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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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I got a new job that I have been waiting on for a while. Better hours, and much higher pay........and all of that means I am finally able to plunk down some real cash on a quality bino. Heck, at this point, I really don't give a squat about my Celestron 25x100's any more. When I get them back from Warranty, they will probably go straight on eBay.
After spending hours and hours reading back through the bino-reviews in this forum, I have finally decided on which bino to get.........(*drum roll*)
The Oberwerk BT-100/45. I showed it to my wife on the Oberwerk website and she just rolled her eyes! LOL.
Unless someone can confidently state otherwise, the Obie BT-100/45 is about the best buy on the market when you consider it comes with the fork mount and tripod.
I have only one nagging question. It concerns magnification and merging the images. I have heard that the maximum "useable" magnification of these binocs is between 50 and 62X. But I have heard of people using 100X and more in these binos. What problems (if any) does this present? Does collimation become a critical issue when magnification reaches a certain threshold? My hope was to use these big-bad-boys at magnifications from 25 upwards to 100+.
Now I just gotta wait for a couple of paychecks to roll in.
(excited like a kid at Xmas!)
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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Anonymous
Unregistered
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As of you know, the higher the magnification, the tighter the collimation tolerance must be to still have a usable (and enjoyable) image. My BT100 is barely usable at 63x. I am guessing that somewhere in the mid to lower 50x is where my cutoff is. At 43x the collimation is fine. You have heard of 100x on the BT? That's a little hard to believe, but I admit it just might be possible with precison end-to-end collimation....although I would not enjoy the ultra narrow FOV personally.
The degree of collimation of your future BT will determine what level of magnification you feel is acceptable. There is no hard limit. It can vary. I think EdZ and I both have BTs with similar collimation and so we have about the same magnification limits. Neither one of us, as far as I know, have not sent our BT to be worked on. Assuming both of our BTs are "typical" in terms of collimation, your future BT I would guess will have, more or less, the same tolerance. I would not count on having the ability to use 100x.
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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Quote:
As of you know, the higher the magnification, the tighter the collimation tolerance must be to still have a usable (and enjoyable) image. My BT100 is barely usable at 63x. I am guessing that somewhere in the mid to lower 50x is where my cutoff is. At 43x the collimation is fine. You have heard of 100x on the BT? That's a little hard to believe, but I admit it just might be possible with precison end-to-end collimation....although I would not enjoy the ultra narrow FOV personally.
The degree of collimation of your future BT will determine what level of magnification you feel is acceptable. There is no hard limit. It can vary. I think EdZ and I both have BTs with similar collimation and so we have about the same magnification limits. Neither one of us, as far as I know, have not sent our BT to be worked on. Assuming both of our BTs are "typical" in terms of collimation, your future BT I would guess will have, more or less, the same tolerance. I would not count on having the ability to use 100x.
Well, I just learned something new. Cloudy Nights is a multi-fold blessing : you learn something new everyday, and you learn humility in the face of superior experience.
I read about a person using his BT-100's at 100 - 125x and then I read about another guy pushing his up to 150x. I forget what eyepieces they were using. I found the webpages on Google while doing some research on the BT-100/45. I'll try to dig them up and share the URLs. The guy who was using 150x said the performance was subpar and he did not recommend it for general viewing. The other guy using the 100x went on and on about how great the views were, but his website looked a little, well, backwards. It left me wondering whether this guy was all there so to speak. I'll try and dig them up for you.
Ok, back to the point, I was under the erroneous assumption that the oft-quoted, arbitrary mag-limit of 50x per inch of apeture also applied to binos. What I had not taken into account was the role that collimation plays in these higher magnifications. This makes me wonder (and other threads have touched on this before), is the maximum magnification of a binocular dictated strictly by collimation? What I mean is this : so for instance you had some ep's capable of giving you 100x in the binos, could one manually adjust the collimation (using the easily-accessible screws on the BT-100/45) to "pull in" the 100x eyepieces and make them usuable? Even if this would require re-adjusting the binocs when going back down to 25 or 43 (or whatever).
And is this collimation/magnification issue what "binoviewers" are designed to overcome? I see these awesome "binos" that are side-by-side, large APO refractors, and those can apparently be used at magnifications higher than 25, 43, 63, etc. How do these kinds of binoviewers address the collimation issue? Is it a fundamental difference in design?
And lastly, given that the binos have trouble merging images at very high magnifications, could I simply close one eye and use the BT-100/45 as a telescope if desired? If I spotted something really nice in the 40-50 power range, could I drop in a 100x eyepiece in one barrel and close one eye to get an up close look?
Part of my decision to purchase the BT-100/45 was the incorrect assumption that I could push the magnification up to around 100. If this is not possible, then I might rethink my decision. However, I am so spoiled on using binos and having a "correct view" of the sky, that I cannot bring myself to get a telescope yet. I want to push the limits of bino-astronomy to the very edge of my personal finances. What kind of bino can I use (if any) to get that kind of magnification?
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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Anonymous
Unregistered
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Please share the addresses of those using their BTs at > 100x. I would really like to see that.
I am not aware of any magnification limit per inch aperture for bins. I have never heard about that in these parts of CN. Is that a suggested limit for reflectors? I have no idea.
You would probably use a barlow & EP to achieve that level of magnification and not just an EP, but anyway..."could one manually adjust the collimation (using the easily-accessible screws on the BT-100/45". I have not used the 45 degree version, but if the prism housing and the floating system used to hold and align the prisms is anything like the straight through version, it is anything BUT easy. There are 3 nuts to adjust per prism...assuming the nuts rotate at all. Mine won't. Regardless, "dailing in" the conditional alignment would not be an easy task. And being that I doubt you have an optical bench with alignment lasers, I think it would be a futile (and foolish) thing to attempt. An intersting thought experiment, but on a practical level, forget it.
I seriously doubt that you could achieve the conditional alignment tolerance to reasonably use 100x. They are still fine pieces of hardware worthy of your consideration, despite the tolerance issue. If you want > 100x, buy a scope!
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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Quote:
If you want > 100x, buy a scope!
Crud! Maybe I will just "settle" for these :
http://www.binoculars.com/products/Miyauchi_BR141__10340.html
And yeah, I thought messing with the collimation screws would likely be a BAD idea, but I had to ask. So I guess the ultimate question of binocular power has been answered....~50x is the limit of useability.
These are the kinds of things I needed to know before dropping $2000 on something.
I don't have the URLs of the "100-power club", but I will dig it up.
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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Anonymous
Unregistered
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Quote:
Heck, at this point, I really don't give a squat about my Celestron 25x100's any more. When I get them back from Warranty, they will probably go straight on eBay.
Hey Mike, why put them on ebay when you can find a good home for them here.
I could adopt them. That way their little brother can keep them company 
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Alby
scholastic sledgehammer
Reged: 02/12/05
Posts: 899
Loc: Ontario, Canada
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Bebs;
I seriously doubt that you could achieve the conditional alignment tolerance to reasonably use 100x. They are still fine pieces of hardware worthy of your consideration, despite the tolerance issue. If you want > 100x, buy a scope!
I'll second what NW writes!
While I haven't gotten my second set of EPs(it's back and forth between Nagler 11/13mm or Pentax XW 10/14mm), I'm hoping before fall.
I think with what's meant to be a wide field instrument(binocs in general) it might be folly to push for 100x in the BTs.
Did I ever mention they rock?
Yes Bebs they do!
IMO the BTs should be treated as rock solid great performing binocs and not a scope substitute.
The BT 100 45s could be a stepping stone to a future scope purchase(8in or bigger?). That to me would seem like a reasonable next step in aperture.
Starting with 25x and in time getting additional EPs, the BT could keep you busy for years.
Once, I did insert a single 13mm EP into my BT 100 45 and the view seemed just fine to me. I suppose if you had assorted EPs, you could have two different powered side by side telescopes going.
It's quite remarkable what these show at 25x. Waiting for those higher power EPs is tough to endure at times!
Just a thought...I've read that you and your wife are into birding also? The BTs as you know are IF EPs, it takes some time to get focus on these(terrestrially)let alone on moving objects! But once that bird is in focus....WOW!!!!
Regardless what you look at I believe you'll be happy:) with the BT 100 45s!!
Congrats on the new job Bebs.
Cheers
Alby
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Alby
Scoping Savant
10in LX200 Classic SCT
Oberwerk BT 100 45
7x50 USSR Binocs
Nikon Action Extreme 10x50 binocs
Edited by Alby (07/15/05 04:13 PM)
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Anonymous
Unregistered
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I am not trying to talk you out of buying the BTs, I'm just stating what I think based on my experience with my BT. I agree with Alby, bins are meant for reasonable and relatively wide FOVs. I feel they are at there best potential when used in that manner. Even if I could use the BT at 63x or even 100x, would I? No. The narrow FOV would be unappealing to me. The ultra wide EPs can compensate for this to a degree, but at a cost of course. I use 25x and 44x currently and would like something in the mid 30's to have a the entire range covered. But I digress. I don't be put out by all of this. These are my opinions and findings.
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Joe Ogiba
Post Laureate
Reged: 02/14/02
Posts: 3363
Loc: NJ USA
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Anyone try 27mm+ field stop 1.25" eyepieces like 32mm Plossls or 24mm Panoptics to see if there is any vignetting ?
Joe
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Pentax PF-80ED
Meade 102ED APO
Orion EON 72
120ST
Apex 127
C6 XLT
CR150
C9.25
XT10
Zeiss 7x42 FL
Canon 10x42L IS WP
15x50 IS
12x36 IS II
Garrett Optical 28x110 HD-WP Signature Series
Oberwerk BT-80 45
Apogee RA-88-SA
Denk II Power x Switch binoviewer w/13mm Ethos, 20mm Pentax XW's, 20mm Widescan III's.
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milt
sage
Reged: 09/13/04
Posts: 430
Loc: Arizona
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Quote:
Even if I could use the BT at 63x or even 100x, would I? No. The narrow FOV would be unappealing to me.
NW, I wish I could have shared views with you of the Moon at 128x through my 100ED binoscope. The "narrow" FOV was exactly right for the terminator to sweep from field edge to field edge giving a strong 3-D sensation.
But you are right, you can't do it without adjusting collimation, which is the strength of the high-priced Astromeccanica 2x3 mirror back end. I had four sets of eyepieces for 27x, 43x, 71x and 128x. As long as I stayed at the lower powers I never had to touch the adjusting knobs. At 71x it started to become more sensitive and at 128x I usually tweeked collimation each time I inserted the ep's.
I don't think it'a a coincidence that fixed collimation proprietary ep binoculars stay at 50x or below. But as we have discussed, you can do a bunch of serious astronomy at those powers.
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Clear skies, Milt
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Anonymous
Unregistered
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Quote:
Crud! Maybe I will just "settle" for these :
http://www.binoculars.com/products/Miyauchi_BR141__10340.html
MikeG
Nah... you won´t like them. They provide an awful view of the sky... I mean, you ever heard the expression "chinese junk"?? 
cheers on your new bino!
Edited by Laszlo Kovacs (07/15/05 06:21 PM)
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Mike B
Starstruck
Reged: 04/06/05
Posts: 4464
Loc: shake, rattle, & roll, CA
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Hi Bebs-
Yeah- i'll second (or third) the idea of getting a scope for the 100x range!  With a 10" SCT and a binoviewer, my lower range is about 60x & around 1 degree FOV... and have the optical clarity to see detail on the planets & moon- from there all the way up to 300+! I can't expect my SCT/BV combo to get more FOV- it can't. Nor would i expect my binocs, a wide-angle instrument by design, to achieve hi-mag views- it can't. Even the $13k Miyauchis are advertised as 25x-45x.
But major kudo's on yer new job!  Maybe if you save enough  on getting the Obies instead of the Miyauchis maybe you can swing a nice telescope outta the deal 
 mike b
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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In reference to high-magnifications on binocs similar to the BT-100's, I offer this from the CN vaults :
http://www.cloudynights.com/item.php?item_id=204&pr=2x48x60
The review is for the I.T.E. LABT-100 Large Aperture Binocular. It uses interchangable, 1.25 standard ep's, and the reviewer discusses using 7mm Naglers and barlowing other combinations of ep's to produce high-power bino views, or high-power "telescope" views using one ep.
Quote:
Specifically, I used:
Televue 40mm plossls (for a magnification of approx. 16x)
Televue 24mm wide-fields (for a magnification of approx. 26x)
Televue 15mm wide-fields (for a magnification of approx. 42x)
Televue 10.5mm plossls (for a magnification of approx. 60x), and
Televue 7mm naglers (for a magnification of approx. 91x)
Out of not too much more than idle curiosity, I decided on one clearish night of good seeing to see just how good the objectives in the LABT-100s really were. Rumour has it, although it's entirely unsubstantiated, that the triplet objectives were manufactured by Zeiss. If so, they ought to be fairly decent, I figured. And fairly decent they in fact are. Better so than fairly decent. (Here the reader is advised to resist the urge to infer the antecedent from our confirmation of the consequent in the previous conditional...). Deciding to forego binoviewing in favor of higher-power mono-viewing, I slipped in a 2x barlow lens in front of one of the 10.5mm plossls for an effective magnification of 120x or thereabouts, and trained the binoscope on Jupiter. Happily, the great red spot was visible, and it was great and spot-like, if not red. At this power, I had a small amount of difficulty keeping the binoscope steady enough to view detail, but when steadied very nice detail was evident in the banding on the planet. I swapped binoscope sides and sure enough, the other side of the binoscope also revealed similar detail, leading me to believe that the objectives are a nice match for each other. I did notice some false color on particularly bright objects (Jupiter, the moon, et cetera) but not an objectionable amount; in fact, given the short focal length of the binoscope, I expected more chromatic abberation than the binoscope exhibits. Again, confirmation that the triplet lens assembly is of very high quality. I also tried barlowing the 7mm naglers at 182x, but by this time the seeing had degraded to the point where I didn't think any reasonable conclusions could be drawn and I haven't since had a night with good enough seeing to try pushing the magnification up that high. In any case, such a magnification is near the theoretical limit for any scope of this aperture, so I'm not holding my breath that it's worth doing anytime soon...
(original review by Joshua Finkler. See link above)
So perhaps with the right coaxing, a bino like the BT-100 could be pushed to high mags than ~50. FOV is still a concern for me naturally. "Correct image viewing" and wide FOV is the hook for me when it comes to binos and a scope just won't do it for me. Well, I still have time to research the decision and mull it over, it'll be a several weeks before I get the cash to actually buy.
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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edwincjones
Post Laureate
Reged: 04/10/04
Posts: 4432
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I think interchangable eps are overrated. I have the Miyauchi 20x100s with the 37x eps also, but rarely use them. The 20x is just more comfortable-maybe it is the wider FOV, maybe greater eye relief, maybe just my bias.
I do enjoy binoviewers with telescopes.
Ed Jones
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n w arkansas
Binocular, Solar, General Amateur Astronomy
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milt
sage
Reged: 09/13/04
Posts: 430
Loc: Arizona
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Quote:
perhaps with the right coaxing, a bino like the BT-100 could be pushed to high mags than ~50
Hi Mike,
I have no doubt that the objectives could easily handle >50x as Ed Z has stated in the past. The problem is that the coaxing you refer to will be coaxing your eyes to merge the images. When you bring your eyes to the eyepieces and see two of everything it gets old in a hurry. Yes, you might be able to tweek the binocular collimation to help but it is not an easy procedure and will be unlikely to hold well enough at mags of 100+ anyway.
In summary I just wouldn't count on being able to push the BT100 (or any fixed collimation binocular) that far, nor do you need to because IMO the 20x-40x range is absolutely enthralling in binoculars! As others have advised, a binoviewed scope is a far easier solution for high powers.
Good luck, Milt
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Joad
Wordsmith
Reged: 03/22/05
Posts: 11923
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Bebs, I doubt that we were separated at birth, but we do have the same desires! And I read a long time ago the very same CN BT review that you've quoted from here. I've just noted that the reviewer was using his scope for monoscopic viewing to push it to 100X and higher, though.
I, too, once thought about upgrading to the new 45° Oberwerk with interchangeable EPs (I already have the older fixed EP 45° Oberwerk at 40X). I decided to go with a new monoscope instead and keep my fixed Oberwerks on Prof. Edz's and Night Watch's advice. I am very glad that I did. As a number of contributors to this thread have noted in one way or another, if giant binos could go to higher than ~50X, they would, but even the super expensive top of the line models don't do that.
Like you, I really dig giant binos. The problem is that you can get much more bang for your buck with a telescope and a bino-viewer. Now, my position is not the same as yours. I already had an Oberwerk 100mm (and if you decide to go with a 100mm binoscope you can't do better dollar for dollar than the model you've indicated here), so my 8 inch SCT complements my bino viewing. However, here's an idea (thanks to your promotion): you can a 45° Oberwerk fixed EP 25X100 mm triplet binocular for around $1200 or less (eBay offers some bargains in this regard) these days becasue of the new upgrade to the line. You can also find scopes like the Meade LX10 8 inch SCT for real bargain prices too. If you find bargains, and they're out there on instruments like these, you could end up with an awesome binocular (for wide field low power viewing) and a very nice telescope for not much more, or even no more, than the cost of the new interchangeable EP 45° Oberwerk (and once you add the EPs necessary to go beyond the 25X they come with, you've gone over the combined price of scope and bino anyway).
There, I've just made your life more complicated. Thanks a lot, Joad.    
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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Ok, I've done a lot of digging around on the web and I have finally conceded that I will not get super-duper 100-200x mags out of binos no matter what I do. Unless of course I buy one of those Astromeccanica "binos" which is really two side-by-side refractors. But the asking price on those is little bit out of my reach - even with the new job.
So I have decided to buy a really good pair of binos and then around Xmas time get myself a refractor as well. As for the binos, I am now leaning towards something in the 25x100 range, but with better optics than my Celestrons. Perhaps the Oberwerk 25x100 might be the answer. I have also looked at those Vixen 30x80mm and I am intrigued. Has anyone used these Vixen binos, and if so, how good are they?
And yeah, I got to thinking, for what I would spend on those BT-100/45's I could get a pair of good binos AND a scope. That will likely happen now.
Thanks for all of the input guys!
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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CESDewar
GorillAstronomer
Reged: 01/16/05
Posts: 1812
Loc: Morganton, GA, USA
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Quote:
So I have decided to buy a really good pair of binos and then around Xmas time get myself a refractor as well. As for the binos, I am now leaning towards something in the 25x100 range, but with better optics than my Celestrons. Perhaps the Oberwerk 25x100 might be the answer.
Well, I would certainly be inclined to agree with you on this. There is just no single solution for all viewing requirements. I have the Oberwerk 25x100mm IF's and have been very pleased with them - yes I've looked through some high end 25x100mm binos, but I also decided that I would save the $1,000 and spend it on a small refractor (I actually spent more for the WO 80mm Fluorite APO, but their ED version at $795 is an excellent scope). You would easily get your 100-150x views with that scope and no binocular is going to touch that (and if cyclopsing is a big issue, another $320-340 or so can get you a Burgess Binoviewer plus a Siebert Optics OCA - Burgess has a very inexpensive OCA that might even work on some refractors).
In fact, while we're on that subject, don't exclude the possibility of getting a short 80/100mm refractor with a binoviewer INSTEAD of binoculars. Even with a 1.8x OCA (you'll need some OCA to bring the binoviewer into focus), you could get down to around 40x with a pair of 21-24mm EP's on the WO Scope. I find the views through the binoviewer on my WO scope to be very satisfying due to the exquisite optics of this scope. And with a pair of 8mm EP's the views of the moon and Jupiter are breathtaking (I even use a 2x Barlow as well for 216x when the skies are good). I often find the moon/planetary views through the binoviewers on that scope are a match for a cyclops view in my SCT.
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Anonymous
Unregistered
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I think you made a wise decision Mike. For the type of observing you would like to do, the BT just will not cover all the bases. A combination of a 25x100 bin, or its equivalent, and a decent scope I think would satisfy your particular observational cravings.
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Glassthrower
Vendor - Galactic Stone & Ironworks
Reged: 04/07/05
Posts: 14703
Loc: Hurricane Alley
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Quote:
A combination of a 25x100 bin, or its equivalent, and a decent scope I think would satisfy your particular observational cravings.
Yes, you are quite right. Now I must begin my quest to find the BEST 100mm binocular in the 500-600$ range. That will leave me another 500-600 to get a decent refractor later this year. But right now, I am on the bino hunt.
Thanks again guys for all the input.
MikeG
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Michael Gilmer - Member of the Meteoritical Society & Collector of Falling Stars.
Galactic Stone & Ironworks - Buy/Sell/Trade Meteorites, Moon Rocks, Mars Rocks, & 35 different falls and types!
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