[Aavso-photometry] DSI Wide

[Mojo]

Hello All,

I have been able to attach an older universal thread mounted SLR lens to the 
DSI. The threads are the same or close enough to work. The filter cradle is 
attached. In order to get a focus, an extension tube about 3/4 inch long, is 
placed between the lens and the filter cradle. The only lens I have with the 
universal thread is a 55mm f/1.4. Older lenses made by Pentax, Ricoh and 
Mimaya (not sure on the spelling) will work. I have been trying to find wide 
angle lenses around 28mm or so and telephoto lenses around 135mm to 200mm 
but no luck. Have seen some on Ebay but have not bought any. The 55mm lens 
gives a good shot of M31 at about a 4 degrees by 5 degrees field. I do not 
have much spare time and good clear nights are few so I'm under the learning 
curve and the photos are not as good as expected. More operating time is 
needed. Actually, using the 55mm lens has been my way of learning to use the 
DSI. Telescope mounting will come later.

As for photometry, AAVSO has a recommended arcsec/pix image scale ( 2-3 or 
3-4, I do not remenber actally what it is) but that would require a much 
longer focal length than most camera lenses. How feasable would a 55mm lens 
or even a 200mm lens be for photometry?

Thanks,

Gary Huffman




----- Original Message ----- 
From: "Keith Robinson" <starlightskies at talktalk.net>
To: <aavso-photometry at mira.aavso.org>
Sent: Friday, December 14, 2007 12:52 PM
Subject: [Aavso-photometry] DSI Wide


> Hello All
>
> I've been trying to get hold of a 'DSI Wide' cradle for the Meade DSI Pro 
> together with adaptor for Olympus lenses. My efforts have been utterly in 
> vain. Anybody any idea where it might be possible to get one of these?
>
> Many thanks
>
> Keith Robinson
> _______________________________________________
>
> Aavso-photometry mailing list
> Aavso-photometry at mira.aavso.org
> http://www.aavso.org/mailman/listinfo/aavso-photometry
>
>