Re: [APML] Two More Wide Field Images

[Ray Butler <ray.butler@nuigalway.ie>]

> Yes, the filter is a 72mm Ha interference filter with a FWHM of 15nm.

So this must be a rear-mounted filter on that LF lens, right? Because 9 
inch focal length at f2 = 230mm f2 = 115mm aperture, at a minimum. If 
the filter were front mounted, the f-stop would really be 230/72 = f3.2. 
(But that's still pretty fast!)

Technical details aside, Bob's images are amazing. What a shame that LF 
and MF options are beginning to dwindle - both the films and the 
hardware. Tamron have just announced that the entire range of Bronica MF 
cameras will no longer be manufactured. On the other hand, Mamiya have 
just announced the Z2, a 36x48mm digital back/camera, compatible with 
all their M645 lenses.

Ray "whose enthusiasm for the future power of digital is sorely tempered 
by the way it is eradicating film-camera options" Butler


> Chuck
> 
> ----------------------------------
> 
>> Spectacular image Chuck. Boy am I going to miss Tech Pan :(
>>
>> Are you privy to any of the deatils regarding the filter ?
>>
>>
>> Regards
>>
>> Bill
>>
>> -- 
>>
>> William R. Mattil  :  http://www.celestial-images.com
> 
> 
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-- 
Dr. Ray Butler (ray.butler@nuigalway.ie || ray@physics.nuigalway.ie)
Lecturer, Dept. of Physics || Computational Astrophysics Laboratory
National University of Ireland, Galway, University Road, Galway, Ireland.
Tel: +353-91-524411 ext. 3788   FAX: +353-91-525700

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