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best 7x35 porros? (1 Viewer)

WJC

Well-known member
... With regard to focusing sequence, if the diopter was set correctly and not touched for focusing, would the sequence still matter? I tend to set the diopter once and then just focus binocularly, only re-checking the diopter if I feel it might have been inadvertently moved.

Regards,

Henning

Hi, Henning:

Unless the instrument is an INDIVIDUAL FOCUS, the order is critical ... PERIOD!

... What Went Wrong?

Why was following this optometrist’s advice wrong? Let’s start by following his instructions, focusing the right eye as directed, to find out. Bingo, your right eye is seeing a great image. But now, with the right eye sharply focused, you turn the center focus wheel or flip the lever to focus the left eye. Since, however, there’s a 2-diopter difference (for example) in your eyes, and since the center focus wheel or lever was designed to focus both sides, sharply focusing your left eye has just defocused your right eye by 2 diopters. Something isn’t right. But, you did what your optometrist told you to do. So it must be you ... right? :cat:

Bill
 
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Patudo

Well-known member
the limited travel issue ... I experienced this once with a Leica pair, but never read about this anywhere else. Leica actually confirmed that their "over-travel" was limited to a certain value by design, which was just short of what I needed to use the pair without my glasses.

There are a few threads covering this issue - try searching for "focus beyond infinity". I am myopic and have found that when observing without glasses some binoculars (including the Nikon EII I tried a couple months back and a couple of Opticrons) will not focus enough beyond infinity to get a sharp image at distance. This, of course, is really my fault rather than the binocular's - I am grateful for those binoculars that will accommodate my visual failings.
 

Hauksen

Forum member
Antarctica
Hi Bill,

Since, however, there’s a 2-diopter difference (for example) in your eyes, and since the center focus wheel or lever was designed to focus both sides, sharply focusing your left eye has just defocused your right eye by 2 diopters.

Maybe it's because I'm a native speaker, but I'm in a state of confusion right now.

What I do once is:

- Center-focus to bring left-eye picture into focus
- Adjust diopter to bring right-eye picture into focus

What I do subsequently is:

- Center-focus with both eyes open

Is that the recommended procedure?

Regards,

Henning
 

Binoscoper

Also a spotting scoper
@WJC.

Thank you for your reply. My diopter adjusting method fits exactly as described in your book. I'm ruling out improper diopter setting. By what the extract in your book says about inadequate focus travel best describes what I saw. Again, thank you for your help.

Ps. I've just ordered your book. From what I've heard about it here, I'm sure it will make an excellent read!
 

WJC

Well-known member
Hi Bill,



Maybe it's because I'm a native speaker, but I'm in a state of confusion right now.

What I do once is:

- Center-focus to bring left-eye picture into focus
- Adjust diopter to bring right-eye picture into focus

What I do subsequently is:

- Center-focus with both eyes open

Is that the recommended procedure?

Regards,

Henning

In the VAST MAJORITY of cases, you are exactly right. If using the Steiner Predator, or a very limited number of others, you are exactly ... wrong. The predator focuses RIGHT EYE FIRST. Only on individual focus instruments does it not matter.

And, don’t worry about being a non-native speaker. I have a specially hard time with Ubangi (see the attachment for details.) :cat:

Bill
 

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WJC

Well-known member
@WJC.

Ps. I've just ordered your book. From what I've heard about it here, I'm sure it will make an excellent read!

Hey, order a case! They’re great for Birthdays, Weddings, Graduations, Bar Mitzvahs, House Warmings, and Party Favors ... at least if the guests are optics geeks. But wait, I’m being redundant. 3:):cat:

Cheers,

Bill
 

Rathaus

Well-known member
Regarding 7x35 Porros -

I’ve just been comparing (daytime viewing) the excellent Nikon E2 with some late 1950s Bushnell FPO 7x35 rangemasters - two of the special edition FPO Rangeaster model, and a couple of the 7x35 FPO Rangemaster including one of the last ones made. I’ve compared them before, but I’d say there isn’t a single area where the old rangemaster isn’t superior to the Nikon, barring compact dimensions and low weight in the Nikon’s favor. The FPO Bushnell are weighing in at about one kg.

Viewing through the Nikon directly after the FPO Rangemaster - the Nikon E2 view feels constricted (noticeably smaller apfov) with a smaller sweet spot and the image to me absolutely feels ‘flatter’, with a noticeably shallower perception of depth of field. My eyes can pull focus within a greater range using the FPO. Without needing to use a resolution chart, the FPO is also focusing and resolving the finest veins on leaves etc with less effort than the Nikon. It’s not difficult to note. Both contrast and resolution are stunning - the FPO Rangemaster posseses one of the finest Porro views I’ve ever seen. It is incredibly easy on the eyes...quite Fujinon like - there is definitely something familial about a current Fujinon (I use the 7x50 fmt-sx) and these old FPO. Obviously the specs are slightly different between the 7x35 FPO and the 8x30 Nikon, but, regardless of specs, the same 7x35 FPO is also clearly superior to a late model Zeiss BGATP 7x42 regarding depth of field perception, sweetspot and fov. Using the 7x35 FPO I can leave my eyes to pull focus for a great deal of the viewing.

Against the FPO is it’s size, weight and minimal eye relief - non optical issues for myself. Also, they’re not ‘new and shiny’ objects, which will strike them off the list for many folks. The FPO are the biggest and heaviest bins for their spec I’ve ever seen. I like that, others won’t.

One of the special edition FPOs I have must be very close to mint condition optically...it was overhauled by a well known optics tech blokes in the USA before I purchased it - and it’s slightly better than an otherwise identical FPO I had refurbed in OZ by my own optics bloke here...but that particular FPO was in fairly crook condition internally before refurb. It was in shocking condition actually. I was aware of this before purchasing it. The optics tech wasn’t impressed with its condition before taking it on and he noted that he was wary of treading the fine line between undercleaning and overcleaning. Even after service, in comparison to the minty FPO it still has a very slightly milky haze to the view. I’m thinking of sending it back to my tech for a second scrubbing...could be risky but worth it.



Cheers,

Rathaus
 
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wllmspd

Well-known member
Must say that the ability to leave the focus alone on the Rangemasters make them a joy to use. I have made some large winged eye cups to help the immersion and cut straylight.

Peter
 

WJC

Well-known member
Regarding 7x35 Porros -

I’ve just been comparing (daytime viewing) the excellent Nikon E2 with some late 1950s Bushnell FPO 7x35 rangemasters - two of the special edition FPO Rangeaster model, and a couple of the 7x35 FPO Rangemaster including one of the last ones made. I’ve compared them before, but I’d say there isn’t a single area where the old rangemaster isn’t superior to the Nikon, barring compact dimensions and low weight in the Nikon’s favor. The FPO Bushnell are weighing in at about one kg.

Viewing through the Nikon directly after the FPO Rangemaster - the Nikon E2 view feels constricted (noticeably smaller apfov) with a smaller sweet spot and the image to me absolutely feels ‘flatter’, with a noticeably shallower perception of depth of field. My eyes can pull focus within a greater range using the FPO. Without needing to use a resolution chart, the FPO is also focusing and resolving the finest veins on leaves etc with less effort than the Nikon. It’s not difficult to note. Both contrast and resolution are stunning - the FPO Rangemaster posseses one of the finest Porro views I’ve ever seen. It is incredibly easy on the eyes...quite Fujinon like - there is definitely something familial about a current Fujinon (I use the 7x50 fmt-sx) and these old FPO. Obviously the specs are slightly different between the 7x35 FPO and the 8x30 Nikon, but, regardless of specs, the same 7x35 FPO is also clearly superior to a late model Zeiss BGATP 7x42 regarding depth of field perception, sweetspot and fov. Using the 7x35 FPO I can leave my eyes to pull focus for a great deal of the viewing.

Against the FPO is it’s size, weight and minimal eye relief - non optical issues for myself. Also, they’re not ‘new and shiny’ objects, which will strike them off the list for many folks. The FPO are the biggest and heaviest bins for their spec I’ve ever seen. I like that, others won’t.

One of the special edition FPOs I have must be very close to mint condition optically...it was overhauled by a well known optics tech blokes in the USA before I purchased it - and it’s slightly better than an otherwise identical FPO I had refurbed in OZ by my own optics bloke here...but that particular FPO was in fairly crook condition internally before refurb. It was in shocking condition actually. I was aware of this before purchasing it. The optics tech wasn’t impressed with its condition before taking it on and he noted that he was wary of treading the fine line between undercleaning and overcleaning. Even after service, in comparison to the minty FPO it still has a very slightly milky haze to the view. I’m thinking of sending it back to my tech for a second scrubbing...could be risky but worth it.



Cheers,

Rathaus

Hi, Rathaus:

You use "FPO" a great deal. What does that mean; I can find no association with the Rangemaster. :cat:

Bill
 

WJC

Well-known member
Must say that the ability to leave the focus alone on the Rangemasters make them a joy to use. I have made some large winged eye cups to help the immersion and cut straylight.

Peter

Hi, Peter:

Since there are no non-electronic "auto-focusing" binoculars, you must be depending on spatial accommodation to keep them in focus. But, please remember two things. Unless you are very young, this will only lead to eyestrain. And two, more often than not, the ability to focus will be superior to depending on your own physiological accommodations. :cat:

Bill
 

wllmspd

Well-known member
FPO=Fuji Photo Optical (latterly fujinon) I believe. My pair are definitely older than I am, though I’m not that young and I feel the need for reading glasses coming on. In daily life ones eyes are constantly refocusing on different things, same with using the Rangemasters, not suffered from eye strain with them or any other bins. It’s nice to not have to keep twiddling the focus, good thing as the focus is a wee bit stiff.

Peter

PS I focus the left eye first! ;-)
 

Synaps

Well-known member
Regarding 7x35 Porros -

I’ve just been comparing (daytime viewing) the excellent Nikon E2 with some late 1950s Bushnell FPO 7x35 rangemasters - two of the special edition FPO Rangeaster model, and a couple of the 7x35 FPO Rangemaster including one of the last ones made. I’ve compared them before, but I’d say there isn’t a single area where the old rangemaster isn’t superior to the Nikon, barring compact dimensions and low weight in the Nikon’s favor. The FPO Bushnell are weighing in at about one kg.

Viewing through the Nikon directly after the FPO Rangemaster - the Nikon E2 view feels constricted (noticeably smaller apfov) with a smaller sweet spot and the image to me absolutely feels ‘flatter’, with a noticeably shallower perception of depth of field. My eyes can pull focus within a greater range using the FPO. Without needing to use a resolution chart, the FPO is also focusing and resolving the finest veins on leaves etc with less effort than the Nikon. It’s not difficult to note. Both contrast and resolution are stunning - the FPO Rangemaster posseses one of the finest Porro views I’ve ever seen. It is incredibly easy on the eyes...quite Fujinon like - there is definitely something familial about a current Fujinon (I use the 7x50 fmt-sx) and these old FPO. Obviously the specs are slightly different between the 7x35 FPO and the 8x30 Nikon, but, regardless of specs, the same 7x35 FPO is also clearly superior to a late model Zeiss BGATP 7x42 regarding depth of field perception, sweetspot and fov. Using the 7x35 FPO I can leave my eyes to pull focus for a great deal of the viewing.




Cheers,

Rathaus

There is something I do not understand.... This bin being made in the 50's makes it not very likely to have high transmission and yet the light transmission efficiency is said to be critical for a good quality image :h?:
 

WJC

Well-known member
FPO=Fuji Photo Optical (latterly fujinon) I believe. My pair are definitely older than I am, though I’m not that young and I feel the need for reading glasses coming on. In daily life ones eyes are constantly refocusing on different things, same with using the Rangemasters, not suffered from eye strain with them or any other bins. It’s nice to not have to keep twiddling the focus, good thing as the focus is a wee bit stiff.

Peter

PS I focus the left eye first! ;-)

Thanks! I was thinking strictly binos. I wasn't thinking that name was used with cameras. Hey, ain't dementia great? By the way ... I don't recall giving you this number. 8-P
 

Rathaus

Well-known member
Thanks! I was thinking strictly binos. I wasn't thinking that name was used with cameras. Hey, ain't dementia great? By the way ... I don't recall giving you this number. 8-P

Bill, and anyone else interested -

Here’s a BF link to a nice write up by John Dracon about the FPO Bushnells.

http://www.birdforum.net/showthread.php?t=230405

Given the monstrous size and weight of these old school porro bins, they are great to work on for a novice tinkerer like myself...even with gorilla sized fingers. I cleaned up one well collimated but filthy (internally) pair as best I could and they came up quite well..much better than expected. The prism housing is huge, which helps. The best pair I have (the Silver Ring FPO) was fully overhauled by your fellow American Cory Suddarth and they are nigh on pristine internally with a view to match. Pristine - as in cherry picked brand new Noctivid type clean. I realise that some specks and minor internal dust don’t ruin a view, but I’m just astounded at how these old things came up. I did some reading on cloudy nights and it appears that Cory Suddarth has overhauled at least a couple of the FPO Bushnells over there. I have an excellent tech here in OZ, but Cory Suddarth’s work is so good that I’m tempted to send him my other pair of Silver Ring FPO to work his magic on.

Rathaus
 

pka45

Member
Great info here. I certainly love my Aculons for the price! Eyecups do flex under pressure, so I wonder if they'd handle a drop, though.
 
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