Focal Length: 600mm; f/7.5
Finderscope: 9×50, straight-through
Telephone: 01582 726522
The Vixen ED80SF closely follows the Japanese company’s original ED80 scope design, which kick-started the whole 80mm refractor imaging movement back in 2003.
The scope’s tube consists of a dew-shield, main body and focuser.
Tube ring clamps are supplied with the scope and these are fixed to a Vixen-style dovetail mounting plate. A slightly loose-fitting plastic dust cap is included.
It also comes with a single-speed Crayford-style focuser.
We found this perfectly adequate, although its tension adjuster lacks a proper locking option.
With the tension adjuster tightened up and the scope pointing close to the zenith, the focuser was just able to hold our DSLR camera without it creeping out of focus, though for peace of mind we’d prefer a separate focus lock as well.
The scope comes in a foam-lined carry case, complete with an excellent 9×50 finder and a 90° flip-mirror unit.
This fits into the scope’s 2-inch eyepiece adaptor and gives you two 1.25-inch openings – one in line with the main optical axis and one at 90° to it.
A moveable 45° mirror can be flipped to divert the optical path from one opening to the other.
This allows you to use an eyepiece and a camera in the same setup; with the mirror diverting the image to the eyepiece you’re able to centre and frame your target visually, then when you’re done, you flip the mirror down and take the shot.
This useful device takes 1.25-inch barrel cameras, like small- to medium-sized cooled CCD cameras.
The Vixen ED80Sf delivers bright, vivid, high-contrast images and this showed well in our Orion’s Sword test sequence.
Red colouration in the main nebula showed up very well in our images (see above), as did the bluish hues of the Running Man Nebula.
The orange stars of the open cluster M35 also came out very well and the adjacent cluster NGC 2158 looked reddish in colour.
All in all, colour delivery from the Vixen was excellent.
We noted a slight elongation of stars toward the corners of the image frame but overall the results were very acceptable.
Once we fitted the Explore Scientific field flattener it produced round stars right into the corner of the image frame.
With our DSLR camera at prime focus, the Vixen gave a field measuring around 1.5 x 2.5°, which delivered an excellent crescent Moon.
Deliciously detailed, the Moon looked amazing hanging in the surrounding black expanse of space.
Our DSLR focused quite close to the end of the focuser drawtube’s travel.
Although this wasn’t a problem, it means that if you’re using a Barlow lens you’ll need an extension tube or diagonal as well.
But overall this is a fine, solid instrument and a good performer for astrophotography.