Re: ATM 35MM- Camera

["Christopher J.R. Lord" <chrislord@brayebrook.demon.co.uk>]

----------
>From: JAMccaf4u@aol.com
>To: atm@shore.net
>Subject: ATM 35MM- Camera
>Date: Sun, Dec 12, 1999, 01:49
>

>
> Hi to all,
>          If you were to purchase a camera for astrophotography work what kind
> would one buy. Your help would be appreciated. If there are any sights that I
> might go to with more information please let me know.

Joe:

The ideal camera in my opinion is an old fashioned mechanical 35mm "System"
SLR. Provided that is, you intend to use it solely for astrophotography. A
"System" SLR has not only the facility to replace/remove lenses, but also
focusing screens and viewfinders.

There are several second hand models I could point out:

Ihagee Exakta Varex IIa (version 1 thru' 4 - 1957-58). This model is heavy,
being made out of nickel plated brass and steel. You can still find the
"Magnear" eyepiece magnifying viewfinder, and aerial focusing screens on the
collector's market. (What you don't need is the ground glass focusing screen
- it is far too coarse for astrohphotography). If you can't get an aerial
type screen (this has a clear centre spot and cross) try polishing the
ground side against a polished steel plate with 3000 grade flour emery,
until you get a dullish polish. Such a screen will give a slightly brighter
image. The real advantage of the good old Varex IIa is the built in cassette
to cassette loading and film knife, which enables you to change films in mid
stream. It was the ONLY 35mm SLR to have this useful device.

Pentax LX - no longer made but a much lighter model than the Varex. The
advantage of the Pentax LX is the much wider throat, and the accurate
metering (although this is no use for deep sky astrophotography of course).
I still use my LX for Lunar and planetary work. You can get aerial screens
and an eyepiece finder - and they're good value on the second hand market
nowadays.

Nikon (models from the original F1 to later - but make sure the viewfinder
is interchagngeable - not all Nikon SLR's have interchangeable viewfinders).

Canon F1 (old FD series breech lock bayonet) - ideal for fiddling around
with in the dark - built like a tank.

What I would avoid is the current generation of ABS bodied auto-everything
SLR's. They have all the features you don't need with perhaps the exception
of the Lieca and the Contax models - but these are way too expensive for
what you really need.

Of all the models ideally suited for astrophotography, my favourite is the
Exakta Varex IIa. It is robust (I dropped mine four feet onto a frozen
concrete floor - what happened - the floor got chipped!). No frills and no
nonsense. You pay only for what you need - and the mechanical quality of a
model freshly serviced and in good unworn order cannot be surpassed - not
even by the Leica.) However I would warn you against the later, cheap and
nasty Pentacon Varex IIa versions 5 thru' 8 made in 1959-61, and the IIb -
they are mechanically inferior to the older 1957-58 IIa. You can easily tell
them apart, the later IIa and IIb have a rectangular black escutcheon plate
instead of the curved nickel plated brass plate of the original Ihagee
models.)

Chris Lord
Brayebrook Observatory
Cambridge
UK