Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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The roof prism construction has some advantages, but one disadvantage is the ray of light phenomenon. This ray of light is mostly only noticeable when looking at strong lights as streetlights in the night and the moon, and makes the image resembling of a star filter picture but with a single ray in each eyepiece. First I thought this was a resultat of the phase displacement in binos without phase coating, but have seen it even in phase corrected roofs as my own Minolta 8x25 D WP XL, and the Nikon HG 8x20.
It makes me confused that this, sometimes without discussion disturbing phenomenon, is accepted by many who have so high demands of the optical quality. Are there any roof prism binoculars without it? Has any manifacturer solved this problem? It is the main reason I rather prefer a porro than a roof binoculars, despite the roof is more handy and durable.
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*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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Hi Pat,
Most of the time we aren't looking at a small, bright spot of light against a dark background.
I've gone to the trouble of taking a small flashlight to the camera store to select a binocular with the least and most even streaks of light. There is one streak on the right side and one on the left, going in the opposit direction.
Before you think that this problem with roof prism binoculars makes observing other objects a problem, I suggest you compare high end porro and high end roof prism binoculars in situations other than a small bright spot against a dark background.
I find the Zeiss FLs, even with the "problem" you mention, are still better than my Nikon SE porro binoculars. Not by a huge amount but a little better.
There is also the benefit, IMHO, of the better hand position of the roof prism binocular. I find roof prism binoculars are easier to hold steady because my hands are closer together.
Rich
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Rich!
As you say this isn't in most cases a problem, for birding maybe never. But when I use a binocular to for example, city view at evening and night, I am little disturbed of the rays. In most cases they dont cause problem. But I think that phenomenon in some cases really are undesirable.
Have you thought about that boating binoculars almost exclusively is of porro type? I think it's because the ray of lights isn't desirable when trying to see details in the dark sea with shining lanterns or a lighthouse in the background. I have never heard this explanation, but it's my guess.
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*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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Hi Pat,
Leica sells a 7x42 binocular with boating in mind. I don't know how popular it is in relation to other binoculars for boating.
I have no problem with selecting a binocular for a given type of observing. If you do a lot of night time observing where there are bright lights, selecting a porro prism binocular is a good idea.
Rich
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Rich!
I am not sure how I will do yet. My choice is now between TS 8x42 Triplet and Pentax 10x50 PCF WP. I think I can endure the roof phenomenom, it will not in this case be the decisive factor.
Much worse is a binocular with a glossy inside tube. I had one time a Steiner Rally 8x30. Very durable porro construction, good optics but with bad coating. When looking at evening outdoors, the glossy inside of the binocular produced a swarm of light circles around the street lights in the entire field of view.
That phenomenom was accordingly an effect of the reflecting inside wall of the binocular and not the lenses or bad coating, and was VERY disturbing.
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*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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The Leica, Swarovski, and Zeiss roof prism 42 mm binoculars all control bright light near the point of interest, but out of the field of view, very well.
You are trying to spend little and want excellent performace. I like the idea, but it seldom gives the results you want.
Rich
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Neil Weiner
member
Reged: 08/29/04
Posts: 98
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Quote:
Leica sells a 7x42 binocular with boating in mind. I don't know how popular it is in relation to other binoculars for boating.
I still intend to report on my complete satisfaction and enjoyment of a Fujinon 8x30 FMTR-SX on a recent Antarctic cruise. In the meantime I can report:
The ship's bridge was equipped with two Zeiss 7x50 porro, also one Pentax and one other brand 7x50 porros. The personal binos of the Captain and First Officer were Leica 7x42 and 8x42, which they used for both navigation and nature observation.
Edited by Neil Weiner (02/21/05 03:02 PM)
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KennyJ
Reged: 04/27/03
Posts: 10163
Loc: Lancashire UK
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< The roof prism construction has some advantages, but one disadvantage is the ray of light phenomenon. This ray of light is mostly only noticeable when looking at strong lights as streetlights in the night and the moon, and makes the image resembling of a star filter picture but with a single ray in each eyepiece >
Patric,
This is the first I've heard of this "phenomenon".
Before I can check for myself tonight ( which I intend to do with my Zeiss 7 x 42 B G AT roofs ) I think I need a little more clarification about what you mean by "resembling of a star filter picture" ?
I note that both of the roof prism models you quote in your example are COMPACT models -- could this be a factor ?
By the way , I see far more annoying reflections through my Telstar and Swift 10 x 50 and Helios 15 x 70 PORROS than I do through the Zeiss roofs !
Regards , Kenny
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If everyone is thinking the same thing , no-one is thinking - General George S.Patton
Zeiss 7 x 42 BGAT
Captain's Helmsman 7 x 50
Nikon 10 x 42 Superior E
Swift Audubon Kestrel 10 x 50
Helios 15 x 70 Observation
Strathspey 20 x 90
Televue 76 APO
Zeiss 85 Diascope
Helios 102 f5 refractor
Various eyepieces barlows tripods mounts etc.
Panasonic Lumix DMC - TZ5 digital camera
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Kenny!
I'm little confused about this thing. I dont know if its bounded to compacts. I asked a birdwatcher and he said he didn't know about that phenomenom...
How is the image in your Zeiss roof if you look to a street lantern or spotlight against a dark background? Don't you see any ray of light crosses a strong light?
--------------------
*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Here is examples of a star filter. It seems exactly like this but with a thinner and single ray per light.
http://www.tiffen.com/star_filters.htm
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*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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Hi Kenny and Pat,
I've seen this "star" effect in all of my roof prism binoculars from 20mm to 50mm.
When looking at a small bright spot against a dark background you do see something much like the pictures made with the star filter shown on that Tiffen link. If you close one eye and then the other eye you will see that each side has one diagonal line. With both eyes open the two lines merge into a bright "X". Often the two lines are not equal in brightness.
Rich
Edited by Rich N (02/21/05 03:58 PM)
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KennyJ
Reged: 04/27/03
Posts: 10163
Loc: Lancashire UK
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Hello again Patric,
Thank you for your prompt reply , and link to very clear illustrations of your "star filter" effects , which of course look very familiar now I've seen them.
Thankfully though ,this is NOT a phenomena I see when looking at a street light , or any other source of light ,through my Zeiss 7 x 42 roof prism binos.
Before reading your latest post ,I just spent half an hour outside checking out the images for such things.
Regards , Kenny
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If everyone is thinking the same thing , no-one is thinking - General George S.Patton
Zeiss 7 x 42 BGAT
Captain's Helmsman 7 x 50
Nikon 10 x 42 Superior E
Swift Audubon Kestrel 10 x 50
Helios 15 x 70 Observation
Strathspey 20 x 90
Televue 76 APO
Zeiss 85 Diascope
Helios 102 f5 refractor
Various eyepieces barlows tripods mounts etc.
Panasonic Lumix DMC - TZ5 digital camera
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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Hi Kenny,
To see the effect it helps to have a relatively dark background and the light source should only take up a small area in the center of the field.
Rich
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KennyJ
Reged: 04/27/03
Posts: 10163
Loc: Lancashire UK
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< To see the effect it helps to have a relatively dark background >
Well -- that rules out northern England then !
< and the light source should only take up a small area in the center of the field. >
With a 8.6 degree TFOV -- even the MOON only occupies a "small area" in the centre of field :- )
Seriously though Rich -- you seem no stranger to good quality Roof prism binos -- what do YOU think about this theory of them being worse than Porros in this respect ?
Kenny
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If everyone is thinking the same thing , no-one is thinking - General George S.Patton
Zeiss 7 x 42 BGAT
Captain's Helmsman 7 x 50
Nikon 10 x 42 Superior E
Swift Audubon Kestrel 10 x 50
Helios 15 x 70 Observation
Strathspey 20 x 90
Televue 76 APO
Zeiss 85 Diascope
Helios 102 f5 refractor
Various eyepieces barlows tripods mounts etc.
Panasonic Lumix DMC - TZ5 digital camera
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Rich N
Post Laureate
Reged: 09/22/04
Posts: 5314
Loc: San Francisco Bay Area, Calif...
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Hi Kenny,
I don't see the "star" with porro prism binoculars. I see it in all my roof prism binoculars.
The images through my roof prism binoculars are outstanding. The star effect doesn't seem to degrade the view very much. My Zeiss 10x42FL gives, IMHO, a little sharper, higher contrast image than my Nikon 10x42SE... even though the Zeiss does show the star effect under the right conditions.
You don't have to go outside to see the star effect. Just put a small flashlight in dark room with the flashlight aimed at your binocular. Focus your binocular on the flashlight. You should see the two (maybe only one) lines with your 7x42 roof prism binocular.
I would prefer that my roof prism binoculars didn't have this star effect but they do and they still perform very well.
Rich
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Thanks Kenny and Rich for your response of my question!
My apprehension is that this phenomenom is to a certain level not visible at all, and then suddenly, when the background is dark enough and the source of light is bright enough it appears. Therefore persons who have never used a roof prism binocular at night may never had seen it. (However I actually have noticed it with my Minolta 8x25 at sunny day when the sun reflects on chrome bumper)
It is possible Kenny, that your Zeiss 7 x 42, shows this phenomenom very moderate, and you therefore didn't noticed it, but if it really lacks it absolutely, then it's only to congratulate!
--------------------
*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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KennyJ
Reged: 04/27/03
Posts: 10163
Loc: Lancashire UK
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< It is possible Kenny, that your Zeiss 7 x 42, shows this phenomenom very moderate, and you therefore didn't noticed it, but if it really lacks it absolutely, then it's only to congratulate! >
Well Patric , I suppose ANYTHING is POSSIBLE , but given what Rich reports , I suspect it's more likely that in my case it IS moderate , but hitherto unseen.
Not unlike the dreaded C.A I see through Nikon HG roofs !
Once you "see it" , it can become a "problem" seemingly out of all perspective to reality.
No binocular is PERFECT , but rather than keep trying to bemoan the "minor faults" of the best models available , I'd rather pronounce their virtues.
It's as much a state of mind or attitude as anything else.
Good luck once again with your current search , Patric.
Your posts have added interest to a quiet weekend here !
Regards , Kenny
--------------------
If everyone is thinking the same thing , no-one is thinking - General George S.Patton
Zeiss 7 x 42 BGAT
Captain's Helmsman 7 x 50
Nikon 10 x 42 Superior E
Swift Audubon Kestrel 10 x 50
Helios 15 x 70 Observation
Strathspey 20 x 90
Televue 76 APO
Zeiss 85 Diascope
Helios 102 f5 refractor
Various eyepieces barlows tripods mounts etc.
Panasonic Lumix DMC - TZ5 digital camera
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Swedpat
Pooh-Bah
Reged: 02/18/05
Posts: 1033
Loc: Boden, Sweden, Scandinavia
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Kenny!
I think you have right. Actually the phenomenom isn't a problem in most cases, and it's also easier to accept them, if I know they are a normal result of the basic roof prism construction and not a result of bad quality or a mistake in the manufacturing.
For the moment I'm just facing the difficult choice between choosing a TS 8x42 Triplet or Pentax 10x50 PCF WP.
Both of them have each advantages and disadvantages. I think you have read the links with review of the 8x42 in the 11x70 thread.
Patric
--------------------
*2,3x40 Constellation View Wide-Bino
*Leupold 6x30 Yosemite
*Leupold Katmai 6x32
*Swarovski SLCNew 7x42B
*Bresser (Lidl) 10x50
*Oberwerk 11x70
*No name (Kunming) 15x70
*Scopos ED APO 66
*Meade 5000 26mm Plössl, Vixen LV 10/5mm
Psalm 19:2
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brocknroller
Carpal Tunnel
Reged: 10/16/03
Posts: 1517
Loc: Liberal, Kansas
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Rich
...There is also the benefit, IMHO, of the better hand position of the roof prism binocular. I find roof prism binoculars are easier to hold steady because my hands are closer together.
Rich, I guess you don't have big paws! I find just the opposite, roofs are hard for me to hold steady because they are so narrow (on average about 5" wide, compared to 7" for porros). I found the 8X32 Noble/Regals very hard to hold steady, even though it had great ergonomics -- side cut outs for my palms, recessed strap connectors, a broader than average bridge that wrapped around the EPs, thumb cut outs high toward the centerpost, just where I needed them, comfortable twist up eyecups, and an easily accessible and smooth focuser. Despite all this, I felt like I was holding a 12X bin, trying to keep them steady. The compactness of this bin would make it perfect for hiking, biking, etc., fits in your pocket (only 4.7" long) and very good CA correction for a roof. But... I was "shakin' all over". The magnification at close focus is greater than 8X, which accounts for some of the steadiness problem, plus I have a slight tremor, however, I can hold most 8X32 and 8X42 porros fairly steady.
With practice, I became better at holding the Noble, but I never was able to hold it as steady as my 8X32 SE or 7X35 Activa WP/FP, which also has great ergonomics (both have front slanted campfering for elbows-in positioning). With the Nobles, my wrists were tense from being forced so close together and from having to use more fingers than palms on the narrow body. I tried switching hand positions and overlapped my hands on the body, but then most of the weight rested on my thumbs, which wasn't very comfortable or steady.
So while many people report greater stability with roofs, I'd bet there must be others out there with large hands who have problems holding roofs steady like I do.
What would be a useful invention is an ergonomic sleeve made from NASA foam material (that takes the shape of your hands), which would slip over slimline roofs so that people with large hands could get a comfortable grip.
Brock
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cota_scope
sage
Reged: 05/16/04
Posts: 356
Loc: sioux city ia
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brock porro prisms are better suited for my hands also and more stable to hold, i see no reason to spend more for the complicated roof design. then a good pair of porro prism such as the nikon se or the E2 series and similar. john
Edited by cota_scope (02/21/05 11:52 PM)
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