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best low light bino 10x (2 Viewers)

"Dennis, there is absolutely no reason whatsoever that Zeiss could not put the appropriate HT glass in the SF without charging a single cent more. With retuned T* coatings to suit, the resultant SF+ would have both higher light transmission AND a more balanced transmission curve with more colourful, more vibrant blues and reds, AND a more neutral colour rendition - finally getting rid of that 'green ham' colour cast ...... of course then they would have to fleece their customers less, but the SF has been out for quite a while now - surely they have made some cost saving productivity increases that they could share with the customer."

True. But if they did they would be cannibalizing the sale of their own HT model. If you can get it all on the SF why buy the HT. They have to differentiate their products in some areas.The HT has the low light market and the SF has the big FOV market. So to get it all you have to buy both.
Haha :) Has Lee abducted you in his blue alien spaceship and brainwashed you so that only the Zeiss marketing vocabulary remains?! 3:) o:D

The two models are merely arbitrary design specifications which Zeiss then spend a great deal of OUR money telling us how super dooper they are! :eek!: :cat:

Anyone would think that HunTers have never ever wanted a lighter bin, and prioritize being able to run over them in their Hummers multiple times! :-O

Or that BirDers only ever go out at midday and so don't need the brightest bins! :smoke:

Maybe a trip to TOTAL RECALL is in order so that they can remove the little blue microchip implant and the 'real' Dennis program can be re-initialized!! ;)

What if instead of saying would you like an extra ~1.5-2% light transmission, "they" said - how about if we give you a 25% reduction in the residual stray light crud floating around in your binocular? .....

What would you say ...... thanks ever so much, but no thanks - I'm strictly a BirDer and have no need for the extra couple of % light transmission that goes along with that! o:D



Chosun :gh:
 
Ed, post 60,
Ed, I will come back to your post later, first I have to celebrate the birthday of two children who will strangle me if I stay behind my computer.
Dennis, although I do not always agree with, this time I support your arguments,
Gijs van Ginkel
 
True. But if they did they would be cannibalizing the sale of their own HT model. If you can get it all on the SF why buy the HT. They have to differentiate their products in some areas.The HT has the low light market and the SF has the big FOV market. So to get it all you have to buy both.

Dennis you are absolutely right. And CJ is also right when she implies that the needs of hunters and birders are sometimes the same. A wide FOV is nice for everyone, as is a higher transmission. But Zeiss decided to take the HT and SF down different paths to suit the markets they were aiming at. CJ disagrees with this path and her view is perfectly viable with this proviso. HT is what would have been called a conventional design a good few years back and of course SF is an open hinge design, so Zeiss have tried to appeal to folks of different aesthetic preferences and these design choices and the specifications that have gone with them are hardly arbitrary.

It is nice to note that CJ loves HT's transparancy of view and it's use of HT glass.

Lee
 
Dennis you are absolutely right. And CJ is also right when she implies that the needs of hunters and birders are sometimes the same. A wide FOV is nice for everyone, as is a higher transmission. But Zeiss decided to take the HT and SF down different paths to suit the markets they were aiming at. CJ disagrees with this path and her view is perfectly viable with this proviso. HT is what would have been called a conventional design a good few years back and of course SF is an open hinge design, so Zeiss have tried to appeal to folks of different aesthetic preferences and these design choices and the specifications that have gone with them are hardly arbitrary.

It is nice to note that CJ loves HT's transparancy of view and it's use of HT glass.

Lee
Haha Lee, I hope you had the MIB (Men In Blue) wave the little flash pen thingy before returning Dennis from the mothership .... :cool:

There are differences in the optical train designs, not least of all being that the HT evolved from the legacy FL design using A-K prisms, and so that 100% internal reflection immediately offers an extra ~1% transmission straight off the bat. So although the SF has S-P prisms and more ocular assembly lenses which cumulatively take their toll on light transmission, Zeiss have seriously missed a trick by not using HT glass in the SF for the reasons I mentioned.

If it's to preserve an arbitrary marketing decision then it's pretty dumb. If it's to fleece customers of top whack pricing while providing less than that in performance then that's ok - that's the sort of thing we've come to expect from Zeiss. Beta testing a green ham view with their full fee paying customers is par for the course. I'm sure the marketing department is already working on the wonderful neutrality of the colour rendition with the HT glass of the new SF+ ........ or will they rename it the 'ST' (Smart Transparency - gawd knows there needs to be something 'Smart' about it to make up for the Slow Focus :) ........ :smoke:

The differences would be minute, and I have already agreed with Bill and Gijs that those differences are likely not detectable in a lot of conditions, or from one time to the next ...... however a 25% improvement in ability to handle glare is nothing to be sneezed at :cat:

So while there are points where we are in agreement, and other points no doubt where I have just about caused an intergalactic diplomatic incident! ....... one thing we are definitely not going to agree on is your recent penchant for b*st*rdizing the Queen's English !! :eek!: For some reason you have taken a real set against the word "the" which I have helpfully highlighted in bold for you :) :t:

I mean, after all, when did we decide to use 1980's 'Japlish' and start economizing on the "the" ..... they neither weigh nor cost that much - surely there is room for them still when referring to a particular model??? :h?: :brains: :-O



Chosun :gh:
 
Zeiss have seriously missed a trick by not using HT glass in the SF for the reasons I mentioned.

If it's to preserve an arbitrary marketing decision then it's pretty dumb.

Chosun :gh:

CJ
Could Zeiss put HT glass in SF, of course they could.

For example, Porsche is perfectly capable of putting a fridge and drinks cabinet in their 911, and Mercedes could make a 2-door pick-up (sorry, Ute) of their S class, but I think most people understand why its unlikely they will do that anytime soon, and I don't think they would blame that on an arbitrary marketing decision.
Arbitrary is defined in the Oxford dictionary as 'based on random choice or personal whim rather than any reason or system'. I think Zeiss have rational reasons behind their choices, you may disagree sometimes.

Lee
 
It’s impossible to know Zeiss’s intention with these binoculars, since the statements they’ve made on the matter (not many) are for public consumption and not to be trusted.

My guess is that the HT was seen as a low-risk facelift of the Victory FL, abolishing the polycarbonate body and complying with the latest buzzwords (e.g. Schott HT glass). The update corrected the sagging Victory FL prices while keeping a winning optical concept.

The SF, which may or may not have been a locked-in certainty when the HT launched, was a more daring endeavour, with a wider field, return to Schmidt–Pechan prisms to allow better aberration correction at reasonable instrument length, extreme weight-reduction methods, and novel ergonomics (the latter perhaps driven by the optical changes rather than vice versa). These features allowed Zeiss to push the price out to the present limit, with the HT remaining to pick up customers who baulk at those prices.
 
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o:)
CJ
Could Zeiss put HT glass in SF, of course they could.

For example, Porsche is perfectly capable of putting a fridge and drinks cabinet in their 911, and Mercedes could make a 2-door pick-up (sorry, Ute) of their S class, but I think most people understand why its unlikely they will do that anytime soon, and I don't think they would blame that on an arbitrary marketing decision.
Arbitrary is defined in the Oxford dictionary as 'based on random choice or personal whim rather than any reason or system'. I think Zeiss have rational reasons behind their choices, you may disagree sometimes.

Lee
Lee, some would say that I disagree a bit more often than that! :king:

At best such an old fashioned (arbitrary) market segmentation (even if based on some tradition) is a 20th Century model and not even a late one at that ..... :cat:

Never mind, it leaves an Outback letter box run (around about up to 10x [or more] ;) your typical country mile :) of room for a less bloated, more business savvy, more technically advanced, yet cheaper AND more profitable upstart to move in and satisfy the customers Zeiss (or their alien overlords :) don't want to. Inin the meantime we can have heaps of funnin' with the HunTer folk ..... 3:)


Your automotive analogies are really duff this time round :brains:
If Porsche put anything heavier than a hairdresser's comb holder in their 911, then it wouldn't be a 911 anymore - since power to weight and overall light weight and handling is the core feature set of the mark. The fridge and drinks cabinet you are suggesting would see the Porsche go from a 911 to a 1800-Jenny !! o:D

An S class ute would certainly be a vast improvement over the Nissan Navarra based X class abomination slated for production! :eek!:

The decision not to use HT glass in the SF WAS arbitrary - it only looks logical from the viewpoint of 20th Century Gemanic business knowledge and practice ...

PS. I'm glad to see you have found at least one "the" ....... it's a start ;)....


Chosun :gh:
 
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Ed, post 60,
Ed, I will come back to your post later, first I have to celebrate the birthday of two children who will strangle me if I stay behind my computer.
Dennis, although I do not always agree with, this time I support your arguments,
Gijs van Ginkel

HAPPY BIRTHDAY to your little folks. B :)

Ed
 
Ed, post 60,
I promised to come back on the FOV-brightness discussion (singing and cake eating is over, the children are happy). The Zeiss scientist I refered to, who pointed out to me, that FOV does not play a role in image brightness, was pointing to calculations done by Zeiss coworkers König and Köhler, who published their calculations and arguments among others in their book "Die Fernrohre und Entfernungsmesser, third edition, 1959, in the chapter "Die lichttechnischen Eigenschaften des Fernrohres", pages 77-84 in which they write after some lenghty theoretical and practical considerations and calculations: "Der Helligkeitseindruck der dem Auge durch das Fernrohr vermittelt wird, ist von der Grösse des Sehfeldes, die ja im Lichtleichtwert enthalten ist, im wesentlichen unabhängig"(translated in short FOV does not pay a role in "Lichtleitwert"). They conclude that "In der Lichtleitwert W eines Fernrohrs...das Pupillenquadrat als entscheidener Faktor auftritt". "Das Pupillenquadrat" stands for (exit pupil P x exit pupil P). The authors also pay attention to light losses due to absorption (small in top quality optical glass) and reflection (now much lowered due to excellent coatings) as other factors of importance.
Gijs van Ginkel
 
Well, this has turned into a greatly enlightening thread for me, if no one else. We have beaten this dead horse enough to cause the most enlightened among us to come forth with something more important to the subject than the perceptions of those seemingly so eager to ignore our many physiological differences.

Cowardly, I must first say that the position I have taken was based on conversations with those infinitely more qualified to comment on the subject than myself. It rang true to my level of understanding. So, I felt confident in passing along what presented itself to be something more than opinions of the inexperienced.

But, looking forward to using some of the words here in a future, updated BINOCULARS:, I would like to boil down some comments to aid my understanding. At this point, I will ask ED and Gijs to comment. You both know why I come here. So, there is no need to worry about being politically correct or soft-shoeing.

So, I will restate my comment and ask that each of you comment as to whether or not the statement is true—I am still unconvinced; convince me:

“In comparing two binoculars on the same magnification, the same aperture, and similar quality, relative to image BRIGHTNESS, the average observer can—overlooking wavelength, brightness of the target, background illumination, photopic and scotopic considerations, vacillating physiological perceptions, and other differing criteria—determine a difference in the instruments.”

I see this as a far-from-practicality project. However, the nitnoids need love too and if this question has a definitive answer I would like to know it, so as to give me a new baseline for additional research.

Ed Yes ______ No _____
Gijs Yes ______ No _____

Bill
 
Ed,

If I may comment on brightness and field of view. For simplicity consider a distant point source of monochromatic light on the optical axis of a simple telescope. The light from the point (or very distant spherical) source spreads as a spherical wave front. The surface brightness will be the total light emitted from the source divided by the area of the ever expanding spherical wave front and so surface brightness will be reduced by the square of the distance from the source. Again for simplicity and to clarify only the role of FOV and aperture, let's ignore anything absorbing or scattering the light on its journey from the source.

When the wave front reaches the entrance pupil (aperture) of the telescope it will be an essentially planar wave front perpendicular to the optical axis.
The telescope collects a portion of the wave equal to its entrance pupil (aperture) area and our presumed perfect objective focuses that light into a spot on the optical axis behind the entrance pupil with no absorption or scattering (due to diffraction effects it is actually a "spot pattern" related to the shape of the aperture). If the point source were off the optical axis slightly, then the same analysis would hold except that the wave front would be at an angle to the optical axis and the spot would form off of the optical axis by that angle. Yet the size of the aperture, the area of the wave front intercepted and the amount of light captured would be the same. And of course this is assuming that as you move off the optical axis there is no vignetting or blockage from elements in our optical system (prisms, oculars, baffles etc.) that we use to magnify and adjust orientation of the spot.

So greater field of view is a statement about the ability to look through the system at greater angles off axis without losing too much, but you are always looking through the same aperture, and intercepting same same area of the wave front, so the aperture determines how much light you gather. It's not as if the binocular were constantly scanning and storing up light in any direction one might choose, but rather that you have greater freedom to look through the system at different angles using the same or almost the same aperture as on axis.

Alan
 
Hi Alan,

Have you taken into consideration that every binocular-telescope has a field stop in front of the eyepiece that limits the angular FOV of the system and, hence, the amount of photons allowed to enter the eye? All other things equal, the ratio of the field-stop areas equals the ratio of total light entering the eyes. And the light entering the eyes, in quantity and quality, is what determines perceived brightness.

All the variables Gijs mentioned earlier are correct, but the FOV and retinal projection area are also a part of perceptual brightness determination.

Ed
 
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Ed and Gijs,

A litle while back I stumbled across an abstract from a scientific paper that might have some bearing on your discussion. It mentioned that the pupil diameter was related to the angle of the illuminated field. I don't remember all the details now, but the key message I took from it was that that at specific luminance levels, the greatest pupil response was to angles between about 5° and 40°. Most current binocular models fall into the 50° to 65° range so perhaps the difference in pupil response would usually be small or nonexistant. Unfortunately I did not bookmark the abstract.

However that paper did have a bearing on my eye examination. When I went for a routein eyetest a couple of years back, I noted that my apparent acuity had dropped from the previous examination, and was now approximately 50% worse than own measurement. The optometrist had recently refitted his examination room, including the lighting, and now did the chart test in much darker room. After some discussion he allowed me to return with a light meter and take a couple of measurements.

Optimum acuity is normally considered to be at luminance levels around 300cd/m2 and I've found that 200 to 1000cd/m2 gives me the same result. The guidance for UK eye tests is that the chart should be over 175cd/m2, and with a nonscientific meter the LCD monitor measured 180cd/m2. However the wall surrounding the monitor was 15-20cd/m2. At 6m the display was about 7° wide and a little less tall. My pupil was estimated by the optometrist at 4.25mm while viewing the chart, far wider than the usual 2.5mm acuity optimum and would completely explain why the optometrist's measurement was 50% worse than I might have expected.

The consequence for my correction has had it's positives and negatives. By my estimates, my daylight acuity has dropped by 5 arcseconds, but low light reading improved by about 30 arcseconds. I guess that's a useful result, but I still switch to my old glasses for critical viewing.

My experience is that angle of view does make a significant difference to pupil diameter, but may not impact on binocular choice.

David
 
o:)


The decision not to use HT glass in the SF WAS arbitrary - it only looks logical from the viewpoint of 20th Century Gemanic business knowledge and practice

PS. I'm glad to see you have found at least one "the" ....... it's a start ;)....

Chosun :gh:

No CJ, you are just being perverse. You know very well that Zeiss designed these two models to appeal to different groups and HT is designed to be particularly useful in low light, hence the use of AK prisms and HT glass. It is not arbitrary to maintain that design ethos by keeping HT's key low light advantage ie HT glass to itself. By all means disagree with this but arbitrary it is not and it has nothing to do with Germanic business practice.

I am surprised you champion the idea of HT glass in SF though as with its SP prisms one might have thought the advantage would be minimal and you would be among the first to point this out. If my memory correct (it often isn't) I seem to remember you describing the advantages of HT glass in the HT when it was launched as 'smoke and mirrors' at the time. Nothing wrong with changing your mind in the light of experience though, but that still leaves the question of whether HT glass would boost SF enough to make a difference. Don't forget it not only has SP prisms it also lacks one bigish objective lens and only gains a small field flattener.

Cheers Lee
 
Ed and Gijs,

A litle while back I stumbled across an abstract from a scientific paper that might have some bearing on your discussion. It mentioned that the pupil diameter was related to the angle of the illuminated field. I don't remember all the details now, but the key message I took from it was that that at specific luminance levels, the greatest pupil response was to angles between about 5° and 40°. Most current binocular models fall into the 50° to 65° range so perhaps the difference in pupil response would usually be small or nonexistant. Unfortunately I did not bookmark the abstract.

However that paper did have a bearing on my eye examination. When I went for a routein eyetest a couple of years back, I noted that my apparent acuity had dropped from the previous examination, and was now approximately 50% worse than own measurement. The optometrist had recently refitted his examination room, including the lighting, and now did the chart test in much darker room. After some discussion he allowed me to return with a light meter and take a couple of measurements.

Optimum acuity is normally considered to be at luminance levels around 300cd/m2 and I've found that 200 to 1000cd/m2 gives me the same result. The guidance for UK eye tests is that the chart should be over 175cd/m2, and with a nonscientific meter the LCD monitor measured 180cd/m2. However the wall surrounding the monitor was 15-20cd/m2. At 6m the display was about 7° wide and a little less tall. My pupil was estimated by the optometrist at 4.25mm while viewing the chart, far wider than the usual 2.5mm acuity optimum and would completely explain why the optometrist's measurement was 50% worse than I might have expected.

The consequence for my correction has had it's positives and negatives. By my estimates, my daylight acuity has dropped by 5 arcseconds, but low light reading improved by about 30 arcseconds. I guess that's a useful result, but I still switch to my old glasses for critical viewing.

My experience is that angle of view does make a significant difference to pupil diameter, but may not impact on binocular choice.

David

Thank you for this.

I was in the process of penning a new thread (may still do if thought useful and/or the Op and Mods would prefer) that poses the question “is there demonstrable benefit in asking an independent Optometrist to proscribe a correction that is biased to maximising one’s low light acuity?” If this is indeed the case as your findings suggest I’m further minded to pursue the idea of having my subsequent *proscription made into 2 circular discs that fit snugly within the eyecups of my preferred bins and retained by appropriately sized stiff rubber ‘O’ rings. (*Note: I’m not at the stage of having to wear spectacles for other than reading albeit I am aware my normal vision is some way from what it once was.)

LGM
 
I am surprised you champion the idea of HT glass in SF though as with its SP prisms one might have thought the advantage would be minimal and you would be among the first to point this out. If my memory correct (it often isn't) I seem to remember you describing the advantages of HT glass in the HT when it was launched as 'smoke and mirrors' at the time. Nothing wrong with changing your mind in the light of experience though, but that still leaves the question of whether HT glass would boost SF enough to make a difference.

Cheers Lee

Quite a few posters here in the forum could not see a significant difference from UVid HD to HD+ (HT glass), so you're probably right here that the average person won't see a difference. I think I could spot the differences over a day out with HD and HD+ and many of us nerds here could , but the average person may not or may not find the diffences significant or even useful to them.

Prism type and HT glass may add extra brightness, but ultimately I'm with Bill here when it comes to larger exit pupil being more significant.

Over the years I've owned several same model bins with different EP:

Leupold Katmai 8x32 --> 6x32
Leupold Cascade/Hawthorne 8x42 --> 7x42
Leupold Yosemite 8x32 --> 6x32
Vortex Viper 8x32 --> 6x32

Not the same model but...Leica Trinovid 2011 version (same optics as UVid non-hd) 8x42 vs UVid HD + 7x42

The most noticeable difference in apparent brightness is of course 8x to 6x ., but
it's also readily seen going 8 to 7.

CJ,
The "green" color cast was supposedly addressed and corrected in the SF according to some reports from forum members.

SF is already a very fine binocular and , as much as I like having Schott HT in my 7x42, I'm not sure if it would make a meaningful difference in The SF, as it already contains high quality Schott glass.
I think the 6mm EP of my 7x42 is why it's so good in low light conditions.
But I do think the HT glass adds something extra ...perhaps cleaner image and slightly boosted contrast.
 
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No CJ, you are just being perverse. You know very well that Zeiss designed these two models to appeal to different groups and HT is designed to be particularly useful in low light, hence the use of AK prisms and HT glass. It is not arbitrary to maintain that design ethos by keeping HT's key low light advantage ie HT glass to itself. By all means disagree with this but arbitrary it is not and it has nothing to do with Germanic business practice.

I am surprised you champion the idea of HT glass in SF though as with its SP prisms one might have thought the advantage would be minimal and you would be among the first to point this out. If my memory correct (it often isn't) I seem to remember you describing the advantages of HT glass in the HT when it was launched as 'smoke and mirrors' at the time. Nothing wrong with changing your mind in the light of experience though, but that still leaves the question of whether HT glass would boost SF enough to make a difference. Don't forget it not only has SP prisms it also lacks one bigish objective lens and only gains a small field flattener.

Cheers Lee
Lee, I can assure you I am never perverse! neither am I contrarian, nor mischievous (cheeky yes! but unsavory - no).

In fact it is you who seems to be on the perverse side of the ledger. Certainly you continue in your blinkered views.

Just because you perceive the truth to be something other than what it is, does not in any way change that truth - only your ability to recognize it ..... :cat:

Blind Freddy can see exactly what Zeiss has done. That doesn't make it right. It doesn't make it savvy. It doesn't make it visionary or revolutionary. It just makes it what it is. A rather old fashioned business (marketing) model - circa the mid 20th Century. :smoke:

The decision to proceed in this fashion was quite arbitrary - based on what someone(s) thought a market segmentation should look like, and their guesses as to what would supply that market, and whatever rubbery figures they could dig up to support their preconceived conclusions.

Unfortunately this led to the ditching of the rather nicely performing GFRP lightweight FL chassis in favour of a misguided perception by HunTers in the superiority of the heavier magnesium chassis for the HT .... oh well, at least you can bludgeon a recalcitrant buck roo more effectively with this lump should the need arise :eek!:

For the sake of completeness, let's not pretend that the HT was anything but an evolution of the FL. The SF more of a clean sheet design. The specific design parameters following on from these decisions (such as focuser location etc) - merely logical consequence.

To nobble one product (the brightness, vibrancy, and colour rendition of the SF) in a misguided effort to protect, or differentiate the HT is a positively prehistoric strategy. I never said it was specifically Germanic - just outdated ..... now the whole marketing zeitgeist of the HT what with it's rather brutalist lines, black rubber and leather connotations in concert with the whole Hairy chesTed thing of HunTing really IS quite Germanic (and perverse! :) 3:)

Establishment Photographic giants CaNikon have found to their chagrin that such strategic inertia and protectionism can have deleterious consequences as witnessed by the rapid rise of Panasonic, Olympus, and Sony Mirrorless Camera intrusion into the traditional DSLR market share.

Folks can argue until they are blue in the face (see what I did there huh? :) that the addition of HT glass to the SF would have only minimal performance increases, but nevertheless they are there.

Your memory is seemingly as dodgy as your automotive analogies! :-O I never said the HT glass was "smoke and mirrors" ..... in fact I recall calculating at the time that the increases in transmission even for S-P prisms, were of the order of up to (or more than ;) :) 1.5~2% in concert with the attendant retuning of the coatings.

Further to that, as you yourself attested upon receiving your HT and looking through it, I fully concurred upon viewing that the entirety of the HT's optical performance was in fact greater than the sum of its incrementally improved parts.

It would cost virtually nothing to add HT glass to the SF, and in fact could fully be absorbed in the existing profit margin paradigm for this ~$2.5+K binocular.

2% more light transmission - nice - not really noticeable for existing users in and of itself in direct comparison in practice - though still nice (especially for new users) ..... but 25% better stray light control, cleaner, more vibrant colours --- awesome! :t: ..... even you'd notice and like that :king:

It is an absolute nonsense to say that just because BirDers are not HunTers that they couldn't use and appreciate a brighter and cleaner view. There simply is no defense of that.

If I said anything was "smoke and mirrors" it would have been the now disproven claims of the ergonomic superiority of the HT. I can place my hands so far forward on my current bins that when I grip around the objective tubes the rearward weight bias is astonishing! An astonishingly frightening prospect for my tootsies!! :eek!:

The correct response to this post would be:- Yes Chosun, thank you ..... however history has shown that your wool is dyed deep (blue :) .... I hope this has helped your understanding ..... not to mention awakened you to a healthy mistrust of your memory! *grin* (don't worry Lee - I've got an uncle who really is going dead set crackers! :)



Chosun :gh:
 
2% more light transmission - nice - not really noticeable for existing users in and of itself in direct comparison in practice - though still nice (especially for new users) ..... but 25% better stray light control, cleaner, more vibrant colours --- awesome!









Chosun :gh:

Yes probably not really noticeable and that's the point...the topic here is apparent/perceived brightness. Where did you get the 25% figure from?
I thought stray light and glare was mainly controlled by baffling.
Cleaner and more vibrant colors is subjective and not something everyone will agree on there. i would think the SF has real quality glass in it already and not sure swapping with HT glass would make a meaningful difference to most people. I could be wrong.
 
Another contentious thread. I think we can all agree that a brighter bino helps you spot more Sasquatches in the deep dark woods:-O
 
...... CJ,
The "green" color cast was supposedly addressed and corrected in the SF according to some reports from forum members.

SF is already a very fine binocular and , as much as I like having Schott HT in my 7x42, I'm not sure if it would make a meaningful difference in The SF, as it already contains high quality Schott glass.
I think the 6mm EP of my 7x42 is why it's so good in low light conditions.
But I do think the HT glass adds something extra ...perhaps cleaner image and slightly boosted contrast.
GiGi,

Even though the actual numerical gains in light transmission from HT glass seem inconsequential - 2% (when our ability in practice to detect differences in brightness is only when it reaches ~3-6%), you, like Lee, observe that somehow the difference in viewing seems rather greater than the sum of these rather incrementally improved parts. I think you are right on in your reasoning.

Light lost in transmission can manifest in all sorts of undesirable ways - some of the light "absorbed" in glass elements gets converted to heat. Other light is reflected which then must be dealt with (to greater or lesser degrees of success) by apertures, baffling etc ..... :cat:

Think of it rather simply like this:
Transmission = 92% , therefore 8% is lost = crud (reflections, refraction, absorption, stray light which degrade the view)
New Transmission (with HT glass) = 94% , therefore only 6% is now crud.

Difference in Transmission is +2% -> a (2÷92) = 2.2% increase.
Difference in Crud is -2% -> a (2÷8) = 25% reduction

That large reduction in crud is letting you see a cleaner, more vibrant, contrastier view as you have so aptly described.

I have only ever seen one transmission curve for the SF from Allbino's - and it was truly tragic - falling off a mountaintop in the blue in particular, and the deep red. Not only would this affect colour vibrancy, colour rendition neutrality, but ultimate brightness too. https://www.allbinos.com/304-binoculars_review-Carl_Zeiss_Victory_SF_10x42.html

HT glass would fix this very nicely indeed since the majority of the gains occur in the blue part of the spectrum. The need for high blue light transmission to give daytime brightness is probably not widely understood here, but the standard has been revised a few times with new models to incorporate this effect. Far from offering a 'colder' view - it will be more vibrant, brighter, more contrasting, and more neutral. It certainly has been good for the UVHD+ and the NV.

I'm sure the relationship between EP, Transmission, and even AFov could be mathematically modeled - but it's just as good in practice to know that your 6mm EP works nicely for you :t: ;)



Chosun :gh:
 
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