Swarovski ATS80HD eye-pieces (1 Viewer)

[rogerscoth]

Originally posted within "Andy Bright's Digiscoping Forum" :-

Does anyone have experience of the new 45xWW eye-piece and the 20-60x zoom used with the ATS80HD 'scope? Is there a very noticable performance difference, compared to the mid-range setting of the 20-60x zoom eye-piece? Ultimately, is the 45xWW eye-piece worth the price of around £200?
Roger

 

[dogfish]

I was just about to pose the same question when I noticed you beat me to it, Roger. Judging by the lack of response, it looks like not many people have the 45w. The 30w, which I bought, is such a stunning eyepiece it does make me wonder how good the 45 is. Several reviewers have mentioned it in passing as being excellent, but we all know most mainstream reviews have to be taken with a pinch of salt.

It struck me that the new zoom was only a very small advance on the old one, whereas the 30w was much better than its predecessor.

 

[Leif]

I was just about to pose the same question when I noticed you beat me to it, Roger. Judging by the lack of response, it looks like not many people have the 45w. The 30w, which I bought, is such a stunning eyepiece it does make me wonder how good the 45 is. Several reviewers have mentioned it in passing as being excellent, but we all know most mainstream reviews have to be taken with a pinch of salt.

It struck me that the new zoom was only a very small advance on the old one, whereas the 30w was much better than its predecessor.

It is an interesting question. A related one is does the 45xw give much advantage over the 30xw, or would a zoom be better? (I am really wondering about the Leica 32xw + Leica 40xw versus the 32xw + the zoom, but it's a not too dissimilar question.)

 

[IanF]

I have the 20-60x zoom which is without doubt very good quality.

I am considering a 30x because the field of view is that much wider and from that I've seen is more suitable for spectacle wearers. Optically it is supposed to be very good indeed.

Just as a personal thing I think I'd rather have the zoom plus 30x as opposed to the 45x.

 

[henry link]

If you already have the zoom eyepiece adding the 45x makes little sense to me unless you need the 3mm longer eye relief. The zoom set at 45x has an apparent field of about 64 degrees with excellent sharpness, center and edge. The apparent field of the 45x is only a few degrees wider. The difference between the zoom at 30x and the 30x eyepiece is about 54 degrees vs 70 degrees on my 30x which is 4 degrees more than the Swarovski specification. The 45x is probably also 70 as I suspect it is the same 30x eyepiece with the addition of a 1.5x barlow.

 

[Leif]

If you already have the zoom eyepiece adding the 45x makes little sense to me unless you need the 3mm longer eye relief. The zoom set at 45x has an apparent field of about 64 degrees with excellent sharpness, center and edge. The apparent field of the 45x is only a few degrees wider. The difference between the zoom at 30x and the 30x eyepiece is about 54 degrees vs 70 degrees on my 30x which is 4 degrees more than the Swarovski specification. The 45x is probably also 70 as I suspect it is the same 30x eyepiece with the addition of a 1.5x barlow.

Thanks. Your informative posting certainly answers my question. I note you refer to a Barlow lens. It is curious - to me anyway - that whereas amateur astronomers use Barlows (1.5x, 2x IIRC), birders never use them and manufacturs of spotting scopes do not provide them. I wonder why?

Also I find it curious that 3rd party manufacturers do not try and produce eyepieces for spotting scopes, although some (Zeiss 65/85, Swaro 80?) can be fitted with an adaptor to allow standard 1.25 inch astro ones. Maybe the problem is that at high powers it becomes too difficult to align the scope, and seeing is rarely that good anyway due to atmospheric turbulence.

 

[rogerscoth]

If you already have the zoom eyepiece adding the 45x makes little sense to me unless you need the 3mm longer eye relief. The zoom set at 45x has an apparent field of about 64 degrees with excellent sharpness, center and edge. The apparent field of the 45x is only a few degrees wider. The difference between the zoom at 30x and the 30x eyepiece is about 54 degrees vs 70 degrees on my 30x which is 4 degrees more than the Swarovski specification. The 45x is probably also 70 as I suspect it is the same 30x eyepiece with the addition of a 1.5x barlow.

Henry,
I have the zoom eyepiece for my Swaro' ATS80 HD, I just wondered if anyone had experience of using the 45x eyepiece as well - there must be someone out there! My main interest is if the 45x eyepiece gives much more brightness than the zoom eyepiece, maybe for use in digi-scoping. The zoom eyepiece itself is commendably bright.

Roger

 

[henry link]

Roger,
I can see no difference in light transmission between the zoom and the 30x. I would estimate about 95-96% for each, extremely good for complex eyepieces. I doubt that the 45x has transmission quite as good as the 30x since the 45x almost certainly has more glass/air surfaces. In photograghy eyepiece transmission differences would be negligible as a 1% difference in transmission equals only about 1/50th of an f-stop. Henry

 

[Leif]

Roger,
I can see no difference in light transmission between the zoom and the 30x. I would estimate about 95-96% for each, extremely good for complex eyepieces. I doubt that the 45x has transmission quite as good as the 30x since the 45x almost certainly has more glass/air surfaces. In photograghy eyepiece transmission differences would be negligible as a 1% difference in transmission equals only about 1/50th of an f-stop. Henry

The main areas where you will see a difference between a 35mm zoom lens and a prime are the contrast, the flare resistance and the distortion. The best zooms tend to flare readily due to the large number of elements (often as many as 20) but otherwise they almost match the primes. I've never compared a fixed Swaro (or other quality make) eyepiece with the zoom at the same FL so I don't know if there is a noticeable difference in contrast. (Lower contrast can of course give the appearance of lower brightness.)

 

[henry link]

Leif,
I have enjoyed reading a number of your posts since I recently joined this group.
Camera zoom lenses evidently require many more elements than eyepieces. The most complex zoom eyepiece I know is the Zeiss Diascope zoom which has 10 elements in 5 groups.The Swarovski zoom uses 8 elements in 5 groups plus a flat optical window to keep it waterproof. The 30x is also complex by eyepiece standards. I haven't seen a cutaway diagram, but my count of reflections indicates 4 groups with no optical window needed since the elements don't move. I am unable to detect any significant difference in contrast between the two Swarovskis or see any flare in the zoom. Center sharpness may be slightly better in the zoom.

Henry

 

[Leif]

I am unable to detect any significant difference in contrast between the two Swarovskis or see any flare in the zoom. Center sharpness may be slightly better in the zoom.

Henry

Henry: Thanks for the useful info. Time to start saving again!

BTW I have seen eyepieces for telescopes, presumably bought by amateur astronomers, that provide a near 90 degree FOV and cost £500!!!!! Ouch. I can see my piggy bank giving me "Don't even go there" looks. Leif

 

[rogerscoth]

Roger,
I can see no difference in light transmission between the zoom and the 30x. I would estimate about 95-96% for each, extremely good for complex eyepieces. I doubt that the 45x has transmission quite as good as the 30x since the 45x almost certainly has more glass/air surfaces. In photograghy eyepiece transmission differences would be negligible as a 1% difference in transmission equals only about 1/50th of an f-stop. Henry

Henry,
Thanks for that info. Henry. I believe many digi-scopers with the ATS80 HD Swaro. 'scope use the zoom eyepiece with some very good results. When I have decided on a suitable camera (still pondering), testing time will be interesting!

Roger

 

[Ragna]

Two weeks ago when looking at Hawfinches i had the chance to compare the Swarovski 30x eyepiece with the zoom set at 30x,the conditions were overcast.The 30x eyepiece was noticeably brighter and the f.o.v.about 20%-25% more, i found the 30x just as bright as the zoom at 20x.

 

[Jay Turberville]

Thanks. Your informative posting certainly answers my question. I note you refer to a Barlow lens. It is curious - to me anyway - that whereas amateur astronomers use Barlows (1.5x, 2x IIRC), birders never use them and manufacturs of spotting scopes do not provide them. I wonder why?

A 20-60x zoom covers birding magnifications quite well. Amateur astronomers on the other hand, might want a magnification choice that is three or four times that range. A properly chosen set of eyepieces and a barlow can almost double the utility of an eyepiece collection for the price of one additional optic.

Furthermore, I think the typical birder wants to know only as much information about their equipment as is needed to make a good purchase and to use it. Most aren't particularly interested in the technical aspects. They are interested mostly in the birds and getting a good view. Ask ten birders how to calculate an exit pupil diameter and I'd be surprised if more than half of them could do it. Its not a matter of ability, its a matter of interest. I'd expect nearly all amateur astronomers to consider such a thing to be very basic. It used to be that one of the hallmarks of amateur astronomy is that they would build their own telescopes - and many would grind their primary mirror to boot!

So it follows that manufacturers of birding optics design and market birding scopes differently. The main measurements that they give are eye relief and scope aperture diameter. Scope focal length and eyepiece focal length are more typically expressed in magnifications. Its simpler and provides the information that is important. I suspect that they find that keeping eyepiece selections relatively simple leads to higher overall customer satisfaction.