Ross Stepmur 10x50

Mfr: Ross, London, England

Date: circa 1960?

AFOV: ~70 degrees

TFOV: 7 degrees

Eye Relief: ~14mm

Prisms: Porro II

Serial Number: 152037A

The Stepmur is a wide angle, center focus, 10x70 in the Porro II configuration.  I find the long body very comfortable to hold.  I am not sure why, but the sample shown here has an "A" at the end of what appears to be the serial number.

I find the Stepmur to have a fairly good, well corrected wide field image with an acceptable amount of astigmatism and distortion at the field edge.  However, there are a couple of very noticeable light and prism leakages in the image, reducing the contrast.  The measured eye relief is good for a 10x50 but unfortunately much of it is wasted by the fixed, deep eyecups.