ASH LURIE 200 - films & filters
The field in a Lurie camera and a Schmidt camera is curved. The
filmholders for the ASH LURIE 200 are designed in such a way that the film is
automatically curved in the necessary radius. They can be very easily
mounted in the
camera and held in place by a magnet.
Easy positioning of
the
filmholders and filters
The following filmholders are available for the ASH LURIE 200:
- 24x36 mm piece of ~ 50 mm long.
- 24x36 mm on roll ( in preparation )
- 56 x 56 mm (6x6) piece of sheet film 2,5” (63,5
mm)
- 56 x 56 mm (6x6) on roll ( in preparation )
- Æ 82 mm piece of 92 mm sheet film
- Æ 90 mm piece of 100 mm sheet film.
The largest filmholder with a diameter of 90 mm covers an astonishing 10,3
degrees. Standard 2" filters can be screwed onto the smallfilm filmholders.
For the larger filmholders 82 or 95 mm filters can be used.
The filmholders are high-precision components. At f/2,5 the focal distance
must be accurate within 0,01 mm even with the change of temperature. In the
camera there is a small hatch that can be opened to mount the filmholders. They
are kept in the exact position by magnetic force. Provision has been made for a
supply connector to add protection gases during exposure.
Filmholders and
filters
Because the filmholder attachment has been mounted on the inner corrector plate, the images
are totally free of any spider effects around bright stars. A feature that is
common in conventional telescopes.
The ASH LURIE 200 is temperature compensated. Three invar rods in
combination with the Astro Sital mirror guarantee accurate positioning of the
focus independent of temperature.
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