to a length in millimeters based of off the scale of my star chart. Then it would just 2*PI*R from there.

Any help would be greatly welcomed

[Helen]

If you try this http://astronomy.tools/calculators/field_of_view/ and plug in your equipment then one of the things it calculates is the field of view.  You can use that to work out how much of your chart you can see

Helen

[AndyWB]

I just drew circles of the required diameter on acetate, and put that on my star chart.

[Martin385]

Thats an awesome link Helen,  been playing around with it (cloudy skies for the last few evenings)

Input my various  optics, and gives me an idea what i should be getting regards viewing

regards

martin

[Helen]

Thats an awesome link Helen,  been playing around with it (cloudy skies for the last few evenings)

Input my various  optics, and gives me an idea what i should be getting regards viewing

regards

martin

Credit to the guys at FLO