Product Description

The Vixen ED 100Sf APO refractor features high-grade glass and quality components. Coupled with a medium f/9.0 focal ratio, the ED "S" series provide a sharp, color-free image of high contrast. For the astronomer that wants the best value for the dollar in a 4" APO, this is the one to buy. Apochromatic refractors from Vixen have extra-low dispersion (ED) lenses that depress residual aberration to achieve a high level of performance. The ED100Sf features a Crayford focuser for smooth operation without backlash. Performs nicely on the Porta Mount for visual observing or as a travel scope, or mount the OTA to a larger telescope for use as a guidescope.

Product Details

• Brand: VIXEN
• Dimensions: 39.60 pounds

Features

• Crayford focuser for smooth focusing without backlash
• Coupled with a medium f/9.0 focal ratio
• Provides sharp, color-free image of high contrast
• For the astronomer that wants the best value for the dollar in a 4" APO, this is the one to get.

Customer Reviews

Excellent value ED refractor
I am using this telescope on a different mount (Losmandy GM-8) so I can't comment on the whole package - although, given Vixen's reputation for making good mounts the porta-mount is probably very nice.

Anyhow, the optical tube assembly is probably the best value 4" visual refractor out there. I note excellent sharpness and color correction is to my eyes 99% as good as a real triplet APO (I've looked through Taks and AP's), which is plenty good enough for visual observations. Astrophotographers may have even stricter needs but I don't know much about that.

I think a perfect example of one of the slightly more inexpensive Chinese ED doublet f/9 refractors may have about the same performance, but the problem is making sure you get a perfect example. For the extra $200 or so you get Vixen's excellent quality control. I'm no star test expert but I estimate around 1/8 wave spherical correction which is excellent. Also in characteristic Vixen fashion the mechanics are solid - the tube has a nice finish, the finder mounting is secure and easily adjusted and most importantly, the focuser action is excellent.

I'm delighted with this scope and consider this to have been a good purchase. Vixen products were nearly unavailable in the USA for a few years there due to distribution problems so I am very pleased to see this great company's products back on the market.