Info On Carton Adlerscope 80mm (1 Viewer)

Anyone ever heard of these? There's one local to me for sale and I can't find much info on them. Looks to be made in Japan maybe in the 60's/70's.

Hi,

Carton built slow focal ratio astro refractors until the 80s - they are quite well regarded. The Adlerscope spotter is a fast achromat (f5.3) and will probably not perform well beyond 40x or so.

Joachim

I remembered an "Adlerscope" 80mm spotting scope used to be sold by Orion Telescopes in the 1980s. I found it in an old catalogue from January 1989 (Carton was one of Orion's OEMs at the time). As Joachim mentioned it was an ordinary achromat priced at $529 for the body with a 25x wide-field eyepiece (2.8º field, 16mm eye relief). Three other eyepieces were available: 15x (3.6º field, 17mm eye relief), 40x (1.7º, 13mm eye relief) and a 20-60x zoom (1.7º-1.1º, 11mm-5mm eye relief - that's right 5mm!).

The $529 price made it quite an expensive achromatic spotting scope in 1989. At about the same time an Eagle Optics price list shows the Kowa TSN-1/2 achromats with 20x wide-field eyepiece selling for $468 (the Fluorite TSN-3/4s with the 20x eyepiece were $888) The Alderscope had one unique feature. It used first surface mirrors instead of prisms for its erecting system. That gave the erecting system housing a bulky faceted appearance. There was a large focusing collar, which must have moved a mirror or possibly a focusing lens (which would have been unusual for the time).

I can't figure out how many mirrors were used or how they were arranged, but even the simplest possible arrangement would have required at least two mirrors, probably aluminized, with a resultant large light transmission loss. Personally I would only be interested in one of these as a curiosity and then only for less than $100.

Henry

Hi Henry,

ah yes... the "Alderscope" of Better View Desired fame... let's just say it didn't do too well in their test...

And it was sold under several labels - I also found one labelled Bresser...

Fully coated (as opposed to multicoated) plus the mirrors will further reduce the image of the fast achromat.

Joachim

I had forgotten about the BVD review, Joachim, even though Mr. Ingraham allowed yours truly to spout off at length in the middle of it! It must have appeared before May of 1991, since that's when I replaced the Tak FC-76 with an FS-78 as my birding scope.

http://betterviewdesired.com/Scope-Fever.php