FOV on Canon 350D with C9.25 f/10

[cygnusx1]

I'm trying to determine the fov size on my images with above setup.

From the pics it looks ~ 1/2 degree.

Does that sound about right?

Any way to actually calculate it precisely?

[GazOC]

arc seconds per pixel = 206*pixel size(microns)/telescope focal length (mm)

[cygnusx1]

arc seconds per pixel = 206*pixel size(microns)/telescope focal length (mm)

Hmm according to my calculations that would mean

arc secs / pp = 206 * 6.3 / 2350 = 0.56

The lcd size is 115000 pixels or 339x339 pixels

That equates to 339 * 0.56 ~ 189 secs ~ 3 mins

I can't believe the field of view on the image is only 3' x 3' !!

[GazOC]

I don't about the camera specs but the equation I gave is correct...trust me!

Is the LCD size in pixels the same as the chip size in pixels?

[GazOC]

Try plugging 3456 x 2304 into that equation, I think thats the Canons chip size?

[Kaptain Klevtsov]

Try this that I wrote

http://www.gas.uk.net/FOV.xls

Kaptain Klevtsov

[jcm]

A very useful program is CCD Calculator by Ron Wodaski

http://www.newastro.com/newastro/book_new/camera_app.asp

This calculates FOV for any combination of telescope , camera , barlow , focal reducer etc.

It also draws the FOV frame on well known objects - M31 , M42 , M33 etc

I used it to work out if I needed a focal reducer with my Atik 16HR when imaging M33 - yep I do!!

John

[cygnusx1]

Thanks guys,

Gaz using your chip size data gives me a FOV of ~ 0.5 degree as i suspected.

KK, your spreadsheet backs this up.

jcm, link bookmarked!

[Kai]

A very useful program is CCD Calculator by Ron Wodaski

http://www.newastro.com/newastro/book_new/camera_app.asp

This calculates FOV for any combination of telescope , camera , barlow , focal reducer etc.

It also draws the FOV frame on well known objects - M31 , M42 , M33 etc

I used it to work out if I needed a focal reducer with my Atik 16HR when imaging M33 - yep I do!!

John

This is fast becoming the thing i check first before anything else when planning a imaging session.

[jcm]

A very useful program.

I believe it is still free as well.

John

[daz]

Yep still free and darned useful!!

[SteveL]

doh! just posted the same info in another thread... must read before posting...