Objective coating Changes (1 Viewer)

[dries1]

I thought I would post a couple of pics of some objective coating reflections on some modern glass.

All are 8X42s

EDG 3007XX
EDG 3013XX

Noctivid 21470XX
Noctivid 21975XX

The pics tell the observer that the coatings have likely been changed/upgraded (if one wants to call it that), with the green reflections on the later serial # glass that gives a slight yellowish tint to the view.

Just some info that coatings are likely being upgraded.

I have no idea what the age difference is between the models.

Andy W.

 

[Tobias Mennle]

Andy, thanks for posting, this is very interesting.

Why would a green reflecting coating give a yellow tint? I´d expect that from a blue reflecting coating like Swaro´s old "Blaubelag".

Regarding the EDG, I have the earlier type and consider it as the reference glass in neutral colour reproduction and contrast (especially global contrast). If the later version is more yellow in colours, Nikon has chosen to boost perceptual contrast to get closer to most competitors. I'm glad I have the earlier version but would like to try the newer one just for fun.

Noctivid, could it be the olive version - which I also have - has different coatings, optimized for hunting? Probably not. But anyway your photo suggests that Leica´s claim about neutral colour reproduction is marketing waffle, as these two coating cannot render the same colour. The late/green Nocti is definitely too yellow for my taste.

 

[John A Roberts]

Both in general, and with reference to my Leica 7x42 and 8x42 UV HD (both pre-Plus):

. . .

I think that it’s generally under appreciated just how much control over the range of perceived hues that modern manufacturers can and do exercise

If we look at a basic . . . roof prism binocular and only consider the primary anti-reflective coatings on the lens surfaces, it will have at least 10 air-to-glass surfaces:
3 eyepiece groups and 2 objective groups including the focuser, each with a front and rear surface - with each having a minimum of 3 coatings

However, this does not mean that the coatings are the same on each surface (there is a large range available)
This is readily apparent with many binoculars when just comparing the main reflection from the objectives to those of the eyepieces
And if you look deeply into an objective you’ll often see a series of different colours reflected from the various air-to-glass surfaces

And manufacturers do tune the coatings of different models in the same range
e.g. my Leica Ultravid HD 7x42 and 8x42 have markedly different coloured reflections from the objectives
(yellow-green and pink verses blue and green; and for what its worth, their numbering is within 2,700 units)

. . .

So it probably does not follow that the external objective coatings necessarily determine the final viewed image hue (?)


John

 

[NDhunter]

Both in general, and with reference to my Leica 7x42 and 8x42 UV HD (both pre-Plus):




So it probably does not follow that the external objective coatings primarily determine the final viewed image hue (?)


John

John:
I think you may be on to something, there is no real way to decide how the objective reflections affect the view through the ocular.

When we think of Zeiss, they have often had a definite red reflection from the objectives, and more so than any others.

Jerry

I wanted to add a photo of the Steiner Firebird, there is quite a red reflection here. I know a fellow that had this model, although I
did not get to look through it.

 

[WJC]

Why should one suppose the wavelength being reflected is the same as the one being transmitted? Often, we are STILL thinking colors and not wavelength.

Bill

 

[Troubador]

Why would a green reflecting coating give a yellow tint?

The late/green Nocti is definitely too yellow for my taste.

Tobias, forgive me for appearing to be a smarta*s but your first question appears to suggest a green coating would not give a yellow tint, while your statement about the Nvid seems to suggest it does. Please explain.

Lee

 

[WJC]

As for as I am concerned, “ruby coatings” were designed to con the unwary. I BELIEVE you will find those coatings in Jerry’s photo to be laser coatings. I saw similar while working in optics at Fort Lewis.

Bill

 

[Patudo]

There's little doubt that the manufacturers do upgrade and improve their coatings over time. However, changes in the colour of lens reflections may not necessarily mean an upgrade/change has taken place.

See this discussion of a binocular where the coating reflection of one barrel is a different colour to the other: https://www.birdforum.net/showthread.php?t=308595.

Birdforum member garymh explains the reason for this in his post #10 in that thread.

 

[Chosun Juan]

.... So it probably does not follow that the external objective coatings necessarily determine the final viewed image hue (?)

John

Why should one suppose the wavelength being reflected is the same as the one being transmitted? Often, we are STILL thinking colors and not wavelength.

Bill

Correct & Correct as far as I understand.

The complete optical train (including glass types and design) has to function as a whole - you can't draw a conclusion just based on one visible surface.




Chosun :gh:

 

[chill6x6]

And to throw a wrench in the coatings/reflections thoughts....here is a Noctivid and a Silverline....both 8X42s....

 

[John A Roberts]

To illustrate my previous post, see the obvious difference between the objective coatings on my Leica UV HD’s: the 7x42 at top and the 8x42 below

And another example that I’ve previously referred to, two 8x30 models from Swarovski: a 2006 production SLC neu roof prism on top, and a 1999 Habicht Porro prism below
While having very different objective coatings, they have an identical very slightly warm image, comparable to that of the Ultravid HD 7x42
(for more detail, see post #1 along with 6 to 8 at: https://www.birdforum.net/showthread.php?t=391231 )

The warmth of all 3 is subjectively half that of a Nikon EII 8x30 Porro prism that I bought in 2014
(so not with the current EII coatings following on from the 2017 anniversary edition, see at: https://www.birdforum.net/showthread.php?p=3894764 )


John

 

[james holdsworth]

Are we sure this isn’t just a case of angle of view? Many of my objectives show different primary colours depending on the angle, even the slight distance between the two barrels is enough to make each objective reflect different colours.

 

[John A Roberts]

Hi James,

At least with my two Ultravids it not just the angle of view: the yellow-green & pink of the 7x42 verses blue and green of the 8x42 is a constant difference
Unfortunately, when I took the shot yesterday I was not able to make it as clear as it is in other circumstances


John

 

[Tobias Mennle]

Tobias, forgive me for appearing to be a smarta*s but your first question appears to suggest a green coating would not give a yellow tint, while your statement about the Nvid seems to suggest it does. Please explain.

Lee

Lee, I would never claim my Noctivid has a purely green transmission. It reflects pink and yellow and a bit of blue... but the image colour is just a bit off, too yellow-green. The strange contrast plays a role in that, too, probably.

The point of Andy´s photos is only that the coatings are very different and have changed, to see more one would have to make photos from different angles and in low and bright light!

Of course, coating colours are not enough to judge image colour fidelity.

I was surprised to see the neutral image colour of the Zeiss Victory pocket 8x25 despite being alarmed by its strong intensity magenta coatings.

With the early SF that was different, but I confirmed that by photographing through different bins and the SF was way too green and the greenest of all. Again, early samples MKI, Zeiss has tweaked coating since.

With my 1961 Habicht though the coatings tell the whole story, the image has a strong yellow cast with a bit of green, and the coatings have the exact opposite colours - a strong blue and a weak magenta ("Blaubelag" they called it).

 

[Tobias Mennle]

To illustrate my previous post, see the obvious difference between the objective coatings on my Leica UV HD’s: the 7x42 at top and the 8x42 below

And another example that I’ve previously referred to, two 8x30 models from Swarovski: a 2006 production SLC neu roof prism on top, and a 1999 Habicht Porro prism below
While having very different objective coatings, they have an identical very slightly warm image, comparable to that of the Ultravid HD 7x42
(for more detail, see post #1 along with 6 to 8 at: https://www.birdforum.net/showthread.php?t=391231 )

The warmth of all 3 is subjectively half that of a Nikon EII 8x30 Porro prism that I bought in 2014
(so not with the current EII coatings following on from the 2017 anniversary edition, see at: https://www.birdforum.net/showthread.php?p=3894764 )


John

John, that is very interesting to me as I am about to order another 7x42 - could you elaborate on what you see in colour differences in the 8x42 and 7x42? I only tested them shortly in a shop and was a bit shocked how much more yellow the 8x42 image seemed. Which would fit with your coating photos.

 

[Tobias Mennle]

I assume the ocular coatings are important, too. In the Noctivid they are high intensity blue with a bit of green.

 

[WJC]

I assume the ocular coatings are important, too. In the Noctivid they are high intensity blue with a bit of green.

Yes, they are. But COLORS mean nothing. AR coatings have no COLOR. What is seen as COLOR is the wavelength being reflected. :cat:

Bill

 

[John A Roberts]

Hi Tobias,

My UV HD 7x42 is #1,621,229 and my 8x42 is #1,623,887, so the numbering is within a 2,700 unit range
However, I have no idea what the differences in the objective coatings mean in relation to either:
a) previous UV HD production, or
b) current UV HD+ production

For example:
- did the coatings differ between the two UV HD models across all of the production, or was there the same change to the whole UV HD line between the two numbers?
- and if the former, do the differences continue on the current UV HD+ production?
(perhaps someone with easy access to a comprehensive Leica retailer could compare current 7x42, 8x42 and 10x42 objectives?)

- - - -

I wouldn’t be at all surprised if manufactures do tune the anti-reflective coatings on the particular models of a product line, such as the three x42 UV HD+’s, or the two Noctivids
However, to head off unnecessary enquiries (‘Hey, why do these two have different colour lenses? Which one is the right one?’), I would imagine that where possible,
manufacturers use the same coatings on the external lens surfaces (so that any differences are 'out of sight, out of mind')

- - - -

In relation to my two UV HD’s, both have the typical Leica slightly warm image colour. However, there is a subtle difference
With the 8x42, especially under bluer light such as heavy cloud cover, the view in general takes on a noticeably colder/ bluer aspect
And while this may be technically a more correct response to the prevailing light, I do find it somewhat unpleasant

However, I’d be cautious about extrapolating to current production. As you know, regardless of the reflections of the current objective coatings,
there’s only one way to be sure of the image colour qualities - you'll necessarily need to see for yourself!


John

 

[Tringa45]

As the reflectivity of high index (flint) glasses is higher than that of low index (crown) glasses, I think it highly likely that, on the higher end products at least, the coatings are tailored to the individual elements, so the reflections from objectives and oculars would not tell us much.
IIRC, Pentax on some of their astronomical eyepeces even had tailored coatings on the internal surfaces of cemented doublets!

John

 

[Tobias Mennle]

As for as I am concerned, “ruby coatings” were designed to con the unwary. I BELIEVE you will find those coatings in Jerry’s photo to be laser coatings. I saw similar while working in optics at Fort Lewis.

Bill

I´d call them Chinese nightmare coatings.