Why do Zeiss's alpha level binoculars like the FL and SF have some of the best CA control of any binoculars? (1 Viewer)

[Hermann]

We also have to take into account that Zeiss is unlikely to put out a new model that either doesn't stack up against the old one, or isn't an improvement.

Really? When Zeiss started producing the Dialyts (e.g. the 8x30 and 10x40), long before phase-coating was introduced, these models were optically vastly inferior to the porros they still made at the time. Leica did the same.

Hermann

 

[[email protected]]

They are very similar, but HT's just look a fraction better, slightly cleaner, sharper, more contrast.... it's hard to nail it down, but we both agree it is a tad 'up'.
I have never noticed CA in the HT's, or FL's, but the HT's are slightly sharper towards the edge. FL's are fine in this regard too, for my liking anyway, not being a 'sharp to the edge' fanatic.
I would be happy with either, but I won't be searching out some mint FL's over my HT's.
We also have to take into account that Zeiss is unlikely to put out a new model that either doesn't stack up against the old one, or isn't an improvement.
A report I read, said Zeiss had indeed nailed it with the HT's after some concern over dropping the FL line, so people all see it different.

I don't know about cleaner, sharper and more contrast. The FL's are hard to beat for sharpness and lack of aberrations. The HT's could have a little more contrast than the FL's because of the newer coatings and Schott HT glass, but some people think they have too much contrast, as in the Cloudy Night's thread below. The Fl's are a little more comfortable to use for extended periods for that reason. The HT's are a little sharper at the edge, but I think the CA control is a little better in the FL. The only HT I had was the HT 8x54 and I really liked it, although it did have quite a bit of edge falloff, way more than say an SLC 8x56. It was one of the best binoculars I have ever had in low light though, and it did have a sharp, clear on-axis view. The HT 8x54 also was very light and small for its aperture, which was a great advantage for a low light binocular because most of them are huge like the FL 8x56.

I also, prefer the ergonomics of the FL with its bigger focuser and warm composite body which makes it lighter than the HT and also is very tough. The FL 8x42 weighs only 27 oz., whereas, the HT 8x42 weighs almost 31 oz. The HT's didn't sell too well outside of the bigger aperture models, so Zeiss dropped the 8x42's, but they were actually a very good binocular. A lot of people want the bigger FOV, flatter field binoculars like the SF and NL now. I have lost my need for extremely sharp edges myself because I have become hooked on the sharp on-axis view of the FL's, with no glare and almost no CA. I think you can find a used FL for cheaper than a used HT generally because the HT's hold their prices, maybe because there is a big market for them with hunters, because they have a good reputation for low light performance. There is a like new FL 8x32 in the classifieds now for £775 plus £12.15 Royal Mail Next Day Special Delivery with full insurance and tracking if you live in the UK like you do.

https://www.cloudynights.com/topic/406978-adventures-with-the-zeiss-victory-ht-and-fl/

Tests of the Zeiss 8x54 HT

I’ve finally finished assembling star-test and other images from the Zeiss 8x54 HT I spent some time with. There are too many images for one post, so I’ve decided to make 5 separate posts. Anybody with comments please wait until all 5 are up. Thanks. The first two images are star-test...

www.birdforum.net

Endurance test of 8x42 binoculars - Final results and summary - AllBinos.com

The best binocular tests on the net. The comprehensive database of binoculars with their parameters and users opinions. Interesting articles and comparisons.

www.allbinos.com

 

[henry link]

They are very similar, but HT's just look a fraction better, slightly cleaner, sharper, more contrast.... it's hard to nail it down, but we both agree it is a tad 'up'.
I have never noticed CA in the HT's, or FL's, but the HT's are slightly sharper towards the edge. FL's are fine in this regard too, for my liking anyway, not being a 'sharp to the edge' fanatic.
I would be happy with either, but I won't be searching out some mint FL's over my HT's.
We also have to take into account that Zeiss is unlikely to put out a new model that either doesn't stack up against the old one, or isn't an improvement.
A report I read, said Zeiss had indeed nailed it with the HT's after some concern over dropping the FL line, so people all see it different.

I compared an 8x42 HT to my wife's early pair of 8x42 FLs here:

Encounters with Zeiss 8x42 HT and SF

I recently spent a week birding on the Outer Banks of North Carolina. While there I ran into a birder who uses nothing but Zeiss optics for birding. She has a very nice collection of Zeiss binoculars going back to the Dialyts, including an 8x42 HT and an 8x42 SF. I was able to spend a little...

www.birdforum.net

I found them to be so close in optical design and aberration levels that they could easily have been two samples of the same binocular. Except for the small real improvements in color accuracy and light transmission I expect most reports of significant differences between the 8x42 FLs and HTs are due to sample variations rather than design differences.

I wouldn't say the same thing about the 8x54 HT and the 8x56 FL. I found that particular HT model to have had some unfortunate design simplifications applied to the focusing element and the ocular compared to 8x56 FL. Those changes appear to have made it a unique flop among the HTs.

 

[[email protected]]

I compared an 8x42 HT to my wife's early pair of 8x42 FLs here:

Encounters with Zeiss 8x42 HT and SF

I recently spent a week birding on the Outer Banks of North Carolina. While there I ran into a birder who uses nothing but Zeiss optics for birding. She has a very nice collection of Zeiss binoculars going back to the Dialyts, including an 8x42 HT and an 8x42 SF. I was able to spend a little...

www.birdforum.net

I found them to be so close in optical design and aberration levels that they could easily have been two samples of the same binocular. Except for the small real improvements in color accuracy and light transmission I expect most reports of significant differences between the 8x42 FLs and HTs are due to sample variations rather than design differences.

I wouldn't say the same thing about the 8x54 HT and the 8x56 FL. I found that particular HT model to have had some unfortunate design simplifications applied to the focusing element and the ocular compared to 8x56 FL. Those changes appear to have made it a unique flop among the HTs.

Henry, how are your house repairs coming along after getting hit by the tree? Nice write up and analysis of the HT 8x42. Did you compare CA at all between the HT 8x42 and FL 8x42? I saw a slight bit more CA in the HT 8x54 than I do my FL 8x42's, so I was just wondering if the HT 8x42 was similar. Also, I found it surprising that the distortion was about the same between the HT and FL. I figured the FL would be a little higher. Also, interesting was the fact that the HT 8x54 was a flop compared to the HT 8x42.

 

[Rg548]

Really? When Zeiss started producing the Dialyts (e.g. the 8x30 and 10x40), long before phase-coating was introduced, these models were optically vastly inferior to the porros they still made at the time. Leica did the same.

Hermann

Really? Porros are easy to make... roofs more complex... they started pushing new optical ideas.
But I think it's fair to say as binos progress, manufacturers tend to make them better.....
Or we wouldnt be enjoying SF's for example, or NL's .... unless you think these are a step back.
You tend to find the same with cameras, computers, phones etc.... it's progression.

 

[Rg548]

I compared an 8x42 HT to my wife's early pair of 8x42 FLs here:

Encounters with Zeiss 8x42 HT and SF

I recently spent a week birding on the Outer Banks of North Carolina. While there I ran into a birder who uses nothing but Zeiss optics for birding. She has a very nice collection of Zeiss binoculars going back to the Dialyts, including an 8x42 HT and an 8x42 SF. I was able to spend a little...

www.birdforum.net

I found them to be so close in optical design and aberration levels that they could easily have been two samples of the same binocular. Except for the small real improvements in color accuracy and light transmission I expect most reports of significant differences between the 8x42 FLs and HTs are due to sample variations rather than design differences.

I wouldn't say the same thing about the 8x54 HT and the 8x56 FL. I found that particular HT model to have had some unfortunate design simplifications applied to the focusing element and the ocular compared to 8x56 FL. Those changes appear to have made it a unique flop among the HTs.

And this is where we differ as bino users I guess.
I would not wish to challenge your opinions on optics, I am aware of your extensive knowledge.
But in all my years of using binos, about 40, there have been 3 instant buys....
1... Nikon 10x42 se (amazed at the time)
2... Meopta (Couldnt believe how good they were for the price, AND they were on crazy offer)
3... Zeiss 8x42HT... instant wow factor, comfort, brightness.... Had to have them.

For me the HTs are the best all round bino I have had the pleasure of using/buying.

 

[Hermann]

Really? Porros are easy to make... roofs more complex... they started pushing new optical ideas.
But I think it's fair to say as binos progress, manufacturers tend to make them better.....
Or we wouldnt be enjoying SF's for example, or NL's .... unless you think these are a step back.
You tend to find the same with cameras, computers, phones etc.... it's progression.

You're comparing apples to oranges. At the time there was no phase-coating. The first roofs, including those made bei Zeiss and Leica, were far inferior to well-made porros. Compare e.g. the old Dialyt 8x30 to the 8x30 or 8x30B porros. The difference is very obvious (resolution, contrast, colour reproduction). Same with Leica: The Trinovid 8x32 was clearly inferior to the 8x30 Binuxit.

Hermann

 

[Rg548]

You're comparing apples to oranges. At the time there was no phase-coating. The first roofs, including those made bei Zeiss and Leica, were far inferior to well-made porros. Compare e.g. the old Dialyt 8x30 to the 8x30 or 8x30B porros. The difference is very obvious (resolution, contrast, colour reproduction). Same with Leica: The Trinovid 8x32 was clearly inferior to the 8x30 Binuxit.

Hermann

No i'm not.
I'm saying generally optics progress.

 

[forent]

(...) At the time there was no phase-coating. The first roofs, including those made bei Zeiss and Leica, were far inferior to well-made porros. (...)

(...) I'm saying generally optics progress.

I think you're both right.

Rg548's statement about general progress is correct - competition leads to better results, not only with optical devices, a truism of capitalism.

Hermann is absolutely right about the optical inferiority of early roof binoculars (without phase correction coating) compared to contemporary Porro models. I myself was unaware of this for a long time, so around 1990 I bought a second-hand Zeiss Dialyt 10x40 B from the early 1970s (this model: https://6cafee39cda19072a21f8fceb2f...upload2/151072_nbigmini_zei_dia1.jpg?SURFLY=R). The Dialyt was in mint condition, but when I opened the package, looked through it and compared it to a Zeiss Jena 8x30 MC, I was stunned: the 8x30 was so much sharper and more contrasty!

But roof prism binoculars weren't just a step backwards at first. The slim design, internal focussing and waterproofing were advantages over Porros that outweighed the optical disadvantages for many users. It should not be forgotten that optical devices generally had considerable weaknesses at the time. I wrote about this some time ago:

(...) These trinovids and dialyts without phase correction were sold at a time when technical image reproduction was far, far behind today's possibilities: spectacle lenses were uncoated, television sets were small grainy hemispheres, camera lenses were good, but the films were coarse-grained and insensitive to light and the slides in the projector were so bent that you could only see half of them in focus. You simply didn't expect ultra-sharp, super high-contrast images from optical devices!

From my own experience: My father had a beautiful Leitz Trinovid 10x40 that he bought in Wetzlar around 1980. It was his pride and joy. We thought the image quality was fantastic back then. When I compared these binoculars 15 years later with my brand new Leica Trinovid 8x42 BA, I was shocked at the difference (...)

 

[John A Roberts]

In terms of Zeiss optics at the time:
Compare those of the Dialyt, to the those of the first post-WWII version of the 8x30 Porro from a decade earlier
(the two images should be very close to scale):



Both were external focus (the objective lens pair moved in the Dialyt). But the Porro was optically more sophisticated.
It had a more complex eyepiece, giving it a FOV of 150 m at 1000 m (150 yds at 1000 yds) vs the Dialyt's FOV of 130 m/ 130 yds.
And the Porro also had a tele-objective giving it a shorter physical length for a given focal length.

The clear advantage of using the Schmidt-Pechan roof prism in the Dialyt was the more compact form factor.

- - - -
In terms of the prisms:
Both Leitz in 1963 with the Uppendahl prism Trinovid, and Zeiss in 1964 with the S-P prism Dialyt, were offering something new
- in terms of binocular styling and handling - but at a considerable cost in optical performance.

Since it wasn't until the introduction of both phase coating and dielectric mirror coating some decades later (both developed by Zeiss),
that the optical performance of the now widely used S-P prism could approach that of the Porro prism.


John


The Dialyt image if of the third version (shorter than the original). For more on the three versions of the Dialyt 8x30 see:
Optical design of 1980s Dialyt 8x30

And for more on the three versions of the Porro 8x30, see: Zeiss 8X30s

 

[jan van daalen]

From left to right 1991, 1976, 1967.

 

[GrampaTom]

competition leads to better results - yes, usually. a truism of capitalism - not so much.

 

[Scott98]

Optics progress, but don't mess with the traditional porro design! My choice of all currently available binoculars in the world for my small, lightweight bino are the 80's and 90's Nikon 7x35E. I've got some of the best Zeiss and Swaro roofs here and the performance of the 7x35's is right there in many ways....sharpness and contrast, and brightness in the one with 90's coatings. E is more comfortable than all but the 42mm SF's in terms of ergonomics.

I just had a chance to buy some 8x30 SFL's to replace them. No thanks, I prefer the 7x35EC in every way, optically and mechanically. 8x30 SFL's were on sale for tax-free for $1250. The 7x is the biggest reason I prefer the porros but there are more.

 

[Maljunulo]

I don't have Nikon porros,, but I do have a Swarovski 8X30 porro that I prefer to use over my 8X32 SF.

Any Specsheet Warrior worth his daily rum ration, will tell you (ad nauseum) that the SF is a much "better" glass.

I still prefer the little porro. The percentage of the time it shows me the "no glass" or the "open window" illusion, compared to roofs, is astonishing.

 

[GrampaTom]

I don't have Nikon porros,, but I do have a Swarovski 8X30 porro that I prefer to use over my 8X32 SF.

Any Specsheet Warrior worth anything, will tell you (ad nauseum) that the SF is a much "better" glass.

I still prefer the little porro. The percentage of the time it shows me the "no glass" or the "open window" illusion, compared to roofs, is astonishing.

I would very much like to try one of the Habichts. Never having seen one in the flesh, I confess the published eye relief specs 8X/12 and 10X/13 are a worry. Do you wear glasses Richard?

 

[Maljunulo]

I would very much like to try one of the Habichts. Never having seen one in the flesh, I confess the published eye relief specs 8X/12 and 10X/13 are a worry. Do you wear glasses Richard?

Only for reading.

 

[Patudo]

But roof prism binoculars weren't just a step backwards at first. The slim design, internal focussing and waterproofing were advantages over Porros that outweighed the optical disadvantages for many users.

That's basically it. The Dialyt/Trinovid might not have been as good optically as the porros of that era, but as a total birding package (handling, weather resistance, weight/size) a lot of people certainly thought they were better. And spectacular optical quality isn't really necessary for a lot of birding.

 

[Maljunulo]

And spectacular optical quality isn't really necessary for a lot of birding.

That is quite true, but you have to admit that it does add something to the experience.

 

[[email protected]]

That's basically it. The Dialyt/Trinovid might not have been as good optically as the porros of that era, but as a total birding package (handling, weather resistance, weight/size) a lot of people certainly thought they were better. And spectacular optical quality isn't really necessary for a lot of birding.

Optical quality IMO is very important for birding, probably more so than say than hunting because when hunting you are concerned about detail recognition and counting the points on a buck's rack but when birding you are concerned about small differences in the shading and coloration of the birds so you can ID them. That is a big reason I stopped using IS binoculars because their optical quality is not on par with say an alpha roof. The optical quality and the view of the bird is a HUGE part of the enjoyment of birding.

One time I was just looking at a simple common Robin, and I was amazed how beautiful the colors and different shadings of plumage were through my alpha roofs, and then I thought I would try my Canon 12x36 IS III to see more detail because of the IS and higher magnification. With the Canon I could see more DETAIL, but I lost the contrast and pop of the alpha, and I realized that watching the bird was not as enjoyable as through the alpha. I sold the Canon 12x36 IS III the next day because it lacked the contrast and pop of the alpha roof, and it was dull and flat in comparison.

 

[GrampaTom]

That's basically it. The Dialyt/Trinovid might not have been as good optically as the porros of that era, but as a total birding package (handling, weather resistance, weight/size) a lot of people certainly thought they were better. And spectacular optical quality isn't really necessary for a lot of birding.

I like your first couple sentences. That largely speaks to why I bought both the The Zeiss 1040 BGA T* and Leica Trinovid 1040BA both in mid '80s and are still around. You might guess I'd quibble with your last. If I was focusing on Peregrines zooming around skyscraper tops in urban settings a couple, few, football field lengths away, OK. But since identifying is only a part, and its the viewing of details Denco mentions, in my mind, that is the place where most birders I encounter go. I wouldn't be doing this if I was limited to tiny blacked out silhouettes, identified by flight patterns or wing/body profiles. I need to see the colors, patterns, behaviors. I can only see the gorgeous markings on a Gadwall if well within a hundred yards or so and with a really good bino. I can only see the the Least Bittern grab the fish while clutching the cattail stalk with best optics and even then at relatively short distances. Good enough aint. I get to each his own.