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View Full Version here: : Review: Zeiss 20-75x zoom and Swaro 25-50x zoom


jeelan
04-07-2016, 10:29 AM
Hey all,

Recently I’ve read a lot of reviews on both here and other forums regarding the quality of the Leica 25-50x zoom eyepiece, which is what prompted me to look into using my spotting scope eyepieces similarly.

These eyepieces are used in spotting scopes, and since I have both the Zeiss 85mm Diascope and the Swarovski ATS 80 HD scopes, I thought Id try the eyepieces out on astronomy scopes.

In view of that I had ordered some adapters from Markus at APM telescopes, which will allow me to use my Swarovski 25-50x eyepiece and my Zeiss 20-75x eyepiece in my telescopes.

Dealing with Markus was a pleasure with quick responses to emails etc. They don’t need an introduction, as people here are familiar with their high level of customer service.

Onto the zoom eyepieces.

SWAROVSKI 25-50x wide angle zoom.

The Swaro is 18.2mm to 9.4mm with an AFOV of 60-70degrees. This is a falls roughly around the same range as the Leica which is a little smaller at the open end and wider at the higher end of the range.

The eyepiece itself is significantly smaller than the Zeiss (or Leica). Its fully sealed, nitrogen purged and waterproof to 4m.

It has a bayonet fitting to lock into the Swaro ATS/STS spotting scopes. The eyepiece has 20-17mm eye relief throughout the zoom range with a twist out eyecup.

The build quality is apparent the moment you handle the eyepiece. Its typical of what you’d expect from the “alpha” European houses.

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0206_zps4fqpmdny.jpg

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0207_zpsvd13pwzs.jpg

The adapter seems very well made and provides a snug friction fit over the O-ring on the Swaro eyepiece. Once the adapter is on, you can tighten the plastic screws to secure in place.

With the adapter on, the eyepiece fits snug into a 2” diagonal with little to no play. Removing it from the diagonal can be tricky, you need to work the eyepiece back out slowly. If you try and pull it straight out, you risk the eyepiece itself pulling loose of the adapter which then means you have to try and work the adapter out of the diagonal separately.

ZEISS DIASCOPE 20-75x zoom

The Zeiss has a much more usable of range of 25.1mm to 6.9mm, however its also slightly narrow AFOV through its range (something like 50-60*, but I don’t have the exact figure).

Physically, the eyepiece is MUCH bigger than the Swaro and about 150g heavier. It seems equally well built, with the zoom function rotating with good friction.

Zoom on both eyepieces is smooth with no clicks so you can adjust to whatever magnification you’re comfortable with.

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0203_zpsxvmczmif.jpg

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0210_zpsa2rujdc0.jpg

Baader do a 2” adapter to use with the Zeiss which fits the Zeiss eyepiece well. Its got cutouts on the inside of the barrel to allow for the Zeiss bayonet lugs to twist against, securing the adapter to the eyepiece. The only thing you have to be mindful of is that this is not a tight fit so when you’re actually zooming, if you’re not holding the bottom of the eyepiece (the fixed portion), the friction on the zoom barrel is enough to twist the entire eyepiece loose inside the Baader adapter – not a big deal but something to be mindful off.

In terms of price, the Baader adapter is significantly cheaper than the Zeiss 2” adapter which sells for a ridiculous price.

Both pieces compared side by side –

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0213_zps060m11pu.jpg

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0217_zpsrztkorbe.jpg

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0218_zps6g5remsl.jpg

Both pieces compared with a Pentax XW 3.5, Pentax XW 20 and a Vixen LVW 42 .

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0214_zpsh8cekh6f.jpg

http://i12.photobucket.com/albums/a227/jeelanamin/Optics/Swaro%20Zoom%20and%20Zeiss%20Zoom/_DSC0215_zpshnlzhjvo.jpg

Using both:

I’ve only had a couple of nights to use these eyepieces so these are only my initial thoughts. They may evolve with more use.

In terms of ergonomics, in a telescope, both eyepieces are the same. The Zoom barrels are easily gripped and zooming itself is a pleasure with no play in the moving parts.

In terms of viewing, I find the Zeiss much more comfortable to view through. On paper while it has LESS eye-relief, in reality the Swaro required more precise eye placement otherwise the view tends to kidney bean a bit. This sort of negated the wider AFOV because moving my eyeball around tended to create more black spots in various parts of the field.

The Zeiss by comparison was very different. I had the eyecup extended fully and resting my eye socket against this, I spent a couple of hours just browsing through ETA Carinae with no issues. Its more forgiving in terms of where you place your eye.

Both eyepieces are parfocal with no focus adjustment required throughout the zoom range.

In terms of quality of the view, again I found the Zeiss much more comfortable to view through. In my opinion, it reproduced colour more naturally (whites were white, blues were blue) whereas the Swaro tended to give a warmer hue.

Contrast in both eyepieces was excellent; easily equal to my Pentax XW’s (nice black backgrounds) and noticeably better than the Vixen LVW’s, which tend to produce a more charcoal/dark grey background.

This bias towards the Zeiss really surprised me as in the spotting scopes, the Swaro has, by far, the better view. Its wider, colour is richer and the field is flat from edge to edge. The Zeiss diascope, while being tack sharp in the centre, shows some obvious pin cushioning in the outer 20% of the field of view, which is not present in the telescope at all. Stars in both eyepieces are sharp points all the way to the edge of the field.

This was particularly evident when looking at Omega Centauri, which filled the entire field at 25mm.

I certainly want to spend more time looking through the Zeiss eyepiece in particular before making any definitive decisions, however prima facie, over the last 2 nights of stargazing, I was astonished at the amount of time I spent actually browsing or studying the object in my scope vs typically constantly changing eyepieces. If the Zeiss continues to perform as strongly as it has the last 2 nights, I will strongly consider selling some of my eyepieces (possibly the LVW’s) and purchasing a second Zeiss zoom to use as a dedicated astronomy eyepiece.

Cheers
Jeelan

dannat
05-07-2016, 07:31 AM
interesting, thanks for posting

Don Pensack
12-07-2016, 06:43 AM
Jeelan,
Sorry I didn't see your post earlier.
Re: your comments about tint: this is consistent with both Swarovski's and Zeiss' high end binoculars, which differ, to my eye, exactly the same way.
Re: your comments about pincushioning (positive rectilinear distortion): sharpness to the edge is not related to distortion. What you see in the outer field of the Diascope (unlike the telescope) is a combination of field curvature and astigmatism. Otherwise, I concur with your analysis--the Swarovski scope is sharper to the edge.

Glad to see a review of the Zeiss eyepiece, With the adapter, it's a truly wide range for a zoom--3.75:1 That makes it very interesting to astronomers.

galaxy
13-07-2016, 06:39 PM
Hi Jeelan
Thanks for the very interesting review. Regarding the Swaro did u have to hold the eyepeice while zooming as i feel the zoom friction is enough to make it turn against the plastic screws.. i found the Swaro to have a zoom with higher friction than the Leica
Cheers
Vaidya

jeelan
15-07-2016, 03:17 AM
Apologies for the late response guys, I've just spent the last 9 days camping at Ningaloo so only just catching up with emails, posts etc.

DON - thanks for your comments into what I thought was pin cushioning. I was wondering how that works. From what i understand, all Zeiss scopes have traditionally had the same effect which leads me to believe (rightly or wrongly) that this might be how the Zeiss spotting scopes are engineered i.e. provide a sharp picture in the centre of the field of view with more pronounced field curvature towards the edge..

VAIDYA - the fit of the Swaro adapter onto the eyepiece is tight enough that I didnt have to hold the eyepiece while rotating the zoom barrel, however the one thing the Swaro eyepiece lacks is a decent area to grip the eyepiece even when inserting into the Swaro spotting scope. Both the Zeiss and Leica zooms have a knurled area where you can hold the eyepiece itself while turning the zoom.

Speaking of this, I also got the Leica 25-50x zoom eyepiece and had a chance to extensively play with all 3 whilst camping. I'd taken the Orion 80mm APO with me (as well as both the Swaro and Zeiss spotters)

The skies at Ningaloo were unbelievable - Night time was an unbroken sky that didnt end till it met the ocean on the northern, southern and western sides and just a little higher on the east where it met a small range.

It was like someone turned on the christmas lights - the arc of the milky way and the nebulosity around this arc was gorgeous to look at with the naked eye.

By midnight the moon had dropped below the horizon so it was clear skies and viewing for the rest of the night.

I'm processing the photos now but i dont think any pics will do justice to how the skies actually looked.

More than the scopes, just gazing through my binoculars was a delight - beautiful 8* view (Swaro EL 8x32's).

more on this later though...right now i've just got to get some rest :-)

cheers
Jeelan