From: Milton Aupperle <milton@outcastsoft.com>

Date: November 18, 2009 9:47:10 PM MST

To: Astro_IIDC@yahoogroups.com

Subject: Re: [Astro_IIDC] Leonid cam [1 Attachment]

Hi Willie;

Almost all IIDC cameras use a C (or CS) threaded mount, as do most higher end Security cameras and old 16 mm movie film cameras too.

http://en.wikipedia.org/wiki/C_mount

The difference between them is that CS mounts have a 5 mm shorter flange distance. You can buy 5 mm extender rings to conert a CS into a C mount too.

To see 120 degrees, need a lens that is about 50% shorter than the lens you found in the drawer. I'd check to see if the lens has anything written on it about focal length and then you'll know what focal length to get. You likely can also check e-bay or your local used camera store too.

HTH..

Milton Aupperle

On 18-Nov-09, at 9:25 PM, Willie Strickland wrote:

I purchased the DMK used and it came with a nosepiece.  I unscrewed the nosepiece and attached a security camera lens which I found in one of the drawers at the observatory.  The security camera lens has the same threads as the nosepiece.  It only gives me about 80 degrees of view.  I would like to find a lens that could give me 120 degrees or more.

Willie