Nikon HGs (1 Viewer)

[tenex]

Personally, I do not like modern dielectrics, which are extremely bright and neutral, but lose this pleasure of viewing, especially on very bright sunny days.

The reason I quickly lose interest in arguments over subtle qualities of color etc is precisely that lighting varies so greatly. From mile-high noon sunlight to rosy winter dawn, what looks best in some conditions doesn't in others.

but, I still don't understand what the advantages of lead glass are, does it show more saturated colors?

I thought a principal advantage was less CA. But at any rate, the cult of leaded glass got started immediately upon the advent of eco-glass, when due to limited experience and computing power, new optical designs were lagging behind. I think they have long since caught up with the types of glass in use today, including new ED varieties that have also helped performance, not to mention better coatings. And as mnich pointed out, there were better and worse designs even with leaded glass. But for the romantic, only romance will do.

 

[Dyrlege]

I think that better color saturation in leaded glass is not a rule. It is rather a combination of several factors, including the design based on such glass. In HG - for example, this is helped by the silver coating on the prism mirror, or the specific characteristics of the transmission graph with a maximum in the red spectrum, as Leica UV binoculars did before HD Plus. Leica binoculars of course have dielectric coatings. I have a few binoculars from the period when silver coatings were more common and you can see a slight warming of the image in such a design. Personally, I do not like modern dielectrics, which are extremely bright and neutral, but lose this pleasure of viewing, especially on very bright sunny days.

Returning to Nikon, of course, MHG will be a better design for everyday use, especially for bird lovers, but for an optics collector, things may look a bit different. Holding the HG in your hand, you feel this "weight" - the quality of the construction, in contrast to the MHG - a bit "toy-like", although the MHG is made of the highest quality materials, and the design is extremely successful, it does not give such a "high" as the HG.

Finally on the subject of leaded glass, a lot of old optics from the 70s, 80s and 90s have leaded glass built in, and yet they are not impressive in terms of image coloring. As I wrote earlier, this is a conglomeration of several parameters in one housing, which can result in the effect of "tweaking" colors.

I will also add that from a technological - scientific perspective, I cannot explain the phenomenon of color saturation in optical glass with the addition of lead. Maybe someone on this forum will come along and be able to delve deeper into the issue, I would be happy to listen.

I asked Gemini:
Lead oxide added to glass gives lead crystal several advantages:
* Increased refractive index: This makes the glass more sparkly and reflective, giving it a brilliant appearance.
* Softer working temperature: Lead glass can be worked at a lower temperature, making it easier to shape and engrave.
* Higher density: This gives lead crystal a heavier, more substantial feel.
* Clearer sound: Lead crystal produces a ringing sound when tapped, unlike ordinary glass.
* Easier to polish: Lead glass can be brought to a high polish in a bath of
acid.

 

[mnich]

I asked Gemini:
Lead oxide added to glass gives lead crystal several advantages:
* Increased refractive index: This makes the glass more sparkly and reflective, giving it a brilliant appearance.
* Softer working temperature: Lead glass can be worked at a lower temperature, making it easier to shape and engrave.
* Higher density: This gives lead crystal a heavier, more substantial feel.
* Clearer sound: Lead crystal produces a ringing sound when tapped, unlike ordinary glass.
* Easier to polish: Lead glass can be brought to a high polish in a bath of
acid.

Thank you for this information, it broadens my perception a bit.

 

[tenex]

I asked Gemini:
Lead oxide added to glass gives lead crystal several advantages:
* Increased refractive index: This makes the glass more sparkly and reflective, giving it a brilliant appearance.
* Softer working temperature: Lead glass can be worked at a lower temperature, making it easier to shape and engrave.
* Higher density: This gives lead crystal a heavier, more substantial feel.
* Clearer sound: Lead crystal produces a ringing sound when tapped, unlike ordinary glass.
* Easier to polish: Lead glass can be brought to a high polish in a bath of acid.

Posting AI output is apparently frowned upon here, although I see nothing dubious in this case.

Of course nearly all of this concerns crystalware not optical instruments. And while a high refractive index can be useful, it's not equivalent to low or anomalous dispersion which seem to be key to optical designs today. But AI isn't going to explain such technical subtleties well, any more than spherical aberration of the exit pupil. Surely a human expert here could do better.

 

[Tringa45]

Optical glasses containing lead oxide were flint glassses with a high refractive index and high dispersion.
For applications such as candelabras or cut glass drinking glasses the high dispersion of lead crystal was a desirable property.
Optical crown glasses generally have low refractive indices and lower dispersion.
An achromatic doublet can be constructed with a strongly converging crown element and a weakly diverging flint element, which restores the dispersion of the former so that two colours are corrected in the focal plane.
The four radii (or three radii in the case of a cemented doublet) of the two elements would be chosen to minimize spherical aberration.
The "superiority" of lead flints is IMO esoteric speculation.

John

 

[NDhunter]

I asked Gemini:
Lead oxide added to glass gives lead crystal several advantages:
* Increased refractive index: This makes the glass more sparkly and reflective, giving it a brilliant appearance.
* Softer working temperature: Lead glass can be worked at a lower temperature, making it easier to shape and engrave.
* Higher density: This gives lead crystal a heavier, more substantial feel.
* Clearer sound: Lead crystal produces a ringing sound when tapped, unlike ordinary glass.
* Easier to polish: Lead glass can be brought to a high polish in a bath of
acid.

Your post is rubbish, as it is about leaded crystal glass in bowls, etc. Nothing about optical glass in optics.
Not sure why you posted...........
Jerry

 

[ananda]

I would like to know whether a large lens affects the contrast and saturation of the image more than a small one?
for example; Monarch 8x20 HGL and 8x42 LX

 

[Tringa45]

I would like to know whether a large lens affects the contrast and saturation of the image more than a small one?
for example; Monarch 8x20 HGL and 8x42 LX

The 8x20 would have a 2,5 mm exit pupil and the 8x42 would have a 5,25 mm exit pupil, so in low light when the observer's eyes are dilated, the 8x42 would be brighter and show more detail. The 8x42 would probably have better viewing comfort and a wider field of view.
Magnification is the quotient of objective and eyepiece focal lengths, so the longer focal length eyepieces in the 8x42 would be easier to design with adequate eye relief for glasses wearers.

John

 

[ananda]

The 8x20 would have a 2,5 mm exit pupil and the 8x42 would have a 5,25 mm exit pupil, so in low light when the observer's eyes are dilated, the 8x42 would be brighter and show more detail. The 8x42 would probably have better viewing comfort and a wider field of view.
Magnification is the quotient of objective and eyepiece focal lengths, so the longer focal length eyepieces in the 8x42 would be easier to design with adequate eye relief for glasses wearers.

John

Thanks for the answer, but it is not answer what I asked...

 

[Dyrlege]

Your post is rubbish, as it is about leaded crystal glass in bowls, etc. Nothing about optical glass in optics.
Not sure why you posted...........
Jerry

Thank you for a very constructive remark!
😄

 

[Dyrlege]

Thank you for a very constructive remark!
😄

And I would assume that as lead in crystal gives a higher refractive index, it would imply thinner glass and as mentioned in the disparaged remark: easier working. It is/was used in the production of (reading) glasses, that may go under the "optics" heading, but the that is probably rubbish in this connection, too.
Per

 

[Patudo]

Leaded glass has been discussed very extensively on this subforum over the period the manufacturers were making the transition to unleaded. The technical aspects of the discussion (eg. leaded glass having high dispersion while modern ED glass types are specifically intended to achieve low dispersion) are pretty interesting for those prone to geeking out, as I suppose we all are from time to time. It would appear, from the excellence of modern alphas and indeed even sub-alphas, that the teething issues with unleaded glass types have long since been worked out, and today's optical designs have more than equalled the best of the leaded-glass era. But good products from that era are still good performers and perfectly functional and usable birding tools.

I have a few binoculars from the period when silver coatings were more common and you can see a slight warming of the image in such a design. Personally, I do not like modern dielectrics, which are extremely bright and neutral, but lose this pleasure of viewing, especially on very bright sunny days.

For what it's worth, my opinion (which is of course only an opinion) is the opposite. I still use a binocular from the silver coated era (Dialyt 10x40 P*) quite regularly, and would gladly upgrade the prisms to dielectric if only I could (Swarovski are to be congratulated for, IIRC, doing just this with Mk II SLCs). The slight but perceptible increase in brightness is helpful, or at least desirable, in more birding situations than it is a hindrance (a very bright binocular can, admittedly, be difficult to use when scanning bright white clouds), and the highly accurate colour rendition that modern binoculars offer, though less of a factor in my own birding, is IMO another small but definite improvement over the silver-coated era. Until the advent of dielectrics, it seemed that only totally internal reflecting prisms (eg. Abbe-Koening) seemed to offer the "washed clean" image that many Schmidt-Pechan prismed models now offer. The slight warm/yellow cast of the silver-coated era may have a kind of vintage charm to some users (although no one seems to hanker for single-coated binoculars, many of which had a similar warm tinge) and in some light conditions (late afternoon is when I see this most) can make the image look very good, but I certainly don't miss it. Give me brightness and colour accuracy every time.