Victory HT:New Zeiss Homepage (1 Viewer)

Henry, et al,

On average, an 8% difference is needed to achieve 75% accuracy in identifying the brighter of two objects presented for brief intervals (i.e., tachistoscopically). That's mid-way between a chance level of 50% and a perfect score of 100%. Since the ability is statistically distributed in the population, it may be that some individuals operate as low as 3% and others as high as 14%. However, keep in mind these experiments require that the subject not know which stimulus is actually brighter. Otherwise, the evaluation ain't scientific.

I think that Zeiss' statements are misleading. For example, take the following:

...A small percentage of light loss through absorption as the light passed through the glass was accepted as inevitable. Until, that is, SCHOTT AG - a sister company *in the Carl Zeiss Foundation - developed new optical lenses with the additional "HT" or High Transmission feature.That was the trigger for the development of the ZEISS HT products.

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First, there can be no doubt that "a small percentage of light loss through absorption" is still present, altho the percentage may be smaller. Second, reducing absorption is different from reducing reflections. Glass absorption, as I understand it, dissipates light energy as heat, whereas reflections damage image quality due to internal scatter. Images of equal quality, would not be improved much, if at all, by a miniscule increment in light intensity, since that's equivalent to changing source illumination.

What do you think?

Ed

Gadzooks! I had a 50-50 shot at being correct, however I suppose I didn't factor the other side into the equation.

I looked longer at the pics side by side, yet determined that the circumstances didn't warrant the reversal of a Custer, Little Big Man(1970), decision.

Interestingly enough though that the two pics aren't quite on the same spot of the monitor and the latter 5559 pic, by my primitive calculations, is slightly over 3% larger than the former.

It's the only defense I can muster as I try to maneuver to high ground.

elkcub said:

Henry, et al,

On average, an 8% difference is needed to achieve 75% accuracy in identifying the brighter of two objects presented for brief intervals (i.e., tachistoscopically). That's mid-way between a chance level of 50% and a perfect score of 100%. Since the ability is statistically distributed in the population, it may be that some individuals operate as low as 3% and others as high as 14%. However, keep in mind these experiments require that the subject not know which stimulus is actually brighter. Otherwise, the evaluation ain't scientific.

I think that Zeiss' statements are misleading. For example, take the following:

Quote:
"...A small percentage of light loss through absorption as the light passed through the glass was accepted as inevitable. Until, that is, SCHOTT AG - a sister company *in the Carl Zeiss Foundation - developed new optical lenses with the additional "HT" or High Transmission feature.That was the trigger for the development of the ZEISS HT products".


First, there can be no doubt that "a small percentage of light loss through absorption" is still present, altho the percentage may be smaller. Second, reducing absorption is different from reducing reflections. Glass absorption, as I understand it, dissipates light energy as heat, whereas reflections damage image quality due to internal scatter. Images of equal quality, would not be improved much, if at all, by a miniscule increment in light intensity, since that's equivalent to changing source illumination.

What do you think?

Ed

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Ed,

I would agree with all that you have said.

This, along with the MIG (although it should be noted - perfectly legal) speculation, and the exaggerated (with HT-Glas / without HT-Glas) image comparisons, it seems, would indicate that the advertising is slipping more over onto the 'Scurrilous' side, than the 'Cheeky' side, Henry Link's practical observations not withstanding. http://www.birdforum.net/showpost.php?p=2390960&postcount=77
Compare .......................................... http://sportsoptics.zeiss.com/hunting/en_de/experience/competence/lens-concept/zeiss_ht.html

Zeiss should be careful of its hard won reputation.

[EDIT]: I couldn't pick the difference in the two images henry presented - and when I thought I could ...... I got it wrong ! :egghead:
(looks like I'm in the bottom half of the class - stay after school!)

Henry Link also makes the relevant point about colour balance, noting the change to the 'T* coatings' in this post
http://www.birdforum.net/showpost.php?p=2385296&postcount=7

I think this is somewhere on the money (i.e. a colour rebalance), however, it's interesting to consider that Zeiss has AFAIK a reputation for a somewhat neutral - bluish colour balance*. What effect this new colour rebalance has on image quality by reducing reflections due to internal scatter will only be known when we 'see' it - and given what Ed has said above, I wonder how easy that will be if in fact an improvement is there.

*I think this may be more 'relative' (to other alpha's) than 'actual' if you look at these transmission curves from the Ginkel 2010 42mm binoculars test - check the last page (20) View attachment Ginkel.2010.Test.42mm.binoculars.pdf

It's also interesting to note that the Swarovski EL 8.5X42 SV has the flattest tr% curve from 475nm to 625nm.
Below 500nm it actually transmits more of the 'bluish' spectrum than the Zeiss Victory 8x42 FL does.

The Zeiss curve from 525nm to 600nm is actually tabletop flat in this test.

Both the Leica Ultravid HD 8x42, and the Swarovski SLC 8x42 HD, have tr% graphs which slope upwards towards the reddish spectrum, until a drop off after 650nm and 600nm respectively.
The Swarovski SLC 8x42 HD has the highest tr% of any of the four alpha bins (just pipping the Zeiss Victory 8x42 FL).

It will be interesting to see the colour balance that the Zeiss Victory HT comes up with -
of course we will need to see the Transmission % curve for that! (and then compare it to the actual view).

When an Official Zeiss Victory HT Transmission % curve ??

Until then ..........we are all still hunting ghosts !



Chosun :gh:

It never occured to me to doubt that the two pics of the stag in the promotion of the Victory HT show the difference as actually seen through the HT, even though most people must feel instinctively that the glow is exaggerated. I saw the light (or lack thereof) only after Henry Link’s experiment, simple (in concept) and effective, demonstrating the reality of 3% (even allowing for a little adjustment if that is necessary for some reason/s). I am shocked at Zeiss’s lack of accuracy here. Sadly, their ads are out of harmony with their impressive role in the history of binocular optics and the excellence of their products.

These ads might appear to compromise the objective honesty one expects of Zeiss (cf. Swarovski) apparently seeking to boost sales while staying within whatever legal rules apply to advertising. Maybe objectivity is not a criterion in the kind of promotion they’re using for the new Conquest and Victory! But I have no doubt it will be be effective. Many birdwatchers, some even keen or serious about their hobby, will be pushed that extra bit by the Victory HT video to buy what is anyway one of the best binoculars for their purpose. The theme is not new at Zeiss for bins. Since more than a quarter-century ago their ads featured hunters in a gentrified setting. The Conquest HD video too turns away from useful info. on optical quality--implying that it is to be taken for granted. All this works.

It seems that Zeiss anticipate very wide sales for the Conquest HD, and figured out a compromise between: slightly lower sales (if lower at all) of Victory HT than Victory FL: vs: high-volume Conquest HD sales plus even more prestige with Victory HT than FL. Also, the _x32 and 7x42 models may be moved to either range/both ranges. This is assuming the co. won’t have another new range on the market soon.

Several sensible people have said in these threads: what’s the point of all this analysis, technical (very competent) and market (see above!)--we’ll soon find out when the bins are available! But I am yet another with the curiosity-hope syndrome. Some of the ideas in these forums might have the same practical impact as Chosun’s merry reconstruction of the discussions at Zeiss HQ: “Sack dem alle!”, etc. On the other hand some may eventually influence policy at Zeiss and other makers.

The “Made in G.” matter is tricky even in regard to the videos. The cigar may be non-G. but then we know the best of them are. However, the plainly identifiable SUV, a Land Rover Discovery descendant, is not only non-G. but not the “best” model in the range of that maker. Maybe in the fatherland of Messrs Benz and Porsche their own SUVs are used by those who choose Jenas, and Range Rovers by those who prefer Leicas! (The videos have more hidden messages. Note the subtle “plug“, in the Victory clip, for what someone in these threads called “Shot” glass!)

The videos should also provide a reality check for ‘birdforum’ members. A birdwatcher (a) is “an envious hanger-on”--as someone in these threads identified the man’s role in the Victory episode, (b) buys second-quality optics--Conquest, contra Victory for the hunter, and (c) emphatically, does not attract charming companions of the opposite sex.

On binocular performance overall I have a skewed view because of an obsession with lightness and smallness (maybe partly due to same parameters in relation to wallet). I’m waiting for a redesigned 10x25, either Victory or Conquest! Flare control and effective f.o.v. for eyeglass wearers will then surely be improved. (I hope that in making that suggestion I sound more diffident than Chosun does in another thread!)

elkcub said:

Henry, et al,

On average, an 8% difference is needed to achieve 75% accuracy in identifying the brighter of two objects presented for brief intervals (i.e., tachistoscopically). That's mid-way between a chance level of 50% and a perfect score of 100%. Since the ability is statistically distributed in the population, it may be that some individuals operate as low as 3% and others as high as 14%. However, keep in mind these experiments require that the subject not know which stimulus is actually brighter. Otherwise, the evaluation ain't scientific.

I think that Zeiss' statements are misleading. For example, take the following:

First, there can be no doubt that "a small percentage of light loss through absorption" is still present, altho the percentage may be smaller. Second, reducing absorption is different from reducing reflections. Glass absorption, as I understand it, dissipates light energy as heat, whereas reflections damage image quality due to internal scatter. Images of equal quality, would not be improved much, if at all, by a miniscule increment in light intensity, since that's equivalent to changing source illumination.

What do you think?

Ed

Click to expand...

Ed,

Your numbers seem about right to me. Since I've been in "brightness discrimination" training for years I believe I'm now a tip top discriminator. I think I could come pretty close to 100% accuracy at 5% and approach 75% at 3%, if only some real scientist would hook me up to a proper test. ;-) Still, I see 5% as very small and 3% as the next thing to invisible.

As for absorption vs reflection, I guess reflection should be a little more damaging to the image, but I think most of the reflections never make it to the eye as scattered light. The trajectories of the reflected photons mostly take them back out of the front of the binocular (the reflections you see from the front) or spray them into the interior walls to be absorbed as heat.

Another point to consider is that most of the internal absorption in high index glasses is in the blue/violet at wavelengths below 450 nm, not a part of the spectrum where the eye has much sensitivity, so an improvement there will be especially hard to see.

Henry

Henry @

i do not agree with you this time. Both pics have the same details, you just increase the brightness of one pic but details are still the same for both pics and this is not the case in real life.

The image even with a 3% increase of brightness keep the same contrast of the original one, and this is true. But there is one more factor, "a mix between threshould contrast and surface brightness", so an image with better surface brightness is more noticeable by the eye, it is like viewing detail that before was impossible.

The difference in terms of brightness between two binoculars is most of the time noticed through others factor, not brightness but visibility of details.

regards

I haven't been able to find any concise information on the relative importance of absorption versus scattering losses inside optical glass. I did find that in quartz optical fibers, scattering from structural imperfections is a significant loss mechanism. Also, I know of a common test used by APO fanciers for distinguishing fluorite from fluoride glass, which is to shine a green laser pointer through the lens. Glass will light up green along the path of the beam, due to scattering, while fluorite will not. In this case, scattering in glass is appreciable. Also, while it may be true that absorbed short wavelengths are ususally reemitted in the infrared, depending on the chemical impurity absorbing the light it could also be reemitted in the visible, contributing to veiling glare. (for example, UV to blue wavelengh shifting compounds are usually added to scintillators which detect penetrating nergetic particles, because the initially emitted UV light cannot penetrate its way out of the material to be detected.)

Designers have done a workmanlike job of suppressing veiling glare with baffling designs and surface finishes, but who is to say these can't be improved?

Statements by Ed (light losses in glass are absorptive and benign) and Henry (veiling glare is already insignificant by design), taken together imply that the current state of the art in veiling glare suppression and the appearance of clarity and transparency cannot be improved. It is always hard to imagine what is beyond the current state of the art, and yet advances come.

Obviously, Zeiss, while sharing some tempting techy-looking information, is not above infotisement, double talk, questionably psychology and damn lies. Personally, I think more improvements have probably gone into this long-awaited generation than they are willing to share or think we care about or could understand. Improved coatings, baffling, and interior surface finishes are usually some things you get with a new model, but they haven't mentioned any of these. The FL was certainly an improvement, although some of the advertising for it is laughable. Considering Zeiss's track record, and I mean their scientists and engineers not their ad men, I am not going to sign an affadavit to the effect that I consider a noticeably cleaner image than the FL to be impossible. I bet they do it.
Ron

ronh said:

Designers have done a workmanlike job of suppressing veiling glare with baffling designs and surface finishes, but who is to say these can't be improved?

Statements by Ed (light losses in glass are absorptive and benign) and Henry (veiling glare is already insignificant by design), taken together imply that the current state of the art in veiling glare suppression and the appearance of clarity and transparency cannot be improved. It is always hard to imagine what is beyond the current state of the art, and yet advances come.

Click to expand...

I think there is still more room to improve the behaviour of optics in respect of veiling glare. There are methods (e.g. ISO standards) of measuring veiling glare in telescopes and binoculars. If you do such measurements you find that all the products from well known makers differ from each other. Maybe it's not only a matter of baffling, blackening and deadening but also a matter of glass quality. Perhaps radius of curvature of the lenses and its effect on reflections within the lens does play a role. The result of suppressing veiling glare is always better contrast and therefore a sharper image.

Steve

henry link said:

Ed,

Your numbers seem about right to me. Since I've been in "brightness discrimination" training for years I believe I'm now a tip top discriminator. I think I could come pretty close to 100% accuracy at 5% and approach 75% at 3%, if only some real scientist would hook me up to a proper test. ;-) Still, I see 5% as very small and 3% as the next thing to invisible.

As for absorption vs reflection, I guess reflection should be a little more damaging to the image, but I think most of the reflections never make it to the eye as scattered light. The trajectories of the reflected photons mostly take them back out of the front of the binocular (the reflections you see from the front) or spray them into the interior walls to be absorbed as heat.

Another point to consider is that most of the internal absorption in high index glasses is in the blue/violet at wavelengths below 450 nm, not a part of the spectrum where the eye has much sensitivity, so an improvement there will be especially hard to see.

Henry

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Henry,

I had a lab technician once who practiced flipping coins so much he came to believe he could earn a living with it. So I asked him to flip a quarter 100 times and recorded his accuracy. Listening to his comments as he flipped away I honestly believed he had done better than chance; but, alas, he got exactly 50% correct. :eek!:

Not sure I can agree with you about: "The trajectories of the reflected photons mostly take them back out of the front of the binocular (the reflections you see from the front) or spray them into the interior walls to be absorbed as heat." (my underline)

Surely some light exits from the front and some is absorbed, but all my references indicate that internal reflections interact, increase with the number of glass surfaces, and reduce image contrast. I'm simply questioning why reduced light absorption in the new Zeiss glass would benefit image quality, except for a slight increase in physical brightness. Moreover, increased transmittance in the blue/violet range, which as you say is hard to see, is also potentially the most damaging to the eye.

Ed

ivan86 said:

Henry @

i do not agree with you this time. Both pics have the same details, you just increase the brightness of one pic but details are still the same for both pics and this is not the case in real life.

The image even with a 3% increase of brightness keep the same contrast of the original one, and this is true. But there is one more factor, "a mix between threshould contrast and surface brightness", so an image with better surface brightness is more noticeable by the eye, it is like viewing detail that before was impossible.

The difference in terms of brightness between two binoculars is most of the time noticed through others factor, not brightness but visibility of details.

regards

Click to expand...

Ivan,

I agree with you. The pictures are not an accurate representation of what the eye would see in low light. They were intended only to show how little change in perceived image brightness results from 3% higher transmission. The 3% aperture obstruction described in post #56 is a much better tool for simulating, under real world conditions, the visible result of a simple 3% difference in light transmission.

Henry

Ron and Steve

I didn't intend to write anything about veiling glare. All the veiling glare I've been able to diagnose came from metal surfaces like lens cells or possibly lens edges. Those surfaces are parallel to the optical axis so refections from them go straight back toward the eyepiece. I've seen ghosting but not veiling glare come from the optical surfaces of lenses, but I'll concede it might happen the same way a ghost image happens if a very bright spot like the sun reflected from one lens forward to another and then back toward the eyepiece.

Ed,

My simple (perhaps too simple) thinking about reflection losses mostly exiting the front goes like this. If a binocular loses 4% total light to reflections at glass to air surfaces then it should be possible to ray trace those reflections in reverse back toward the front of the binocular with about the same 4% loss occurring in the reverse direction, so around 96% of the reflected light would exit the binocular as it entered, leaving only a tiny amount (4% of 4% of the light that originally entered) reflecting back toward the eyepiece.

Henry

Henry et al., if this is addressed adequately in ‘birdforum’ or elsewhere then sorry and disregard. In general, as the benefit of an improvement in brightness--small but discernible--why would one consider only the extra time at dusk? Surely as important is access to extra depth of shade throughout the day in relevant habitats, mostly woodland. A centre-field improvement in the HT--even only in brightness, if not, as Zeiss claim or imply, in resolution--will benefit at all times not only hunters but also in the observation of birds in regard at least to position and movement.

pompadour said:

Surely as important is access to extra depth of shade throughout the day in relevant habitats, mostly woodland. A centre-field improvement in the HT--even only in brightness, if not, as Zeiss claim or imply, in resolution--will benefit at all times not only hunters but also in the observation of birds in regard at least to position and movement.

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I think the ability to see more detail (in shade) is a complex one. I once compared a Nikon 10x42 SE to a Swarovski 10x42 SV in misty conditions and the Swarovski showed a brighter (less washed-out) image with greater constrast and detail. Not because of higher transmission I think (I seem to remember the Nikon has higher transmission values), but because of more contrast (due to better coatings, less internal refections?).

George

Henry,

yes, I was aware you didn't. My remarks were only generally speaking. Veiling glare seems to be a kind of science of its own since it's seems to be a challenge even for the best experts of the companies.

Back to the glass. Schott does provide many informations and much reading stuff on their website.
This one is probably already known here: http://www.schott.com/advanced_opti..._ht-glass_may_2011_en.pdf?highlighted_text=ht
Here is much more reading stuff: http://www.schott.com/english/company/publications/
I recommend in particular the "SCHOTT guide to glass" (available only as a brochure, not online), see at the bottom on this site. Though it contains not yet information about HT-Glass, it is otherwise very informative.

Steve

14Goudvink said:

I think the ability to see more detail (in shade) is a complex one. I once compared a Nikon 10x42 SE to a Swarovski 10x42 SV in misty conditions and the Swarovski showed a brighter (less washed-out) image with greater constrast and detail. Not because of higher transmission I think (I seem to remember the Nikon has higher transmission values), but because of more contrast (due to better coatings, less internal refections?).

George

Click to expand...

George,
what you are describing is exactly the effect of reduced veiling glare and better contrast. The Swaro has slightly higher transmission, though. Butt there are other binoculars that perform even better than the Swaro SV in respect of avoiding veiling glare.

Steve

hinnark said:

... Butt there are other binoculars that perform even better than the Swaro SV in respect of avoiding veiling glare.

Steve

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Steve,

Could you be talking about Leicas? You seem to have investigated glare problems more than the rest of us. Why do you think even alpha binocular companies can't be counted on to get the baffling right? One would think veiling glare would be visually detected at the prototype stage and fixed.

Henry

hinnark said:

Henry,

yes, I was aware you didn't. My remarks were only generally speaking. Veiling glare seems to be a kind of science of its own since it's seems to be a challenge even for the best experts of the companies.

Back to the glass. Schott does provide many informations and much reading stuff on their website.
This one is probably already known here: http://www.schott.com/advanced_opti..._ht-glass_may_2011_en.pdf?highlighted_text=ht
Here is much more reading stuff: http://www.schott.com/english/company/publications/
I recommend in particular the "SCHOTT guide to glass" (available only as a brochure, not online), see at the bottom on this site. Though it contains not yet information about HT-Glass, it is otherwise very informative.

Steve

Click to expand...

Steve,

Thanks for the references. Any ideas about which of the HT glass types are actually used in the HT binoculars?

Henry

henry link said:

Steve,

Could you be talking about Leicas? You seem to have investigated glare problems more than the rest of us. Why do you think even alpha binocular companies can't be counted on to get the baffling right? One would think veiling glare would be visually detected at the prototype stage and fixed.

Henry

Click to expand...

I think that Leica as a producer of high end photo lenses has indeed much experiences with measures to suppress veiling glare. Perhaps as a maker of photo equipment they take that problem more serious than others do. At Leica the photo lenses are produced in the same factory as the binoculars. To, as you wrote, get the baffling right is much more tricky than most of us would think. However, I have no doubts that all alpha makers are capable to do so. But from the producer's point of view these measures are an expense factor. I could imagine they're simply think they have done enough for the "baffling" and the user of the optics doesn't need more. Have I already mentioned that AFAIK there are (almost) no birdwatchers working at the optical industry?

Steve

henry link said:

Steve,

Thanks for the references. Any ideas about which of the HT glass types are actually used in the HT binoculars?

Henry

Click to expand...

Henry,

I'm sorry but I don't go for this because too speculative for me. Perhaps after a couple of look-throughs I'll could be more in the mood for this kind of food for thought. But, unless you are the developer and know the optical calculation, guessing the glass types of a given pair of binoculars is still a kind of guessing game then. Though, a nice one anyway.

Addendum: Apropos speculations. With every transmission measurements I know the values for "transmission at night" are lower than those of "transmission at day". Perhaps due to improved transmission at the blue end of the spectrum, the use of HT gives the possibility for the first time that the night values rise up at the same level than the day values.

Steve

henry link said:

You mean, if I buy these binoculars, I'll be just like the Baron von Zeiss? My life filled with fine cigars and whiskey and a comely young guide/girlfriend to place a garland on my hat after I strut my stuff? ... OK! Sign me up! ;-)

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Henry is right - this "movie" is one of the most obnoxious adverts I have ever seen.