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Old Wednesday 25th January 2017, 00:24   #251
elkcub
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Originally Posted by SMark View Post
Thank you. I would agree that it is clearly not meant to be an adjustable eyecup, as it is quite difficult to both remove and then replace. I meant to say only that it unscrews. The rim underneath it then also unscrews, thereby allowing the diopter setting to be adjusted if needed, which this one did need when I got it. I can't even budge the left side, so I can't say if it is different or similar. On the newer model, the left side has a bayonet attachment for the eyecup, the right side is threaded and tightens to put downward pressure for the diopter.
Not sure what's going on with yours, but my white model has bayonet mounted eyecups on both sides. Please elaborate.

Ed
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Old Wednesday 25th January 2017, 03:04   #252
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Not sure what's going on with yours, but my white model has bayonet mounted eyecups on both sides. Please elaborate.

Ed
Perhaps I simply don't have the correct understanding of what a bayonet mounted eyecup is. In the pic below, the left eyecup attaches tightly with a quarter-turn twist. The right eyecup screws-on with about 4 complete turns. A tight fit is required or the diopter will slip.
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Old Wednesday 25th January 2017, 03:54   #253
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I suspect that on your specimen the bayonet mounted eyecup is frozen. Since it's mounted above the diopter, when you forced it to turn the diopter cover came out with it.

The left and right eyecups are identical and interchangeable.

Ed
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Old Wednesday 25th January 2017, 04:13   #254
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I suspect that on your specimen the bayonet mounted eyecup is frozen. Since it's mounted above the diopter, when you forced it to turn the diopter cover came out with it.

The left and right eyecups are identical and interchangeable.

Ed
Indeed, it looks like that is the case. Separating them should be fun... Okay, that wasn't so bad. Just a little upward pressure while unscrewing separated them. Everything seems good now.
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Old Wednesday 25th January 2017, 04:27   #255
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I removed the right eyecup on the green letter Audubon again just to take more pics. I still can't budge the left one, but I suspect there isn't much difference between them...

BTW, there are no set screws in that ring. Just for spanner wrench points, I guess.
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Old Wednesday 25th January 2017, 04:46   #256
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Here's something else ya'll might find interesting...

While I'm not really a Swift Collector, I generally collect wide angles. So one of my favorite wide angles is the Swift Holiday. One of my Holidays is very similar to these two Audubons. And it's actually more similar to the green letter Audubon, except that it's not green. But it has the same eyecups, the same "Coated Optics," and no JB numbers. The right prism plate (cover) graphics look more like the second Audubon, and then it's missing the trademark symbol as well. So it would appear to come from this same era anyway. And it is also my favorite Holiday of the 5 that I own (2 of the 5 are duplicates.)
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Old Wednesday 25th January 2017, 07:37   #257
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Originally Posted by SMark View Post
Here's something else ya'll might find interesting...

While I'm not really a Swift Collector, I generally collect wide angles. So one of my favorite wide angles is the Swift Holiday. One of my Holidays is very similar to these two Audubons. And it's actually more similar to the green letter Audubon, except that it's not green. But it has the same eyecups, the same "Coated Optics," and no JB numbers. The right prism plate (cover) graphics look more like the second Audubon, and then it's missing the trademark symbol as well. So it would appear to come from this same era anyway. And it is also my favorite Holiday of the 5 that I own (2 of the 5 are duplicates.)
First type Holiday here, issued by Swift & Anderson. Field of view, already generous with 578 ft/1000 yds, went up to 600 and even 630 in the 1970's and 80's.
Ed, an interesting thing of which I don't know if we ever discussed it, are the serial numbers of 1960's Holidays. While we never were able to find Audubons with sn's from 1963 and 1964 (our infamous gap) we did encounter Holidays from these years. Tamron-Zuiho, company number 4 preceding the sn.

Renze
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Old Wednesday 25th January 2017, 20:07   #258
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Hi Renze,

Yeah, I remember doing a marginally productive analysis of our Swift database. My current thinking is that after the transition from Swift & Anderson to Swift Instruments in 1960, the early Type 1a, and possibly Type 1b, continued to be provided by Tamron-Zuiho until changed to Hiyoshi Kogaku (with Type 1c). And it seems like Tamron-Zuiho also encoded the date into the s/n after 1960.

In 1969 the S&A catalog lists Model 766 7x35 Holiday Mark II at the same level of quality as the 804 Audubon, — costing $56.25 vs $58.50. I shall scan and attach the first few pages, which cover several topics discussed here including quality, bayonet mounted eyecups, RLE, 804 Audubon and 766 Holiday.

Ed

PS. Swift Instruments consistently included the RLE factor in it's catalogs throughout it's corporate history — right into the 21st Century. More about that later since it is kind of interesting (well, to me anyway )
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Old Thursday 26th January 2017, 05:07   #259
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The best technical explanation that I've come across for "RLE" appeared in Dr. Henry Paul's 1965 book: "BINOCULARS and All-Purpose Telescopes."* There was a reasonable rationale for the metric, but it doesn't appear to have been applied correctly or uniformly, even though Swift used it into this century.

In 2000 the RLEs for the new Models 820 and 820ED were given values of 44.2 compared to 44.0 39 yrs. earlier for the 804. Virtually no credit (only 0.45%) was given to multi-coating advances made in the interim.

Recalculating, given a measured transmission of 89%, the 820 should have an RLE = 2x(44/8.5)^2x.89 = 47.7. This is 9% greater than the single coated version made in 1961. And since the human eye perceives a 'just noticeable difference' (jnd) of about 3% for brightness, the modern version is distinctly brighter.

(Note: *Rotate the view clockwise in Acrobat Reader and print in landscape mode if you'd wish).

Ed
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Last edited by elkcub : Thursday 26th January 2017 at 09:23.
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Old Wednesday 3rd May 2017, 00:11   #260
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Hello, I’ve just registered on Birdforum and this is my first post. I hope that it will be within the forum rules.

I’ve read with great interest the discussions about the history of the Swift Audubon binoculars and the article by Edward M. Huff and Renze de Vries that tried to build a timeline of the different versions. Why this interest? Because 36 years ago I bought a Swift Audubon 804 Mark II in an optician shop in The Netherlands. During all these years it has been heavily used by me on an almost daily basis (and often mistreated in less ideal circumstances, as can be seen on the photos) for aircraft spotting and bird watching. It even fell on concrete once when the neck strap broke, resulting in some damage to the right hand ocular lense.

I’ve always been very satisfied with the wide field angle, the sharp image and the good performance in dark circumstances. But in the last years this satisfaction slowly faded away because the bridge became more and more unstable and the diopter moves when holding the binos with one hand. This is caused by a crack in the diopter ring. Also the vision became less clear, apparently because of some haze on the inside of the left objective. Furthermore collimation may be needed. For these reasons I was looking for new binoculars, but now that I’ve read on this forum that maintenance and repair by a qualified company in The Netherlands may be possible, I will now first look into that option.

My 804 has manufacturer code J-B56 and serial number 811979 and is of type 3b (gold ribbon), but with a metal (not rubber-coated) focus knob. Another remarkable point is the red text “wide field 8.5°” on the right cover plate instead of “extra wide field” as is present on all the photos that I’ve seen except the one on the right of page 14 of the document by Edward M. Huff and Renze de Vries. It has no “H.R.” on it, just “Audubon”.

The upper parts of the rubber eyecups went missing on my 804 since I kept them always in rolled down position, what caused that these parts broke off after the rubber had dried out.

Ad
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Old Wednesday 3rd May 2017, 00:56   #261
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Hello, I’ve just registered on Birdforum and this is my first post. I hope that it will be within the forum rules.

I’ve read with great interest the discussions about the history of the Swift Audubon binoculars and the article by Edward M. Huff and Renze de Vries that tried to build a timeline of the different versions. Why this interest? Because 36 years ago I bought a Swift Audubon 804 Mark II in an optician shop in The Netherlands. During all these years it has been heavily used by me on an almost daily basis (and often mistreated in less ideal circumstances, as can be seen on the photos) for aircraft spotting and bird watching. It even fell on concrete once when the neck strap broke, resulting in some damage to the right hand ocular lense.

I’ve always been very satisfied with the wide field angle, the sharp image and the good performance in dark circumstances. But in the last years this satisfaction slowly faded away because the bridge became more and more unstable and the diopter moves when holding the binos with one hand. This is caused by a crack in the diopter ring. Also the vision became less clear, apparently because of some haze on the inside of the left objective. Furthermore collimation may be needed. For these reasons I was looking for new binoculars, but now that I’ve read on this forum that maintenance and repair by a qualified company in The Netherlands may be possible, I will now first look into that option.

My 804 has manufacturer code J-B56 and serial number 811979 and is of type 3b (gold ribbon), but with a metal (not rubber-coated) focus knob. Another remarkable point is the red text “wide field 8.5°” on the right cover plate instead of “extra wide field” as is present on all the photos that I’ve seen except the one on the right of page 14 of the document by Edward M. Huff and Renze de Vries. It has no “H.R.” on it, just “Audubon”.

The upper parts of the rubber eyecups went missing on my 804 since I kept them always in rolled down position, what caused that these parts broke off after the rubber had dried out.

Ad
It looks well used, but mostly well loved. You will probably find that it will need a good amount of work. Here's one just like it that looks almost unused, for a price that most would consider very good...

http://www.ebay.com/itm/322496721913
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Old Wednesday 3rd May 2017, 20:47   #262
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Hi Ad,

Congratulations on actually having worn out a 1981 Audubon. At this point it would be questionable repairing what you have considering what they sell for on eBay. For example, [see HERE]. Even so, keep in mind that modern coating make a big difference and the HR/5 models are more handy (but perhaps not as durable as the one you have).

Ed
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Old Monday 31st July 2017, 05:51   #263
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Audubon collectors might be interested in a 1959-60 "original" Audubon on SALE HERE for the next two days.

Ed
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Old Monday 31st July 2017, 07:56   #264
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Someone must have made 'em a deal they couldn't refuse.
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Old Monday 31st July 2017, 08:22   #265
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Wow, that was quick.

Ed
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