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New Zeiss Victory SF !!!!!! (1 Viewer)

jan van daalen

Well-known member
Brock,

Isn't CA caused by the inability to focus all the wavelengths of the color spectrum to the same focal plane? I would think the correction has to take place in the objective lens for it to work.

Bob

Bob,

This is why I found it "odd" that Leica upgraded their Geovid to HD by simply replace the focusser lens for an Fluorite containing lens.
Makes no sence at all, other then for marketing reasons!!

Jan
 

Troubador

Moderator
Staff member
Supporter
CF,

Two fluorite lenses would also give more justification for the cost.

My own take is that Zeiss used the triple bridge because they had already designed the same focuser for the HT, so why reinvent the (focus) wheel? And they had to add the objective bridge or it wouldn't look like an EL. And barrels that long w/out a brace wouldn't be sturdy, which is probably why Swaro went with that design with the EL.

Brock

Brockadoodle

Here is something we can agree on: physically, SF looks like a development of HT to me too.

Optically, it appears to have come from another planet.

Lee
 

Troubador

Moderator
Staff member
Supporter
Brock,

Isn't CA caused by the inability to focus all the wavelengths of the color spectrum to the same focal plane? I would think the correction has to take place in the objective lens for it to work.

Bob

SF has two ED lenses, so it seems that one of them is in the eyepiece group.

This is probably crazy, but I wonder if focusing is done by simultaneous movement of two lenses, one each side of the prisms.

Lots of photographic lenses have lens groups that shuffle about during zooming and focusing.

Lee
 

ceasar

Well-known member
Bob,

This is why I found it "odd" that Leica upgraded their Geovid to HD by simply replace the focusser lens for an Fluorite containing lens.
Makes no sence at all, other then for marketing reasons!!

Jan

Jan,

Is that the one with the Perger Porro Prism or the older one? They both have HD designation.

I wonder if the Perger design would make a difference?

Bob
 

ceasar

Well-known member
SF has two ED lenses, so it seems that one of them is in the eyepiece group.

This is probably crazy, but I wonder if focusing is done by simultaneous movement of two lenses, one each side of the prisms.

Lots of photographic lenses have lens groups that shuffle about during zooming and focusing.

Lee

That seems awfully complicated with 2 collimated telescopes involved, wouldn't you think?

But Roofs are already very complicated compared to Porros.

Bob
 

ronh

Well-known member
I guess it's possible that the focusing lens is a cemented ED doublet. If the focusing lens carries enough of the net power, it could be necessary to preserve FL levels of color correction. Giving the focusing lens more power would thin out the group at the front of the binocular even more, shifting the balance rearward, and result in 2 ED elements.

In principle, lateral color will be present with any widely air spaced objective, but lots of it also originates in the eyepiece per se, and that part can be controlled to some extent by eyepiece design.

Considering the flow of the discussion, I think I needn't apologize for the speculation!

Ron
 
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Vespobuteo

Well-known member
Actually, I'd just really prefer lighter weight! Much seems to be made by the Blue suit marketing types of the 780g weight, and yet that's more than the FL's! (what was that about emperor's new clothes, and everything old being new again?!) ;)

Chosun :gh:

if you want to go true lightweight,
then go for the Swarovski SV 8x32,
cheaper, lighter (580g), more compact, wide FOV,
top-notch viewing comfort, 20 mm eye relief, works even for me who is very picky,
If I would buy a new pair of binos today
I would very likely choose them,

(currently using Zeiss 7x42 FL)
 

CloseFocus

Well-known member
Bob,

This is why I found it "odd" that Leica upgraded their Geovid to HD by simply replace the focusser lens for an Fluorite containing lens.
Makes no sence at all, other then for marketing reasons!!

Jan

Jan,

Televue is a high end astronomical scope company that has been using a "Nagler-Petzval" design to great success:

"This four-element air-spaced Nagler-Petzval system has a 127mm aperture ED doublet at the front of the scope, with a second field-flattening/aberration-correcting ED doublet at the rear."

Using a color correcting lens away from the objective has a long history, and it's probably cheaper than using more expensive or multiple lenses at the front. As long as all the colors of the spectrum come to a focus when they reach the eye, it doesn't matter how it's done.

Joe
 

brocknroller

A professed porromaniac
United States
Jan,

Televue is a high end astronomical scope company that has been using a "Nagler-Petzval" design to great success:

"This four-element air-spaced Nagler-Petzval system has a 127mm aperture ED doublet at the front of the scope, with a second field-flattening/aberration-correcting ED doublet at the rear."

Using a color correcting lens away from the objective has a long history, and it's probably cheaper than using more expensive or multiple lenses at the front. As long as all the colors of the spectrum come to a focus when they reach the eye, it doesn't matter how it's done.

Joe

Thanks, Joe. I wondered if the faster, shorter focal length systems of binoculars required having the ED element in the doublet, because that seems to be the standard arrangement in binoculars. However, if it could be done more cheaply in the EPs, it makes more sense to do that, but if so, why it isn't done?

Perhaps adding yet another optical element to a company's standard EP design requires that the other optical elements need to redesigned to accommodate the ED element, which could add costs rather than savings. Whereas with a doublet, they would only have to redesign one element to accommodate the ED glass. There's got to be some reason other than "if it ain't broke, don't fit it" that they always put the ED glass in the objective.

I also wonder if companies know that negative focusing elements increase CA, then why do they continue to use them instead of using positive focusing elements?

Brock
 

CloseFocus

Well-known member
Thanks, Joe. I wondered if the faster, shorter focal length systems of binoculars required having the ED element in the doublet, because that seems to be the standard arrangement in binoculars. However, if it could be done more cheaply in the EPs, it makes more sense to do that, but if so, why it isn't done?

Perhaps adding yet another optical element to a company's standard EP design requires that the other optical elements need to redesigned to accommodate the ED element, which could add costs rather than savings. Whereas with a doublet, they would only have to redesign one element to accommodate the ED glass. There's got to be some reason other than "if it ain't broke, don't fit it" that they always put the ED glass in the objective.

I also wonder if companies know that negative focusing elements increase CA, then why do they continue to use them instead of using positive focusing elements?

Brock

Brock,

There may be some brands that have color correcting lenses only behind the objective, but these are probably not what we would call premium binoculars. But there are probably many other types of high performance glass besides ED and fluorite that we know nothing about. For all the more difference they make, sometimes I think these much advertised new lenses are just an excuse of the manufacturers to jack up the price of their binoculars. But they wouldn't do that, would they?

Joe
 

Chosun Juan

Given to Fly
Australia - Aboriginal
I guess it's possible that the focusing lens is a cemented ED doublet. If the focusing lens carries enough of the net power, it could be necessary to preserve FL levels of color correction. Giving the focusing lens more power would thin out the group at the front of the binocular even more, shifting the balance rearward, and result in 2 ED elements.

In principle, lateral color will be present with any widely air spaced objective, but lots of it also originates in the eyepiece per se, and that part can be controlled to some extent by eyepiece design.

Considering the flow of the discussion, I think I needn't apologize for the speculation!

Ron

Ronh,

This is precisely the type of thing I had in mind when I posed the question. I had hoped that the optical design guru maven mob (henrylink, holger et al.) may have jumped in before now with some further options, but two superachromat groups (one objective, one focusing), would definitely make use of the uber-fluoride glass and succeed in shifting the weight back, whilst tackling CA.

It would also leave some room in the eyepiece for some HT glass, 'cause sure as dammit Swarovski has got something equivalent like that in their SV's when you look at the very high ("exceeding the value of 93%") blue spectrum transmission achieved as with the 10x42 SV as measured by allbino's: http://www.allbinos.com/223-binoculars_review-Swarovski_EL_10x42_Swarovision.html
:cat:



Chosun :gh:
 

henry link

Well-known member
I had hoped that the optical design guru maven mob (henrylink, holger et al.) may have jumped in before now with some further options...

This member of the mob wouldn't go beyond Ron's suggestion that the focusing lens could be a doublet, like the 56mm FLs. I like it when the suppositions stay a little grounded in what is known. In this case we know the focusing lens is positive and the fixed objective group has reportedly been reduced from 3 elements to 2. So, I think it's most probable that the SF has a version of the 3 element design used in the old Swarovskis with the addition of FL glass. It doesn't make sense to me to put any label on the the separate parts of the objective (super-achromat, etc.) because they're designed to work together, and I sure don't plan to join Brock and Joe down in the rabbit hole discussing irrelevant or fanciful objective designs or glass types "we know nothing about".

Henry
 
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CloseFocus

Well-known member
This member of the mob wouldn't go beyond Ron's suggestion that the focusing lens could be a doublet, like the 56mm FLs. I like it when the suppositions stay a little grounded in what is known. In this case we know the focusing lens is positive and the fixed objective group has reportedly been reduced from 3 elements to 2. It doesn't make sense to me to put any label on the objective groups (super-achromat, etc.) because they're designed to work together, and I sure don't plan to join Brock and Joe down the rabbit hole of discussing irrelevant or fanciful objective designs or glass types "we know nothing about".

Henry

Henry,

I wasn't making any suggestion about what kind of optical design a binocular has, only that there are many possible design options available. As to the glass types we know nothing about, I don't recall CA being too much of an issue before the HD lines started coming out, and frankly, I don't think they have made that much of a difference. So the unnamed glass that performed so well before has now been supplemented with expensive new lenses that greatly increase the price of the binocular, but don't really seem to improve the view more than a few percent, for those who can see a difference at all.

Joe
 

The Kingfisher

Well-known member
It is always interesting with new binoculars of high quality, but the focus wheel seems to be located more towards the center (just as in the HT) than eg Nikon EDG. I do not like it at all because it means that I can not grab the binoculars in the way I usually do. I wear glasses and tend to support the binoculars by keeping my index fingers against my forehead. Completely impossible to use this method with Zeiss HT..and probably also with the new Zeiss SF. Is there no one else who thinks that the focus wheel on these models seems misplaced?
 

james holdsworth

Consulting Biologist
It is always interesting with new binoculars of high quality, but the focus wheel seems to be located more towards the center (just as in the HT) than eg Nikon EDG. I do not like it at all because it means that I can not grab the binoculars in the way I usually do. I wear glasses and tend to support the binoculars by keeping my index fingers against my forehead. Completely impossible to use this method with Zeiss HT..and probably also with the new Zeiss SF. Is there no one else who thinks that the focus wheel on these models seems misplaced?

I thought so too, but it took all of a few minutes to adapt. Now they are the best balanced, best handling bino. I have and everything else feels awkward.
 

Troubador

Moderator
Staff member
Supporter
It is always interesting with new binoculars of high quality, but the focus wheel seems to be located more towards the center (just as in the HT) than eg Nikon EDG. I do not like it at all because it means that I can not grab the binoculars in the way I usually do. I wear glasses and tend to support the binoculars by keeping my index fingers against my forehead. Completely impossible to use this method with Zeiss HT..and probably also with the new Zeiss SF. Is there no one else who thinks that the focus wheel on these models seems misplaced?

I used to focus using my middle finger. Since getting my HTs I now grab the bins by the barrels and my 1st finger falls immediately on the focus wheel and away I go. It now feels totally natural and such an improvement from th FL.

Lee
 

Alexis Powell

Natural history enthusiast
United States
It is always interesting with new binoculars of high quality, but the focus wheel seems to be located more towards the center (just as in the HT) than eg Nikon EDG. I do not like it at all because it means that I can not grab the binoculars in the way I usually do. I wear glasses and tend to support the binoculars by keeping my index fingers against my forehead. Completely impossible to use this method with Zeiss HT..and probably also with the new Zeiss SF. Is there no one else who thinks that the focus wheel on these models seems misplaced?

I wear glasses and am very happy to see the focus wheel moved farther from my face. The original B&L Elite was excellent in that regard, with the focus wheel on the other side of the hinge. My glasses are robust, so I support my bins by pressing them into my glasses. The benefit of moving my hand farther from my face is that it allows for better air circulation around my glasses and less contribution of perspiration from my hands and wrists to the humidity of the air around my bins, thus reducing the tendency of my glasses to fog (which can be a problem in hot and humid situations). It's one of the reasons I prefer most full sized bins over most x32 models.

--AP
 

eddy the eagle

Well-known member
I am going to the UK birdfair for the first time and I hope I can get my hands on the New SF,pun intended,as I find the double bridge of the Swarovski SV awkward for hand placement but the HT with it´s long barrels perfect even for one handed viewing.The SF has a triple bridge so it will be interesting how the ergometrics work with my large hands.Time will tell......Eddy
 

brocknroller

A professed porromaniac
United States
Be careful Brock, there are those who may deem your topic irrelevant.

Joe

I'm irrelevant? You're irrelevant. This whole court is irrelevant! ;)

Henry's all right, he helped me recently when I asked for his advice in a PM about a problem I had with a bin. I just feel he could use a bit more patience and tact when explaining technical issues to others.

Brock
 

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