Here are the new modular Swarovski scopes (1 Viewer)

[John Russell]

Henry,

Perhaps we are a little at cross purposes here.
I have no doubt that one needs more than 1x magnification per mm of aperture to explore the resolution capabilities of a good scope, and that large apertures and high magnifications will give a more detailed and pleasing view under ideal conditions.
What I doubt is the frequency with which high magnifications can be of use in making an ID in a practical birding situation. I was out birding today and although I was able to identify Eurasian Teals across a lake by size and shape, it was not until the sun came out that I could see their green speculum feathers despite a moderate 2,2 mm exit pupil. Over land mirage then became a problem at 30x magnification and additional aperture and magnification would have been of no benefit.

John

 

[Swissboy]

Henry,

Perhaps we are a little at cross purposes here.
.....John

It's also clearly a matter of one's priorities. Having turned 70 not too long ago, I have trimmed my equipment in the direction of less weight. Thus, a 65 scope will now be my standard.

I had long ago done the same with my photo tools. Can't have it all, I'm afraid. Thus I'm happy to still have my unrestrained mobility.

 

[kabsetz]

John,

I'm not going to argue the case much further here. Of course there are lots of situation where there is enough mirage or not enough light so that high magnifications are rendered useless. What I have said and will continue to say, is that there are enough situations where high magnification is useful, sometimes even essential (yes, I have been in situations where 75x ID's a bird that 60x would not). There are even more situations where the bigger exit pupil that you get with an 80, 82, 85, 88 or 95mm objective lens gives a decided color visibility advantage over scopes with lesser aperture, and this is certainly one of the clearest differences I see between my current 82mm Nikon @ 75x compared to the 95mm SW @ 72x. And, like Henry said, there is the resolving power advantage that comes with a bigger-aperture scope, and that advantage has practical value when ID:ing birds at great distances. Also, a scope that has higher maximum resolution due to larger aperture not only resolves finer detail, but also has better contrast at spatial frequencies larger than the maximum resolution, and this is of substantial practical significance in all ID:ing situations where one is struggling with wee and far birds.

So, size matters, magnification matters, and how close or far your particular scope is from being diffraction-limited matters. Your eyesight acuity also matters. And where and how you bird matters.

Where I bird, and how, what I want is a near diffraction-limited scope of the maximum aperture I'm willing to lug around, with magnifications reaching at least as high as 70x. Those who have not had the chance to use such a scope might not and need not agree, but for us who have there's no going back. The next best thing, and one I could have been happy with for a long while, is all of the above but with magnification limited to 60x (read: Kowa 883), but with that one compromise, I have not been inclined to trade for one yet.

The ATX 95, providing I can find a sample as close to diff-lim as my current Nikon, will give a 15% improvement on distance at which detail can be resolved under ideal conditions, a brighter and higher-contrast image at all times when using magnifications higher than about 40x, and a much improved field-of-view throughout the zoom range.

Kimmo

 

[DRodrigues]

As also an high power fun, that use sometimes >120x magnifications to read alphanumerical codes of marked birds at great distances, I'm adding an other perspective that I found with my binoviewing combo and confirmed with my present 100ºAFOV zoom combos - highpowers are addictive and show their best at close distances!!! If you find superb to see the water drops moving on the back of a duck at 50-60x, see it at 75-90-120x and you will notice what you have being loosing...o
If until recently high powers would mean small fields (and the old Nikon zoom is an example of that...), with new widefield zooms and extrawidefield fixed eps, this is no longer an important limitation.

 

[John Russell]

Kimmo,

Thank you for the extensive answer. As Robert suggested above, it's really a question of achieving the right personal compromise and, being of a similar age, portability is a major issue for me.

Holger Merlitz once quoted some rather old military research, and if I recall correctly the result was that 90% of the time there was little to be gained with magnifications above 30x or exit pupils larger than 2,5 mm for terrestrial use. Now those figures may vary greatly according to the situation and although I would prefer to observe with a Kowa High Lander Prominar, Docter Aspectem or big apo with binoviewer, I willingly forgo the 10, 20, or 30% of IDs for the mobility offered by the small scope.

John

 

[birderk]

I wonder, in regards, to Kimmo's and Henry's response above whether for most birding situations in terms of useable detail visable, it would be better to have the Nikon 82 at 75x or the Kowa 883 at 60x provided both were both excellent specimens?

I use the Nikon 82 at 75x when atmospheric conditions permit but sometimes wonder in some situations such as unstable air or low light condition whether it would be better to use the Kowa 883 and whether that could result in more details being seen.

Brendan

 

[kabsetz]

Brendan,

Haven't used the 883 enough to be able to say for sure, but from the side-by-sides I have had with it & the testing I was able to do with it, the differences are slight. Very likely there would be some rare situations where the Kowa would show colors a bit better with the help of its larger exit pupil at equal magnifications, and there may be the rare occasion where the Nikon might show more detail due to its higher magnification, despite having slightly lower true resolution. This latter would also depend on the viewers' eyesight acuity, in that with better acuity you are less compromised by the lower max mag of the Kowa.

Anyway, although I'm a detail freak, I decided not to get the Kowa as I thought it would not be more than, at best, a very marginal improvement over the 82 Nikon. But, for those asking my opinion on a new scope, I used to recommend the 883 as the best option overall.

Kimmo

 

[Gijs van Ginkel]

Gentlemen,
I found some useful information regarding resolving power of binoculars and telescopes in the booklet "Binoculars and Scopes" by Paul R. Yoder and Daniel Yukobratovich from 2011. The authors are professionals with a lot of theoretical and practical knowledge about binoculars and telescopes and the book is really worth buying if one is interested.
These authors write about resolution:
"The ability of the eye to resolve details in an object viewed unaided or through a scope varies significantly with luminance L of the scene observed. Typical values for the unaided eye :
Daylight: luminance smaller then 0,03 cd/sq m: eye resolution 4 arcmin to 40 arcsec
Twilight: luminanc 0,03-0,001 cd/sq m: eye resolution 4-13 arcmin
Night: luminance smaller tehn 0,001 cd/sq m: eye esolution 13-30 arcmin
The resolving power of the eye is reduced if the observed object has inherently low contrast, as is the case for most natural objects. Reductions in contrast also occur because of lighting irregularities, atmospheric effects, diffraction, aberrations in the eye, focus errors and effects of misalignments and aberrations in any optical system employed".
The authors also describe on page 50 that the limiting resolution is determined primarily by the instruments Exit Pupil diameter , its magnification, its light transmission and the scene luminance. So a lot of parameters to consider before one can decide which instrument is most suited and what magnification is optimally suited for the circumstances in front of the lens.

 

[henry link]

Brendan,

There is a way you could answer this question for yourself using just your telescope and a 76mm aperture mask. The effective aperture of your scope with the mask in place approximately matches the aperture ratio of your scope to a Kowa 883. Ideally you would want to compare the stopped down aperture to the full aperture using magnifications that duplicate the exit pupils that would be involved if you compared your scope at 75x to an 883 at 60x, but I think it will work well enough in this case to just use 75x for the stopped down aperture and your best effort to set the zoom to 60x for the full aperture. Now, try to see which shows the smallest details to your eye under whatever conditions you choose, a 76mm scope at 75x or an 82mm scope at 60x.

Henry

Edit: In the spirit of keeping the thread on topic I should mention that this same trick could be done to simulate how a high quality scope of any aperture would approximately compare to the new 95mm Swaro, at least in terms of image brightness and resolving power.

 

[birderk]

An interesting experiment, thanks. I will try it.

 

[gulf1263]

Hello all:
A question for Henry, et al, would the new 95mm Swaro also substitute for a astro scope?
Could it be used for both birding and astro work?
I am trying to justify the price...help me out here.
Thanks
Art

 

[mooreorless]

Art the angled version would be ok. You can buy an Orion 100ED off Astromart for as little as $400. Not WP of course. I have one and use it for both, well besides the 2 Nikon Fieldscopes I have.

 

[RJM]

Of course a fieldscope can pull double duty for astro work. I have used my mine for solar observation and comets.

BUT, you can get significantly better optics from a dedicated astro scope of similar aperture or larger and for half the $$. Even a lowly mirrored scope like the Celestron C5 with the right eyepiece will optically surpass the Swaro ATX95.

The benefit of a fieldscope is not in the optics but its mechanical features and ergonomics tailored for the nature observer tramping around the countryside, e.g., significantly lighter weight, compact/robust body, built-in 45deg erecting prism, internal close/fast focus, weather sealing and fog resistance.

If you only observe nature from the comfort of your car or covered backyard deck, then an expensive fieldscope is not the best use of your $$.

 

[henry link]

Art,

Sure you can use the Swarovski 95mm for astronomy. Why not? You can see the same things with a well corrected specimen that you would see with an equally well corrected astronomical APO of the same aperture and magnification. You probably already know what's not optimal for astronomy; like a 45º instead of 90º prism, rather low maximum magnification and no ability to substitute different eyepieces. And of course there's price. If astronomy is your first use and you already have eyepieces and diagonals think about what $4000 will buy you in the way of an astronomical APO optical tube.

Henry

 

[clive ward]

Hi Guys
I have just picked up the 95mm version. First impression was not wow when I compared it to my old 60mm Kowa but that was indoors out of a small window. I then took it to the local park for twenty minutes yesterday and WOW I have never seen so much detail . I can't wait to get out this weekend. I will be going to Cornwall in a few weeks time and I would like to do some sea watching. Do you think I should get a filter to protect my investment if so what one? I can't seem to find any with a 97mm thread are there any made that size?

Cheers Clive

 

[kabsetz]

Clive,

If you use the objective cover while transporting the scope and exercise normal caution while using it, you don't need a filter in my view. I've certainly never had one on my scopes, and the objectives have been fine. Also, the filter will compromise the image quality slightly, with some increased glare, some loss of brightness, and potential loss of resolution as well. Moreover, bear in mind that there needs to be pretty bad damage to the objective lens surface before it becomes visible in the view. Small individual scratches would not be enough to compromise the view, the damage would need to be something that breaks the lens, causes a chink that makes a significant scatter point, or else some major abrasion that influences a sizable portion of the lens surface. Individual fine scratches, by far the most likely damage, are not going to be visible in viewing even if they make your heart bleed.

Others may have other advise, but I think it is best to forgo filters and just give the scope normal, sensibly cautious but not excessively overprotective care.

- Kimmo

 

[clive ward]

Hi Kimmo

I just want to be careful with it. As last time I went to the Scilly Isles and I was useing my bins on the boat, I got some sort of oily film on them. And upon returning to my car which was parked on the sea front I could not drive for 30 mins as I had to clean the wind screen. I would only use the filter for sea watching.

Regards Clive

 

[Dixie07]

For you guys that have seen the new 85mm ATX, how much better would you say it is compared to an ATM/ATS 80mm HD?

 

[proudpapa56]

We now have a 95mm Obj

Hey all you central PA folks. We now have all 3 Objective sizes if you want to take a look. The 95mm is a beast and I'm more impressed with how the 70X holds up than I thought. We were pretty lucky to get one, they're pretty scarce right now.
Anyone else can PM me if there's any interest.

 

[proudpapa56]

Well, that 95mm Objective was only in the shop for about 2 hrs. One of our customers is a long range shooter and I gave him a call right after the last post. Turns out he'd been waiting for that call and was in and out of the shop pronto with the only ATX/95mm Scope in Central PA.