Zen Ray ED2 7x36 evaluations and review (1 Viewer)

[FrankD]

As it happens, I went home for lunch and tried the very thing Surveyor mentioned. There has been some discussion about this and that suggestion came up. I can see a bit of the dreaded crescent doing that. But boy does it seem like a funny and un-natural eye position for me. Maybe this is a face shape issue. At least I now have a bit of an inkling of what is being seen.

I spent a great deal of time today out in the backyard with both of the new Zen ED2s. I finally see the crescents that have been mentioned previously. I thought I came to some profound conclusion but come on to see that Steve and a few others have already beaten me to the punch.

For me it is eye positioning that is the culprit. I have a fairly large nose and deepset eyes so I rest the bottom of the eyecups on the bridge of my nose for normal use. Under these conditions I was not able to notice enough of a crescent in regular use to be able to comment on it.

Well, I started tinkering with eye positioning and was able to induce the crescent if I moved the binoculars up so that the top of the eyecups rested on my brow....if I had the sun at an approximate 40 degree angle to the bins. When I then went back to my normal eye positioning the glare all but disappeared even at that 40 degree angle but I was still able to notice a very small amount now that I have been "trained" to see it.

At least I feel as if I am not totally crazy with this one.

 

[Kevin Purcell]

does not look like it is the case.

http://birdforum.net/showpost.php?p=1563053&postcount=68

Just to clarify what my post says:

The 8x43mm ED2 has the same amount of glare as the ED1 and all the other CHinese ED open-bridge bins I have.

The 7x36mm does seem to have a little more glare than the 43mm.

I think it's more important to focus on the model rather than the "brand".

I don't think there are any significant optical changes aside from dielectric mirror coating prism in the 8x43. No change in implementation. No change in design. No change in objective or focuser mounting design (or color).

I think it's more likely to be something to do with scaling of the design for the 7x36mm and perhaps the bigger FOV than a simple implementation detail. The internals of both size of ED2 are "the same" AFAIK.

 

[Kevin Purcell]

Eye Placement and Stray Light

I was thinking of the SE analogy when I read FrankD's post today. Very similar sort of issue in that facial shape, bin setup, eyeglass dimensions and prescription all play a role in if you have a problem or not. Add in lighting in this case and you have a mix. So I decided to take a closer look.

I always wear glasses when using binoculars. That makes binocular placement a bit more flexible than those that don't. The bones around the eyes in the brows, bridge of the nose and the cheeks can dictate what bins (or eyecups) work and where they sit.

So I decided to try the bins without glasses to see how that affects the glare problems people see.

It turns out if I try one common method of aligning the bin (touching the brow with the bin and the bottom eyecup doesn't touch my face) then I get really bad glare results. If I try with the bin resting on the orbit below the eye and not touching the brow -- that's more natural for me too -- then I reduce the problem to where the glare is not a problem or non-existent. That positioning moves the eye up with respect to the ocular and away from any stray light at the bottom of the exit pupil.

The difference between the two positions is between annoying in the worst case and fine. So I believe there is some facial features that ultimately end up preventing people moving their eye up in the exit pupil to reduce the effect when they don't use glasses.

When wearing glasses of course ones brow doesn't get in the way and there is a fair amount of freedom to move the bin around with respect to the eye. But there is one extra issue that the further the eye is away from the ocular the larger the glare problem. I think this much be a geometric effect with the stray light getting broader behind the exit pupil. So close fitting glasses like the ones I usual wear show the problem less than less close ones (like my polarizing sunglasses).

I think you get a similar problem for folks, like edz, that make an effort to center their entrance pupil in the exit pupil; they may come off worse too (if they won't move the eye up).

This means the problem is a mixture of a stray light at the bottom of the exit pupil (which depends on the illumination) plus the variability across the user population so difference people experience the underlying issue with different severities.

I suspect there are some people that don't or can't align entrance pupils to exclude that bottom part of the exit pupil where there is stray light.

In fact there is another interesting case when the exact opposite technique that works for you is the opposite of what works for me. I think that's down to face shape. For example, SteveC's technique is holding the bin to the brow and it works for him but it doesn't for me.

I note when I used them I tend to place my eye above the center to avoid problems. This is important to note because some people with perfect technique who lines things up just right may still have this problem. The problem is it certainly hits quite a few people. And some can't use the bin with it.

There may be another factor here too: the entrance pupil size of the eye. Someone with smaller entrance pupils will have less of a problem on average. Those with larger entrance pupils will have more of a problem.

But the stray light amount is larger in the 7x36 than it is in the 8x43. That's another contributing factor to the problem.

So I think we might have a clue why we have a big variance in the reports of glare.

I think it's important that SteveC and FrankD can reproduce the issue. I spent some of today playing with the bins and exchanging emails with them though some early comments seemed to have pushed them to come to the same conclusions I've come to. So that's good to know. It seems Ron also came across the same effect at the same time too. Obviously a collection of "great minds think alike" (as an British saying goes).

 

[Surveyor]

a bright edge on the focusing lens cell visible in his photo.

Henry;
I see the same thing in both tubes, the right tube having the larger "shiny spot".

The picure shows both tubes, bottom set with the bins right side up and the top set, upside down. I did this to make sure the shiny spot was on the metal and not a reflection.

Best
Ron

 

[NDhunter]

Eye Placement and Stray Light

The problem is it certainly hits quite a few people. And some can't use the bin with it.

I was thinking of the SE analogy when I read FrankD's post today. Very similar sort of issue in that facial shape, bin setup, eyeglass dimensions and prescription all play a role in if you have a problem or not. Add in lighting in this case and you have a mix. So I decided to take a closer look.

I always wear glasses when using binoculars. That makes binocular placement a bit more flexible than those that don't. The bones around the eyes in the brows, bridge of the nose and the cheeks can dictate what bins (or eyecups) work and where they sit.

So I decided to try the bins without glasses to see how that affects the glare problems people see.

It turns out if I try one common method of aligning the bin (touching the brow with the bin and the bottom eyecup doesn't touch my face) then I get really bad glare results. If I try with the bin resting on the orbit below the eye and not touching the brow -- that's more natural for me too -- then I reduce the problem to where the glare is not a problem or non-existent. That positioning moves the eye up with respect to the ocular and away from any stray light at the bottom of the exit pupil.

The difference between the two positions is between annoying in the worst case and fine. So I believe there is some facial features that ultimately end up preventing people moving their eye up in the exit pupil to reduce the effect when they don't use glasses.

When wearing glasses of course ones brow doesn't get in the way and there is a fair amount of freedom to move the bin around with respect to the eye. But there is one extra issue that the further the eye is away from the ocular the larger the glare problem. I think this much be a geometric effect with the stray light getting broader behind the exit pupil. So close fitting glasses like the ones I usual wear show the problem less than less close ones (like my polarizing sunglasses).

I think you get a similar problem for folks, like edz, that make an effort to center their entrance pupil in the exit pupil; they may come off worse too (if they won't move the eye up).

This means the problem is a mixture of a stray light at the bottom of the exit pupil (which depends on the illumination) plus the variability across the user population so difference people experience the underlying issue with different severities.

I suspect there are some people that don't or can't align entrance pupils to exclude that bottom part of the exit pupil where there is stray light.

In fact there is another interesting case when the exact opposite technique that works for you is the opposite of what works for me. I think that's down to face shape. For example, SteveC's technique is holding the bin to the brow and it works for him but it doesn't for me.

I note when I used them I tend to place my eye above the center to avoid problems. This is important to note because some people with perfect technique who lines things up just right may still have this problem.

There may be another factor here too: the entrance pupil size of the eye. Someone with smaller entrance pupils will have less of a problem on average. Those with larger entrance pupils will have more of a problem.

But the stray light amount is larger in the 7x36 than it is in the 8x43. That's another contributing factor to the problem.

So I think we might have a clue why we have a big variance in the reports of glare.

I think it's important that SteveC and FrankD can reproduce the issue. I spent some of today playing with the bins and exchanging emails with them though some early comments seemed to have pushed them to come to the same conclusions I've come to. So that's good to know. It seems Ron also came across the same effect at the same time too. Obviously a collection of "great minds think alike" (as an British saying goes).

I'm glad to see that the detectives have been working today. For me and some others, who have adjusted and played around with these things, it seems that these do not fit well, so it is not imagination.
As Sherlock Holmes said "It is quite a 3 pipe problem". !!

 

[Kevin Purcell]

The picure shows both tubes, bottom set with the bins right side up and the top set, upside down. I did this to make sure the shiny spot was on the metal and not a reflection.

I'm not sure that I follow that?

It shows the reflection is locatized (and that it "breaks the symmetry of the tube") but I'm not sure that it follows from that that the reflection is from metal.

I would have though a reflection from something symmetric in the tube. Like the prism.

Could you expand on that, Ron?

 

[Surveyor]

Hi Kevin,

What I see when looking into the objective (going from memory here since I do not have the bin with me) is a round, flat surface parallel to the longitudinal axis that appears to be a different surface color than the rest of the same surface, like a shiny reflective area. But, an assumption to be sure, I would expect that since the image remains constant regardless of rotation of the bin, a reflection from a common light source would also stay constant relative to the image. This area does not stay constant with relation to the image but stays constant to the mechanical position as the bin is rotated. The area is mirrored in the left side, only smaller. So, if the optics are the same, I would expect a reflection to be the same size.

Reminds me of a part placed on a rod for coating and the area contacting the rod not receiving the coating.

All of this is supposition since I can not really see anything well enough, I just can see a shiny point in each tube, but of different sizes.

Best
Ron

EDIT: Kevin, you may be right about the prism edge reflection, they would remain constant to the mechanical position. I do not understand the size difference yet, but will look into it with a light tonight. Just thought of something else to try. When I get home, I will take a strong light and see what that area looks like. Someone may get to it quicker and post.

 

[dipped]

I just posted this on my shootout thread. These are photos of the oculars of the 7x36s at infinite focus and minimum focus. The controversial grey crescent of doom (or intermittent faint non-existent crescent of nothing, depending) occurs to the lower left of this left barrel, opposite the bright reflection in the infinite focus picture:

Infinite focus

Minimum focus

Hi

Are you able to highlight or point to exactly where this crescent is in your picture(s)?

I'm not sure where it is. It may be my monitor or me being stuipid. There seems to be a lot going on inside there.

Thanks - Nev

 

[Surveyor]

Nev,
Look at the ends of the yellow lines. The lines are drawn between the bright spots on the surface.
Ron

 

[dipped]

Nev,
Look at the ends of the yellow lines. The lines are drawn between the bright spots on the surface.
Ron

Hi Ron

And in Fireforms picture(s)?

Nev

 

[Surveyor]

Nev, I can't open Fireform's images from work. The firewall will not allow access to them. Sorry

 

[henry link]

The problem is visible in the "Minimum focus" image. Notice that the very edge of the exit pupil is actually a bright ring of reflections from an interior surface, brightest at the bottom. This is precisely the kind of internal reflection that causes the veiling glare under discussion. To the eye it appears as a fuzzy crescent when actually viewing through the binocular because the binocular internals are so far out of focus. It's absent from the "Infinite focus" photo presumably because it comes from the edge of the focusing lens which moves toward the prism and out of view at long focusing distances. None of the other internal reflections in the photos are likely to cause any problems, they're too dim, or too far from the exit pupil or masked by the eyepiece fieldstop in normal viewing.

If that one ring of reflection were blocked by a properly designed baffle installed at the edge of the focusing lens cell this whole discussion would go away. There would be little or no glare problem for anybody, no matter what the lighting conditions, focusing distance or eye pupil size or pupil position.

 

[Surveyor]

Thanks Henry. For me, it is really a non-issue type of thing since I have to really work at seeing it.

 

[Pileatus]

The problem is visible in the "Minimum focus" image. Notice that the very edge of the exit pupil is actually a bright ring of reflections from an interior surface, brightest at the bottom. This is precisely the kind of internal reflection that causes the veiling glare under discussion. To the eye it appears as a fuzzy crescent when actually viewing through the binocular because the binocular internals are so far out of focus. It's absent from the "Infinite focus" photo presumably because it comes from the edge of the focusing lens which moves toward the prism and out of view at long focusing distances. None of the other internal reflections in the photos are likely to cause any problems, they're too dim, or too far from the exit pupil or masked by the eyepiece fieldstop in normal viewing.

If that one ring of reflection were blocked by a properly designed baffle installed at the edge of the focusing lens cell this whole discussion would go away. There would be little or no glare problem for anybody, no matter what the lighting conditions, focusing distance or eye pupil size or pupil position.

Henry,

I'm curious why they make such fundamental mistakes to begin with. In any case, you've nailed the problem and the discussion can now move on to sloppy focus mechanisms and cold weather lubrication. By the third or fourth iteration they may have a winner!

John

 

[falcondude]

Guys, I think you are selectively focusing on my criticisms and ignoring the many aspects of these bins I've justly praised. My FLs aren't perfect either. I sent the $1800 EDGs back, too.

I enjoy reading your quality review on the shoot out. It is one of the best I have read here. It is sad to see all the good information in that review was lost or buried when people simply focus on one issue that affects few people, while ignoring the rest.

 

[Kevin Purcell]

Henry;
I see the same thing in both tubes, the right tube having the larger "shiny spot".

The picure shows both tubes, bottom set with the bins right side up and the top set, upside down. I did this to make sure the shiny spot was on the metal and not a reflection.

When I try this in the field and observe (in this case a Anna's Hummingbird in the top of a Cedar 40 degrees up with overcast sky behind it) I can get "Crescents" with a given eye placement at the bottom of the field. The usual case.

if I then invert the bins (focuser down ... nice thumb focusing!) and do the same I get "Crescents" with a given eye placement at the bottom of the field.

The "Crescents" are always opposite the light source -- in this case at the bottom of the field.

Which I don't think goes along with your observation.

 

[Fireform]

I enjoy reading your quality review on the shoot out. It is one of the best I have read here. It is sad to see all the good information in that review was lost or buried when people simply focus on one issue that affects few people, while ignoring the rest.

I don't think it was lost. A few people seem to be over-sensitive to criticism of the Zen, but that happens. A few small bug-fixes and the Zen will definitely move to my keeper column.

Thank you for the kind words on my review. It was fun and educational for me.

 

[dipped]

The problem is visible in the "Minimum focus" image. Notice that the very edge of the exit pupil is actually a bright ring of reflections from an interior surface, brightest at the bottom. This is precisely the kind of internal reflection that causes the veiling glare under discussion. To the eye it appears as a fuzzy crescent when actually viewing through the binocular because the binocular internals are so far out of focus. It's absent from the "Infinite focus" photo presumably because it comes from the edge of the focusing lens which moves toward the prism and out of view at long focusing distances.

Thanks for that Henry. So not as Fireform was saying, a grey crescent in the infinite focus picture. I can see why I was getting a bit confused...

Nev

 

[Fireform]

Thanks for that Henry. So not as Fireform was saying, a grey crescent in the infinite focus picture. I can see why I was getting a bit confused...

Nev

The bright fingernail shape in the upper right of the black area outside the exit pupil of my infinite focus photo is a reflection of the light bouncing off the rim of the focus lens ring. It is not the cause of the glare, but a product of the same reflection that causes the glare.

 

[kristoffer]

I got them now. First impressions:
Very nice box and package. They fit very nice in my hands. The focus is way too stiff but I hope it will loosen up. The image is spectacular, one of the best I have tried. I do see some glare but I can reduce it by changing how wide the bin is (with center hinge). It is cloudy today so I need to test with more sunlight.

I will do more testing tomorrow.