FOV Calcuations

[Grimmeister]

Hi All,

I am hoping someone can help me work out what my FOV is on my AP set up, I have run the maths but don't believe the result I am getting.

I have the following set up on the main imaging scope:

William Optics Megrez 90 http://www.williamoptics.com/telescopes/megrez90_spec.php F6.2 (90mm * 558 MM long)
William Optics Field Flattener 4 http://www.williamoptics.com/accessories/flattener4_features.php (0.75 - 0.8 * Power)
Canon EOS 600D (no point linking this one :) )

So my main issue is how to work out what the field of view becomes once I add the Flattener as it is a 0.75 - .08 * power and adds lenght to the image path. Also I have read by some that this is not actually a ~0.75 * power and more like a 1.18 * Power????

If any one is able to assist I would be most grateful as I want to plan the targets I can image (with good detail) and fill most of the field of view.

Thanks in advance for your help.

Cheers

Anthony

[rainwatcher]

I have given up using calculations for FoV, some seem OK and others not - probably me. For all my stuff i have simply taken photos or used live view on my computer and measured it on a start chart.

[Merlin66]

Use Craig Stark's freeware CCDcalc.
It will show the FOV with many scope/ camera combinations

[DJT]

try this vrom the sky at night. It also adjusts for focal reducers etc and cameras.

http://www.skyatnightmagazine.com/astronomy-tools

[Grimmeister]

Hi All,

Thanks for the ideas, I will check these out to see what fits best.

Cheers

Anthony