Erfle Eyepieces

Why are Burgess Optical Erfle Eyepieces better than standard Erfle Eyepieces?

We started with a classic 5 element Erfle design then added High Index glass (or in the case of the 39mm - Ultra High Index glass). This allows for more efficient bending of light. We addressed the common problem of inferior edge performance that is in the classic Erfle design by splitting one of the doublets. With these modifications we were able to achieve 5 element eyepieces with sharp star images to the edge of the 67-70 degree FOV (field of view) and 90 degrees FOV for the 39mm eyepiece. This eyepiece design uses no barlow elements, thus eliminating magnification change across the entire field which reduces curvature of field. The only drawback to our Erfle design is it's short eye relief which makes producing high power versions of the eyepiece impractical.

16mm Erfle Eyepiece

Construction

Height - 65mm (56.5mm with eye cup down)
Width - 44mm @ Eyecup
Weight - 76 grams
Barrel Size - 1.25"
FOV - 67 - 70 Degrees
Eye Relief - 14mm

Features

5 Element Modified Erfle Design
18mm Field Stop
Fully Broadband Multi Coated
CNC Machined Barrel
Laser & Mechanical Engravings
Fully Baffled Low Barrel to Reduce Stray Light

24mm Erfle Eyepiece

Construction

Height - 80mm (73mm with eye cup down)
Width - 48mm @ Eyecup
Weight - 188 grams
Barrel Size - 1.25"
FOV - 67 - 70 Degrees
Eye Relief - 18mm

$99

Features

5 Element Modified Erfle Design
26mm Field Stop
Fully Broadband Multi Coated
CNC Machined Barrel
Laser & Mechanical Engravings
Fully Baffled Low Barrel to Reduce Stray Light

35mm Erfle Eyepiece

Construction

Height - 120mm (109mm with eye cup down)
Width - 60mm @ Rubber Grip Ring
Weight - 460 grams
Barrel Size - 2.00""
FOV - 67 - 70 Degrees
Eye Relief - 18mm
Out of Stock

Features

5 Element Modified Erfle Design
39mm Field Stop
Fully Broadband Multi Coated
CNC Machined Barrel
Laser & Mechanical Engravings
Fully Baffled Low Barrel to Reduce Stray Light