I am a sweet spot junkie and love a wide edge to edge sweet flat image..
I have some Meopta Meostar 8x42's that I have compared with Swarovski SCL neu and EL (not SV), Zeiss FL, and some others...
While the Meopta has a slight warm color bias, in low light testing I cant appreciate any additional brightness from the Binos above.
I have seen the sweet spot and edge resolution to be the equal of the swarovski and much more preferable to me than the FL.
WHat other Binos have these field flattener lenses? I wish the FL would add them. The FL and EL were much more neutral in color than the Meoptas.
I think Nikon uses these but in a different location than Meopta.
By the way, im struggling with wanting an SLC HD 8x42 but when I look through my Meoptas Im having trouble justifying it!!!!!!
IS anyone else addicted binos that use these lenses?
The Nikon SE porros have a field flattener in the EP.
The Nikon EDG roofs (which you allude to but don't mention the model)
Some of the Fujinon bins (FMTX 6x30 and 8x30, I think) also have a field flattener.
The Canon IS bins. The IS system needs a flat field otherwise the image would distort as the IS system moved to compensate for movement. The side effect is both flat field and IS in the 10x30 for $350ish.
The original Zen Ray ZRS (not the current 2010 design) also had an LaK field flattener in the design. It would be the "obvious" feature to add to the current batch of positive focuser Chinese ED bins. Though as ZR found that LaK element did add a reddish color bias that some found objectionable (and others didn't have a problem with) so life is more complicated than just adding another element.
The Zeiss FL bins actually have a flat field already but they trade off the flat field for other aberrations (astigmatism?) at the edge of field (hence the blurriness). Remember that a flat-field doesn't imply "sharp to the edge" though marketers like to make that connection. A field flattener does reduce the constraints on the eyepiece design (as it no longer has to flatten the field) though with modern EPs with multiple elements unless they really do put an element in to flatten the field they're more likely to add an extra element then optimize on flat field and astigmatism and coma at the field edge.
I suspect the next Zeiss top-of-the-range bin will also follow this trend and be "sharp to the edge". I suspect they'll have a price to match the other three. Same with Leica.
Thanks Kevin