Christmas present:  zoom eyepiece, 9 – 27 mm.   And eventually, last night, a clear hour to test it in.  Not a very rigorous test, complicated as it was by flashing Christmas lights on houses, numerous passing cars, failing battery in red dot finder, bedroom lights going on, moon shining in a glaring haze through the trees … you get the idea.


We used the 5 inch scope, and looked at Jupiter first. The 27 mm setting gave a widish field of view to find the planet, then we zoomed slowly in to 9 mm – the idea is, of course, that using this you don’t have to keep taking eyepieces in and out to change powers.  The image was fairly good  but the sweet spot seemed quite small.   I don’t think this zoom eyepiece will replace the others for planetary observing:  last night we tried a number of eyepiece combinations, and the most useful for seeing detail on Jupiter was a 12 mm eyepiece with a 2x Barlow, effectively 6 mm, and on really good nights the 5 inch scope will bear a 10 mm eyepiece plus 2x Barlow (i.e. 5 mm).

Using it for M42 in Orion was more promising, however, as you don’t necessarily want a high magnification for nebulae and such.  Here it seemed helpful to turn the ring slowly and seek the best available view of stars and nebulosity (such as it was on this unpromising night). This would have been quite irritating to do with multiple eyepieces and Barlows being swapped in and out.

I was unable to try my new toy to observe the moon, as cloud was coming in before the moon rose properly, but I suspect it may be quite good for this too.  And of course I’m curious to see how it does in the 10 inch … one fine night … maybe?

3 responses »

  1. Oh cool… never tried a zoom eyepiece before so I’m curious to know what you think once you’ve had a chance to properly test it. Which brand is it?

    I have a couple of barlows and I like those… just a 2x and a 3x… I like the ability to boost the magnification and still keep a decent FOV, plus, of course, they suddenly double your available magnifications without the expense of additional eyepieces 🙂

    • The spec is here http://www.harrisontelescopes.co.uk/acatalog/SkyWatcher_HyperFlex_9_-_27mm_Zoom_Eyepiece_1.25_.html

      I find the Barlows useful too – only have 2x in the repertoire at present. I think the serious astronomers say that any multi-element eyepiece is going to lose some light, including zoom eyepieces. On the other hand, if like me you are rather given to getting lost in a busy star field, or regularly drop things into the garden, the zoom might be useful! The loss of focus around the edges of the view is a bit more serious. Mine is a bit up from entry level, I think – the best ones cost more than my telescope … will keep you informed if we ever get any more sky.

      • Yeah, I’ve seen some pretty expensive zooms. The loss of focus on the edges of the FOV could definitely be a problem, especially when it comes to spotting faint ‘n fuzzies with averted vision.

        Let me know how it goes 🙂

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