How does the Pentax Papilio close-focus work? (1 Viewer)

MacGee · Sep 17, 2006

With ordinary binoculars, the closer you focus them, the closer together you have to bring the optics. At 100m my interpupillary distance is about 60mm, which means I could happily use the Papilio (min IPD 56mm) but at the Papilio's closest focus, my IPD would be about 52mm, so if the Papilio does work like ordinary binoculars they're no good to me. Does the Papilio's clever close-focus mechanism mean you don't have to keep moving the objectives in, and if so does this apply throughout the focus range or only at close distances?

Michael.

Alexis Powell · Sep 17, 2006

I know exactly what you mean about adjusting the IPD down with closer distance. The reason for doing this is two-fold; (1) as you state because your IPD decreases, but also (2) to help increase the "taking" image overlap between the two objectives. The optical centers of its closely set and tiny (21 mm) objectives are very close together, so Papilio is inherently mostly immune to the second problem (actually, mostly reverse porros are pretty good in this respect). I find a small amount of adjustment of the IPD between infinity and 18 inch focus is beneficial but not necessary, unlike most other binos where it is essential. My IPD is 62 mm at infinity.
--AP

MacGee · Sep 17, 2006

Alexis Powell said:
I know exactly what you mean about adjusting the IPD down with closer distance. The reason for doing this is two-fold; (1) as you state because your IPD decreases, but also (2) to help increase the "taking" image overlap between the two objectives. The optical centers of its closely set and tiny (21 mm) objectives are very close together, so Papilio is inherently mostly immune to the second problem (actually, mostly reverse porros are pretty good in this respect). I find a small amount of adjustment of the IPD between infinity and 18 inch focus is beneficial but not necessary, unlike most other binos where it is essential. My IPD is 62 mm at infinity.
--AP

Thanks, Alexis, that's a great help. It sounds as if they might actually suit me, which is welcome news. I spent Saturday morning at an Optics Fair, where I discovered that none of my last hope binoculars (Zeiss Victory and Conquest and Leica Ultravid) would do, because the combination of moving the oculars in and the large size of the eyecups made for some discomfort in the outlying nasal areas.

Can I ask you a couple of supplementary questions? What's the diameter of the Papilio eyecup? And what binoculars do you use, apart from the Papilio?

Michael.

PS. I see I wrote 'objective' in my OP when I meant to write 'ocular.' Sorry about that.

Alexis Powell · Sep 17, 2006

The outside diameter of the Pentax Papilio eyecup is ~34 mm.

Other binos that I regularly use besides the Pentax 6.5x21 Papilio are the Swarovski 8.5x42 EL, Leica 8x42 Ultravid, Leica 8x32 BA Ultra/Trinovid, Zeiss 8x32 FL, Leica 8x20 Ultravid, and Zeiss 8x20 Victory. I keep handy a Swift 8x42 Ultralight (older version than the current model) for my wife, a Nikon 8x25 Sportstar (older wider angle version) for my 5 year old son, and a Bausch & Lomb 8x42 Discoverer (waterproof porro version) to lend a friend who likes porros. I own another 20+ binos, most of which I used a fair amount at one time but don't anymore (not because they are inadequate but because they are functionally redundant and slightly less preferred on one niggling ground or another). Among my favorites are the Zeiss 7x42 Classic, Nikon 8x32 SE, Nikon 8x30 EII, Nikon 10x42 Venturer LX/HG, Bausch & Lomb 8x42 Elite (older waterproof version--great for butterflies!), and Bausch & Lomb 7x26 Custom (older all-metal unrubberized version--also great for butterflies). I guess I'm a collector of sorts, my general criterion being 8x42 and smaller birding or butterflying binoculars that in some way offer an optical and/or ergonomics improvement over something already in my possession. Most older and new models don't, so my collection won't be growing much or very quickly in the future.
--AP

AlanFrench · Sep 17, 2006

Hmmm. I seem to recall that the Papilio objectives slide along a pair of "converging" tubes so that they both look at the same field, even close up. You don't get the two overlapping views you get with most reverse porros at close focus.

Not quite sure if this means the IPD can stay fixed....

Clear skies, Alan

Swissboy · Sep 17, 2006

AlanFrench said:
Hmmm. I seem to recall that the Papilio objectives slide along a pair of "converging" tubes so that they both look at the same field, even close up. You don't get the two overlapping views you get with most reverse porros at close focus.

Not quite sure if this means the IPD can stay fixed....

Clear skies, Alan

Alan, you are correct, the objectives do slide in converging tubes. I just gave it a quick try, only in the house as it is dark outside at present. So the results may not be fully conclusive. I still felt like moving the eyepieces a little. But the effect was minimal, so it was very well possible to use the binoculars at a fixed IPD position.

MacGee · Sep 18, 2006

Alexis Powell said:
The outside diameter of the Pentax Papilio eyecup is ~34 mm.

Thanks again, Alexis; that should be fine for me.

Alexis Powell said:
Other binos that I regularly use besides the Pentax 6.5x21 Papilio are the Swarovski 8.5x42 EL, Leica 8x42 Ultravid, Leica 8x32 BA Ultra/Trinovid, Zeiss 8x32 FL, Leica 8x20 Ultravid, and Zeiss 8x20 Victory. I keep handy a Swift 8x42 Ultralight (older version than the current model) for my wife, a Nikon 8x25 Sportstar (older wider angle version) for my 5 year old son, and a Bausch & Lomb 8x42 Discoverer (waterproof porro version) to lend a friend who likes porros. I own another 20+ binos, most of which I used a fair amount at one time but don't anymore (not because they are inadequate but because they are functionally redundant and slightly less preferred on one niggling ground or another). Among my favorites are the Zeiss 7x42 Classic, Nikon 8x32 SE, Nikon 8x30 EII, Nikon 10x42 Venturer LX/HG, Bausch & Lomb 8x42 Elite (older waterproof version--great for butterflies!), and Bausch & Lomb 7x26 Custom (older all-metal unrubberized version--also great for butterflies). I guess I'm a collector of sorts, my general criterion being 8x42 and smaller birding or butterflying binoculars that in some way offer an optical and/or ergonomics improvement over something already in my possession. Most older and new models don't, so my collection won't be growing much or very quickly in the future.
--AP

Amazing. I must admit I share your desire to collect bins, but I can't see my wife sympathising. I can hear her now if I bought a second pair. "Why on earth do you need two pairs of binoculars?" Still, I'll be lucky if there are two bins in the whole world that fit my face.

Michael.

MacGee · Sep 18, 2006

AlanFrench said:
Hmmm. I seem to recall that the Papilio objectives slide along a pair of "converging" tubes so that they both look at the same field, even close up. You don't get the two overlapping views you get with most reverse porros at close focus.

Swissboy said:
Alan, you are correct, the objectives do slide in converging tubes. I just gave it a quick try, only in the house as it is dark outside at present. So the results may not be fully conclusive. I still felt like moving the eyepieces a little. But the effect was minimal, so it was very well possible to use the binoculars at a fixed IPD position.

Thanks for this encouraging information. I'm going to go to a Pentax dealer in Edinburgh and see if I can try a pair. These things have been so well reviewed that I guess they must have been flying off the shelves. So maybe before long there'll be an 8x32, or even 8x42 Papilio. Is there any technical reason why not?

Michael.

Alexis Powell · Sep 18, 2006

MacGee said:
So maybe before long there'll be an 8x32, or even 8x42 Papilio. Is there any technical reason why not?
Michael.

Yes. The main way that the Papilio acheives its excellent left and right field overlap is by having very closely-set small objectives (I'm not sure that it actually "crosses its eyes" to any great extent, if at all). Being that the objectives are 21 mm diameter and almost touching at closest focus, the optical centers are not much more than 21 mm apart A larger model with a 42 mm diameter objective would have twice this separation. Also, the long travel necessary for such close focus would probably make a larger model a bit unwieldy.

As for my bino collection, it's impossible to justify on anything other than irrational grounds, but then I feel the same way about buying anything other than a reliable, fuel-efficient, used, hatchback car (So I've bought four cars in 20 years, which have cost me $7,000 total to purchase). Lots of people buy vehicles for $15-20 thousand and think nothing of it (Or a boat for $10-20 thousand that they only use a few times a year), but wouldn't dream of spending even $500 on binos. We all have our priorities.
--AP

MacGee · Sep 19, 2006

Alexis Powell said:
Yes. The main way that the Papilio acheives its excellent left and right field overlap is by having very closely-set small objectives (I'm not sure that it actually "crosses its eyes" to any great extent, if at all). Being that the objectives are 21 mm diameter and almost touching at closest focus, the optical centers are not much more than 21 mm apart A larger model with a 42 mm diameter objective would have twice this separation. Also, the long travel necessary for such close focus would probably make a larger model a bit unwieldy.

Alexis, thanks again for helping me to understand. What you say makes sense, even to me. Actually, I thought the Papilio was a new thing, but I was talking to a binocs shopkeeper today who said they'd had them in a couple of years ago, but they'd taken a long time to sell.

Alexis Powell said:
We all have our priorities.

Absolutely. With me it's dictionaries. I have dictionaries in book form, on computer, in little hand-held machines - old ones, new ones... My wife indulges this, probably because I've always been like it. Whereas she's doesn't look so kindly on my more recent inclinations to amass laptops or radio-controlled watches. People ask collectors, "Why do you need another one?" But it's not that we need another one; it's that we need this one.

Michael.

MacGee · Sep 21, 2006

Two days ago I looked for a pair of Papilios to try. Apparently they'd been stocked by some shops in Edinburgh, but hadn't sold well and had been dropped. My wife, who is unfortunately addicted to saying sensible things, suggested that this might be because for seven months of the year there's nothing around to close-focus on. I guess it does make less sense to buy butterfly-binoculars in Scotland than in more balmy regions of the earth.

Michael.

Tero · Sep 21, 2006

Amazing. I must admit I share your desire to collect bins, but I can't see my wife sympathising. I can hear her now if I bought a second pair. "Why on earth do you need two pairs of binoculars?" Still, I'll be lucky if there are two bins in the whole world that fit my face.

Michael.

LOL
I have gotten past that. There are four of us and sometimes we go look at eagles. But I can't explain why we need more than 4.

Marko_ · Sep 25, 2006

MacGee said:
Two days ago I looked for a pair of Papilios to try. Apparently they'd been stocked by some shops in Edinburgh, but hadn't sold well and had been dropped. My wife, who is unfortunately addicted to saying sensible things, suggested that this might be because for seven months of the year there's nothing around to close-focus on. I guess it does make less sense to buy butterfly-binoculars in Scotland than in more balmy regions of the earth.

Michael.

Hello Michael.

I got my Papilio last summer, and I found out they are also very nice for examining flowers and other wild plants, in addition to butterflies. Also they work well as all-round binoculars. I have the 6,5x model.

I haven't had to adjust the oculars at all after their initial setup. It seems the moving of the objective lenses is really a brilliant innovation. I hope you find some Papilios somewhere!

Marko

MacGee · Sep 26, 2006

Marko_ said:
Hello Michael.

I got my Papilio last summer, and I found out they are also very nice for examining flowers and other wild plants, in addition to butterflies. Also they work well as all-round binoculars. I have the 6,5x model.

I haven't had to adjust the oculars at all after their initial setup. It seems the moving of the objective lenses is really a brilliant innovation. I hope you find some Papilios somewhere!

Marko

Thanks, Marko. We've now ordered the Papilios, but the shop is quoting a delivery time of six weeks. I'm checking to see if they're in stock in other places. If I ever get a pair I'll post back.

skiingfool · Sep 29, 2006

Hi I just thought you might like this web address. A friend of mine bought some at this web site www.parkcameras.com regards Clive

spitfiretriple · Aug 13, 2009

MacGee said:
Amazing. I must admit I share your desire to collect bins, but I can't see my wife sympathising. I can hear her now if I bought a second pair. "Why on earth do you need two pairs of binoculars?" Still, I'll be lucky if there are two bins in the whole world that fit my face.

Michael.

Ask her how many handbags she has.

And tell her it could be worse. With you, it's bins. With me, it's motorbikes.

How does the Pentax Papilio close-focus work? (1 Viewer)

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