Field flattener binoculars (1 Viewer)

[Binoseeker]

I started a list on vortex subforum but i think it should be a separate thread so i move it here......

I tried to make a list of bins with field flatteners but didn´t get very far...please add to or correct the list ?

Zen Ray Prime HD
Leupold BX-4 McKinley
Swarowski EL Swarovision
Hawke Frontier ED
Nikon EDG
Nikon SE
Fuji 6x30 FMTR-SX
Nikon Prostar
Canon 10 x 42 L IS WP, 18 x 50 IS All Weather
Pentax 20x60 PCF WP
WP Series 8 X 32 http://www.captainsnautical.com/1011...Binocular.html
8x42MM Passport ED http://www.burgessoptical.com/passport-series.html


Anders

 

[FrankD]

I was not aware that the Hawke Frontier ED had a field flattener element. It's base design is the same as the Zen Ray ED series and the Promaster Elite ED series and neither of those utilize a field flattener element. I have owned all three and they are more alike than not. Just curious.

You can also add the Meopta Meostar and Nikon Premier/Venturer HG/HGL series to your list.

 

[typo]

Frank,

I think I'm to blame for the suggestion that the Frontier ED has a field flattener. I'm quite sensitive to magnification distortion and I found they had a pronounced moustache distortion which I associate with a field flattening element. A discussion with Charles led me to believe that the ED2 and ED3 have one too, though I've never tried them myself. I don't see the same kind of distortion with the HGL or the Meostar though so I presume they have a different mechanism for reducing the field curvature.

David

 

[oetzi]

You can also add the Meopta Meostar

Are you sure?

Kowa Genesis had Field flattener lenses, too

 

[Binoseeker]

Oetzi, where did you find info about field flatteners in the Genesis?

On this site they don´t mention it, but it seems it has dielectric coating on the prism due to the high reflectance curve.
See
http://www.kowa-prominar.com/product/bino/genesis44/xd33.htm

Anders

 

[[email protected]]

All of the Fujinon FMT's, not just the 6x30 but also the 7x50, 8x30, 10x50, 10x70 and 16x70. The Pentax PIF series also has field flattener lens elements.

Steve

 

[Binoseeker]

Well, here is an updated list with some more suggestions...
Please add or remove bins on the list if not 100% sure they have field flatteners...

Zen Ray Prime HD
Leupold BX-4 McKinley
Swarowski EL Swarovision
Hawke Frontier ED
Hawke Panorama ED series (Flat field technology….i guess it could be field flatteners)
Nikon EDG
Nikon SE
Nikon Prostar
Nikon Premier/Venturer HG/HGL series
Fujinon FMT series
Canon 10 x 42 L IS WP, 18 x 50 IS All Weather
Pentax 20x60 PCF WP
WP Series 8 X 32 http://www.captainsnautical.com/1011...Binocular.html
8x42MM Passport ED http://www.burgessoptical.com/passport-series.html
Pentax PIF series
Pentax 20x60 PCF WP
Meopta Meostar series (info from studying drawings)
Kowa Genesis series

Anders

 

[Leif]

Frank,

I think I'm to blame for the suggestion that the Frontier ED has a field flattener. I'm quite sensitive to magnification distortion and I found they had a pronounced moustache distortion which I associate with a field flattening element. A discussion with Charles led me to believe that the ED2 and ED3 have one too, though I've never tried them myself. I don't see the same kind of distortion with the HGL or the Meostar though so I presume they have a different mechanism for reducing the field curvature.

David

I would be surprised if the Hawke Frontier ED 8x43 (Mark 2) has a field flattener, as it has substantial field curvature. I am not sensitive to rectilinear distortion, and only saw pincushion when I looked for it (I did not check carefully for any higher order distortion). I am sensitive to magnification distortion, I notice it immediately, even when not panning.

 

[kabsetz]

Leif is right, the Frontiers don't have field flatteners.

Canon 15x50 IS AW has it just like the 18x50.

Kimmo

 

[pompadour]

• Anders, your list is a fine idea.
• Nikon 10x70? 18x70?
• There's a fine review of the Hawke Frontier ED 8x43 in the Reviews section, by Leif, who points to it in a post up just now in the Hawke section. There its field curvature is stressed.

 

[Binastro]

Canon 12 x 36 IS Mk1 a fine binocular but heavy and 15 x45 IS also I think, maybe one field flattener rather than two.

Fujinon and Nikon image stabilisers ??

Swarovski 10 x 25? it has a lot of elements.

Any Opticron?

 

[oetzi]

Oetzi, where did you find info about field flatteners in the Genesis?

On this site they don´t mention it, but it seems it has dielectric coating on the prism due to the high reflectance curve.
See
http://www.kowa-prominar.com/product/bino/genesis44/xd33.htm

Anders

My fault, I thought the XD lenses served as field flattener

 

[Binoseeker]

Thanks for your replies, here is the updated list,

Zen Ray Prime HD
Leupold BX-4 McKinley
Swarowski EL Swarovision series
Hawke Panorama ED series (Flat field technology….i guess it could be field flatteners)
Nikon EDG
Nikon SE
Nikon Prostar
Nikon Premier/Venturer HG/HGL series
Fujinon FMT series
Canon 10 x 42 L IS WP, 15x50 IS AW, 18 x 50 IS AW, 12 x 36 IS Mk1, 15 x45 IS
Pentax 20x60 PCF WP
WP Series 8 X 32 http://www.captainsnautical.com/1011...Binocular.html
8x42MM Passport ED http://www.burgessoptical.com/passport-series.html
Pentax PIF series
Pentax 20x60 PCF WP
Meopta Meostar series (info from studying drawings)


Has anyone tested the WP Series 8 X 32 or the 8x42MM Passport ED that claims to have field flatteners?

Cheers,

Anders

 

[oetzi]

One would think that Meopta would make this public, using field flatteneres, that is.
From comparing Meostar B1 8x32 and Kowa Genesis 8x33 side-by-side, the latter has the less pronounced field curvature and a better sharpness towards the edge.

 

[Binoseeker]

Yes, there are probably more manufacturers with binos using field flattener "out there" that don´t announce it.
Like Kowa with their new prism coating name for the Genesis, i couldn´t find the word dielectric anywhere...
Opticron seems also to be a company that uses names for coatings etc...

Anders

 

[Robert Wallace]

I am fascinated by the importance of a "flat field". I was very aware of the concept last year when comparing the Nikon Edg 10x42 against the Zeiss FL. But that was comparing side by side. I understand that straight lines do not exist in nature and I am quite satisfied with all my birdwatching binoculars non of which have "field flatteners".

 

[Troubador]

I am fascinated by the importance of a "flat field". I was very aware of the concept last year when comparing the Nikon Edg 10x42 against the Zeiss FL. But that was comparing side by side. I understand that straight lines do not exist in nature and I am quite satisfied with all my birdwatching binoculars non of which have "field flatteners".

Me too Robert.

Even when birding in coniferous plantations with all those straight up and down trees I never noticed the pin-cushion in my Zeisses.

Lee

 

[Torview]

I am fascinated by the importance of a "flat field". I was very aware of the concept last year when comparing the Nikon Edg 10x42 against the Zeiss FL. But that was comparing side by side. I understand that straight lines do not exist in nature and I am quite satisfied with all my birdwatching binoculars non of which have "field flatteners".

Me too Robert.

Even when birding in coniferous plantations with all those straight up and down trees I never noticed the pin-cushion in my Zeisses.

Lee

I`ll third this, not anywhere near the top of my list.

John.

 

[hinnark]

I understand that straight lines do not exist in nature

The horizon is such a line and it needn't be that far away when standing at the shore of a lake or river. But I find pincushion distorsion more bothersome when viewing along a path or a road in front of me because it irritates the perception of perspective. I prefer the use of official paths and roads in order not to disturb the wildlife. I also found that, at the long run this way most birds could be found. The law of linear perspective means that things in the distance seem to get smaller than close ones. Here is a typical example, where the distance between both rails seem to get closer with increasing distance to the observer: http://en.wikipedia.org/wiki/File:Railroad-Tracks-Perspective.jpg
When you look at the same scenery with binoculars of pincushion distorsion, the distance between the rails don't get closer in the distance as they should. This view is not what the visual system use to anticipate. The same or similar happens from different angles of view along a path as well.

Steve

 

[Binastro]

It may be that Flat Field is being mistaken here for Distortion Free field.
They are quite different.

My understanding is that flat field eyepieces say in 15 x 50 Canon IS is that stars are point sources at the centre and edge without refocussing and without using any eye accommodation.

I think however that the Canons have pincushion distortion, I will check.

Distortion free as in Russian 7 x 30? and 10 x 42? with 7 or 8 element eyepieces means straight lines are straight eveywhere except the very edges, where the magnification can drastically change.

Distortion free does not mean Flat field and vice versa.
In fact I will have to think if there are ANY binoculars with both.

Nagler eyepieces are Flat Field but not Distortion Free.

Lack of pincushion or barrel distortion is not Flat Field.
Flat Field means the field is Flat.