Why are Zeiss so sharp on-axis compared to other binoculars? (3 Viewers)

[ArchStanton]

The EL is generally not as good at CA control as the SF or FL. It depends on what Kowa Genesis you are talking about when you are considering CA control.

The Genesis 8x33 isn't as good as the SF or FL, but the Genesis 8.5x44 is probably a little better. The Kowa Genesis 8.5x44 is right up there with the SF and FL as being one of the best binoculars for CA control.

The trouble with Kowa's is they have a lot of fall off at the edges, and it is very abrupt so you see a noticeable fuzzy ring around the FOV which is annoying.

I have verified all these CA results with Allbinos also because I have had all these binoculars at one time or another.

Kowa Genesis 8x33 - binoculars review - 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

Kowa Genesis 8.5x44 - binoculars review - 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

Swarovski EL 8.5x42 Swarovision - binoculars review - 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

Carl Zeiss Victory SF 8x42 - binoculars review - 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

At a local birding event this weekend, I looked through the following binoculars: Kowa Genesis 8x33, Genesis 8x22, Kowa BD II 6.5x32, 8x32, 8x32, BD25 8x25, Vortex Razor UHD 8x32, Razor HD 8x42, Viper 8x42, Zeiss Conquest HD 8x32, 8x42, and 10x42. IMHO the Kowa Genesis 8x33 provided the best view. I did like the lower priced Kowa BD II’s as well, but there was a very noticeable difference in clarity and edge to edge sharpness between these and the Genesis. If the extended eye cups had been installed on the Conquests, I might have preferred them. The Fuji HC’s didn’t appeal to me due to their ergonomics and weight, so I didn’t even bother taking them out for a look. I passed on the more expensive offerings because my price range maxes out at 1K.

 

[Binastro]

Some elements used in binoculars are molded and I think not ground.

The molded elements can be spherical or aspherical.

They can be all glass or glass plus a plastic aspherical element attached to the glass.

In addition, polishing can be traditional or high speed.
High speed polishing is usually just not as good as traditional polishing.
In addition, in traditional polishing the elements in the centre of say a twenty element array are usually better than those at the edge.

I think that some of the awful quality Chinese binocular optics, such as one half of my VisionKing 5x25 are just byproducts of low cost meaning everything and zero quality control.

How far up the scale of precision made binoculars these cost cutting procedures go I don't know.

As to glowing reviews of binoculars, one thing that bothers me is that just one example is tested, maybe supplied by the maker, instead of three bought privately from different batches.

There is a good current review of the Celestron 15x70ED binocular weighing 2 kgs.
This is different to the much disliked low cost, low weight 15x70 or the better heavier non ED 15x70.
But again the 15x70ED was supplied by the maker.
Even this is only actually about 66mm or 67mm aperture, where the low cost 15x70 is about 62mm.

Regards,
B.

 

[tenex]

Remember that Zeiss owns Schott so who do you think gets the best glass?

Perhaps one can understand such enthusiastic repetition, having somehow just learned this a few minutes ago. More accurately, Carl-Zeiss-Stiftung owns both Zeiss AG and Schott AG, but there is no evidence that Zeiss has access to better glass from Schott than anyone else, or that Swarovski doesn't also use Schott glass, although there seem to be some dubious rumors to that effect online. They may order glass of somewhat different specification, in accordance with their optical design -- and designs vary enough that not all Zeiss-Swaro comparisons may turn out as Henry's did, as he tried to say above. But you go for the simplistic conclusion every time. (Which is actually not at all like Einstein.) And of course, the one that pumps up your enthusiasm of the moment. Classic confirmation bias.

Yet even such a thread as this can lead somewhere interesting...

Here the troubles started: Whatever the fellow in his lab tried, it delivered inconsistent results. He used all kinds of lenses of different focal lengths and qualities and got results which just made no sense.

Almost everything about the aberrations that affect "sharpness" can be seen and explained with a boosted magnification star test and the true resolution itself can be accurately measured at boosted magnification for the full aperture and at smaller apertures to simulate the daylight observations.

Both observers here faced the same task: using other optics (camera/lens vs eye/tripler) to evaluate binocular resolution on a test pattern, yet one seems to succeed while the other fails. If Henry tried different doubler/triplers, would he start seeing inconsistencies too? (I suspect not, and perhaps he already has.) Or are camera lenses or sensors the problem, and why? Or is it the greater complexity of trying to measure a full MTF curve?

P.S. Sorry and surprised to hear about your house, Henry. I didn't think Debby had high winds; was it sheer quantity of rain? Best of luck with repairs.

 

[Hermann]

Threads like this are so discouraging to me. The OP has been here for 20 years and yet he is asking the same old newb questions and offering completely unsubstantiated newb answers snatched from thin air.

Nearly everything you need to know about how binoculars actually behave has been covered here multiple times by people who know what they're talking about (there's a search function for that.)

In German such people are sometimes called "merkbefreit und lernresistent".

That's all from me for now. Tropical Storm Debby brought a large oak tree down on our house and mostly destroyed it, so I'll be dealing with that for quite a while. Happily, no binoculars lost their lives.

That doesn't sound good. All the best to you!

Hermann

 

[Paultricounty]

The EL is generally not as good at CA control as the SF or FL. It depends on what Kowa Genesis you are talking about when you are considering CA control.

The Genesis 8x33 isn't as good as the SF or FL, but the Genesis 8.5x44 is probably a little better. The Kowa Genesis 8.5x44 is right up there with the SF and FL as being one of the best binoculars for CA control.

The trouble with Kowa's is they have a lot of fall off at the edges, and it is very abrupt so you see a noticeable fuzzy ring around the FOV which is annoying.

I have verified all these CA results with Allbinos also because I have had all these binoculars at one time or another.

Kowa Genesis 8x33 - binoculars review - 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

Kowa Genesis 8.5x44 - binoculars review - 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

Swarovski EL 8.5x42 Swarovision - binoculars review - 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

Carl Zeiss Victory SF 8x42 - binoculars review - 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

I really can’t go by allbinos or other reviews, I have to go by my side by side comparisons with a few other observers under different conditions, over a couple of outings to come to my conclusions. I had compared all the Kowa’s in 33 and 44 with the EL’s, SF’s, MHG’s and a few NL’s in corresponding sizes and magnifications. The general consensus was the Kowa Genesis had the least amount of CA in the groupings. If someone is very sensitive to CA and doesn’t need to have the top-of-the-line alpha, the Genesis is the way to go, imo. I’d suggest to anybody, don’t go by allbinos to tell you how much CA you will experience.

 

[John A Roberts]

Where do the premium binocular manufacturers source their glass?

Well with Swarovski, they've said: 'We purchase glass blanks from Germany and Asia . . . '


The above is from page 71 of the Sustainability Report published in 2016. The 136 page report contains much still useful information
and can be downloaded by using the link in the most recent post at: Swarovski Optik’s 2016 Sustainability Report
(For those who may be interested, I’ve previously quoted additional info about component sourcing in post #195 at: EL 10x42 casing deterioration. )


It's likely that all three premium manufacturers use glass from a variety of sources, taking into account various factors,
such as - specific optical requirements - along with the cost, availability and reliability from/ of various suppliers.


John

 

[henry link]

It looks pretty conclusive to me! Different specimens aren't going to be that different unless Swarovski and Zeiss have totally lousy QC, and I doubt that very much since they check every one thoroughly for build quality and optics before leaving the factory, especially the alpha level binoculars.

A Lemon NL or SF just isn't going to happen. It is very, very unlikely. Not with the QC these two titans have in place. C'mon, let's get real here!

I have never bought a high-end alpha level binocular like an NL or SF and had consistency problems between any two samples, that would amount to a hill of beans. Now, MIC junk that costs less than $500 is another story.

You're dreaming if you think you could repeat the test and get totally different results. Swarovski and Zeiss have excellent QC, and it simply would never happen. Swarovski and Zeiss would laugh at you if you told them that!

Learn how to star-test binoculars at high magnification (including Zeiss Swarovski) and also measure resolution on a line pair chart at high magnification. Then prepare yourself for some unpleasant surprises.

 

[henry link]

Both observers here faced the same task: using other optics (camera/lens vs eye/tripler) to evaluate binocular resolution on a test pattern, yet one seems to succeed while the other fails. If Henry tried different doubler/triplers, would he start seeing inconsistencies too? (I suspect not, and perhaps he already has.) Or are camera lenses or sensors the problem, and why? Or is it the greater complexity of trying to measure a full MTF curve?

The examination scope that's placed behind the eyepiece of the tested optic has an easy job. Firstly, its effective aperture is stopped down to the exit pupil diameter of the tested optic and, secondly, we only see the stopped down examination scope's aberrations magnified by its own relatively low magnification. If the series is reversed by placing the examination scope in front of the tested optic the total magnification of the series will remain the same, but then the examination scope's full aperture aberrations will dominate what is seen at the eyepiece.

I have used many different binoculars, monoculars and scopes as examination scopes and never visually observed any significant difference in the outcome of resolution measurements and also no difference in the appearance of star-tests. Photographs are a different story. I've never succeeding in getting star-test or resolution photographs to equal what I can see at the eyepiece.

P.S. Sorry and surprised to hear about your house, Henry. I didn't think Debby had high winds; was it sheer quantity of rain? Best of luck with repairs.

Thanks everybody for your commiserations with our situation. We were only expecting flooding rain from Debby here, but we did get a period of wind gusts between 50 and 60 mph. One of those, combined with totally saturated ground was probably all it took for this particular tree.

Henry

 

[Dennis Mau]

Learn how to star-test binoculars at high magnification (including Zeiss Swarovski) and also measure resolution on a line pair chart at high magnification. Then prepare yourself for some unpleasant surprises.

Do you really think star testing and measuring resolution on a line pair chart at high resolution is meaningful for binoculars that are going to be used at low magnification? Even if one binocular has higher resolution when tested this way, will our eyes be able to detect the difference?

It is scary that a tree of that size would be blown over by 50 to 60 mph winds. You would think it would have enough root structure to hold it, but I guess as if you say the ground was saturated, anything is possible. How tall was the tree and what type, if you don't mind me asking? I have some big trees in my yard that I might have removed.

 

[Dennis Mau]

Where do the premium binocular manufacturers source their glass?

Well with Swarovski, they've said: 'We purchase glass blanks from Germany and Asia . . . '
View attachment 1595865

The above is from page 71 of the Sustainability Report published in 2016. The 136 page report contains much still useful information
and can be downloaded by using the link in the most recent post at: Swarovski Optik’s 2016 Sustainability Report
(For those who may be interested, I’ve previously quoted additional info about component sourcing in post #195 at: EL 10x42 casing deterioration. )


It's likely that all three premium manufacturers use glass from a variety of sources, taking into account various factors,
such as - specific optical requirements - along with the cost, availability and reliability from/ of various suppliers.


John

Very nice, John. You find some of the most interesting facts! You must dig deep to find some of that good information. Not only that, but you always make great contributions when you post on a thread.

 

[Dennis Mau]

I really can’t go by allbinos or other reviews, I have to go by my side by side comparisons with a few other observers under different conditions, over a couple of outings to come to my conclusions. I had compared all the Kowa’s in 33 and 44 with the EL’s, SF’s, MHG’s and a few NL’s in corresponding sizes and magnifications. The general consensus was the Kowa Genesis had the least amount of CA in the groupings. If someone is very sensitive to CA and doesn’t need to have the top-of-the-line alpha, the Genesis is the way to go, imo. I’d suggest to anybody, don’t go by allbinos to tell you how much CA you will experience.

Kowa's do in general have good CA control. I like the Kowa Genesis 8.5x44, except for the smaller FOV and weight and size. It does have superb CA control.

The Kowa Genesis 8x33 is a nice binocular, but when I tried it I was into sharp edges because I just had a Swarovski EL 8x32 so the edges bothered me.

Maybe now that I have adjusted to somewhat softer edges with the Zeiss FL 7x42, I would like it more. I do like the build quality and ergonomics of the Genesis.

 

[henry link]

Do you really think star testing and measuring resolution on a line pair chart at high resolution is meaningful for binoculars that are going to be used at low magnification? Even if one binocular has higher resolution when tested this way, will our eyes be able to detect the difference?

It is scary that a tree of that size would be blown over by 50 to 60 mph winds. You would think it would have enough root structure to hold it, but I guess as if you say the ground was saturated, anything is possible. How tall was the tree and what type, if you don't mind me asking? I have some big trees in my yard that I might have removed.

It was a Red Oak (Quercus Rubra), a tree that has shallow roots (for an oak) and a tendency to lean, in this case toward our house. I counted 107 growth rings at the bottom of the trunk after it was sawn away from the root ball (which was quite flat).

As for the first paragraph. Look at the USAF 1951 photos in my link and be sure to look from the correct distance for your eyesight acuity. Superior "sharpness" is evident with the lower aberration binocular even for the largest elements on the chart, which are easily resolved by both binoculars. No more conversation from me until you've successfully done some homework.

 

[jan van daalen]

Very nice, John. You find some of the most interesting facts! You must dig deep to find some of that good information. Not only that, but you always make great contributions when you post on a thread.

Has it ever crossed your mind that it shows that your post was pure BS?

 

[tenex]

I don't know where the pump and dump theory came from.

I just have to say that Dennis is absolutely right about this: it's insulting and totally unjustified, and I say that as a critic of many of his posts which are another story. (I used the word "pump" myself above but only in relation to enthusiasm.) His cycle of interest may seem odd but his asking prices are quite fair, typically further reduced daily, and many forum members have benefited from that. Just once I recall him asking why he should mention what he didn't like about a bin when trying to sell it, but few people do anyway and it's all so subjective, so I consider that a perfectly honest and natural remark into which it would be wrong to read deception or dishonesty. I'm tired of hearing this myself and wish people would be more careful about it, and focus on content and facts which give ample opportunities for criticism.

 

[Dennis Mau]

Has it ever crossed your mind that it shows that your post was pure BS?

No, I meant it. John, is a great contributor to Bird Forum and I think we all appreciate his research. I certainly do. He answers a lot of questions for me.

 

[Dennis Mau]

It was a Red Oak (Quercus Rubra), a tree that has shallow roots (for an oak) and a tendency to lean, in this case toward our house. I counted 107 growth rings at the bottom of the trunk after it was sawn away from the root ball (which was quite flat).

As for the first paragraph. Look at the USAF 1951 photos in my link and be sure to look from the correct distance for your eyesight acuity. Superior "sharpness" is evident with the lower aberration binocular even for the largest elements on the chart, which are easily resolved by both binoculars. No more conversation from me until you've successfully done some homework.

One more question. If you had 5 Zeiss 8x32 binoculars and 5 Swarovski NL 8x32 binoculars lined up on a table without boosting them, are you saying that with your eyes alone you could rank them from best to worst optically?

My point is if you can't see the difference with normal eyesight in the real world, why worry about any differences. It is kind of like the old philosophical question, "If a tree falls in a forest and no one is around to hear it, does it make a sound?"

Thanks for the information on the tree. I am going to look at the big tree I have in my front yard and evaluate the risk. It could hit the house.

The light rings indicate the first of the growing season and the dark rings indicate the last part of the growing season. So how many dark rings were there? That would indicate how old the tree is. How big of diameter was the trunk? Thanks!

 

[agus_m]

It was a Red Oak (Quercus Rubra), a tree that has shallow roots (for an oak) and a tendency to lean, in this case toward our house. I counted 107 growth rings at the bottom of the trunk after it was sawn away from the root ball (which was quite flat).

As for the first paragraph. Look at the USAF 1951 photos in my link and be sure to look from the correct distance for your eyesight acuity. Superior "sharpness" is evident with the lower aberration binocular even for the largest elements on the chart, which are easily resolved by both binoculars. No more conversation from me until you've successfully done some homework.

Very interesting posts, and the thread that you mentioned too. Do you know why the Habicht has lower resolution than the stopped down FL? Is it just the difference in focal length that would enhance the aberrations of the Swaro, or these could have been corrected by a different set of lenses?

 

[Binastro]

Certainly, if I carefully examined six seemingly identical good binoculars, I could rate them one to six by eye alone.
It may be that two turn out identical.

Also each tube will be different.

My eyes would need to be rested.

It depends what one is looking at.

I would use a clock face or double stars.

There is also vernier acuity.

Then there are observers with double or treble my acuity.

I could repeatedly tell the difference in my optometrists extended tests of 75 to 90 minutes the difference in focus using his 1/8 dioptre lens. i.e. plus or minus 1/16 dioptre.
In his thirty years of testing I was only one of three patients who could do this.
Also I could repeatedly assess my small astigmatism to 2.5 degrees. I.e. plus or minus 1.25 degrees.
This is far beyond the normal increments used in most opticians tests.
He would write my prescription to these limits and say to the boss at the lab that he had a crazy astronomer who wants you to attempt these accuracies.

It comes down to observing skill.

The conclusions of the test of the 150 or so F14 Tomcat pilots with average vision of 20/8 was that the normal opticians tests were woefully inadequate when they got older and needed glasses.
Much higher standards are needed.

With binoculars using 4 to 6 times boosters clearly shows the optical quality.

However, in actual observations one does not always need the very best optics.
It depends what one is observing.

With telescopes I could quite easily test them using 50x, 75x and 100x per inch of aperture.
Some have gone up to 150x per inch of aperture.

Again, with many observations these high powers are not needed.
I would initially use 265x with my 12.5 inch Dall Kirkham on planets, then go to 400x and if the atmosphere was good enough and I was looking at Jupiter's moons. 600x.

William Herschel discovered Uranus using 250x, 450x and 900x with his 6.5 inch self made speculum telescope.

Uranus had been seen many times by others but only Herschel had the skill to say 'This is not a star'.

Are high resolution binoculars necessary?
Not always, but it is better if they are.

Regards,
B.

 

[Dennis Mau]

Here is my current Zeiss trio. The SF 10x32, FL 7x42 and FL 8x32. Only $4000 for all three, or only $1000 more than the price of one NL. It pays to buy used.

They all are very glare resistant, very bright, very sharp on-axis, they have practically no CA, no FP and the armor won't fall off.

Each one has its strong points. The SF 10x32's strong points are FOV and CA control. At 7.5 degree the FOV is huge and the biggest FOV in all the Zeiss lineup and Allbinos says it has the best CA control of any binocular they have ever tested.

The FL 7x42's strong points are brightness especially in low light, DOF, easy eye placement, and the ease of holding it steady.

It is the most unusual binocular of the three, and the superb DOF gives the view an almost porro-like 3D feeling. I have never used a binocular like it.

The FL 8x32's strong points are versatility and compactness, along with the light weight. It is hard to beat a 8x32 for all around use in the daytime, and the FL 8x32 is among the smallest and lightest 8x32 made. Even with the objective covers and rain guard installed, it barely weighs over 20 oz.

 

[Dennis Mau]

Certainly, if I carefully examined six seemingly identical good binoculars, I could rate them one to six by eye alone.
It may be that two turn out identical.

Also each tube will be different.

My eyes would need to be rested.

It depends what one is looking at.

I would use a clock face or double stars.

There is also vernier acuity.

Then there are observers with double or treble my acuity.

I could repeatedly tell the difference in my optometrists extended tests of 75 to 90 minutes the difference in focus using his 1/8 dioptre lens. i.e. plus or minus 1/16 dioptre.
In his thirty years of testing I was only one of three patients who could do this.
Also I could repeatedly assess my small astigmatism to 2.5 degrees. I.e. plus or minus 1.25 degrees.
This is far beyond the normal increments used in most opticians tests.
He would write my prescription to these limits and say to the boss at the lab that he had a crazy astronomer who wants you to attempt these accuracies.

It comes down to observing skill.

The conclusions of the test of the 150 or so F14 Tomcat pilots with average vision of 20/8 was that the normal opticians tests were woefully inadequate when they got older and needed glasses.
Much higher standards are needed.

With binoculars using 4 to 6 times boosters clearly shows the optical quality.

However, in actual observations one does not always need the very best optics.
It depends what one is observing.

With telescopes I could quite easily test them using 50x, 75x and 100x per inch of aperture.
Some have gone up to 150x per inch of aperture.

Again, with many observations these high powers are not needed.
I would initially use 265x with my 12.5 inch Dall Kirkham on planets, then go to 400x and if the atmosphere was good enough and I was looking at Jupiter's moons. 600x.

William Herschel discovered Uranus using 250x, 450x and 900x with his 6.5 inch self made speculum telescope.

Uranus had been seen many times by others but only Herschel had the skill to say 'This is not a star'.

Are high resolution binoculars necessary?
Not always, but it is better if they are.

Regards,
B.

Interesting observations, Binastro. What is a speculum telescope? I am an amateur astronomer, but I have never heard of it.