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 )
•   82 mm piece of 92 mm sheet film
•   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.