I guess you don't mean the distance between manufacturer's printed circles, but rather something which represents the actual performance of the lens. I marked on the power cross-section (blue) the...
Type: Posts; User: Raanan Bavli; Keyword(s):
I guess you don't mean the distance between manufacturer's printed circles, but rather something which represents the actual performance of the lens. I marked on the power cross-section (blue) the...
I'm not a lens manufacturer. My comapny develops lens inspection (and mapping) systems. The process is simple: if you send me a lens, I'll map it, and email you the lens map, along with software for...
Bill,
I beleive that such plots are very useful, but not those presented by the manufacturers. examining plots (power and cyl maps) MEASURED by an INDEPENDENT body can be found here:...
Although it's hard to tel due to lack of numerical scale, it seems to me that MOST lenses have clearer corridor, compared to the two you show here.
So, where can we see therse?
that images of smiling models and a nice scening view, are more informative than power and astigmatism maps?
Creation has clearer far-vision zone on the nazal side
Tens of thousands of $. Beyond the reach of optometrists, and probably beyond their needs....
If so, my opinion is that the design software has probably been made by top professionals and has been thoroughly debugged. Moreover, this software is tested tens of thousands of time per day by...
As back progressive FF lenses have curvatures which do not enable measuring the way lensometers are supposed to work, an alternative method should be used.
A right way of doing this would be as...
Attached are the sphere and astigmatism maps and the corridor cross section. I marked the borders of the round segment on the maps. There's a smart choice of segment size and position - the border...
Actually, the formula is:
RMSerr(x,y) = SQRT( (Sph(x,y)-Sphref(y))^2 + Cyl(x,y)^2)
Sphref has no horizontal coordinate since it is defined as the power inside the corridor for each vertical...
John,
You are welcome to send me lenses. I think that the best choice for Rx, for comparison purposes, is plano. You may send other Rx values.
Two point worth mentioning; 1. A web site as...
I've always wondered, how these people expect us to be impressed by looking at the package or a transparent lens. Just look at the images in this page , and try to draw any conclusions related to the...
Well, I can't show too much here, but I made a comparison between Comfort and Panamic, and found something very interesting; While the power maps are almost identical, there are significant...
I drew both astigmatism and power cross-sections of both lenses. The horizontal cross-section passes through the center of the lens, and the vertical one goes from the center 20mm up.
Not the same!
in Accolade's far vision zone, the power does not change horizontally but continuoesly decreases when going up towards the top of the frame.
In Physio, the aberrations are different-...
Yes, this is all correct. I only ask that you agree that this map will also be used (if Harry decides to do so) in the Association of Technical Opticians (ATO) project described by Harry at the top...
I agree. Couldn't have said that better!
I'm not a lens manufacturer. My comapny develops lens inspection (and mapping) systems. The process is simple: if you send me a lens, I'll map it, and email you the lens map, along with software for...
There's a lot of relevance. It depends on what you are looking for. Harry's goal was to establish some address to professionals who wish to provide their patients with the best available lens. As you...
Indeed, ideally the line you talk about should be zero. After years of mapping thousands of lenses, I can say that this is never the case. In reality almost all lenses have at least one point along...
Wouldn't it be nice if they gave you power an cyl maps along with these lenses?
Why don't they provide power and cylinder maps?
Just because someone switched your lung x-ray with a PAL map....