Posts Made By: Nils Schoultz

I've been curious for a long time what binoviewing with a 4-inch refractor would be like. I binoviewed with a 3-inch apo for a long time, but eventually settled down to using this combination only on the moon, planets, and the sun. The brightest of DSOs (double cluster, m42, Pleiades) were ok, but once the novelty wore off I tended to monoview even these objects.

As we do, I started to wonder more and more about a bigger and more expensive 4-inch refractor, and read as much as I could here and elsewhere about what the difference would be. Eventually I decided I would just have to take the plunge and see for myself. I've now had a week with my new TMB 102/800 and can offer some initial thoughts to anyone making the same decision. For me, it is the same old story with the binoviewer: planets, moon and sun much nicer, brightest of dsos very nice, too - but really I'll spend most of the time with this refractor in mono mode as well. I had thought that the step up from the approximate equivalent of a 57mm binocular (this is what the surface area of my old 80mm worked out to binoviewed) to a 72mm binocular (the new 4-inch with binoviewer) would be noticable. It is, but not quite enough to make the scope suitable for 100% or even majority bino use. Aside from the slight dimming of the views, any bino will necessarily make the perfect star images in a high quality refractor seem a bit less sharp, partially negating one of the reasons for having the refractor in the first place.

For me, the binoviewer seems best used with big aperture. An obvious point that has been made over and over, but as worth repeating as any of the usual nonsense here. The views with the Denkmeier II in my Orion xt10 are better than mono on every single object, every single night. Also worth repeating is the fact that slightly lower magnifications in the binoviewer are necessary. I observed a variety of dim and bright open clusters last night as well as m42 and Saturn, and only on Saturn did I reach for higher magnification than the 167x that a pair of 18mm Celestron ultimas gave me with the 2.5x setting on the powerswitch. About 90% of the time, the approximately 70-120x of a pair of 25mm TMB orthos gave the most satisfying views. I don't regret selling the high power pairs of 11mm and 13mm Naglers, and I don't have nearly the eyepiece-switching compulsion that I do when mono-viewing. So in the end the cost issue of pairs of eyepieces may not be a deal-killer if anyone is reading this post thinking of trying binoviewing.

No earth-shaking news here, just some more or less conventional wisdom that I thought bore repeating. Sometimes we just have to try things for ourselves before we believe them.
Nils

Has anyone done a direct comparison of these eyepieces? I was a bit puzzled when the 20t5 came out. The 22mm and 17mm t4s would seem on paper to be the better choice with their greater eye relief. Perhaps there are telescopes that can handle the 1lb 20t5 but not the 1.5lb t4s? Perhaps the t5 is sharper at the edge in fast scopes? I do notice that my 17t4 is doesn't hold up as well towards the edge in my f4.5 reflector as it might. But it isn't bad at all, and I can't imagine replacing what for me is otherwise the perfect eyepiece with the t5 when it is more expensive and has much less eye relief. Still, I'm curious about this new t5 and haven't seem many reports about it. Anyone compared it to a t4?

I recently bought a pair of these used and spent a couple of afternoons and nights with them before returning them. This was not long enough for a full review, but because of the interest and the scarcity of user reports, I thought I would post my impressions here. I've had a pair of Fujinon Polaris 7x50s for 3 years now, they have given me some of my most enjoyable views in this hobby. For all of their great qualities, they are also well-known for being too heavy and with only a moderately wide apparent field of view. The Miyauchis are lighter and have 66 degrees afov (9.5 degrees real fov), so it was with great interest that I read the reports of Holger Merlitz and Fan Tao on their performance. Both of these experienced observers noted issues with their Miyauchis, but were generally satisfied. Here is my experience.

The Miyauchis are indeed small and light compared to the Fujinon. Held above your head, you would guess they weigh half as much as the Fujinons, and they are very comfortable to hold. They also come with a beautiful brown leather case that is easily the finest I have seen for any binocular. The binoculars themselves look great, too, although a close inspection shows that the finish on the silver metal parts is perhaps not as even as it could be. The maroon leather is very nicely done.

The coatings seem a nice dark green, although they do not quite have the apparent quality of the Fujinons. More seriously, there was a slight haze on the inside of one of the 3 element objective lenses, and there were a couple of faint wipe marks on the inside of the other lens. These flaws are really unfortunate, and would be reasonable grounds for many customers to return for a refund. Additionally, when looking through the objective lenses towards the prisms and eyepieces, there were uneven areas on the prism coating. It looked as if circular areas on the center of the prisms were well-coated, but that outside this circular area the coatings had a mottled appearance. I have not seen anything like this before in a binocular. Perhaps it has no effect on the view if the areas I describe are out of the light path, but really it is another thing you don't like to see in an expensive binocular. Additionally, the prisms seemed much smaller than the Fujinon's, although this may be a consequence of the unusual porro-II arrangement of the Miyauchi.

These faults sound bad, but I was ready to overlook them if the Binons performed well. First views outside were promising - the view is indeed impressively wide. A neighbor and my dad both really liked them, as did I. Then, however, I sat down for a rigorous comparison with the Fujinons. On looking at a tree trunk in the middle distance, it was clear that the Fujinon showed more detail in the center of the field. Not much more detail, but there was a clear difference that I expect anyone who compared both would see. Here my experience is different from Holger Merlitz's, so perhaps this is a sign that I did not get as good a pair. Additionally, although the field is certainly smaller in the Fujinon, a much greater proportion of the field is sharp. The result is that when viewing a telephone pole in the near distance, a greater area of the telephone pole could be seen clearly without moving the Fujinon than could be seen in the Miyauchi.

(continued)

I have a similar Intes Micro M603 which does show me more detail than my 80mm refractor (although I have never used a TV 85). One thing to seriously consider is cool down time. Maksutovs, and especially these big russian ones, need to be set up outside for a minimum of an hour before you can do any kind of critical observing. If you've got a nice deck on your house, no dew problems, and the temperature doesn't fall quickly at night a lot (the cool down problem again), I'd go with the Intes. If you live in an apartment or have to drive somewhere to observe, by all means stick with the TV85.
If you do switch, you may find you have been spoiled by the focuser on the Tele Vue. You can replace the Intes focuser, though. Hope this helps,
Nils
I haven't looked at current asking prices, but I wouldn't be surprised if you could sell a TV85 here on astromart for enough money to buy a new Intes or Intes Micro (better baffling system and focuser).

I've only had a couple of chances to use my new 40mm XW, so I can't write a detailed report. Some impressions: it is heavier and much larger than the 40mm XL, it is just as comfortable to use as the XL, the step up from 65 to 70 degrees AFOV is much more dramatic than I expected, and it looks sharp to the very edge in my f10 Maksutov and f7.5 refractor. It was a lot of money (although they can be had for $75 less than normal by looking around) but I don't miss anything I sold and replaced it with (40mm XL, 30mm Widescan type 3). No buyer's remorse here.

Thanks Barry,
So you think the extra money is worth it? I've got a 501 which I use with my 10x80 flak binos (cloudy nights finally posted the review if anyone is interested) and although the 501 holds them, they do feel undermounted. I had thought about one of the larger Bogen fluid heads but the cost is so much more for something that looks so similar. But the 20x100 feel a lot more secure on the 516? I also find that one of the handles falls off every once in awhile, no matter how tightly the little allen head screw is secured. It looks like the 516 avoids this problem by having one-piece arms. Is this the case?
thanks again,
Nils

Hm, I was even stupider than I thought. I wonder how long I would have puzzled over that on my own. Thanks, Walter.

Now that is a good idea, Milt. I was at the beach this weekend with binoculars, and as usual passersby who wanted a look were amazed at how much you can see with binoculars. Your setup would have really impressed them. Must take some biceps, though.
As to the coatings, I remember reading a post on a photo website once from a guy purporting to work for a coating company. He sounded bona fide, and he said that even the big camera companies outsource for their coatings. I do not know how this squares with Fujinon's claims for their proprietary EBC, Pentax's SMC, Zeiss' T* etc. He said that for camera lens multicoatings, there was usually little difference between the coatings on lenses in more or less the same price class, and that a good percentage of his and other coating companies' effort was devoted to making sure the color was correct. Nikon wants their coatings to have that green your binos have, Zeiss have a rosy pink, Pentax a soft gold/green etc. The impression I got was that the color of the coatings was purely a marketing issue.
Again, this is secondhand knowledge, and I don't remember the source. I was convinced, though. I certainly wouldn't expect more or less CA based on the color of coatings, this would be a function of the optical design and coatings don't affect it as far as I know.
Coffee is ready, time to get to work. Thanks for the suggestion -I'm sure a lot of folks will try it.
Nils

Tom has a great article there.
Sooner or later, I reckon you'll want a pair that gives you the maximum field of view you can get in the 1.25" format. These include the 24mm Panoptic, 24.5mm Meade SWA, 23mm Celestron Axiom, 30mm Takahashi LE and 30mm Ultrascopic/Ultima. Some use the 32mm TV ploessl or 35mm Ultima, but these have wierd eye relief problems (too long) and do not actually give any wider field. Many people end up using this wide field pair the most, because you are more likely with a binoviewer to use a barlow/corrector for higher powers than to switch out eyepieces.

Floyd,
I think it is more the size of the prisms, the clear aperture in microscope prisms is just not big enough to illuminate all telescope eyepieces. Microscope eyepieces I've had have either been a bit smaller than .965" barrel or a bit smaller than 1.25" and widefield eyepieces for microscopes don't seem to be as wide as what we are used to. Binoviewers for telescopes started to become popular when purpose built binoviewers allowed the use of eyepieces with around 26mm field stop - like 24 Panoptics, 30mm Ultima/Ultrascopics, 24.5mm SWAs etc. I would bet that the microscope heads are 22mm clear aperture or less - I measured one microscope head at 17mm aperture, but I don't know that this is any kind of standard.
Nils