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Swift HR 5 (1 Viewer)

Binastro

Well-known member
. Does anybody know the percentage transmission of a completely optically clean 1985 Swift HR 5 8.5×44 binocular?

Is the percentage transmission of a later model greater?

All the best.
 
. Does anybody know the percentage transmission of a completely optically clean 1985 Swift HR 5 8.5×44 binocular?

Is the percentage transmission of a later model greater?

All the best.

A picture of the cover plates would help to identify your specific model variant. In 1985, Model 804R was introduced in the USA by Swift Instruments. In Europe, Swift-Pyser sold the same instrument differently marked as HR/5. In both cases I believe the optics were the same and marked "multi-coated." By 1989 the coatings were improved, but still marked multi-coated... probably because more glass surfaces were multi-coated. By the early-1990s the HR/5 Audubons were marked "fully multi-coated," but they were also upgraded in the late 1990s. [The Model 804 series was discontinued in 2000.]

Although I don't have specific transmission values for any of these, I can say that, by inspection, the relative brightness did increase with each coating improvement, and color contrast as well.

Attached is a transmission spectrum for a late-model 804ED (1998?), which was considered outstanding at the time.

Best,
Ed
 

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. Thank you very much Ed,
. The information is very useful and the transmission spectrum quite detailed.

I had the choice of several HR/5, but I chose the best one, which is perfectly clear and unmarked but from 1985. This was best for me as a later one, although it might have greater transmission, if it is not perfectly clear then it will be inferior.

As I'm interested in the transmission at night, it would seem that my one might be about 78%, and the later one shown 83%. 78% is not great but it is what I use.

Would you think that there is any is vigneting in the Swift HR/5 binoculars?

I would think that the Minolta Activa 12×50 and some examples of the cheap 15×70 Revelation, which are multicoated on every surface, may reach 90%. Although the Revelation in particular is supposedly 63 mm not 70 mm. Some of these Revelations do not have multi coating on every surface despite what the suppliers say. I will have to look closely at the Minolta to see the actual aperture.

Although figures of 95% are claimed sometimes, I think that only the Fujinon actually achieve this, although this might not be a night. The weight of some of these may be too much for me. And maybe the Zeiss HT. Possibly some Nikons also.

But for astronomy, one just really needs a slightly larger aperture to compensate for not the best transmission.

The problem with the 1985 HR/5 is more that there are ghost images of streetlights. This in fact degrades the view more than any lower transmission.

I was testing some other binoculars and it is the veiling glare that drastically reduces the visibility of faint stars.

It is this veiling glare and ghosting that really affects the view. Here Leica binoculars generally perform well, as does the Conquest HD. I'm not sure that Porro prism binoculars are actually any better than roof prism binoculars as normally the roof prism binoculars are shielded much better from ghost images.
 
Hi Binastro, I have a model 804 HR5, not sure of the year, but have never noticed a glare problem with it. I did however notice such an issue with the earlier Audubon, gold band model, which I solved by stripping down and matt blacking the inside of the body, including the chrome nuts which hold the lanyard fixing.
I now slightly prefer view of the older gold band model, although must be said the HR5 is a lot less weighty and easier to handle.
 

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. Hi Ben,
. That is a nice Swift case. I don't have one with my binocular.

The serial number will tell you the year it was manufactured.

Try viewing some stars about 10° or 15° above the horizon, maybe 20°. This is when streetlights are shining at you and near to the field of the binocular or actually when the streetlights are within the field of view.
With the streetlights within the field of view I'm pretty sure you will have ghost images. And depending on the position you may have glare issues issues with the streetlights just outside the field of view.

With some good quality roof prism binoculars even this severe test hardly produces any ghosts or glare.
 
Thanks Binastro, the binocular has little smear inside, and 2 tiny pin marks on the right eye lens coating, otherwise mint. I will give your suggestion a try later and let you know how it goes. I have a really nice Opticron Minerva that suffers the same issues, in daylight it's a cracking little binocular, but at night it suffers with bad ghosting and glare.
 
I've owned two 804 HR5 MC from the 1980s and three FMC from the 1990s including the ED version, and the FMC were noticeable brighter, more color neutral, and had better color saturation. The ED version had the smallest sweet spot and the most pincushion.

For stargazing, my MCs were better because they had larger sweet spots and very low astigmatism and coma started >75% out and didn't get bad until the edge. The FMC had more aberrations but were better for birding because of their more advanced coatings. Very, very sharp images.

Ideally, I'd like a FMC 804 with as good edges and lower distortion like the MCs.

Brock
 
I've owned two 804 HR5 MC from the 1980s and three FMC from the 1990s including the ED version, and the FMC were noticeable brighter, more color neutral, and had better color saturation. The ED version had the smallest sweet spot and the most pincushion.

For stargazing, my MCs were better because they had larger sweet spots and very low astigmatism and coma started >75% out and didn't get bad until the edge. The FMC had more aberrations but were better for birding because of their more advanced coatings. Very, very sharp images.

Ideally, I'd like a FMC 804 with as good edges and lower distortion like the MCs.

Brock

The MC and FMC versions of the 804 HR/5 Audubons differ only in lens coatings. The optics and mechanics are otherwise the same. In fact, the parts are interchangeable. The 804 ED has a somewhat different opto-mechanical design, but was also produced with different multi-coating variations.

Astigmatism, coma and distortion are monochromatic aberrations that do not vary systematically with lens coatings. I very much doubt that the "sweet spot" varies with lens coatings either. However, since there is no optical definition for it, anything goes.

For sky observation I'd strongly recommend considering a late-model 10x50 HR/5 Audubon Kestrel, which were manufactured until about 2002 and were fully multi-coated. They're also a great birding binocular.

Ed
 
Thank you very much Ed for Post 8.
Most helpful.

P.S.
What is the field of view of the 10x50?

Do HR/5s vignet?

10x50 7.0 degrees maybe.
 
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The MC and FMC versions of the 804 HR/5 Audubons differ only in lens coatings. The optics and mechanics are otherwise the same. In fact, the parts are interchangeable. The 804 ED has a somewhat different opto-mechanical design, but was also produced with different multi-coating variations.

Astigmatism, coma and distortion are monochromatic aberrations that do not vary systematically with lens coatings. I very much doubt that the "sweet spot" varies with lens coatings either. However, since there is no optical definition for it, anything goes.

For sky observation I'd strongly recommend considering a late-model 10x50 HR/5 Audubon Kestrel, which were manufactured until about 2002 and were fully multi-coated. They're also a great birding binocular.

Ed

Yours maybe, but not mine.

Brock
 
Thank you very much Ed for Post 8.
Most helpful.

P.S.
What is the field of view of the 10x50?

Do HR/5s vignet?

10x50 7.0 degrees maybe.

Hi Binastro:

The FOV is 367ft. at 1000 yds (122m at 1000m).

I'm not sure about vignetting. The eyepieces have distinctly round exit pupils, and I haven't found any falloff in image brightness, as might be the case with BK7 prisms. My impression is that the eyepieces are interchangeable with the 8.5x44 Audubon's, — the objectives having a longer focal length, of course.

All in all, it's a great binocular.

Ed
 
Swift-audubon-8.5x44 - Hr-gold

This is a nice find, virtually mint condition Audubon Gold Band model, case and all straps never used, boxed with all it's original bits and bobs. I have a slightly earlier one of these, just as good really. see <a href="https://www.flickr.com/photos/95019762@N07/10244486083/in/dateposted-
 

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Makes me miss my now *SOLD* 804 HR/5 MC Audubon, which had the same case. All I have left is the box.... and memories of staying out for hours using the Audubon for stargazing. Very low astigmatism, very tight stars. Even Sirius was a round ball on a night with "good seeing." When my pockets are jingling again, which better be soon, instead of buying a new roof, I think I will buy back the 804s, if the buyer still has them.

Brock
 
This is a nice find, virtually mint condition Audubon Gold Band model, case and all straps never used, boxed with all it's original bits and bobs. I have a slightly earlier one of these, just as good really. see <a href="https://www.flickr.com/photos/95019762@N07/10244486083/in/dateposted-

Yes, it's a mighty nice find. Keep in mind this is a gold-ribbon Type 3B marked "H.R," a picture of which is shown on pg. 14 of our 2005 paper. But there were also white-ribbon and no-ribbon variants, only the latter marked "Fully Coated Optics" (FC). Neither of your gold-ribbon specimens is marked FC, so does the paperwork clarify whether or not they are? That would be of historical significance. [Unfortunately, only after our paper was published did we discover that the year of manufacture is the first two digits of the s/n, so all these variants probably can now be put in historical order.]

According to our classification, Type 4b is the first of the "HR/5" Audubons, and like Type 4a (804R) had multicoated optics (MC). This made a major improvement in the view. I'm not sure what H.R. or HR/5 meant exactly. Or maybe I knew 10 yrs. ago and forgot. Any idea?

Hope you enjoy your new toy.
Ed
 
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Hi Ed, yes the brochure I have on Swift models says that all glass to air surfaces are fully Coated on Gold band models. HR is high resolution, but don't know about the 5, likely Binastro is right, it uses 5 part erfle system. The first two digits are 84.
 
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Bencw/Binastro,

Well, of course, Renze and I thought of 'High Resolution' too, and realized that there is a 5-element eyepiece, which Swift advertised copiously since the first Audubon in 1957. However, I never found a written definition of the abbreviation H. R. (Type 3), or HR/5 (Type 4). That's what I'm looking for (don't ask me why. ;))

Do you have brochures issued by Swift-Pyser covering that period by any chance?

Ed
 
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Sorry Ed, only have this Brochure for the early gold band period:

https://www.flickr.com/photos/95019762@N07/10244837135/in/dateposted-public/

https://www.flickr.com/photos/95019762@N07/10244835745/in/dateposted-public/

https://www.flickr.com/photos/95019762@N07/10244927153/in/dateposted-public/

No idea significance of the bands in relation to other models, just a Pyser marketing ploy I guess.

Binastro, remember you mentioned the timex watch in another thread, I then came across a mickey mouse timex from 1970, good condition, just couldn't stop myself, bought it on whim, bit of fun.
 
My first pair of dedicated birding bins in the late 80s were Swift Audubons 8.5x44s. I always regretted mislaying them (think I must have given them away to a relative), so when I saw a pair in a 2nd-hand shop at the weekend I couldn't resist. They're 1990 HR/5s (type 4b) and in great condition - the view through them is really great (not far off the Leica BAs I upgraded to back then); they're now sitting on my desk for garden bird viewing. Just wish I still had the old hard case - god knows where that went!
 
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