Orion E-Series 7-21mm Zoom

[Nightspore]

 

 

I bought the Orion E-Series 7-21mm Zoom for £56.99. There are other zooms that appear identical to this eyepiece selling under other brand names. They undoubtedly originate from the same OEM. There doesn’t seem to be a great difference in their respective retail prices. The first thing that I noticed with the Orion ‘E-Series’ was how physically light it was. 

 

 

The Orion website says it is 136g (although I weighed it at 150g) which would make it around 20-25g lighter than my unbranded ‘Sky-Watcher’ 7-21mm zoom of almost identical proportions. The E zoom is 94mm tall, 43mm wide, and I make the eye lens and field lens 25mm and 16mm respectively. Orion Telescopes and Binoculars claim a 16mm field stop. They also state that there are six elements with a 40.0° - 57.0° FOV and the lens edges aren’t blackened. 

 

 

The housing and barrel are aluminium and the barrel has an undercut and a filter thread. The coatings seem fine and the other thing that I noticed is that it doesn’t seem to rattle as much as its ‘Sky-Watcher’ equivalent. In the past I haven’t had much success with 7-21mm (or thereabouts) zooms. The ‘Sky-Watcher’ 7-21mm zoom was prone to a bit more chromatic aberration than I can generally tolerate. My Pentax XF zoom (6.5-19.5mm) also displays some lateral colour on lunar and planetary targets.

 

 

At around 22:15 BST on the 27th of May there weren’t many twilight stars to observe. The transparency was decidedly below average, although according to some of my software the seeing was predicted to be good. I got first light with the E-Series zoom placed in a 3x BST Barlow with my modified ST80. This gave a range of around 57x to 171x. The target was a very visible Arcturus; the fourth brightest star in the sky. The rubber eyecup doesn’t seem to include the ability to be folded down or removed but the overall ergonomics were satisfying. I found that the eyepiece was pleasant to use with no eye placement issues.  

 

 

My first impression was that it was showing some chromatic aberration. I rapidly realised that this was a combination of the 0.2 magnitude of ‘ɑ Bootis’ and the fact that I was using an inexpensive achromat. I had a quick look at Vega, the fifth brightest star in the sky, and patiently waited for the night to get darker. As soon as I could discern ε Bootis through the poor transparency I decided to try and split it. The anxieties I had earlier about false colour were abated. The split at around 160x was very sharp and apparent. It appeared like the Orion had an acuity superior to my Celestron zoom. The magnitude 4.7 binary companion was very distinct and the colours of both stars were quite striking. I thought that the zoom mechanism itself was fairly smooth and precise. There is no clickstop indicator. 

 

 

I then tried Cor Caroli which is an old favourite of mine. I was still impressed by the overall clarity and colour separation from a zoom in this price range. Next up were a rising Albireo and ε 1 & 2 Lyrae. The seeing may have been better than the transparency as the ‘Double Double’ was a particularly effortless split. All four stars were cleanly and sharply split even at around only 100x magnification. At 170x they were still incredibly bright and acute. I spent the next hour splitting other doubles until it inevitably clouded over. 

 

 

I initially purchased this zoom primarily for double star observing while placed in a Barlow. It hasn’t disappointed me. The combination of light weight, relatively comfortable ergonomics, and visual acuity seems to belie its competitive retail price.

 

[Marmot]

Another interesting review.

I have often thought about a zoom, for pure ease of use. However, I am trying to prioritise a selection of fixed focal length eyepieces that work for me before looking at other items. I can see myself re visiting this review further down the line.

[Nightspore]

46 minutes ago, Marmot said:

Another interesting review.

I have often thought about a zoom, for pure ease of use. However, I am trying to prioritise a selection of fixed focal length eyepieces that work for me before looking at other items. I can see myself re visiting this review further down the line.

 

Thanks. I've had experience with a few zooms over the years. 

 

 

The much vaunted Vixen LV was returned (three times in total) due to debris in the field. The Lunt suffered the same fate. I don't have either of these now.

 

 

The Vixen had a limited FOV and the transmission was poorer than any other zoom I've ever used.

 

 

Regardless of what 'experts' on other forums claim the 'Meade', 'Celestron' and 'Astromania' 8-24mm zooms above are identical and are supplied with identical eyepiece containers. They almost certainly all issue from the same factory.

 

 

The Pentax XL is very good, but the smaller XF has some chromatic issues.

 

 

The TV Nagler zoom (3-6mm) is a bit specialist but unrivalled for planetary viewing.

 

 

The BHZ (above) is probably the best zoom for astronomy, unlike the Pentax zooms the Baader Hyperion wasn't primarily designed for use in spotting scopes. It's only 1.25" but the removable 2" skirt helps it sit lower in 2" diagonals.

[RT65CB-SWL]

I too have 7-21mm zoom e/p. Though I do not know what brand it is, I purchased it from AstroBoot a few years ago. It is the ideal companion for when I travel light or ‘grab & go’.

[Nightspore]

10 hours ago, Philip R said:

I too have 7-21mm zoom e/p. Though I do not know what brand it is, I purchased it from AstroBoot a few years ago. It is the ideal companion for when I travel light or ‘grab & go’.

 

I think the convenience of a zoom is the thing that appeals to me the most.

[Nightspore]

 

'SvBony' version of the E-Series. These zooms are identical and could be potentially used in a binoviewer. 

 

 

SvBony version in an Altair 3x Tele-Extender placed in a Baader sital mirror diagonal in my Altair 60 EDF doublet.

[Nightspore]

I gave the SvBony version a session in my 60 EDF last night. I didn't see any CA and it performed superbly. 

 

 

Highlights included Iota Cass, ε Boo, Struve Σ 2470/2474 (the other Double Double), M57 and M13.

[Nightspore]

 

My Baader Hyperion Zoom 2.25x Barlow was originally bundled with the Hyperion Zoom itself. 

 

 

I mostly use the BHZ with a 2" skirt. The Barlow wouldn't thread into any other zooms I owned and remained unused.

 

 

That is until I tried it in the Orion E-Series. Effectively turning it into a 3.1mm - 9.3mm zoom. 

[Marmot]

Interesting! I never realised those little screw in barlows existed. I assume it’s similar to a removable lens cell being unscrewed from many other barlows that allow it and then screwed into the EP.

I also see that you had a thread compatibility issue also......even on a 1.25 thread!

[Nightspore]

26 minutes ago, Marmot said:

Interesting! I never realised those little screw in barlows existed. I assume it’s similar to a removable lens cell being unscrewed from many other barlows that allow it and then screwed into the EP.

I also see that you had a thread compatibility issue also......even on a 1.25 thread!

 

The BHZ barlow is intended for the BHZ.

 

 

As with everything Baader, it's a bit of a Lego set. It wasn't just that the threads were incompatible with the 'Meadatron' zooms. The male thread on the 1.25" Baader adapter didn't even mate up with the female thread on the zoom barrels. Their respective pitches must be hugely different. Oddly, GSO Wratten and Baader 1.25" filters will thread into the Celestron/Meade zooms. I'm really pleased that it fits the Orion/SvBony zooms though. It had been sitting on a shelf for years. They're not cheap either.

[Nightspore]

I recently used the Orion zoom and BHZ Barlow combo for observing Jupiter and Saturn with my 72ED DS Pro. I directly compared the combo with a 3.2mm TMB clone (131.25x) and a 4mm Astro Hutech orthoscopic (105x). The combo gave a maximum of 135x. The ortho' gave the sharpest view, unsurprisingly, with the TMB close behind. But the zoom/Barlow combo was remarkably sharp and contrasted between around 100~120x. Considering the zoom lenses aren't edge blacked and combined with the Barlow adds up to a lot of glass to look through, I was quite impressed. 

[Marmot]

I find it of interest that the TMB clone has, yet again, done so well. These eyepieces definitely seem to punch above their weight!

[Nightspore]

30 minutes ago, Marmot said:

I find it of interest that the TMB clone has, yet again, done so well. These eyepieces definitely seem to punch above their weight!

 

They were a good planetary design from the outset.

[Nightspore]

 

The eyeguard does fold down. Although I needed a wider end cap.