[ScoutMan]

It's generally a given that for the same dollar spent you get better optical quality in a porro over a roof.

The downside seems to be that because of their design, porros are not as durable as roofs especially in holding their collimnation. This is true because roofs focus internally and have a single hinge.

I thought I saw somewhere that manufacturers had found a way to focus porros internally and to have them hold their collimnation with a single hinge.

Would anyone please comment.

[trashbird]

I have found that porros offer a transparency of view that all but the best roof prism binos cannot offer. The porro prism system is simpler. One less trip through the reflections of the prism. It also seems true that porros are somewhat more delicate than roofs. And I believe you are right about internal focussing porros being more rugged -- as well as better for waterproofing/fogproofing. Pentax porros have been internal focussing for many years. Minox and Leupold have recently offered internal-focussing binos that are impressive. One drawback to the internal focussing design seems to be a modest field of view compared to conventional porros and the best roofs.

[henry link]

ScoutMan,

Internal focus Porros are nothing new. Kern Focalpin Porros from 30 years ago used an internal focusing lens system just like the one used in many current roof prism bins. Swarovski SL Porros from 20 years ago had completely immobile cemented prism clusters and a single hinge. Neither of these things has anything to do with the prism type.

Among current Porros there are some internal focus models with single hinges sold by Minox, Leupold and Opticron. Pentax Porros have single hinges, not sure about internal focus. The idea that roof prisms hold their collimation better probably comes from the inferior method of collimation used in most cheap Porros now in which set screws are used to adjust the prism shelf. It's more shock resistant to have an fixed shelf and collimate with eccentric objective rings.

Henry

[Steve C]

Scoutman,

Conventional wisdom does indeed hold the position that porros are less robust and far less water resistant than roofs. Conventional wisdom also holds the position that pooros are easier to get a decent image with than roofs. However, just because a porro binocular is iherently less rugged than a similar roof does not mean that a porro is necessarily a wimp of an instrument. It really gets to the particular use any prospective user has for binoculars. If you spend a lot of time in rugged areas in extreme conditions which include lots of wet weather, then a roof is likely abetter choice. Also I know a couple of folks whose middle might as well be klutz because they are always doing something dumb (quite unitentionally) with their binocular and thus inadvertantly inducing extreme conditions by dropping, etc. However porros have also benefitted from manufacturing advances as well. Many more are now advertised as waterproof. So if you are not prone to being inadvertantly hard on equipment or do not use a binocular much in extreme conditions, I would have no qualms about a porro glass. If you have large hands they may even be the best choice. I used a 8x40 Swift Nighthawk porro I got in 1969 as my primary binocular for nearly 30 years before it needed to go back for a refit. Internal focus in porros, as Henry Link says are not new, but it seems to me that thos internal focus models are equipped with far less FOV than more conventional pooro counterparts.

For a current outstanding inexpensive, optically outstanding, weatherproof porro binocular from a company with an outstanding service reputation you need look no further than the $100 or less Leupold Yosemite.

Steve

[ScoutMan]

Originally Posted by Steve C

Scoutman,

For a current outstanding inexpensive, optically outstanding, weatherproof porro binocular from a company with an outstanding service reputation you need look no further than the $100 or less Leupold Yosemite.
Steve

Thanks Steve. Have the Yosemite 6x30. Outstanding glass.

SM

[Tero]

My down side is close viewing with porros. I get eye strain etc easily with porros. At 100ft the view is OK for me.