Swarovski ATX 95 binoculars
Posted 26 October 2013 - 04:49 AM
From what I see in the ATX 95, I don't really think that a double mirror EMS system can have that much better transmission and contrast, but could be wrong about that. The light loss in the Schmidt prism with total internal reflection, two multicoated glass-air surfaces and some absorption in the glass is not very substantial. The total scope, objective, focusing lenses, prism and complex zoom eyepiece has a total transmission of 86% (in Gijs' lab measurements, 87%), so there is no great room for improvement by replacing the prism. Also, star-testing the scope with a 3x booster shows such good behavior of the Airy disk that not much can be improved. On the contrary, it is possible that SA would increase by replacing the prism with mirrors as the prism is probably figured in the optical calculation and hence the figuring of the objective unit. In my scope there is so little SA that I would not really dare to change its amount one way or another.
Posted 26 October 2013 - 11:38 AM
I am also interested in how EMS-Ultima visual back performs against Swarovski prism/eyepiece unit. I may get a pair of Swarovski zoom eyepiece for the binoscope later so that I can test prism unit against EMS-Ultra a little fairer way.
Regarding SA/CA, I may see difference but I am not expecting to see much difference since I would not use the scope at high magnification. Maybe sometimes.
From past experience with a few relatively fast refractors (f/4, f/5.5, f/6.3, f/7, f/8), I see little artifact created by prism diagonal until somewhere f/5.5 or faster.
For low power/wide night sky (my main interest), I doubt I see difference between Swarovski Prism unit and EMS-U mirror.
I don't know you come across Matsumoto-san's aluminum v.s. new silver coated mirror article used for EMS. New silver coated mirror did improve in visible margin over aluminum mirror, specially toward lower spectrum.
I also found it interesting that dielectric mirror v.s. silver mirror experiment and see-through experiment.
I am planning to do the same experiment that I did for Kowa Highlander v.s. APM 100ED by photographing exit pupil to check image (field) brightness, system throughput measurement.
Kowa Highlander v.s. APM 100ED exit pupil comparison
I am hoping that ATX 95 is brighter than Kowa Highlander We'll see.
Posted 26 October 2013 - 03:41 PM
In terms of cost, two ATX 95 objective lens modules $3,800, EMS $1,600, guesstimate of other parts $1,000+. I guess around $7,000 compact 95mm f/5.8 binoscope.
I think Swarovski ATX objective lens module includes field flattener. There is a report below, stating that it produces pin-point star to the edge with Nagler.
This Swarowski ATX 95 binocular story sounds really interesting! Could be a Kowa Highlander killer. I look forward to further news.
Posted 27 October 2013 - 12:20 PM
Thanks for the link to the mirror comparison. A 3% light loss from the mirrors is probably about the same as the loss from the ATX Schmidt prism. One real advantage of the EMS system would be the possibility to reach proper high magnifications. The 72x of the ATX eyepiece falls short of delivering what the scope is capable of.
I also looked at your exit pupil comparison photos. It is interesting that you got the highlander to have so much better transmission than the APM. Granted, I have not viewed with the Highlander, but have viewed quite extensively with a Kowa 823 Prominar and the 883 Prominar, and neither of these has particularly high transmission.
Gijs van Ginkel has lab-tested the transmission of numerous scopes as well as binoculars, and in post #109 in the following link:
he has the results for the 883, which is more recent and very likely has better transmission than the 823 or the Highlander. In the thread I linked earlier were his measurements for the ATX 95, which were 10% higher than for the Kowa 883.
The one area where the Kowas are better is chromatic aberration, which especially the 884/4 have practically none of, whereas the ATX 95 has some although not too much, in my opinion.
Posted 02 November 2013 - 11:36 AM
From what I see in the ATX 95, I don't really think that a double mirror EMS system can have that much better transmission and contrast, but could be wrong about that.
You might be right - I was forgetting that the EMS has 2 reflections - but I'm always amazed with the light/contrast of my TMB92, specially when looking through the eyepiece without an image erector - the Nikon FSA-L2 don't "consumes" much light but, without it, is another dimension of light/contrast. Anyway the X95 is also slower than the TMB and also has at least more 2 lens, from the internal focuser... But I'm very curious with Tammy's evaluation...
Since you have Leica Zooms you don't need to purchase Swaro zooms to compare with your X scope. If you want more similar power range you should purchase the new Kowa zoom instead...
Posted 02 November 2013 - 07:19 PM
One real advantage of the EMS system would be the possibility to reach proper high magnifications. The 72x of the ATX eyepiece falls short of delivering what the scope is capable of.
My main interest isn't going high power but going wider by decent 2" eyepiece with EMS setup. Yes, going high power is sometimes nice
So far I have a few eyepieces in mind for ATX 95 binoscope. Green high-lighted ones would be my favorite.
mag tfov exit-pupil 17.8 3.94 5.34 Hyperion 31 [color="green"]20.4 3.16 4.66 Panoptic 27[/color] 25.0 3.22 3.79 Nagler 22T4 32.4 3.08 2.93 Ethos 17 34.4 2.29 2.76 Nagler 16T5 [color="green"]44.1 2.01 2.16 Docter UWA 12.5[/color]
Anyway the X95 is also slower than the TMB and also has at least more 2 lens, from the internal focuser... But I'm very curious with Tammy's evaluation...
I am willing to take some hit (transmission, I doubt I can see the difference in transmission/contrast but I can definitely see field curvature without flattener in 500-600mm focal length scope) to gain field flatness. So flattener/inner focus lenses in ATX 95 objective module is positive than negative for me. I am looking for light-weight, compact, inter-changeable eyepiece, wide and flat field bino-viewing instrument. ATX 95 binoscope meets all I am looking for. I guess except cost...
Posted 05 November 2013 - 11:55 PM
It is a compact 95mm f/5.8 binoscope. Hood retracted OTA length itself is 285mm. I guess EMS part is about 100mm judging from the photo. I think weight is about 10lb without eyepieces.
I hope it arrives before I leave for ASAE.
Looking forward to ISON, Lovejoy as the first light observation.
Here is how it looks like:
- Stellarfire likes this
Posted 06 November 2013 - 10:18 AM
I'm looking forward to your pictures of this instrument with a pair of 2" eyepieces.
Posted 06 November 2013 - 10:26 AM
Posted 06 November 2013 - 11:02 AM
I could have asked Matsumoto-san to paint EMS (mine is #4) in different color but I didn't. I am fine with original color (Tak-greenish)
Here is what it (ATX95 binoscope #3) looks with 2" eyepieces and the EMS is painted in black.
Yes, I am going to do side-by-side comparison with Kowa Highlander.
Looking forward to ISON/Lovejoy observation.
Posted 06 November 2013 - 12:22 PM
Do you happen to know what 2" 32mm Konigs are in #3?
Posted 06 November 2013 - 12:35 PM
Do you happen to know what 2" 32mm Konigs are in #3?
I think it is Kasai Trading Co. Extra Wide View 32mm, AFOV 85 degree, 20mm eye relief. I think it is popular among binviewing people (relatively) small barrel size, ie: binoviewing friendly.
I think it was discontinued... I may be wrong.
Posted 06 November 2013 - 12:45 PM
I hope it survives trip from Japan to California.
That would be this one?
The eyecup portion looks different.
I think it is the eyepiece.
Here is closeup shot on Televue 76 binoscope.
Posted 07 November 2013 - 06:32 AM
beside the Matsumoto-san items (EMS etc...), it seems that the Swarosvski ATX 95 parts needed are the 2 Modular Objective Lens without any other components. Am I wrong ?
Did you ask Mastumoto-san to have enough focus to use your magnificent eyepieces 12.5, the TAK 30 ? Do you think the Ethos 13mm should fit too ?
Thanks for your time.
Posted 07 November 2013 - 10:34 AM
Here is two sets of Swarovski ATX 95 Binoscope major parts. They are all designed and made by Matsumoto-san.
Regarding focusing with various eyepieces, he made extra effort to make sure most off-the-shelf eyepieces come to focus to infinity.
Some eyepieces need special adapter or/and 2" barrel to be shorten etc.
Most eyepieces that I am planning to use with the binoscope are good.
Panoptics 27, Docter UWA 12.5. Probably Ethos SX 4.7/3.7 for high power.
Here is a photo of the mount plate from bottom. Easy to adapt for my mount.
You can find Matsumoto-san's binoscope making journal here in 2013. He shows how he comes up with an idea, prototyping, progress, feedback, etc. Not every journal is written in English but he has short English description. English part isn't always translation of what he wrote in Japanese, though. You find his witty comments in Japanese
Hmmm, it seems that ATX 95 binoscope got stuck in Japanese custom for inspection due to declared high price...
Posted 07 November 2013 - 11:10 AM
Just a practical question. Considering that Matsumoto-san had already created some ATX 95 parts to comply with the EMS, was it necessary to send him the two ATX95 tubes ?
In other words, once he has already all the measures, size, of the components do you think it would be risk to order just the components without sending him the tubes ? I am saying this just because it would be quite expensive to send the tubes and maybe, beside the delivery expenses, to pay some custom duties because of the tubes.
Posted 07 November 2013 - 11:23 AM
I love Matsumoto-san's clever designs; his equatorial ring mount for binos (shown in your last link) is too cool!
Posted 07 November 2013 - 11:45 AM
I asked Matsumoto-san the same question. ATX 95 objective lens module is quite expensive.
Even though he has parts measurement done for ATX 95 binoscope, he needs to make every part almost from the scratch when he gets an order. He is one man shop (well, he told me his 88 year old mother helps him packaging , making binoscope at home besides his day job.
Anyway, having ATX 95 objective lens module at hand is important to make good final product, not to mention critical alignment, EMS collimation, etc...
So I decided to ask him to buy two ATX 95 objective lens modules in Japan as part of this order so that he can make the scope with confidence
It appears that price of ATX 95 module went up bit since I bought one for spotting scope.
Posted 07 November 2013 - 11:52 AM
Yes, he is very proud of the GEM binoscope mount
Posted 07 November 2013 - 12:54 PM
It seems that it is not a good idea not to have the scope entirely assembled by Matsumoto-san.
Anyway, thanks Tammy.