Victory HT:New Zeiss Homepage (1 Viewer)

henry link · Mar 13, 2012

Temmie,

A single light transmission number based on the average from 400 to 700nm would be an odd choice for marketing purposes. It won't be as impressive as peak or "day" transmission because of the inevitable roll-off in the blue/violet (even with HT glass). If you were Zeiss, wouldn't you assume that your competitors are likely to use the highest number possible, like peak transmission, and do the same yourself?

Henry

henry link · Mar 13, 2012

Holger Merlitz said:
Hi Henry,

Is there any hard evidence for this claim? I mean, is the center resolution of the Nikon EDG or Swarovision inferior to the center resolution of Zeiss/Leica?

Holger

Holger,

I'm not even sure what is meant by "resolution" in the Zeiss material. Are they using the term properly to mean the true resolving power of the telescopes or is it just another word for "sharpness"? My experience measuring Zeiss FL's is that the axial resolution varies quite a bit with individual units. I don't think I've ever seen exactly the same resolution for both sides of the same binocular. That's due to sample defects like astigmatism, pinching, coma, etc, that are usually worse in one side than the other. The best barrels have approached diffraction limited resolution, but most don't. I'll be very surprised if the HT binoculars are any different in that respect.

The few binoculars with field flatteners I've measured (only one Swarovision and one EDG) showed no worse results for axial resolution than typical FL's. The lowest aberration individual binocular I've seen, with the best resolution for its aperture, was a Nikon 8x32SE with a field flattener.

Henry

temmie · Mar 13, 2012

Henry,

I am not a transmission specialist, but it seems like more bins can reach a peak of > 95%.
So what would be the most impressive:
1. claiming that the HT has a peak of (let's say) 97-98% compared to e.g. 95-96% in competitors, or
2. claiming that the HT has an average of 95% while the competition has around 90%?

I cannot back up this example by real data, so it's still all wishfull thinking ;-)

NDhunter · Mar 13, 2012

Juan:

Those day and night transmission numbers were straight from the Ginkel Europa binocular
review from 2010. It presents some spectophotometer scores for 2 common transmission levels. Very hard to post them all in a condensed form.

I did not interpret them in any way, as I am a novice, but an interested binocular user.

Do a search of this review, you will then see how they did things and how many binoculars
will compare.

Jerry

james holdsworth · Mar 14, 2012

henry link said:
Holger,

I'm not even sure what is meant by "resolution" in the Zeiss material. Are they using the term properly to mean the true resolving power of the telescopes or is it just another word for "sharpness"? My experience measuring Zeiss FL's is that the axial resolution varies quite a bit with individual units. I don't think I've ever seen exactly the same resolution for both sides of the same binocular. That's due to sample defects like astigmatism, pinching, coma, etc, that are usually worse in one side than the other. The best barrels have approached diffraction limited resolution, but most don't. I'll be very surprised if the HT binoculars are any different in that respect.

The few binoculars with field flatteners I've measured (only one Swarovision and one EDG) showed no worse results for axial resolution than typical FL's. The lowest aberration individual binocular I've seen, with the best resolution for its aperture, was a Nikon 8x32SE with a field flattener.

Henry

I thought you said that your 56 FL made the SE look ''mushy and dull'' and that your FL also tested the highest for arc/ sec resolution of all models you have previously tested?

Chosun Juan · Mar 14, 2012

*** EDIT Chosun Juan post #58 ***

NDhunter said:
Juan:

Those day and night transmission numbers were straight from the Ginkel Europa binocular
review from 2010. It presents some spectophotometer scores for 2 common transmission levels. Very hard to post them all in a condensed form.

I did not interpret them in any way, as I am a novice, but an interested binocular user.

Do a search of this review, you will then see how they did things and how many binoculars
will compare.

Jerry

Jerry, All

Oops! After looking into this further, it is indeed us "down under" (or at least me anyways - hey it was 3am after all!) that are *rs* about with Day /Night.

500 nm is taken as the 'Night' level (or I have read 505 nm, or even 510 nm)
555 nm is taken as the 'Day' level

*************************************************************
It's too late for me to Edit my - Chosun Juan post #58, so I'll correct it here.
The figures for the test on allbino's of the Zeiss Victory 8x56 T*FL should be (reading off the graph):

90 +/- 1% ...... 500 nm - Night level
93.6 +/- 1% ... 555 nm - Day level

*************************************************************

The choice of ~500 nm and ~555 nm has to do with the rods (peripheral) and cones (central) of the eye.

They correspond to the peaks of the Photopic Curves (cone biased) and Scotopic Curves (rod biased).

There is some 'by-product' discussion of these values, and useful 'maven' inputs in this thread:
Comprehensive 10x42 test in German magazine http://www.birdforum.net/showthread.php?t=180743

You may also find this information on the curves (in relation to lighting) useful, here:
http://www.gelighting.com/na/busine...hite_papers/download/photopic_scotopic_lb.pdf

Other useful information on the photopic / scotopic curves can be found here:
Brightness and Night-Day Sensitivity http://hyperphysics.phy-astr.gsu.edu/hbase/vision/bright.html

Allbinos has a good article on the colour spectrum here:
http://www.allbinos.com/index.php?art=160

Now considering these 'brightness' transmission points / values, the way the eye works, and the light spectrum before / at twilight ...

Is Zeiss onto something here ?

A brighter, but (relatively - as opposed to boosting the upper wavelengths to high heaven) less contrasty view ??

Chosun :gh:
_____________________________________________________________

Until we see the transmission graph, I think Herr Bob Dylan had it right 'the answer my friends is p***ing in the wind' ...... |

|

henry link · Mar 14, 2012

james holdsworth said:
I thought you said that your 56 FL made the SE look ''mushy and dull'' and that your FL also tested the highest for arc/ sec resolution of all models you have previously tested?

James,

Yep, I did say those things. Strangely enough, they’re true and yet not inconsistent with anything in the post you quoted.

I’ve measured the resolution of 6 pairs of FL’s and star tested an additional 4 or 5. The right barrel of my 8x42FL has the best resolution per mm of aperture of the lot, but its raw resolution is only better than my 8x32 SE because the aperture is larger. The SE is about as close to diffraction limited for its aperture and both barrels are about equally good.

If you go back and read the description of the 8x56 FL star test in my old review you’ll see that its optical performance is not very good at full aperture. However, when it’s effectively stopped down to 20-30mm by the pupil of the eye in daylight most of the nasty full aperture aberrations are eliminated and it becomes the optical equivalent of a superb small aperture binocular. Unfortunately that excellent little binocular is forever trapped inside the body of a very large and very heavy one.

Henry

temmie · Mar 14, 2012

henry link said:
Unfortunately that excellent little binocular is forever trapped inside the body of a very large and very heavy one.

Love that quote! B

spacepilot · Mar 14, 2012

henry link said:
I was assuming that light from the entire exit pupil could enter the eye. If your pupil only dilates to 5mm then, of course, every 10x binocular is limited to an effective aperture of 50mm and every 8x binocular is limited to 40mm,

I had forgotten that Ron Harper came up with a very clever way to make an aperture stopdown that remains constant even if your pupil is smaller than the exit pupil. Instead of a square at the edge of the objective lens you make a wedge with the point of the wedge positioned over the center of the lens. Each 3.6º of width corresponds to a 1% obstruction. In the photo below I made a very approximate 2% obstruction by cutting out a 7º wedge. It can be used to compare 2% brightness differences under any lighting conditions.

I've compared all sorts of apertures in low light. You don't even need a 56mm binocular to see the brightness difference between 42mm and 56mm in low light. You can stop down a 42mm binocular to 30mm and see the same proportional difference.

Henry, thanks for the photo. The wedge would eliminate most of the concern about the relative sizes of the exit and entrance pupils.

With all else being equal, the binoculars with higher transmission number is expected to help us see more details in dim light. However, all else is rarely equal. Color balance, CA, etc. affect how much details we can see in the dark. That's why I think even if the difference between the HT and FL is "clearly visible", as Zeiss claims, I would still wonder how much is of the HT advantage can be attributed to the slightly better light transmission until some experiment like I describes is carried out. That's also why I asked if you've compared the low-light performance of the 8x42 and stopped-down 8x56. I assume they have similar light transmission number, but the stopped-down 8x56 has lower aberrations. So if the stopped-down 8x56 helps you see more into the dark, it's probably due to something other than light transmission.

henry link · Mar 15, 2012

Eyesight acuity is very poor in dim light, so I don't think the differences in aberrations among the binoculars we're talking about here will have have any significant effect on what details can be seen. I think only two things really matter for seeing detail in very dim light: the photon count at the retina and the magnification.

If Zeiss' claims of a 2-3% difference in transmission between the Zeiss HT and FL binoculars are true, then I doubt that any brightness difference can be detected between them even in a direct A/B comparison. However, it could be that the HT's will appear brighter than the next tier below the FL's. If, for the moment, we assume a threshold of 3-4% as the smallest transmission difference that can be detected and assign 95% to the HT, 92.5% to the FL and 90% to brand X we have an interesting situation. You can't tell the difference between Brand X and the FL and you can't tell the difference between the FL and the HT, but you can detect a difference between the HT and Brand X.

Of course, if you really want to see more detail in dim light I wouldn't split hairs among 42mm binoculars. I'd just buy one with a larger aperture.

Henry

brocknroller · Mar 15, 2012

henry link said:
James,

Yep, I did say those things. Strangely enough, they’re true and yet not inconsistent with anything in the post you quoted.

I’ve measured the resolution of 6 pairs of FL’s and star tested an additional 4 or 5. The right barrel of my 8x42FL has the best resolution per mm of aperture of the lot, but its raw resolution is only better than my 8x32 SE because the aperture is larger. The SE is about as close to diffraction limited for its aperture and both barrels are about equally good.

If you go back and read the description of the 8x56 FL star test in my old review you’ll see that its optical performance is not very good at full aperture. However, when it’s effectively stopped down to 20-30mm by the pupil of the eye in daylight most of the nasty full aperture aberrations are eliminated and it becomes the optical equivalent of a superb small aperture binocular. Unfortunately that excellent little binocular is forever trapped inside the body of a very large and very heavy one.

Henry

Henry,

Couldn't they make an 8x42 with as long a FL as an 8x56? It would be long, narrow bin, but the 8x56 Dialyt is long and narrow (though that didn't seem to help with the CA at the edges, according to allbinos, and the FOV is not wide).

I'm wondering if it's just a matter of convenience and preference that binoculars seem to be getting shorter rather than longer?

Aside from unwieldy ergonomics, are there optical restrictions associated with elongating an 8x42 such as limiting FOV?

Brock

ronh · Mar 15, 2012

Henry,
Not a disagreement, I just want to say, for the sake of stargazers present, stargazing is not like low-light terrestial observation. It can be extremely demanding of optical quality.

Even in the dark of night when the eyes are fully dark adapted, the small and intense image of a star will stimulate the eye's cone cells, and thus its most acute vision. Because the eye pupils will be wide open, this situation will test the outer regions of the objective lenses, and the eyesight, to the max.

I agree a 3% brighter light bulb won't make a difference. But I am hopeful that a 50%ish reduction in veiling glare will.
Ron

henry link · Mar 15, 2012

Ron,

I thought you might pipe up on that score. Yep, stars are hard.

I was thinking more of the poor hunters trying to count antler points in the dark.

Brock,

I think Zeiss has been forced to make the AK binoculars shorter than optimum because short and light is what the market wants.

If the focal length of the 8x42 were increased that would increase the size of the ariel image formed by the objective, so something has to give. If the eyepiece focal length is increased to maintain the same magnification, then the FOV (both real and apparent) will shrink unless the EP fieldstop is enlarged, which then requires larger EP elements and larger heavier prisms and so it goes until you have a 35 oz binocular that nobody will buy. In the end I might prefer to stick to the 8x56 for the luxurious exit pupil and even the extra heft which I've come to believe makes for a steadier image.

Henry

dalat · Mar 16, 2012

henry link said:
If Zeiss' claims of a 2-3% difference in transmission between the Zeiss HT and FL binoculars are true, then I doubt that any brightness difference can be detected between them even in a direct A/B comparison.

Here is your A/B comparison

http://sportsoptics.zeiss.com/hunting/en_de/experience/competence/lens-concept/zeiss_ht.html

David Swain · Mar 16, 2012

dalat said:
Here is your A/B comparison

http://sportsoptics.zeiss.com/hunting/en_de/experience/competence/lens-concept/zeiss_ht.html

Yup, virtual night vision! It would seem a simple deal to make a birding equivalent to that page, but no, it would appear hunters are the primary audience for these.

David

Star Farmer · Mar 16, 2012

David Swain said:
Yup, virtual night vision! It would seem a simple deal to make a birding equivalent to that page, but no, it would appear hunters are the primary audience for these.

David

I assume only hunters will fall for that ad?

henry link · Mar 16, 2012

dalat said:
Here is your A/B comparison

http://sportsoptics.zeiss.com/hunting/en_de/experience/competence/lens-concept/zeiss_ht.html

Thanks dalat. Do you think we need to notify the Consumer Protection Agency? ;-) Hopefully, no one in the world could be gullible enough to believe that those images accurately represent the difference in light transmission between an HT and non-HT binocular.

In Zeiss' defense, I would say that it's tough to graphically illustrate a difference as small as 3% (HT vs FL) and expect to generate much excitement. I cropped out the hopelessly dim non-HT image and used the exposure control and histogram in iPhoto to try to brighten it by about 3%. One of the photos below is unmodified and the other is approximately 3% brighter.

Star Farmer · Mar 16, 2012

I give up. Which one is it?

By the way, that buck is one for the records. No way their photographer found that in the wild. So, at best, it's a museum shot. Worse, it's taken from the Guiness archives and docked.

Nixterdemus · Mar 16, 2012

Picture #2 is lighter. I judged that originally by clicking on the first & then the second. I had doubts about my perspective, so I then compared them side by side.

The surroundings are more of a giveway than the critter in the pic.

Anywho that's what I see.

henry link · Mar 17, 2012

The brighter one is actually the one on the left. I notice that on my computer monitor I can't get a consistently correct impression. For some reason, if I place the two images side by side the right one always looks brighter than the left, no matter which one is on the right. Apparently some unevenness in the screen brightness overwhelms the tiny difference between the two images.

If I look at the image in iPhoto and toggle the exposure control up and down by 3% I can see a very slight difference in the image at the instant of the change and I can watch the histogram jog back and forth, so I know the left one really is brighter. I think this is a pretty good demonstration of just how little difference 3% makes. I imagine hunters can continue their twilight stalking for about 10 seconds longer with an HT than they can with an FL of the same aperture and magnification.

Victory HT:New Zeiss Homepage (1 Viewer)

Well-known member

Well-known member

Well-known member

Experienced observer

Consulting Biologist

Given to Fly

Well-known member

Well-known member

Well-known member

Well-known member

porromaniac

Well-known member

Well-known member

...

Well-known member

Well-known member

Well-known member

Attachments

Well-known member

Well-known member

Well-known member

Similar threads

Users who are viewing this thread