Binos with or without field flatteners (1 Viewer)

Bass359 · Jun 25, 2017

Greeting Bird Forum,

I am looking for a list of present day alphas with or without field flatteners. By way of background, I casually bird in the PNW with my wife while walking the dog. We see raptors and woodpeckers around Seward Park in Seattle on our daily walks. You could say I am more of a walker with an optics habit rather than a serious birder. For binos I have Nikon 10x42 HG (originals with leaded glass and aluminum body- heavy), Lieca 8x32 BA (my wife's fav), Swaro 8.5x42 EL and a 80mm Swaro ATS scope.

Might be looking to upgrade my Lieca 8x32 BA to something more modern. I have researched allbinos and here. Really like the Zeiss 8x32 T* FL and the 8x25 Victory Pocket. However, I want my wife to look thru field flattened binos and non field flattened binos. Does any have a list they could share? Are the new Lieca Noctovision the only non field flattened alphas right now? Not sure and looking for guidance.

Binastro · Jun 25, 2017

Hi and welcome.

The Canon 10x42 L IS and some other Canon IS have field flatteners.
Also Swarovski 10x42 and 8x42 EL, I think.

Some field flattener binoculars do not completely flatten the field.

Bass359 · Jun 25, 2017

Binastro said:
Hi and welcome.

The Canon 10x42 L IS and some other Canon IS have field flatteners.
Also Swarovski 10x42 and 8x42 EL, I think.

Some field flattener binoculars do not completely flatten the field.

Good point. Any list would preferably be in order of severity of correction. For example my Swaro 8.5x 42 EL, I can notice rolling ball when looking for it and when panning in dense forest. It seems minor to me and does not bother me.

henry link · Jun 25, 2017

"Field Flattener", unfortunately doesn't have a consistent meaning. The way it's often used here conflates field curvature and distortion, two completely unrelated optical characteristics.

Field curvature refers only to blur at the field edge because of a change in focus between the field center and the edge. It can be corrected without affecting distortion at all.

Distortion causes the shape or size of objects to change between the center and edge or causes straight lines to bend toward the edge or both. It appears to me that complaints about a "flat field" are nearly always really complaints about the type of distortion a binocular displays. Rolling ball in the 8.5x42 SV results entirely from Swarovski's choice of "mustache" distortion". That's a form of compound distortion in which normal pincushion is gradually reduced in the outer part of the field, causing angular magnification distortion to build toward the edge. That causes objects to compress, giving them the illusion of beginning to round the side of a rolling ball when the binocular is panned. The right amount of pincushion distortion prevents angular magnification distortion, but pincushion causes lines to bend. Simultaneous correction of both pincushion and angular magnification distortion is not possible.

You are already using two binoculars with "field flatteners", although IMO the Nikon 10x42 HG corrects astigmatism better than field curvature. It uses a little pincushion distortion to partly correct AMD.

WJC · Jun 25, 2017

henry link said:
"Field Flattener", unfortunately doesn't have a consistent meaning. The way it's often used here conflates field curvature and distortion, two completely unrelated optical characteristics.

Field curvature refers only to blur at the field edge because of a change in focus between the field center and the edge. It can be corrected without affecting distortion at all.

Distortion causes the shape or size of objects to change between the center and edge or causes straight lines to bend toward the edge or both. It appears to me that complaints about a "flat field" are nearly always really complaints about the type of distortion a binocular displays. Rolling ball in the 8.5x42 SV results entirely from Swarovski's choice of "mustache" distortion". That's a form of compound distortion in which normal pincushion is gradually reduced in the outer part of the field, causing angular magnification distortion to build toward the edge. That causes objects to compress, giving them the illusion of beginning to round the side of a rolling ball when the binocular is panned. The right amount of pincushion distortion prevents angular magnification distortion, but pincushion causes lines to bend. Simultaneous correction of both pincushion and angular magnification distortion is not possible.

You are already using two binoculars with "field flatteners", although IMO the Nikon 10x42 HG corrects astigmatism better than field curvature. It uses a little pincushion distortion to partly correct AMD.

Ah, Henry, there ya go with all that logic stuff, again. I really hope those on the forum appreciate what you contribute to the forum.

BASS 359:

Find out when Skip is going to be in at Captain's Nautical in Ballard and try to get there on that day. He is their compass adjuster and is on call. He's not really an optics guy but he is honest and knows more than most of the "optics guys" in the area.

Inventory is not back to where it was before the crash and the new owner is buying a lot of Steiner, but you can get around that. :cat:

Cheers,

Bill

Bass359 · Jun 26, 2017

Finished with salespeople. I have non field flattened and flatten binos but they are older and heavy so would prefer my wife to look thru current models. Nobody has a list? Is the Noctovid the only current alpha with flattening?

Rathaus · Jun 26, 2017

Regarding your OP, in a nutshell, here is a small list of current roof Alpha from the top of my head -
My observations and opinions are purely in relation to my own viewing and personal taste - not sourced from data (or dubious nomenclature).

I have especially found the Zeiss SF and the Swarovski Swarovision series to present images which have been highly manipulated and crushed flat. Though they are incredibly engineered binoculars, I'm not a fan. All binoculars present a set of compromises, and these are the least rewarding to my eyes.

To me, The Zeiss Victory HT series, Leica Ultravid and Leica Noctivid present wonderfully natural and 'unflattened' images which, to my eyes, appear to be far less manipulated. A far more pleasant set of compromises to me personally.

I own binoculars from both camps, and prefer the 'unflattened' images by far. It's just what I like. Others will differ.

Rathaus

jring · Jun 26, 2017

Hi,

so we've got Swarovision Models and Zeiss SF and Canon 10x42 IS on the list, henry (beside explaining what field flattening really is - thanks a lot) has mentioned the Nikon HG/LX series, L or not.
I think we have to add Nikon EDG (and SE, but they're not really available new).

As for my taste, I like my SE a lot, so obviously I like good field flattening. But Nikon is the king of field flattening - their system works very well and without the dreaded "Absam-rings" in early flat Swaro glass.

And once again, distortion (usually pincussion) has nothing to do with field flattening - very large afov EPs introduce some distortion (but that's more a problem of the astro guys with their 82 deg afov naglers or 100 deg afov ethos EPs) and some is introduced on purpose by some binocular manufacturers to combat rolling ball effect.

And indeed, the presence of some distortion seems to help the brain with 3d perception. There is a nice movie on the web showing that for cine lenses - when I find it, I'll post the link.

https://www.youtube.com/watch?v=z5febma4_OE

Interestingly the flat Leica glass didn't fare well in this comparison - maybe Leica engineers learned their lesson?

Also this has been done by photographers all the time who want very fast lenses with very short depth of field and a nice bokeh to get their subject in front.

Joachim

Binastro · Jun 26, 2017

Cooke won an Oscar for their lenses fairly recently, and they are are well liked, as they have been for almost a century.
Many of the classic films like the Wizard of Oz were made using TTH or Cooke lenses.

chill6x6 · Jun 26, 2017

Bass359 said:
Finished with salespeople. I have non field flattened and flatten binos but they are older and heavy so would prefer my wife to look thru current models. Nobody has a list? Is the Noctovid the only current alpha with flattening?

Flat FOV
Swarovski EL Swarovision
Zeiss Victory SF
Nikon EDG

Non-Flat FOV
Zeiss Victory HT
Swarovski SLC
Leica Ultravid HD Plus and Noctivid

HTH

Binastro · Jun 26, 2017

To add to list.

Non-flat FOV
Zeiss 20x60S.

Nikon WX. Not sure.

henry link · Jun 26, 2017

The WX has a field flattener. The new Nikon Monarch HG, a bit more likely to be used by birders, also has one.

Keep in mind that not all field flatteners are equally effective and the distortion profile can't be predicted by the presence or absence of a field flattener.

Bass359 · Jun 26, 2017

chill6x6 said:
Flat FOV
Swarovski EL Swarovision
Zeiss Victory SF
Nikon EDG

Non-Flat FOV
Zeiss Victory HT
Swarovski SLC
Leica Ultravid HD Plus and Noctivid

HTH

Much appreciated. Hate to ask, but as to field flattened, is there an order of severity? Lightest touch to more pronounced? Already have the Swaro EL SV so no problem taking for a test. There is a Lieca store by us, so maybe that is the place to start. BTW, thanks again Chill6x6.

chill6x6 · Jun 27, 2017

Bass359 said:
Much appreciated. Hate to ask, but as to field flattened, is there an order of severity? Lightest touch to more pronounced? Already have the Swaro EL SV so no problem taking for a test. There is a Lieca store by us, so maybe that is the place to start. BTW, thanks again Chill6x6.

You're welcome!

Flattest FOV honor goes to the Swarovski EL Swarovision....about 100% of the FOV is flat. Zeiss SF, next....EDG next.

edwincjones · Jun 27, 2017

to most birders, does flat field really matter,
or matter enough to pay for it?

when I go with birding groups locally,
a few SWs, maybe a Zeiss
but most binos are generic

edj

jring · Jun 27, 2017

edwincjones said:
to most birders, does flat field really matter,
or matter enough to pay for it?

Hi,

I don't think a totally flat field is a must-have for birding bins - it's the usable field aka sweet spot that counts - you want a reasonably wide field which is in focus to find and follow birds. If there is some not quite sharp area around it - that's useful too - you will notice movement in there regardless and can quickly switch the target.

That's why I love my E2 - huge sweet spot and some field more around it...

In a spotter you can sometimes frame two or more birds in the field - then sharp to the edge has obvious advantages...

Joachim

Click to expand...

jgraider · Jun 27, 2017

edwincjones said:
to most birders, does flat field really matter,
or matter enough to pay for it?

when I go with birding groups locally,
a few SWs, maybe a Zeiss
but most binos are generic

edj

Seems like it usually comes around to another basic question, is an "alpha" worth it when you have a Toric, Maven, Conquest HD, Meopta HD at half the cost, or less?

Bass359 · Jun 27, 2017

Is the reason field flatteners are so prevaiiant because wider fields of view require flatteners or because the customers is demanding the almost edge to edge sweet spot? Or both? Just wondering why most optical designers are going that way. As to alpha or not, I am fine with expanding the list of binos with or without field flatteners. Really don't need another thread/post on if alphas are worth it. To some they are and to some they are not. It's great if somewhat overwhelming to have so many choices. When I bought my first nice bino 20 years ago choices were limited.

ceasar · Jun 27, 2017

Bass359 said:
Is the reason field flatteners are so prevaiiant because wider fields of view require flatteners or because the customers is demanding the almost edge to edge sweet spot? Or both? Just wondering why most optical designers are going that way. As to alpha or not, I am fine with expanding the list of binos with or without field flatteners. Really don't need another thread/post on if alphas are worth it. To some they are and to some they are not. It's great if somewhat overwhelming to have so many choices. When I bought my first nice bino 20 years ago choices were limited.

It has always been possible to make binoculars with a big "sweet spot," so Field Flatteners never really were "prevalent."

Nikon, the leader in this field, has had binoculars with Field Flatteners since about 1998 in their top ranked binoculars beginning with their now discontinued SE Porro Prisms: The 8x32 SE, 10x42 SE and 12x50 SE. It helped that they had partly modular construction so that they all used the same flat field eyepieces and prisms and prism housings.

Nikon also started using FF's about 2001/2002 in their (now discontinued) top of the line Roof Prism HG and HGL series and continued it in their current EDG Series since 2008.

Leica has never AFAIK had a flat field binocular and Swarovski and Zeiss haven't had them until recently and they are in their most expensive top of the line binoculars.

Meanwhile, Nikon put FF's into their 2nd line Monarch Series in 2016. Specifically into the Monarch 8x42 HG and 10x42HG which are both priced under $1000.00. No one else has done this, AFAIK, with their 2nd line binoculars so far.

Bob

PennineBirder · Jun 27, 2017

Although I enjoy reading about and discussing optics I am no expert so please excuse me if the following comment about field flateners is mistaken.

I have good, recent, binoculars with and without FF lenses (Zeiss Victory HT 8x42 and Swarovski EL 8x32) and both are excellent optically so the FF doesn't make a large difference to me personally. But it seems to me all good optics manufacturers are capable of producing FF designs as I have a Leica Televid scope (15 year old) and this is sharp right to the edge. I seem to recall that my vintage Bushnell Spacemaster scope was also sharp to the edge too although I no longer have this so can't check.

It seems to me that FF lenses are essential in a scope where you view the image from a fixed position with the scope usually mounted on a stand and therefore need the ability to assess the full image from edge to edge to avoid constantly adjusting the tripod. A pair of bins however does not 'need' to have FF. as the user normally hand holds the instrument and can easily place the target object (bird in our case) in the centre. Binocular users who use them for astronomy though will have a similar need to scope users I guess so for that use FF would be a great bonus.

If the above holds true we may wonder why binocular brands such as Leica and Zeiss have only recently started to produce FF designs when they could have done so years ago (as with their scopes) had they wanted to? Fashion trend perhaps?

Peter

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