Make the reverse Porro great again (thoughts and questions) (1 Viewer)

[yarrellii]

At some point in the past, before I got interested in binoculars, I had a Pentax compact reverse Porro, not sure about the model or specifications, I pretty much forgot about it. Later on I got the Pentax Papilio which is really a surprising little device, but it got out of alignment (most likely my daughter had something to do about that). Anyway, in my quest for compact/pocket binoculars I’ve come across some pretty interesting models that appeal to me for several reasons.

First of all, they all have a single hinge design that I find so convenient and way less finicky than some 8x25/20 that (even from top models of great brands) make using compact/pockets a chore and not a pleasurable experience.

• 8x25 Nikon Travelite (AKA Prostaff ATB). Compact but hefty, very close to the handling of an 8x32, but lighter and smaller, large focus wheel and (with a small mod) wide/regular eyecups like in a larger model. Great value.
• 7x20 Nikon CF III. Superlight, supercompact, large eyecups, more than decent focus wheel. A true gem.
• 6x18 Vixen @Six. Diminutive and extralight, amazing FOV and close focus, great value and big fun.

This has made me very interested in the reverse Porro configuration. Reading the archives of BF it seems that there have been some amazing models in the past, like the much acclaimed 7x26 Bausch & Lomb/Bushnell Compact Custom/Elite in different iterations.

However, currently reverse Porro seem to be relegated at the very low end of the price bracket of most brands, and may seem to carry one in their catalogue (Vortex, Opticron, etc.) as an inexpensive option for novices.

Anyway, all this intro in order to present several questions/doubts and invite any member with useful info/opinions/experience to chime in.

• How good are the best Pentax reverse Porro? (since this brand seems to have a plethora of models and vast experience in the reverse Porro format). Is the UP WP any good compared to the Nikon Travelite 8x25 (AKA Prostaff ATB).
• What would you say are currenty the nicest models on sale?
• Why on earth are the 7x26 Bushnell you can find on sale so expensive? It seems a bit out of proportion, I wonder if it’s worth it.
• Surfing the net I’ve discovered some models from brands I don’t know like the SKW Optics 6x24 Waterproof 8,9º FOV that looks at least intriguing.
• Do you have a favourite reverse Porro?

Are reverse Porro dismissed for “serious” performance simply because they “look cheap”? (since most reverse Porro are entre-level binos). I think reverse Porro have some much going on for them in terms of ease of use and comfort (and most possibly image quality) that I find surprising there is no more interest in them (for high quality binos). Imagine a 7x21 reverse Porro Habicht with the glass and coatings of the Curio, but with single hinge, decent sized focus wheel and eyecups that would elevate the viewing experience to unknown levels… In fact, we know that fashion and trends come and go (some garmets people wear these days would have been rejected just a few years ago), so maybe there could be a trend to reviving the reverse Porro format and giving it back all its glory.

 

[[email protected]]

It is funny you should start a thread on reverse porros because I have been having the same thoughts! I recently purchased a Nikon Venturer II 8 X 23 6.3° off of eBay for $50 because I had one about 40 years ago, and I remember it as being a very good compact binocular especially for the price. About 40 years ago, the Nikon Venturer 8x23 was tested in a Consumer Report buying guide for binoculars which they don't seem to do anymore and came out first place over a $1000.00 Leitz roof prism binoculars and twenty-five other binoculars including 10x50's and was rated a Best Buy.

Nikon was going to replace them with the Traveller, but since there was so much demand for them after the Consumer Reports test was released, they continued making them for several years. It surprised me how good they are even after 40 years has passed, and they will still hold their own with more modern compact roofs. The Nikon Venturer II 8x23 even beat the more modern Pentax Papilio 6.5x21 in the linked test below.

They have a 6.3 degree FOV which is considerably wider than the 5.6 degree FOV of the current Nikon Traveler 8x25 and the nostalgia factor is off the charts. Perhaps, it is time to take a second look at reverse porros because they are an incredible value for the money in the compact market, similar to the way bigger porro's are a great value compared to more expensive roofs.

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[mwhogue]

yarrellii,

You certainly have a nice trio of reverse Porro compacts. Awaiting more expert input my thoughts are:

Whatever the handling advantages, in terms of mass market appeal, reverse Porros look "odd" or at least different so likely to depress sales especially as the price goes up.

Many are larger than similar format roofs, again probably depressing sales for those looking for a more compact glass.

If I understand correctly, Porro models are less expensive to produce primarily because less expensive coatings are required to deliver similar optical performance compared to a roof. Any increase in costs above a certain level would likely achieve only better build quality rather than better optical performance -- not a "seven - two punch combination" so to speak as prices rise.

Finally, many members can and do use the generally smaller pocket / compact roofs without significant problems, especially the high end makes, making it harder for more expensive reverse Porro models to compete on the high end.

Mike

 

[Binastro]

Porroprisms need less accuracy for the prisms, which reduces cost.

I have a truly dreadful Chinese Pentax 8x25, which is a glare monster.

I also have a top end old Japanese 8x24 Pentax that is wonderful but has fungus.

The UCFs can be quite good, but there is sample variation.

There was a wide angle Olympus version but I cannot remember the specs.

The old Chinon 10x25 reverse Porroprism outresolves all the other 10x25s I have seen, but the bridge is strange and gets in the way.
Only for non glasses wearers and horizontal use.

If folks here stopped insisting on buying the most expensive of binoculars they might be happier with lower priced options, which are not so robust and may go out of alignment.
But they may be very comfortable to use.

Regards,
B.

 

[[email protected]]

Reverse Porro's look "odd" because they are not what you are used to looking at. Compact roofs dominate the high-end market, and that is what you think a compact binocular should look like. It is true Reverse Porro's are larger and slightly heavier than compact roofs but in truth there is more to hold onto and for many people with larger hands they might find them more comfortable and easier to hold steady than some of the tiny diminutive roofs like the Leica Trinovid 8x20.

They also have a single hinge like a regular binocular, so they are much easier to set for your IPD versus the double hinges on many smaller roofs. You don't need to increase the costs or the quality of a reverse porro because they are already very close in optical quality to the much more expensive compact roofs. The big advantage of a reverse porro is VALUE, as far as I can see it. The Nikon Venturer II 8x23 above beat out roof prism binoculars like Leica's costing $1000, and you can find the Venturer II for $50 on eBay.

If you can't find the Venturer II 8x23, you can buy a new Nikon Travelite 8x25 for about $80 which is almost optically equal except for a slightly smaller FOV. Frankly, the Nikon Venturer II 8x23 shocked me how good it was just like it did Stephen Ingraham when he tried one, and I don't have a small Leica Trinovid 8x20 to compare it with right now, but I bet it would hold its own for 1/10 the price of the Leica. The reverse porro's are the porro of the compact binocular market, and they represent the same value as do the larger porros compared to larger roofs.

Stephen Ingraham
"Nestled among them was a single Nikon 8x23 Venturer. I don't know how it got there. I really was not looking for compacts, and honest, I hadn't read Consumer Reports, I'd never heard of the things, but I picked them up and glanced through them. Whoo . . . what gives? Those little mites blew away the 7x35s and 10x50s on display, and showed the camo roof prism pockets up for what they were (two tubes of eye fuzz on a floppy hinge). Plus, they were the first binoculars I had looked through that had anything like enough eye relief to be comfortable with my glasses. They wanted $79.95 for them! After only a brief struggle with my conscience and my budget, I headed for the checkout."

 

[Binocollector]

My favourite reverse porro is still this one, even though the bridge hits my nose so I cannot see the whole FoV but it's still wide enough.

 

[mwhogue]

Philipp,

WOW!!!

If I had those I would seriously consider an emergency reduction of my proboscis.

Mike

 

[Binastro]

My only binocular for ten years was the C.Frank Nipole 7x23 micro reverse Porroprism with 9.5 degree field.
Similar to the Pentax above.

I could see the whole field.

It travelled the world with me.

I didn't want anything else and I don't think I missed having a larger binocular.

Mid 1960s cost about £14 I think.

Regards,
B.

 

[albie...]

The best reverse porro I had was the Bushnell Elite Custom Compact 7x26 . I wish I hadn't sold them . I had an opportunity recently to buy a nice used one for a good price , I couldn't get off the fence in time . Nice glove box glass . The Papilio's are my second favorite reverse porro ,I still have those , not giving them up .

 

[Sancho]

Opticron Taiga 8x25 and Vortex Vanquish 8x26.

 

[Swedpat]

Interesting that I actually wondered about this. Why not an updated reverse porro model with modern large eyepiece design with long eye relief!

 

[OneH]

I gave up in buying any more reverse porros they seem too fragile and easy to get out of collimation. Mostly Pentax and Nikon's purchased multiples of received uncollimated probably bumped during shipping and weren't able to get refund through ebay on many of them. Also tried just about every single Amazon generic brands imaginable in which nearly all were sent back for refund estimated around 180 out of 200 of them I had previously purchased I returned and this is counting the multiple duplicates of each I had bought and planned to only keep it one each of the best ones due to sample variance.

The Pentax Papilio II 6.5x I kept are decent but they're grossly overpriced at $100 for a toy like plasticy bin. Correction it wasn't 8x.

The Nikon Trailblazer 8x25 seem to be the best bang for the buck small lightweight extra wide 8.2° FOV bins I've ever used and are actually worth buying for their typical $60-$70 ebay selling prices I'd rate them very good quality with surprisingly clear glass which seem way more durable than any reverse porros I bought. I even compare it to my Zeiss Victory Compacts which aren't worth 15x the price of the Nikon's.

Here is the cheapest one I found today.

"Nikon Trailblazer 8x 25 mm Binocular 8217 18208082179 | eBay" Nikon Trailblazer 8x 25 mm Binocular 8217 18208082179 | eBay

I have two of them in 8x25 and one in 10x25. I bought two in the 8x with a plan to keep the better one and return the other for refund but both were identically clear and smooth functioning so I kept both.

 

[Patudo]

What surprises me is that there are not more Porro IIs. If the Canon IS models are anything to go by, this design allows a similar form factor to roof binoculars while (presumably) maintaining the advantages of porros (less stringent tolerances needed). I've heard that the prism mountings of Porro IIs may not be as sturdy as Porro Is, but the Canon IS models don't appear to be too fragile in that respect.

But apart from Canon not a single manufacturer seems to have any interest in making them. It'd be interesting, though, if Kunming could couple an advanced eyepiece design with Porro II prisms...

 

[Hermann]

I've heard that the prism mountings of Porro IIs may not be as sturdy as Porro Is [...]

That's probably only because most Porro IIs are nowadays cheap binoculars. Before the invention of coatings many top military binoculars used Porro II, because they had somewhat better transmission. Examples are e.g. the Ross 7x50, the Zeiss Septarem 7x50H and the Zeiss 8x60H. These were undoubtedly sturdy ...

Hermann

 

[Patudo]

The references I've come across, noting issues with prism fracture due to the prisms (apparently) not being well supported etc, have seemed to be in relation to WWII era binoculars. But I wonder whether the design could be rethought in some way?

It's a really interesting design that seems to me to overcome some of the issues with Porro Is (shape, bulk). Maybe Kunming could revisit something like the Vixen Ascot 10x50 (8.8 degree field of view), improving consistency and performance and giving it a more roof-like (or something narrower, similar to a Canon IS) shape.

PS. I found a photo of David Attenborough using a quite unusual binocular (link to larger photo here) - I think it might be a Ross Porro II civilian model like the (Porro II) Stepmur?

 

[Hermann]

The references I've come across, noting issues with prism fracture due to the prisms (apparently) not being well supported etc, have seemed to be in relation to WWII era binoculars. But I wonder whether the design could be rethought in some way?

Well, these binoculars are really old by now. That the Canada balsam failed after so many years in some binoculars was almost to be expected. After all, it is a natural product. Nowadays better cements are available. And that the prisms may not have been well supported was maybe the case in some binoculars, in that case the designers just made a mistake. I think a well-known example was a binocular Leitz made during the war. But there are quite a few examples of Porro IIs that never had these problems, for instance the Zeiss 8x60H. And there was of course the Zeiss Jena Asiola, a very nice scope Zeiss made for about 50 years (Zeiss Spektiv Asiola). Never heard of any problems with that one.

It's a really interesting design that seems to me to overcome some of the issues with Porro Is (shape, bulk). Maybe Kunming could revisit something like the Vixen Ascot 10x50 (8.8 degree field of view), improving consistency and performance and giving it a more roof-like (or something narrower, similar to a Canon IS) shape.

There's of course nowadays the Perger prism, cf. e.g. Perger prism - Wikipedia or Merlitz 2023: 51-54. Unfortunately Leica bought the patent and only uses it in their rangefinder binoculars. I had hoped they'd use in in "normal" binoculars as well. That's one binocular I would have ordered sight unseen.

Hermann

 

[Swissboy]

The references I've come across, noting issues with prism fracture due to the prisms (apparently) not being well supported etc, have seemed to be in relation to WWII era binoculars. But I wonder whether the design could be rethought in some way?

It's a really interesting design that seems to me to overcome some of the issues with Porro Is (shape, bulk). Maybe Kunming could revisit something like the Vixen Ascot 10x50 (8.8 degree field of view), improving consistency and performance and giving it a more roof-like (or something narrower, similar to a Canon IS) shape.

PS. I found a photo of David Attenborough using a quite unusual binocular (link to larger photo here) - I think it might be a Ross Porro II civilian model like the (Porro II) Stepmur?

View attachment 1604422

I have no idea what is meant by Porro II except that Pentax has an updated Papilio with the suffix II. And that one is surprisingly better than its predecessor as it is fully coated. I had them both for a while just to compare. And it was clear which one to keep.

I wonder why the Attenborough photo is shown in this thread. He clearly does not have a reverse Porro (the original topic of this thread) in his hands that he is looking through.

One major drawback of the Papilio is its lack of being waterproof. Don't know about other reverse Porros though.

 

[Ignatius]

As usual, @John A Roberts has a good explanation of porro I vs porro II.

As to the Attenborough image: reverse porros apparently often use the porro II configuration, as does the bino in Mr. A's hands.