Software advice

[Moonboy (Gus)]

Hello everybody,
A few weeks back I was planning on buying some new eyepieces, so I did some research and found that I needed some simple equations to find out the Actual field of view and magnification.
(the equations are found here)

This is not a problem.
But doing the some equation's 10 times, for 10 different eyepieces to find out which eyepiece would best suit my telescope really bugged me.
So I decided to make a program to do all of the calculations for me .

I am still designing it and I would like some advice/help/ideas.
So far, it can calculate the magnification, FOV and focal ratio.

Please comment with any ideas, request's, anything, tell me if this would be useful or if I am just wasting my time
Thanks


P.S if there is already a program out there that does this sort of thing, please post a link to it

[RickS (Rick)]

Originally Posted by Moonboy

P.S if there is already a program out there that does this sort of thing, please post a link to it

Not meaning to be a smartarse, but: http://office.microsoft.com/en-us/excel/

[Moonboy (Gus)]

hahaha
Thanks for that.
That was the first program that I used to make this. But it ended up having infinite loops.
I wanted something that looked better then a spreadsheet so I choose to make it with visual basic.

[AstralTraveller (David)]

My spreadsheet doesn't have infinite loops. It's up to you but I think you are using a sledgehammer to crack a peanut.

[Moonboy (Gus)]

hahaha
yeah, I do tend to over do things
Could you possible zip that spreedsheet and upload it for me
thanks

[h0ughy (David)]

try openoffice - its free but as for the field of view do a search on IIS

[Allan_L (Allan)]

Hi Gus,

Did you post a link for your program?
or did you abandon the project due to negative feedback?

I was interested to have a look.

[Barrykgerdes]

The occular plug in in stellarium does this calculation for you and will then display a window of your selected area.
Select configuration-plugins-occular-configure and fill in the boxes
It needs FOV of Eyepiece
Focal length of eyepiece
Focal length of scope
Orientation up down true or reversed
Barry

[Octane (Humayun)]

^^^

I think he just wanted to write a standalone program.

H

[Moonboy (Gus)]

Originally Posted by Allan_L

Hi Gus,

Did you post a link for your program?
or did you abandon the project due to negative feedback?

I was interested to have a look.

No, I did not post a link for it. I am still developing it
I will post a link when it is completed.

Originally Posted by Octane

^^^

I think he just wanted to write a standalone program.

H

And yes it will be a standalone program.

Thanks for all of the comments

[AstralTraveller (David)]

Originally Posted by h0ughy

try openoffice - its free but as for the field of view do a search on IIS

I did say spreadsheet - not Excel file.

[Moonboy (Gus)]

I have just completed it
Please give it a go and post some feedback
Just unzip and run it

Thank you to everyone for your comments

[AstralTraveller (David)]

Originally Posted by Moonboy

I have just completed it
Please give it a go and post some feedback
Just unzip and run it

Thank you to everyone for your comments

It won't run under Linux! Actually not even under Wine. Does it require a specific version of Doze? Does it need .NET?

[AdrianF (Adrian)]

Good program. I will use this one.
As for the negative feedback how many times have the wheel
Been reinvented? Each time just a little better.

Adrian

[scopemankit (Chris)]

Make the FOV reading more comprehensive - eg, give it as arc mins etc but also in terms of moon diameters.

[Barrykgerdes]

I hate to be a wet blanket but isn't this a rather lenghty way to solve a simple mathmatical problem that can be handled by two steps on a hand calculator.

Divide the eyepiece manufacturers listed FOV (in deg) by the magnification F1/F2 to get the true field in degrees.

Or is it something I have missed. I could not run the program on my computer because it needed another .net program download as well.

Barry

[Moonboy (Gus)]

Originally Posted by scopemankit

Make the FOV reading more comprehensive - eg, give it as arc mins etc but also in terms of moon diameters.

Could you (or anybody who knows) please tell me the formula or equations to calculate this, as I do not know how to do it

Originally Posted by Barrykgerdes

Divide the eyepiece manufacturers listed FOV (in deg) by the magnification F1/F2 to get the true field in degrees.
Barry

This is true, but if you want a more accurate answer the equation that is attached. It requires the field stop of the eyepiece, which isn't always given by the manufacturers. It is also a lot more accurate when the FOV is higher than 60°.

[Barrykgerdes]

Originally Posted by Moonboy

Could you (or anybody who knows) please tell me the formula or equations to calculate this, as I do not know how to do it .

1. The moon visual diameter is approximately 31 arc minutes but varies quite a bit depending on where it is in its orbit. This is probably nice to know for comparative purposes but needs other information for any accuaracy.

When the size is given in degrees and fractions multiply the decimal fraction by 60 to get minutes and the "rest" by 60 to get seconds eg.

FOV = .477 degrees 12" LX200 with 26mm eyepiece no field stops
x60 =28.62 minutes
rest .62
x60 =37.2 seconds
If it is given in Radians
multiply radians by 57.29577951 to get degrees.

In regard to field stops. Yes this is a factor that can be taken into account but will also need other information from the field stop. A calculator in most instances would need to default to "1" as a multiplying factor if this information is not published or otherwise available.

Barry

PS kowing the size of objects and your approximate FOV will show that most of the best DSO's do not need a magnification of better than 30x for the best views.

[Barrykgerdes]

Hi Gus

I downloaded your program but regrettably it does not work on any of my computers as it requires a different version of .net framework than I have installed so I don't know what results it gives.

Because I was interested I then wrote a short program in Qbasic to calculate the true FOV as per the formulae. This probably won't run on Windows 7 64 bit as it is compiled basic but seems to run OK on 32 bit versions.

Barry