Zeiss Jena D.F. 7x50 "Gas Mask Oculars"
Mfr: Carl Zeiss Jena, Germany
Date: WWII
AFOV: ~51 degrees
TFOV: ~7.3 degrees
Eye Relief: ~24mm
Prisms: high index
Serial Number: 2072622 (dated 1940 according to Seeger)
This version of the Zeiss 7x50 WWII service glass has "gas mask" or high eye relief oculars. The large eyepieces have sliding rubber eyecups (worn away on the sample shown). This particular sample has a leather eyepiece cover attached with a metal elastic material (covered in fabric). There is a reticle on the right side with vertical and horizontal tick marks at "10 20 30 40 50/16°". The optical coatings have a bluish purple tinge.
This sample of the gas mask 7x50 is marked "Scheinw. u. Fluwa." indicating it was issued for use for searchlight and antiaircraft watch. Markings found on other versions of this model indicate their use for artillery and coastal flak units.
The 7x50 with gas mask oculars is very comfortable to view through, even with glasses on. The apparent field of view, though moderate, seems larger than it is probably due to the exceptional eye relief. The image is well corrected and sharp nearly to the edge. Additionally, this binocular is fairly light in weight and easy to hold. In my opinion, modern commercial makers have not surpassed the performance of the Zeiss gas mask 7x50.