What if...... (1 Viewer)

Hi John,

Thanks for posting the cutaways. I tend to forget about the compacts, so I hadn't even noticed the high transmission. It must be at least partly due to the relative simplicity. The only other contributing factor would seem to be a shorter light path through the glass of the tiny prisms and thin lenses.

Looking just now at a cutaway of an old Swarovski compact from a 1999 catalogue I see it has a more complex design than the Leica, with a 5 element (2-1-2) eyepiece and a glass cover plate in front of a 2 element (1-1) objective, giving a total of 16 surfaces (including 4 from the prisms) compared to 12 for the Leica (including prisms).

In Gijs' 2005 tests I can't see the Swarovski's 4 extra surfaces accounting for more than a 1-2% difference in transmission and the length of the light path through glass would have been about the same. Perhaps in 2005 Leica was also using better AR coatings and higher reflectivity mirror coating in their compacts than Swarovski or Zeiss.

Henry

Gijs van Ginkel said:

Renze, post 397,
I do not agree with Tobias Mennle at all.
Gijs van Ginkel

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Me either.

I respect his work, but this time he is serving up a set of misconceptions about the effects of baffling. I don't have time to address the subject properly right now, but just to begin, what he calls "aggressive" baffling does not dim the image in the center of the field at all, unless the baffle is so small that it actually acts as an aperture stopdown, but even then it would effect image brightness only if the eye is open larger than the reduced exit pupil resulting from the reduced aperture.

There are several ways to observe and measure the effects of vignetting in binoculars. I'll post some techniques I use when I can.

Henry

jan van daalen said:

The final findings of the report from Gijs are on our website.

https://www.houseofoutdoor.com/wp-content/uploads/2020/02/Leica-kijker-test-dd-25-febr-2020.pdf

Happy readings

Jan

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Hi Jan, Hi Gijs,

thanks a lot for the interesting report.

So the transmission of the Retrovid is very high also at the end of the spectrum, at violett and deep red. The only downside compared to the old models is the slightly smaller field of view.

Thomas

Herman66 said:

Hi Jan,

Now I understand why you had such a nice discount on the Leica’s in your store.

Too bad Leica is doing this to their dealers. Lucky for me in this case, that you are not just letting this happen. But I totally understand that you are doing this
I really enjoy my Trinovid 10x42HD now hoping for better weather to use them a bit more.

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Hallo Herman,

Welcome to BF:t:
You're the guy who used to bring his dog along, right?
The Trinnie has found a good home.
Enjoy.

Jan

jan van daalen said:

The final findings of the report from Gijs are on our website.

https://www.houseofoutdoor.com/wp-content/uploads/2020/02/Leica-kijker-test-dd-25-febr-2020.pdf

Happy readings

Jan

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Many thanks, Jan and Gijs!!!
Canip

jan van daalen said:

The final findings of the report from Gijs are on our website.

https://www.houseofoutdoor.com/wp-content/uploads/2020/02/Leica-kijker-test-dd-25-febr-2020.pdf

Happy readings

Jan

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Very well done report! Thanks, Jan and Gijs. I had my Leica Retrovid's 7x35 out today and my eyes agree with your result's. They are a very bright and sharp binocular. Not much bigger than an 8x25 Zeiss Victory or Swarovski CL-P and much brighter with more comfortable eye placement with the 5mm exit pupil. I see why the original Trinovid 7x35 was so popular. it is very small and compact yet it performs like a full size binocular.

Hi Henry (post #401),

I too am inclined to the view that the main cause of the difference in transmission between the 8x20 Leica and Swarovski pocket models was the quality of the coatings
The 8x20 Ultravid was introduced in 2004, following on from the larger models in 2003, and obviously benefited from Leica’s latest technology

In contrast, the Swarovski was introduced in 1989. For comparison see the attached copies of the optics
I suspect that it’s coatings had not been updated to Swarovski’s then start-of-the-art versions
And in addition, we know that it was not until 2009 that the whole Swarovski line was overhauled with the introduction of the current style of ‘paper white’ Swarotop lens coatings
see the comments of Dale Forbes of Swarovski at: https://www.birdforum.net/showpost.php?p=1628752&postcount=6

- - - -
In relation to Tobias’ comments, while I don’t necessarily agree with all of his reasoning,
I do find that with some reservations my observations as to the view through different binoculars are largely the same as his


Firstly, my general position is that more transmission is of course better then less (and as I get older, my vision increasingly benefits from a brighter image in many situations)
e.g. in comparing like-to-like, I have 8x30W Swarovski Habichts dating from around 1962 (with DV coating), 1999 (with the 2nd version of Swarotop that was used on the Habichts)
and 2013 (with the 3rd Habicht version)
And unsurprisingly I see fine detail more easily as the models progress

However, when comparing different designs it gets more complicated - the meat of Tobias' mega 8x42 review


What I find most interesting is the differences in performance in ‘difficult’ lighting conditions:
A) at low ambient light levels (early morning or late afternoon), and especially
B) where there is veiling glare or ghosting (from strong light sources either near to or in the field of view)

Particularly in comparing the lower transmission Ultravids, to the higher transmission EL SV’s (and some others), my experience is:
- in situation A), while the image may be technically slightly dimmer, the contrast and hence discernible detail in the Ultravid is as good, and
- in situation B), more detail is more easily observable in the Ultravid (especially in the centre of the field of view, as noted by Tobias)!


As to the explanations . . . ?


John


p.s. In relation to the Ultravids, I have both an 8x42 and 7x42 (along with an 8x20) in the HD/ pre-Plus versions
My comparative impressions of the two x42's match those of Tobias with the HD+ versions
And only my Zeiss FL 7x42 comes very close to my Ultravids in relation to B) above (my pre-Lotutec FL seems to perform better than the FL that Tobias tested)

jan van daalen said:

Hallo Herman,

Welcome to BF:t:
You're the guy who used to bring his dog along, right?
The Trinnie has found a good home.
Enjoy.

Jan

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Yes indeed! That’s me.

Thanks.

John,
Re. post 407.

With street lights in the field of view at night my old 8x32 BA is vastly superior to any binocular that has glare or flare, even if only moderately bad.

Binoculars that are good near streetlights are the 10x42 Conquest HD, Ultravid 12x50, Canon 18x50 IS and other IS. Bausch and Lomb Elite old 10x42 etc.

Some binoculars that are praised here by others I find useless.
This is particularly true when trying to make out faint aurorae or noctilucent cloud.

I find similar results during the day with the Sun hidden behind a roof top but trying to observe near the Sun.

Regards,
B.

John A Roberts said:

...I too am inclined to the view that the main cause of the difference in transmission between the 8x20 Leica and Swarovski pocket models was the quality of the coatings
The 8x20 Ultravid was introduced in 2004, following on from the larger models in 2003, and obviously benefited from Leica’s latest technology...In contrast, the Swarovski was introduced in 1989. ...I suspect that it’s coatings had not been updated to Swarovski’s then start-of-the-art versions...

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I don't know whether Swarovski used its state-of-the-art coatings with the Pocket, but I do know that it updated the pocket model coatings several times over the production of the model. Later versions were _substantially_ better, but I never thought they matched the Ultravid for transmission (based on side-by-side comparison by eye). By contrast, I found later production (i.e. after the update to dielectric prism coatings) of the Zeiss 8x20 Compact to be very bright and a match to the 8x20 Ultravid.

--AP

Gigs

I have a question... What is the cause of the undulating transmission across the spectrum represented in the graph? I had remembered the UVHD+ 8X42 exhibited a very similar trait.

chill6x6 said:

Gigs

I have a question... What is the cause of the undulating transmission across the spectrum represented in the graph? I had remembered the UVHD+ 8X42 exhibited a very similar trait.

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It looks like some sort of interference, but I also wonder how and where exactly that might be generated.

Cheers,
Holger

Holger, post 412,
I had already reacted on your question, but it disappeared mysteriously (must be top secret information...)
We talked it over in the lab and we think it is a thin layer interference effect (coatings), nothing to worry about but it looks strange at first sight. We see it sometimes occur.
Gijs van Ginkel

Gijs van Ginkel said:

Holger, post 412,
I had already reacted on your question, but it disappeared mysteriously (must be top secret information...)
We talked it over in the lab and we think it is a thin layer interference effect (coatings), nothing to worry about but it looks strange at first sight. We see it sometimes occur.
Gijs van Ginkel

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Hi Gijs,

I think it is. Yet it seems strange that this effect shows up in some cases only, despite the fact that these coatings are present with every binocular. Perhaps even the optics designer aren't able to predict this behavior (their ray-tracing codes won't account for interference patterns).

Thanks so much for your measurements,
Holger

I think that the thickness of the layers differs depending what glass type is used.

With top lenses all surfaces are coated including cemented surfaces.

The coatings can be tuned also for dealing with off axis rays.

So not all coatings are the same.

Even blackening at the sides differs depending on glass types and may be two layers.

B.

Holger Merlitz said:

It looks like some sort of interference, but I also wonder how and where exactly that might be generated.

Cheers,
Holger

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Gijs van Ginkel said:

Holger, post 412,
I had already reacted on your question, but it disappeared mysteriously (must be top secret information...)
We talked it over in the lab and we think it is a thin layer interference effect (coatings), nothing to worry about but it looks strange at first sight. We see it sometimes occur.
Gijs van Ginkel

Click to expand...

Holger Merlitz said:

Hi Gijs,

I think it is. Yet it seems strange that this effect shows up in some cases only, despite the fact that these coatings are present with every binocular. Perhaps even the optics designer aren't able to predict this behavior (their ray-tracing codes won't account for interference patterns).

Thanks so much for your measurements,
Holger

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Thanks for the info!

To be clear, Leica is out and stays out, but I am curious.
We are more than one month further now and how is the Retrovid treating you? Is it a hick up model (you bought it mainly out of curiosity but don't use it anymore) or is it a regular (you use it often)?

Stay healthy folks.

Jan

Not sure who you are talking to, Jan.

In case it‘s me: yes, in the last two months, the binos I have most often used are the 8x40 Retrovid, followed by the 7x35 (I fear that the previously most used model, the 7x42 UV HD+, will never forgive me ...)

I am still very pleased with both (still preferring the 8x40 by a small margin).

Canip

jan van daalen said:

To be clear, Leica is out and stays out, but I am curious.
We are more than one month further now and how is the Retrovid treating you? Is it a hick up model (you bought it mainly out of curiosity but don't use it anymore) or is it a regular (you use it often)?

Stay healthy folks.

Jan

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So my Retrovid 7X35...

I REALLY like it! I've used it a good bit...even today. Went out with both the Trinovid BN 7X42 and the Retrovid 7X35. Quite frankly I thought the BN was outclassed. The Retrovid points very instinctively....Focus adjustment is smooth as silk. FOV seems larger than it actually is. I like the Retrovid better than my 8X30 CL B. So far really nothing but good to say!

@Canip&Chuck,

Good to hear and same here. Smooth focus, eye cups that stay in place and that nice steady 7x clear view.
The only minus I can find (my fault) is that my right little pinky finger tend to cross the right objective lens something that does not occur with my CL30 because of the much smaller bridge.
For me, she is a keeper. Nice to look through and nice to look at.

Jan