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-   -   the 92% compared with the 95%... (http://www.birdforum.net/showthread.php?t=351631)

spiralcoil Thursday 5th October 2017 03:43

the 92% compared with the 95%...
 
Good day to those have the compassion or knowledge about:

Comparing the Leica Noctivid 8x42 & the Zeiss HT 8x42, all specs are about the same, expect the light transmission of 92% vs 95%...

My question would be that - is the 3% more makes a visibly difference in a better way?

Do you think Leica is not capable of producing the same amount of transmission or it is a way of balance something else in the design?

Which one of those two 8x42 binoculars is a better user you may feel?

sbb Thursday 5th October 2017 04:03

Quote:

Originally Posted by spiralcoil (Post 3626059)
Good day to those have the compassion or knowledge about:

Comparing the Leica Noctivid 8x42 & the Zeiss HT 8x42, all specs are about the same, expect the light transmission of 92% vs 95%...

My question would be that - is the 3% more makes a visibly difference in a better way?

Do you think Leica is not capable of producing the same amount of transmission or it is a way of balance something else in the design?

Which one of those two 8x42 binoculars is a better user you may feel?

Depends what you want to see. High contrast or good colours. Noctovid for sure if you are birding :)

Rathaus Thursday 5th October 2017 05:55

An alleged 3% difference in spec would be the last thing Iíd be concerned about. Doesnít anybody trust their own eyes? Have a look through them. Initially, It took me between five and ten seconds to see the benefits of the Noctivid over other alpha roof bins. I spent another couple of minutes having a gawk and thatís it. If you canít see the benefits itís a good thing because you can be content and save money.

(The HT is good by Zeiss standards, but has never been an absolute benchmark in light transmission. There are a bunch of bins which have superior light transmission to the Zeiss HT. eg: various Fujinon and every Habicht...theyíve been around for decades)

Hermann Thursday 5th October 2017 06:01

Quote:

Originally Posted by Rathaus (Post 3626067)
(The HT is good by Zeiss standards, but has never been an absolute benchmark in light transmission. There are a bunch of bins which have superior light transmission to the Zeiss HT. eg: various Fujinon and every Habicht...theyíve been around for decades)

Please note that these are all porros with relatively simple optical designs.

Hermann

PHA Thursday 5th October 2017 11:30

Hi,

Having compared, not 8x but 10x, this two binoculars, my HT 10x42 and the shop's Noctivid, for several hours, the LEAST thing I would be concerned, is the light transmission difference!! To me, the TRULY EXCEPTIONAL veiling glare control of the Noctivid is really a BIG step over the others first class binoculars, overlapping 2 or 3% of light transmission!!!
I read the GLOBETROTTER's Noctivid mechanical problems with some concern...I hope it would be an initial samples issues...the Noctivid will be my next binocular!!!

PHA

Vespobuteo Thursday 5th October 2017 11:45

Quote:

Originally Posted by spiralcoil (Post 3626059)
Good day to those have the compassion or knowledge about:

Comparing the Leica Noctivid 8x42 & the Zeiss HT 8x42, all specs are about the same, expect the light transmission of 92% vs 95%...

My question would be that - is the 3% more makes a visibly difference in a better way?

Do you think Leica is not capable of producing the same amount of transmission or it is a way of balance something else in the design?

Which one of those two 8x42 binoculars is a better user you may feel?

Zeiss HT have AK-prisms, I think that explains most of the difference in light transmission. AK-prisms are of longer physical length (compared to SP prisms) and would not fit in a compact design like the Noctivid.

dwever Thursday 12th October 2017 22:35

1 Attachment(s)
Brightness:

"The brightness of a binocular is important to birders, especially if they like to go out owling or want to watch woodcocks displaying at dawn. To check out the brightness of our test binoculars in dim conditions, we took them outside and compared what we coud see on our resolution chart as the light diminished.

However, we found no perceptible differences in the brightness of Zeiss (SF), Swarovski (EL), and Leica (NVD) binoculars. This is what one would expect, considering they all have special glass and the most advanced coatings. They all have light transmission specifications over 90%. It would take expensive scientific instruments to objectively detect any difference this small. Your eye doesn't see it. Since we scored all three binoculars as perfect in brightness, brightness did not contribute to any difference in the overall scores.

Experts in vision say that the unaided human eye is not a reliable instrument for measuring small differences in brightness, because the brain is always involved in seeing, interpreting what we see.

For example, in the image below, it seems obvious that the right page is darker than the left. But as soon as you cover the fold with your thumb, you see they are the same shade of grey. Image by R.Beau Lotto.Ē birdwatching.com
__________________

james holdsworth Friday 13th October 2017 01:43

All three of those should have [essentially] the same trans. figures, so of course they would appear nearly identical.

My FL's and HT's are reportedly within a few % but I can clearly see the difference in dim light....but these things are very individual-centric...and perception of brightness can be down to things like contrast or colour balance.

Gijs van Ginkel Friday 13th October 2017 11:55

Rathaus,
post 3,
Your remark about the transmission of the HT is not correct, you have to do more homework to see that you are wrong.
Gijs van Ginkel

chill6x6 Friday 13th October 2017 13:32

Until a very short time ago I had the HT, FL, and Conquest HD 10X42s.....95%, 92%, and 90% respectively(using 8X42 data). Never could I tell any brightness difference whatsoever. Though a fine binocular I sold the HT because of redundancy. I DO notice the Conquest HDs increased FOV though. It is my belief that anything less than 5 or 6 % difference probably won't be noticed by the vast majority of users if one doesn't know binocular "A" has higher light transmission over binocular "B." Myself included.

Rathaus Friday 13th October 2017 13:38

Quote:

Originally Posted by Gijs van Ginkel (Post 3629566)
Rathaus,
post 3,
Your remark about the transmission of the HT is not correct, you have to do more homework to see that you are wrong.
Gijs van Ginkel

True....Perhaps not quite every Habicht ever made ;)

Troubador Friday 13th October 2017 17:06

Quote:

Originally Posted by Rathaus (Post 3626067)
An alleged 3% difference in spec would be the last thing Iíd be concerned about. Doesnít anybody trust their own eyes? Have a look through them. Initially, It took me between five and ten seconds to see the benefits of the Noctivid over other alpha roof bins. I spent another couple of minutes having a gawk and thatís it. If you canít see the benefits itís a good thing because you can be content and save money.

(The HT is good by Zeiss standards, but has never been an absolute benchmark in light transmission. There are a bunch of bins which have superior light transmission to the Zeiss HT. eg: various Fujinon and every Habicht...theyíve been around for decades)

Zeiss HT is the absolute benchmark (at the moment, until someone does better) for light transmission among modern roof prism binos and if you are often viewing during the 1st half hour or last half hour of light in the day then you would struggle to better it with another roof prism bino. Of course there are many other aspects of importance to a bino's performance but we are discussing light transmission here. Personally I wouldn't put extreme light transmission such as the HT's as the most important priority, but HT has a very nice transparancy of view and handles really well too.

Lee

Rathaus Friday 13th October 2017 17:44

Quote:

Originally Posted by Troubador (Post 3629655)
Zeiss HT is the absolute benchmark (at the moment, until someone does better) for light transmission among modern roof prism binos and if you are often viewing during the 1st half hour or last half hour of light in the day then you would struggle to better it with another roof prism bino. Of course there are many other aspects of importance to a bino's performance but we are discussing light transmission here. Personally I wouldn't put extreme light transmission such as the HT's as the most important priority, but HT has a very nice transparancy of view and handles really well too.

Lee

HT may have one of the benchmark transmissions for roof, yes.
For Binoculars, no.

Itís probably a moot point anyway because Iím in the dubious camp re folk who think they can detect a 2 or 3% (depending on data source) difference between the HT and a NV or numerous other modern roof bins regarding brightness. I believe various other factors will present themselves long before the 2-3% transmission will ever be detected.

Rathaus

james holdsworth Friday 13th October 2017 18:36

This discussion mirrors those on some sports car forums I inhabit. Those owning cars with lesser horsepower will contend an extra 25 bhp is ''invisible'', those with that horsepower are sure it makes a big difference....

jgraider Friday 13th October 2017 18:41

Quote:

Originally Posted by james holdsworth (Post 3629691)
This discussion mirrors those on some sports car forums I inhabit. Those owning cars with lesser horsepower will contend an extra 25 bhp is ''invisible'', those with that horsepower are sure it makes a big difference....


This example is as ridiculous as you claiming you can see a 1-3% difference in light transmission.

dwever Friday 13th October 2017 19:06

Wow. Maybe West Texas is still really hot.

wdc Friday 13th October 2017 19:25

Quote:

Originally Posted by chill6x6 (Post 3629599)
It is my belief that anything less than 5 or 6 % difference probably won't be noticed by the vast majority of users if one doesn't know binocular "A" has higher light transmission over binocular "B." Myself included.

I'm not even sure what 100% actually means in terms of our ability to detect a light source at full strength, since even our own eyeballs are reflecting some percentage of light. Is our cornea not to be considered an 'air to glass' surface? Furthermore, if one is wearing glasses, you have to add 2 additional air to glass surfaces, which, I can attest, do play a role in affecting one's image, even when NOT using binoculars..

Chuck states that a 5-6 percent difference might not be noticed in a blind test. Consider that in comparative percentages, a difference of 85 to 91% in light transmission is actually 6.6% (85/91)

For the internet shoppers, the spec based approach can really play a frustratingly devious role in trying to find the right binocular. If you think of a binocular like an item of apparel that is built to a certain level of quality, then issues like weight, IPD, and eye relief are probably the most important one's to consider. The physical fit to your eyes, hands, and face are pretty crucial. I would include FOV in that, but I'm starting to even question some of the logic in that.

For example, the notion that a wider field confers a 'big' advantage at close range seems entirely rational until one starts to look at the numbers a bit.

Binocular 'A' has a 372' FOV at 3000'
Binocular 'B' has a 430' FOV at 3000'

That's a 58' difference..... at 3000' It looks BIG on paper until you realize that difference only exists over a half mile away.

Where I bird, I consider close range viewing to be around 100' or closer, at which point the relative difference is 1/30th of 58', or 23.2 inches. Consider that a highly caffeinated target warbler is centered in your view, and it jumps out of the field to another spot in the foliage. Since it can only exit one side of the image circle at a time, the difference at any point on the perimeter is less than 12", or a little over 2 warblers stacked end to end. The closer you get, the difference gets ever smaller. I'm not saying there is no practical advantage to a wider field, but the spec numbers can imply a gain much greater than what real world use might reveal.

Another point to consider is whether eye relief, whether wearing glasses or not, allows one to see the entire field, at which point there may be no wide field advantage at all to be had, even if the image quality is wonderful.

Just some food for thought.

Bill

elkcub Friday 13th October 2017 21:02

Quote:

...For example, the notion that a wider field confers a 'big' advantage at close range seems entirely rational until one starts to look at the numbers a bit.

Binocular 'A' has a 372' FOV at 3000'
Binocular 'B' has a 430' FOV at 3000'

That's a 58' difference..... at 3000' It looks BIG on paper until you realize that difference only exists over a half mile away.

For an 8x binocular, 'A' provides a 57.09 deg. AFOV at the retina.
Similarly 'B' provides a 65.65 deg. AFOV.

The additional 8.56 deg. in "apparent field" allows for greater depth cues and peripheral motion perception.

The widest Porro binocular I own has a 96 deg. apparent field, which is 30 deg. larger than 'B'. Unfortunately, eye relief trades off with FOV, making this one not suitable for use with glasses. Other than that, however, the huge extra field is very beneficial for birding. By comparison, the 57.09 deg. AFOV in 'A' borders on tunnel vision.

I'd think in terms of the eye rather than the physics of the binocular.

Ed

wdc Friday 13th October 2017 22:15

Quote:

Originally Posted by elkcub (Post 3629774)
For an 8x binocular, 'A' provides a 57.09 deg. AFOV at the retina.
Similarly 'B' provides a 65.65 deg. AFOV.

The additional 8.56 deg. in "apparent field" allows for greater depth cues and peripheral motion perception.

Ed

Thanks for the input. I've got plenty to learn. Are you saying that a larger apparent field of view projects an image on a larger area of the retina? Perhaps that is self-evident to many, but I just want to make sure I understand.

Bill

james holdsworth Saturday 14th October 2017 00:34

Quote:

Originally Posted by jgraider (Post 3629694)
This example is as ridiculous as you claiming you can see a 1-3% difference in light transmission.

...and I see the future too...:t:

Rathaus Saturday 14th October 2017 04:17

Quote:

Originally Posted by elkcub (Post 3629774)
The widest Porro binocular I own has a 96 deg. apparent field

Nice. Which Porro is it?

elkcub Saturday 14th October 2017 05:16

Quote:

Originally Posted by wdc (Post 3629815)
Thanks for the input. I've got plenty to learn. Are you saying that a larger apparent field of view projects an image on a larger area of the retina? Perhaps that is self-evident to many, but I just want to make sure I understand.

Bill

Correct.

elkcub Saturday 14th October 2017 05:24

2 Attachment(s)
Quote:

Originally Posted by Rathaus (Post 3629900)
Nice. Which Porro is it?

Linet Imperial made by Hiiyoshi Kogaku (c. 1 980). Quite a beautiful binocular.

Ed

Rathaus Saturday 14th October 2017 06:01

Quote:

Originally Posted by elkcub (Post 3629910)
Linet Imperial made by Hiiyoshi Kogaku (c. 1 980). Quite a beautiful binocular.

Ed

Highly drool worthy. Just lovely. Are these related to the earlier Japanese FPO products?

Rat

pshute Saturday 14th October 2017 09:24

Quote:

Originally Posted by jgraider (Post 3629694)
This example is as ridiculous as you claiming you can see a 1-3% difference in light transmission.

In normal light, 3% more light reaching the eye should result in the pupils shrinking slightly, so one should never notice that the image is brighter.

But a smaller pupil means slightly more depth of field, doesn't it? And perhaps a reduction in the effects of eyesight aberrations like astigmatism?

Could those be noticeable?


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