Comprehensive 10x42 test in German magazine (1 Viewer)

The quarterly German magazine, Vögel (Birds) has conducted a test of eleven 10x42 binoculars in 3 consecutive issues and I will try to summarize the results of 14 pages briefly here.
Tests were carried out in the laboratories of Leica, Minox and Zeiss and the tabulated results together with a test of the Swarovski EL Swarovision (which was not available at the start) are due to be published in December.
I will try to provide an update then.
Transmission curves for each bin were provided and as I do not have the means to scan these, I will give the results for 470 nm (blue), 670 nm (red) and the maximum value.

CANON 10x42 L IS WP

Wide FOV and excellent sharpness and contrast to edges. Low CA and least scatter of all test candidates. Excellent functioning of image stabilizer. Tripod thread and filter threads. Weight > 1 kg, eyecups too large when used without glasses.
470 nm: 80%, 670 nm: 85%, max: 87% but 85% between 490 nm and 670 nm.

KOWA XD PROMINAR 10,5x44

Lowest CA in test but lowest transmission. AFOV > 65°, highest in test but eye relief possibly critical for glasses wearers and eyecups too large for use without glasses. Focussing on test example imprecise. Filter threads and good accessories. Weight almost 1 kg.
470 nm: 77%, 670 nm: 75%, max: 83% @ 600 nm.

LEICA ULTRAVID 10x42 HD

Very good contrast with brilliant colours due to low scatter. Sharpness decreases towards edges due to field curvature rather than astigmatism. Pincussion distortion somewhat less than Zeiss FL and old Swarovski EL. Despite lower transmission than Zeiss, Swarovski and Nikon the twilight performance did not suffer due to the good contrast. Excellent finish and mechanics.
470 nm: 82%, 670 nm: 83%, max: 90% @ 610 nm.

LEUPOLD GOLDEN RING 10x42 HD

Contrast amongst the best. Warm colours but not yellowish. CA low with centered pupils but apparent when decentered. Wide FOV and only moderate fall-off in sharpness towards edges. Transmission below average and critical eye-relief for glasses wearers. Close focus 1,6 m. Poor diopter adjustment as with Kowa. Filter threads and lockable hinge. Good accessories and lifelong guarantee.
470 nm: 73%, 670 nm: 80%, max: 85% between 580 nm and 630 nm.

MEOPTA MEOSTAR B1 10x42

Resolution in right barrel average but very good 3,5" in left barrel. Good AFOV and low fall-off in sharpness towards edges. Low scatter and low CA (extra low dispersion glass?). High maximum transmission but low blue transmission leading to yellow tone. Compact dimensions but focussing wheel rubs on armouring. Poor rainguard and objective covers. Lowest price and best value for money in test.
470 nm: 77%, 670 nm: 87%, max: 91% between 600 nm and 650 nm.

MINOX APO HG 10x43 BR ASPH.

Wide FOV and good contrast. Natural and brilliant colours. Low CA, compact and light. Distance scale on focussing wheel and quick focus at short distances. Oppulent presentation box but case too small and no objective covers.
470 nm: 78%, 670 nm: 78%, max: 85% between 540 nm and 630 nm.

NIKON 10x42 HG L DCF

Relatively bright and good contrast of greens and browns. Good eye relief but narrow FOV. Low pincussion distortion and excellent edge sharpness. Best collimation in test but pronounced CA. Fast focusssing (1/5 turn for 10 m to infinity).
470 nm: 83%, 670 nm: 86%, max: 91% @ 610 nm.

NIKON 10x42 SE CF

Very bright with natural colours. Former due to lack of mirrored surfaces and fewer air/glass surfaces (external focussing). Wider FOV than HG-L and relatively low CA. Resolution in both barrels 3,5", close to Leica/Swarovski/Zeiss. Close focus 4 m. Eye relief 17 mm but rubber eyecups possibly too short for non-glasses wearers. Nikon invented twist-up eyecups - why not on this model? Not waterproof and objective covers cannot be attached to bin.
470 nm: 85%, 670 nm: 88%, max: 91% from 600 nm to 650 nm.

PENTAX DCF ED 10x43

Contrast high, resolution low. Close focus < 2 m. Narrowest FOV. Low CA but effective aperture < 40 mm. Worst collimation in test. Light and compact (similar to Minox). Why no water-repellent coatings, when the cheaper SP series has them? Mechanics stiff at low temperatures.
470 nm: 78%, 670 nm: 83%, max: 87% @ 610 nm.

SWAROVSKI EL 10x42 WB (old model)

Bright and sharp but colours less intense than some competitors with very high contrast. Nevertheless very natural due to exemplary transmission. Excellent resolution on a par with Swarovision. Better edge sharpness than Leica and Zeiss but more scatter than these two. Pronounced pincussion distortion and noticeable CA. Limited eye relief. Good case.
670 nm: 76% but in excess of 85% from 460 nm to 650 nm, max: 88%.

ZEISS VICTORY 10x42 T* FL

Best resolution together with both Swarovski bins. Unsurpassed correction of aberrations in the center enabling recognition of details which could not be seen in some other bins (use of tripler). Reflections from roof edge were undetectable. Optimized for highest transmission where the human eye is most sensitive in daytime (green /yellow, 555 nm) and hence light green bias. Ribbed armouring good for use with gloves but may not appeal without.
470 nm: 85%, 670 nm: 76%, max : 94% @ 560 nm.

To be continued.

John

Well, well ! Surprissingly, this rigorous test matches very well with our absolutely non-rigorus "test...." comparing the Nikons HGL and SE and the Zeiss FL !!! I agree 100% with this results.

Regards

PHA

John,

Thanks very much for going to the trouble to do this. I wonder if I can trouble you some more to report light transmission for 555 nm and 510 nm. It would be useful for comparison purposes since those are the usual reference points for "day" and "night" transmission measurements corresponding to the points of maximum photopic and scotopic eyesight sensitivity.

I'm very impressed that in Germany a birding magazine would pay for such sophisticated lab tests, even including transmission curves. Quite a contrast to the shoddy testing done in the US by Cornell and others.

Henry

John Russell said:

The quarterly German magazine, Vögel (Birds) has conducted a test of eleven 10x42 binoculars in 3 consecutive issues and I will try to summarize the results of 14 pages briefly here.
Tests were carried out in the laboratories of Leica, Minox and Zeiss and the tabulated results together with a test of the Swarovski EL Swarovision (which was not available at the start) are due to be published in December.
I will try to provide an update then.
Transmission curves for each bin were provided and as I do not have the means to scan these, I will give the results for 470 nm (blue), 670 nm (red) and the maximum value.

CANON 10x42 L IS WP

Wide FOV and excellent sharpness and contrast to edges. Low CA and least scatter of all test candidates. Excellent functioning of image stabilizer. Tripod thread and filter threads. Weight > 1 kg, eyecups too large when used without glasses.
470 nm: 80%, 670 nm: 85%, max: 87% but 85% between 490 nm and 670 nm.

KOWA XD PROMINAR 10,5x44

Lowest CA in test but lowest transmission. AFOV > 65°, highest in test but eye relief possibly critical for glasses wearers and eyecups too large for use without glasses. Focussing on test example imprecise. Filter threads and good accessories. Weight almost 1 kg.
470 nm: 77%, 670 nm: 75%, max: 83% @ 600 nm.

LEICA ULTRAVID 10x42 HD

Very good contrast with brilliant colours due to low scatter. Sharpness decreases towards edges due to field curvature rather than astigmatism. Pincussion distortion somewhat less than Zeiss FL and old Swarovski EL. Despite lower transmission than Zeiss, Swarovski and Nikon the twilight performance did not suffer due to the good contrast. Excellent finish and mechanics.
470 nm: 82%, 670 nm: 83%, max: 90% @ 610 nm.

LEUPOLD GOLDEN RING 10x42 HD

Contrast amongst the best. Warm colours but not yellowish. CA low with centered pupils but apparent when decentered. Wide FOV and only moderate fall-off in sharpness towards edges. Transmission below average and critical eye-relief for glasses wearers. Close focus 1,6 m. Poor diopter adjustment as with Kowa. Filter threads and lockable hinge. Good accessories and lifelong guarantee.
470 nm: 73%, 670 nm: 80%, max: 85% between 580 nm and 630 nm.

MEOPTA MEOSTAR B1 10x42

Resolution in right barrel average but very good 3,5" in left barrel. Good AFOV and low fall-off in sharpness towards edges. Low scatter and low CA (extra low dispersion glass?). High maximum transmission but low blue transmission leading to yellow tone. Compact dimensions but focussing wheel rubs on armouring. Poor rainguard and objective covers. Lowest price and best value for money in test.
470 nm: 77%, 670 nm: 87%, max: 91% between 600 nm and 650 nm.

MINOX APO HG 10x43 BR ASPH.

Wide FOV and good contrast. Natural and brilliant colours. Low CA, compact and light. Distance scale on focussing wheel and quick focus at short distances. Oppulent presentation box but case too small and no objective covers.
470 nm: 78%, 670 nm: 78%, max: 85% between 540 nm and 630 nm.

NIKON 10x42 HG L DCF

Relatively bright and good contrast of greens and browns. Good eye relief but narrow FOV. Low pincussion distortion and excellent edge sharpness. Best collimation in test but pronounced CA. Fast focusssing (1/5 turn for 10 m to infinity).
470 nm: 83%, 670 nm: 86%, max: 91% @ 610 nm.

NIKON 10x42 SE CF

Very bright with natural colours. Former due to lack of mirrored surfaces and fewer air/glass surfaces (external focussing). Wider FOV than HG-L and relatively low CA. Resolution in both barrels 3,5", close to Leica/Swarovski/Zeiss. Close focus 4 m. Eye relief 17 mm but rubber eyecups possibly too short for non-glasses wearers. Nikon invented twist-up eyecups - why not on this model? Not waterproof and objective covers cannot be attached to bin.
470 nm: 85%, 670 nm: 88%, max: 91% from 600 nm to 650 nm.

PENTAX DCF ED 10x43

Contrast high, resolution low. Close focus < 2 m. Narrowest FOV. Low CA but effective aperture < 40 mm. Worst collimation in test. Light and compact (similar to Minox). Why no water-repellent coatings, when the cheaper SP series has them? Mechanics stiff at low temperatures.
470 nm: 78%, 670 nm: 83%, max: 87% @ 610 nm.

SWAROVSKI EL 10x42 WB (old model)

Bright and sharp but colours less intense than some competitors with very high contrast. Nevertheless very natural due to exemplary transmission. Excellent resolution on a par with Swarovision. Better edge sharpness than Leica and Zeiss but more scatter than these two. Pronounced pincussion distortion and noticeable CA. Limited eye relief. Good case.
670 nm: 76% but in excess of 85% from 460 nm to 650 nm, max: 88%.

ZEISS VICTORY 10x42 T* FL

Best resolution together with both Swarovski bins. Unsurpassed correction of aberrations in the center enabling recognition of details which could not be seen in some other bins (use of tripler). Reflections from roof edge were undetectable. Optimized for highest transmission where the human eye is most sensitive in daytime (green /yellow, 555 nm) and hence light green bias. Ribbed armouring good for use with gloves but may not appeal without.
470 nm: 85%, 670 nm: 76%, max : 94% @ 560 nm.

To be continued.

John

Click to expand...

Nice comparison review. I agree with their results. Especially the enormous CA in the Nikon HGL. It sounds like Zeiss FL's are at the top of the heap again which I agree with.

Wholly agree with henry link's sentiments.
This is the kind of numerical objective data that is missing in most binocular reviews. Telescope makers have learned that an objective product analysis is a powerful competitive marketing advantage. That the binocular makers remain content to rehash discounted adjectives and hyperbole rather than to use documented performance is incomprehensible to me. In fairness, there are several figures of merit for binoculars and % light transmission is only one. So a full test series would not be that simple or cheap to produce. However, given the competitive challenge posed by the lower cost Asian producers, the alpha glass makers will need something like this to maintain their market leadership, imo.

henry link said:

I wonder if I can trouble you some more to report light transmission for 555 nm and 510 nm.

Click to expand...

Henry,

I chose the frequencies of 470 nm and 670 nm quite arbitrarily so was half expecting your request ;-). I will happily comply and try to give the transmission for 555 nm (first) and 510 nm to the nearest percent.

CANON IS: 86%, 86%

KOWA XD44: 82%, 82%

LEICA ULTRAVID: 88%, 85%

LEUPOLD GR HD: 83%, 80%

MEOPTA B1: 87%, 84%

MINOX APO HG: 85%, 82%

NIKON HG L: 86%, 85%

NIKON SE: 87%, 85%

PENTAX DCF ED: 86%, 83%

SWAROVSKI EL (old): 88%, 88%

ZEISS FL: 94%, 90%

Regards,

John

Add another voice to my surprise and delight that a birding magazine would have such a comprehensive review, particularly of 10x models, most birding reviews focus on 8x bins. OTOH, most hunting bin reviews I've read focus on 10x bins.

I remember reading a review of midsized bins in Birdwatching Digest by the Porters (others participated in the evaluation, but the Porters wrote it).

After putting the magazine down, I remember thinking that other than the ER comparisons, I really had no idea which bins (other than the alphas) performed better than others because the reviews were rather superficial and based mainly on consensus not objective tests. There was one comment on "fuzzy edges" on the Eagle Optics 8x32 Ranger, but not much else in that regard.

Not that a consensus method wouldn't have been somewhat useful. Other than Henry, Ron, Kevin, and a few others, that's pretty much the way most of us evaluate bins, by reading different reviews and getting a feel for what trends seem to develop in them.

And they did have a good sized group of observers, it's just that the characteristics they evaluated were very limited, which didn't give the reader a wide enough basis for comparison.

Some observations on the German reviews...

I noticed that on the 10x42 Ultravid HD, they did not rate the CA control like they did on the other bins. Given the recent controversy over this feature, it would have been nice to get an expert opinion on this, particularly on the 10x model, where CA is more likely to show up.

Another surprise was this one on the Meopta 10x42. "Low scatter and low CA (extra low dispersion glass?)."

Frank D. and others have commented on the CA in the 8x42 and 10x50 models. How is the 10x42 able to get a low CA rating? Did Meopta upgrade its coatings or glass? Nah, not without fanfare.

John - Did the article say how many people were involved in this review? Given the thoroughness of the other tests, I would assume they just didn't look through the bins randomly to determine CA, but did a more controlled test like Henry does.

Here's another interesting comment on the Meopta: "High maximum transmission but low blue transmission leading to yellow tone."

This has been a show stopper for some birders, though I gather not an issue and perhaps an asset for hunters.

According to Frank D. and another reviewer, the 8x32 model has a more neutral color balance. So Meopta was aiming this model at birders, and it shows this yellow bias was a purposeful design decision for hunters, who do most of their hunting in lower light, drab winter months, and not an unintended consequence. Swaro SLCs had a similar yellow bias a while back, likely for the same reason.

Interesting that the PENTAX DCF ED 10x43's measured aperture was less than 40mm. Edz could add that to his collection of under spec bins. OTOH, Edz measured the actual aperture of the 10x42 IS L as 37mm, but the Germans make no mention of this in their review??? This is a puzzler.

"Nikon invented twist-up eyecups - why not on this model?" they asked.

The simple answer is because the Nikon 10x42 SE was first released in 1995, and except for upgrading the coatings and perhaps changing over to lead free glass sometime between 2000 and 2007, Nikon has kept the SE essentially the same.

The answer behind the answer is that despite having a "cult" following, the SE, and indeed porros in general, are "yesterday's news" to most birders.

No surprise on the report of "pronounced CA" in the 10x42 HGL. I reported that on these forums myself years back, and also how the HGL seemed to have a bit more CA than the previous HG model. Others have since echoed that observation, but I have not seen any experts comment on this. Though they did say "low scatter," so it should also have low CA.

An important comment left out of the KOWA XD PROMINAR review was about its pronounced "rolling ball effect," which Holger Merlitz mentioned in his review of the 8.5x model. An important consideration for those who are sensitive to this effect. Apparently, the German reviewer(s) were not.

Also interesting was the comment on the (old) 10x42 EL: "Pronounced pincussion distortion and noticeable CA."

I tried an old 8.5x (question is how old was their old sample, allegedly, and I hope I'm not propagating rumors here, the coatings were upgraded in 2006, though Dale says they are continually updating their coatings, so who knows? But was their sample a pre-2006 ELs like the one I tried?).

The old 8.5x EL had more CA than I would have liked but not as much as the HGL. I did NOT notice excessive pincushion on the 8.5x model.

Is this peculiar to the 10x model, and did they retain this distortion in the 10x SV? Is this the reason there has been some "cherry picked" reports of less "rolling ball" in the 10x SV? Or did the users eyes add the pincushion on the 10x SV?

No mention of the steep fall off in sharpness at the edges of the ZEISS VICTORY 10x42. I know it's a birding review where edge sharpness is not highly valued, but they did bother mentioning the good edges in the Meopta and HGL (oddly, no mention of this in the 10x42 SE mini-review).

Well, John summarized the results of 14 pages of reviews, so my questions might have been answered in the full version.

Too bad this is not available online. Btwn Broken English Fish and my three years of German in HS/college, I might have been able to understand it.

Thanks John for those summaries and the day/night percentages.

Brock

Brock,

There is no mention of the involvement of others in the test so I assume that, apart from quantifiable measurements, other aspects were the subjective opinion of the author, Stephan Gröhn.
No doubt some subjectivity has also crept in with my selection of what to include in the synopsis. There was, however no mention of CA in the Leica but my own impressions, when I compared it to the 10x42 Victory FL (which I bought), were that eye placement was more critical. I concur that there is a fall-off in sharpness at the edges in the FL due to astigmatism.
Apart from the Pentax it was mentioned that the exit pupils of Canon and Minox and, to a lesser extent, Leica did not conform to specifications. We shall have to wait until December for the exact figures.
BTW, I don't think there is any correlation between scatter and CA. Perhaps I should have written "stray light."

Regards,

John

henry link said:

John,

Thanks very much for going to the trouble to do this. I wonder if I can trouble you some more to report light transmission for 555 nm and 510 nm. It would be useful for comparison purposes since those are the usual reference points for "day" and "night" transmission measurements corresponding to the points of maximum photopic and scotopic eyesight sensitivity.

I'm very impressed that in Germany a birding magazine would pay for such sophisticated lab tests, even including transmission curves. Quite a contrast to the shoddy testing done in the US by Cornell and others.

Henry

Click to expand...

Henry,

I believe the so-called "day" vs. "night" transmission values are obtained by computing the dot product of the normalized transmission vector with the photopic and scotopic sensitivity vectors, respectively. In English, the percent transmission at each visible frequency is multiplied by the relative retinal sensitivity at that frequency, and the results added to produce an overall metric. In general, the results need not be the same as the simple transmission values at 555 and 510 (the peaks of the two sensitivity functions), and could even be quite different depending upon the particular shape of the transmission curve. In principle, it is also possible for the night value to exceed the daylight value, although I haven't seen that occur.

I would agree that the transmission values at the peak sensitivity points are usually good first approximations, but by the same token I wouldn't want folks to think they define the metrics.*

The example below is for the Swift 7x36 Eaglet.

Ed

* Of course, I could be wrong .

PS. It occurs to me that a more meaningful understanding of perceived color effects might result from publishing the cross product vectors, rather than just the vector sums (as day and night values). By comparison with the sensitivity function, we might then see where the optics emphasize or deemphasize various regions of the spectrum. Just a thought.

Ed, do you have a sample computation of this? I have tried several methods, from simple summation of averages to full integration of the products and never got the results to match various testers results.

I have attached curves of some of my binos, with retinal sensitivity values overlaid.

Point me to a specific link with a good equation or sample. Thanks, have a good night.

Surveyor said:

Ed, do you have a sample computation of this? I have tried several methods, from simple summation of averages to full integration of the products and never got the results to match various testers results.

I have attached curves of some of my binos, with retinal sensitivity values overlaid.

Point me to a specific link with a good equation or sample. Thanks, have a good night.

Click to expand...

Hi Ron,

I fully expected this would peak your interest. No, I don't have a sample computation to offer up, although I've also tried to model various reported results, which never quite equal the peak sensitivity values. So, I've assumed that the automation is using empirical sensitivity functions that just don't correspond with mine. It's maddening.

If we could get hold of the software, of course, the algorithm would make it readily apparent what they are doing, — but, that's probably proprietary. So this is my best guess, and I'm open to any reasonable explanation.

If something like what I described isn't being done, then I'm unwilling to accept the day and night values as meaning anything, and would just as soon revert to the 555/510 values. At least they are understandable, if not potentially misleading.

Regards,
Ed

Hello Ed,

I, too, have been intrigued by the manufacturers reports of transmission as a unified single figure to represent a spectral response, and have no idea of what they are reporting.

I have not been able to correlate any figures to a consistent single spectral point for day or night, nor have I found a valid curve fitting for the retinal sensitivity curves, though I also assume that is what is being done, I would just like to know how.

Sometime tomorrow I will try to make a list of some of the methods I have tried so you can compare to your efforts. Maybe someone out there knows what is being reported and how it is measured and correlated.

Have a good day.

Ed,
I agree that transmission values picked off at 510 or 555 nm are crude representations of night and daytime performance, those wavelengths being only the peaks of the visual sensitivity in those lighting conditions, and leaving a lot of information out, like, the rest of both functions! But both transmission and visual sensitivity are scalar functions of wavelength.

The best single value to report for day or night performance would be the "convolution integral" of those two functions. That is, the integral of the product of the transmission curve and the appropriate visual sensitivity curve. The integral would run over wavelengths where that product is non zero. 400 to 700 nm should do it.
RonH

ronh said:

Ed,
I agree that transmission values picked off at 510 or 555 nm are crude representations of night and daytime performance, those wavelengths being only the peaks of the visual sensitivity in those lighting conditions, and leaving a lot of information out, like, the rest of both functions! But both transmission and visual sensitivity are scalar functions of wavelength.

The best single value to report for day or night performance would be the "convolution integral" of those two functions. That is, the integral of the product of the transmission curve and the appropriate visual sensitivity curve. The integral would run over wavelengths where that product is non zero. 400 to 700 nm should do it.
RonH

Click to expand...

Unfortunately, I started this business without having time to carry through. We're leaving on a three week vacation very shortly and are busy packing.

RonH, convolution integrals can be computed, but why would they be the best measure of day or night performance? As you can see, my simple minded thinking runs along the lines of just weighting the value of the transmission at each frequency in proportion to the eye's ability to use it.

You may be right, but I need more of a rationale to understand it.

Thanks,
Ed

Like Ed (THREE WEEKS!!) I'm getting ready for a lousy 1 week vacation, so maybe this can wait. Here are a few random thoughts before I go.

Thanks again for the numbers, John. I'm not so sure that everyone uses the same methods for "night" and "day" transmission figures. I was told by someone at Zeiss that their numbers are simply transmission at 500 nm and 550 nm. In Ed's example weighting doesn't seem to make much difference. Simply using 510 and 555nm would change things by only about 0.5%. I think that's only a fraction of the variation to be expected from different labs and different binocular samples. I saw some results of transmission tests done by Swarovski and Leica for a German hunting magazine in 2000. The very same binoculars were tested by both labs. There was not one case of exact agreement between the labs and sometimes the difference was as much as 4%. However they're calculated, two numbers are not that informative compared to a full transmission curve and even that doesn't necessarily prepare us for how a particular curve will look to the eye. A better predictor of how the transmission appears to the eye was what I had hoped to accomplish with my photo method, which I still think could work with better controls.

I am curious about a few more points. Did all the labs measure all the binoculars? If so, how was the published curve determined? Was more than one sample tested? Was there any description of the test methods used?

Based on my subjective experience, the one odd measurement is the 10x42 SE. For my eyes the image brightness in daylight of my old 8x32 SE has equaled or bettered all comers over the years, except the Zeiss 8x56 FL and there the difference is quite small. The daylight transmission sure looks like 93-95% to me.

One last thing. I'm happy to see mention of the green bias in the current Zeiss FL, something I see and was able to photograph.

Henry

Hello Ed, Henry,

I used the Swift 7x36 file above for an example here and attached a spreadsheet with the binocular data, photopic and scotopic constants for you, or anyone else, to use. I have also attached a plot (normalized to 1) for colormetric parameters for the individual RGB sensitivities.

I did not go through all the stuff I looked at in the past. As you can see, if you normalize to the peak of either curve, you just reproduce the curve normalized to the transmission value at 555 and 510 nm.

As you can see graphically, the area used by the photometric values only occupy about 25% of the radiometric spectrum passed by the binocular. Even then, the eye is constricted to a smaller pupil diameter than the binocular most of the time indicating that the optics are passing more light than the eye can use.

All of this has led me to believe that Henry’s contention of just the peaks at 555 and 510 nm are used may be correct, although the figures I have seen never exactly match the tables with them. For instance, the report used shows values of 91.6% and 88.2% on the face of the report, but the tabular values for 555 and 510 nm are 92.11% and 88.82%. It seems to me that no matter how you process the retinal data, there is no way to get to a 90% value of the measured spectral data.

For reference purposes, the area between the raw photopic curve (max 100%) and the normalized photopic curve is about 2.18%. The area between the two photopic curves and below the measured transmission line is about 1.7%

All of this is the main reason I consider transmission numbers only a fair indicator, probably not even the main contributor, of “brightness” of an instrument. I find the transmission curves to be invaluable for colorimetric values like color temperature and bias though, plus a decent indicator of expected saturation levels. These are far more important to me than a peak transmission figure.

Hmmm, just noticed something. Ed, do me a favor and tell me what color bias you see in these binoculars. You should either see a very light yellow/green bias, very light, just a few percent toward a dominant wavelength of 570 nm (yellow) or a slight reddish brown bias, something along the order of 5%-8% from white toward 683 nm (orange to red/orange) dominant wavelength. I thought I had the German figured out but it now appears that the CIE and Lab coordinates may be for the source light, maybe illuminant E from a 3200K CCT. I ask because something did not look exactly right and I went and looked at several other curves by the same lab and all showed about the same coordinates though the spectra was considerably different. I ran the spectra through my freebie software and got substantially different bias and CCT numbers.

Best.

John,

Thanks for providing the summary. On some of the binoculars, you provided the resolution figure, but not for the Canon. Was this mentioned, and if so, could you please give that for reference?

Kimmo

kabsetz said:

On some of the binoculars, you provided the resolution figure, but not for the Canon. Was this mentioned, and if so, could you please give that for reference?

Click to expand...

Kimmo,

The only resolution figures mentioned in the text were for the Nikon SE and Meopta B1. Tabulated results have been promised for the December issue and I will try to relay as much of that information as possible when it becomes available.

Regards,

John

Ed,
I think I get your vector concept (new to me) of transmission and sensitivity, like, an element at every 1 nm step for example. Then, the dot product would be the same as the integral I was talking about. Sorry for the digression, everybody.
RonH

henry link said:

One last thing. I'm happy to see mention of the green bias in the current Zeiss FL, something I see and was able to photograph.

Click to expand...

To my eyes my Zeiss 8x56 FL is the most unbiased, true-to-reality binocular I've seen (and that includes all the A brands). It should be said however that if I was forced to accept some bias, it definitely would be green.

Renze