I have been told by a well known digital surfacing lab that when you take a lens like Shamir Autograph II and go over a -13.00 or so, you lose alot of clarity due to something having to do with the polishing of the center? Is anyone aware of this ?
Clarity issues in high minus free-from ????
I have been told by a well known digital surfacing lab that when you take a lens like Shamir Autograph II and go over a -13.00 or so, you lose alot of clarity due to something having to do with the polishing of the center? Is anyone aware of this ?
I was unaware anyone had even gone that high in free form. I was never able to get any for myself.
Now they are polished with a sort of balloon-type adaptive lap.
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
Are they? Three of the major free-form lens reps have told me they've done away with the fining/polish step entirely due to their lenses extreme amount of awesomeness. Or something like that.
Only refund I've had all year was a seiko 1.67 freeform -9.00, main complaint was blurry distance.
...she was refunded instead of fixed to buy back my sanity.
Yeah, they come out of the generator ready to polish, then they use a freeform conformable balloon to polish it.Originally Posted by Uilleann
http://www.dac-intl.com/equipment-sp...p-polisher.htm
DragonlensmanWV N.A.O.L.
"There is nothing patriotic about hating your government or pretending you can hate your government but love your country."
The clarity issues could be due to the surface quality before polishing or the inablity of most polishing equipment to polish very steep curves. Edge issues are likely due to unsupported lens surfaces during lens cutting and polishing. If the lens is not fully supported during lens surfacing and polishing the results will probably sub standard. It is issues like this that makes it possible to get a good lens of the same design from one lab but not another.
Shamir's FreeForm will go up to -16.00 or so in the higher indexes (1.67, 1.74).
We've never had a remake or complaint at our lab for issues with distance vision.
The lenses are cut to polish and use a "soft" lap polishing tool. While they are re-usable for several jobs, it's possible that you got a job that was polished on an over used one.
There are rules. Knowing those are easy. There are exceptions to the rules. Knowing those are easy. Knowing when to use them is slightly less easy. There are exceptions to the exceptions. Knowing those is a little more tricky, and know when to use those is even more so. Our industry is FULL of all of the above.
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