oval uncut

[pete]

its a wonder nobody has come up with an oval uncut? Is this possible?It would be particularly useful for high plus
Many thanks

[Rich]

Spheres, OK, but compounds... at what axis?

[PAkev]

Pete,

Not sure if your familiar with ZEISS PAL's; but they come in oval uncuts.

Need to be careful with deep B measurements; otherwise they work very well.

Kevin
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[Chris Ryser]

In some cases you will have to apply the lens stretcher........................

[shanbaum]

Our SL/2 generator (among others) will crib lenses to a more-or-less elliptical shape. This is de rigeur in Europe, but it's a particularly useless thing to do (in fact, it's counterproductive).

[Jerry Thornhill]

I like the oval uncut and find it extremely useful when processing minus lenses on 8 Bases for wrap frames. It sure helps eliminate the overhang and allows for a better flow when fining and polishing.

You do have to be careful not to go too narrow and lose the corner. Being able to adjust the amount of the oval helps. I would actually prefer a little more of a rectangle shape.

Jerry

[jofelk]

The Loh generator allows for oval uncut.
We do not use this option, prefer to give accounts the most blank for cut-out.

[rsandr]

shanbaum,

Our SL/2 generator (among others) will crib lenses to a more-or-less elliptical shape. This is de rigeur in Europe, but it's a particularly useless thing to do (in fact, it's counterproductive).

I crib all our plus power varifocal orders to an oval before processing (except where fittings heights wont permit).
In a standard round blank the thinnest parts are always top and bottom, then when you cut into it nasty surprise.
With an oval it can be more clearly seen whether its possible to remove more substance.
Same goes for +sph+cyl with the axis around the horizontal, it can make for a much better job.
Rick