FoV Calculator numpty question

[Shelster1973]

Am having a senior moment day today, so please accept my apologies.

As it is the usual perma-cloud here in Plymouth and am waiting on the Canon lens and Geoptik adaptor so that I can use my CCD for some wide field action on my Star Adventurer, am having a look at the FoV calulator and just wanted to double check my numbers.

For the focal length am putting in 50mm (is a 50mm lens I bought) and for the aperture I have put that in as 12.5mm as I intend to image with it at f4.....is that right?  Have basically divided focal length by the f number

[cloudsweeper]

Not sure about all the AP stuff, but f-no. = FL/aperture, so FL divided by f-no. = aperture.

Doug.

[Stu]

I'm not sure the aperture actually makes any difference to the calculations anyway (well, I'm actually pretty certain it doesn't).

The only thing which affects the field of view from the telescope or lens perspective is the focal length.

[StuartJPP]

As above, focal length is focal length so 50mm is what you need to use (unless you were using a reducer/extender of some sort). You also need the physical CCD sensor size.

To calculate arcseconds per pixel, you will also need the pixel size.

[cloudsweeper]

Sorry Stu - I should've known better than to reply to an AP query!   I was strictly just responding to the OP's final statement: Have basically divided focal length by the f number.

Doug.

[Scooot]

Have a look at this link

http://www.astro.shoregalaxy.com/dslr_calc.htm

You also need to input the measurements for your camera sensor to calculate its FOV

So as an example this is my canon with a 50mm lens. I presume you can get similar info for your ccd camera

[Stu]

1 minute ago, cloudsweeper said:

Sorry Stu - I should've known better than to reply to an AP query!   I was strictly just responding to the OP's final statement: Have basically divided focal length by the f number.

Doug.

Doug, I know very little about AP either!  

[cloudsweeper]

More than me anyway!! 

Doug.

[Scooot]

It’s also easier if you can use Sky Safari. You can just set up your camera in the equipment section with various lens and view the fov on a screen.

This is an example of my canon with a 50mm lens. FOV is the blue rectangle.

[StuartJPP]

18 minutes ago, Scooot said:

It’s also easier if you can use Sky Safari. You can just set up your camera in the equipment section with various lens and view the fov on a screen.

This is an example of my canon with a 50mm lens. FOV is the blue rectangle.

You can do the same with Stellarium if you haven't got Sky Safari.

[gtis]

2 hours ago, Scooot said:

It’s also easier if you can use Sky Safari. You can just set up your camera in the equipment section with various lens and view the fov on a screen.

This is an example of my canon with a 50mm lens. FOV is the blue rectangle.

I have sky safari pro and I have tried this I must be doing something wrong

[Scooot]

42 minutes ago, gtis said:

I have sky safari pro and I have tried this I must be doing something wrong

Add your lens to the telescope section in equipment.

Add your camera into the camera section

Then in display select the combination of camera & lens, and turn on the “show even if not connected to telescope” button.

see below, hope it helps.