Search:

Type: Posts; User: Raanan Bavli; Keyword(s):

Page 1 of 3 1 2 3

Search: Search took 0.05 seconds.

  1. Replies
    12
    Views
    25,430

    Before asking this, there's a need for a definition of "corridor length"

    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...
  2. Replies
    48
    Views
    24,910

    Still willing to map lenses sent to me

    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...
  3. Design plots

    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:...
  4. Replies
    20
    Views
    21,240

    Although it's hard to tel due to lack of...

    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.
  5. Replies
    40
    Views
    30,006

    Contour plots

    So, where can we see therse?
  6. Replies
    40
    Views
    30,006

    No real info there. Why is it that they think

    that images of smiling models and a nice scening view, are more informative than power and astigmatism maps?
  7. Replies
    5
    Views
    7,730

    See the differences

    Creation has clearer far-vision zone on the nazal side
  8. Replies
    10
    Views
    7,769

    Class Plus

    Tens of thousands of $. Beyond the reach of optometrists, and probably beyond their needs....
  9. Replies
    10
    Views
    7,769

    Are you asking why practitioners should trust the design?

    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...
  10. Replies
    10
    Views
    7,769

    The right way of doing this

    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...
  11. Replies
    12
    Views
    7,882

    How does it really look?

    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...
  12. Replies
    38
    Views
    20,202

    RMS function

    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...
  13. Thread: GT2 Short

    by Raanan Bavli
    Replies
    22
    Views
    12,123

    Lens Maps

    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...
  14. Replies
    9
    Views
    11,379

    I've always wondered, how these people expect us...

    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...
  15. Replies
    13
    Views
    18,835

    Comfort vs. Panamic

    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...
  16. Replies
    13
    Views
    18,835

    A graphic comparison

    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.
  17. Replies
    13
    Views
    18,835

    Differences between the two lenses

    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-...
  18. Replies
    48
    Views
    24,910

    Yes, this is all correct. I only ask that you...

    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...
  19. Replies
    4
    Views
    2,829

    As an Israeli

    I agree. Couldn't have said that better!
  20. Replies
    48
    Views
    24,910

    Lens mapping

    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...
  21. Replies
    48
    Views
    24,910

    Relevance

    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...
  22. Replies
    48
    Views
    24,910

    Corridor

    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...
  23. How does this lab do the QA?

    Wouldn't it be nice if they gave you power an cyl maps along with these lenses?
  24. Replies
    20
    Views
    18,821

    All that "information" without what's really matters

    Why don't they provide power and cylinder maps?
  25. Thread: GT2 Short

    by Raanan Bavli
    Replies
    22
    Views
    12,123

    A bad reason for giving up smoking

    Just because someone switched your lung x-ray with a PAL map....
Results 1 to 25 of 60
Page 1 of 3 1 2 3