Scopetronix Zoom 7mm-21mm

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Brand and Model:Scopetronix Zoom 7mm-21mm
Price ($USD):$64.95
Type:Zoom
Focal Length:7-21 mm
Barrel Size:1.25 in
Apparent FOV:50.0 degrees
Field Stop Dia.:0.0 mm
Eye Relief:0 mm
Elements:0
Weight (lbs):
Description:

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Scopetronix Zoom 7mm-21mm
I picked up this Scopetronix Zoom used for just $35 on Astromart because I wanted to see if I liked using a zoom. First impressions are that it quite small and lightweight. FOV is 40 degrees at 21mm and a wide 60 degrees or more at 7mm. The coatings are very good with low surface reflectivity - similar in appearance to my Ultimas and Vixen LV eyepieces. The zoom action is solid and silky smooth. Eye relief was quite generous at 13-15mm and focus was nearly parfocal across the 7-21mm zoom range.

I didn't expect much from such an inexpensive zoom but am very surprised. I tried it out on several nights of good seeing on Saturn, Jupiter and several deep sky targets in a head-to-head comparison with my 12.5mm, 10mm and 7.5mm Ultimas and a 9mm Vixen LV. The zoom's images were equal in brightness, contrast and sharpness to any good plossl. It crisply showed banding and the Cassini division on Saturn with four moons in my 6 inch reflector. Jupiter showed very detailed banding with the GRS, festoons and the shadow of a transitting moon very sharp. It also gave very nice and contrasty views of M42 and several open clusters.

What really surprises me is that on all targets, the sharpness contrast and clarity of the Scopetronix zoom virtually equalled the Ultimas and its eye relief was much longer. Frankly, this cheap zoom's images were significantly brighter and sharper than my Vixen LV with nearly similar eye relief.

The only negative on this zoom is the narrow field of view at lower powers (as is the case with any zoom). But it is definately a keeper. My Vixen LV's might be going bye bye.

Overall Rating: 9
Optics:9 Value:9
Weight: 10 (Trustworthy Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=338022

Scopetronix Zoom 7mm-21mm
FOV at 22mm is somewhat narrow. But otherwise FOV expands nicely as you go up in power. Sharpness is great with only very minor abberations at the extreme edge of field. Nicely machined black anodized aluminum and is very light and won't cause balance problems. Zoom mechanism does get stiff in cold temps so maybe you might not want to use it in extreme conditions. Does have nice looking coatings on the eye lens and also on the bottom element. Not sure about the rest of the elements. Edges are not blackened.
I use this ep on my Orion ST80 for lunar, planetary, and solar viewing, and I give it two very enthusiastic thumbs up. The ability to zoom to just the right power for seeing conditions is great. Works great in my Ultima barlow also, giving me up to 108X in my ST80. With this ep, my Ultima Barlow, and my Ultima 30mm I am good to go at a moments notice. Excellent performance for the price. I would also be greatly interested in hearing how this ep compares to the Vixen/Orion/Celestron LV zoom and also to the Televue zoom.

Bert Pourchot

Overall Rating: 8
Weight: 3 (Unreliable Vote)
Date:
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Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44144

Scopetronix Zoom 7mm-21mm
Got this zoom eyepiece for my nexstar 80mm looking at the eyepiece it has multi-coated glass surfaces that look dark green in color did some testing on day time objects very sharp.I use this zoom eyepiece and a 3x barlow.at 7.4 I max out at 162x even at that high power i still get a good image!keep in mind my nexstar is only a 400mm fl. looked at the moon very sharp this under a hot texas night 89`f. stars were pinpoints from edge to edge all this for $65.00
a must buy. brightness is very good and great er.

Overall Rating: 10
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44146

Scopetronix Zoom 7mm-21mm
Very nice for the price. Sharp down to about 10mm, then fuzzes out a bit (has a little image distortion). Some false color but not much. Field of view average, not particularly great at high powers. Weight very nicely light, zoom mechanism works adequately, eye relief is a little short. Again, very nice for the price. At 22mm, was as bright as a comparable plossl. Ditto at 10mm.

Overall Rating: 8
Weight: 1 (Unreliable Vote)
Date:
By:
Link to this vote: http://www.excelsis.com/1.0/displayvote.php?voteid=44145

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