Originally Posted by
Berno
Hi everyone!
I have a question about the difference between a manual Lensometer.. which has what I believe is called a corona-style target (a cross with a circle of dots in the middle) versus the cross-line target (which is a cross of 3 seperated lines and 2 thinner lines)
I've never worked with latter and was wondering if the measuring system is different..
With the first one (the cross and circle of dots in the middle) if for example [working with - cyl ]:
The higher plus clears one line at +1.75 @ 35
Then I keep going toward the minus and get the other line clear at +1.00 (@125) The Rx will be:
+1.75 -1.00 X 125
Someone told me that wth the cross-line target (assuming the same scenario above) the axis will be x35 and I should get the sphere lines (the thin ones) clear first..
I'd really appreciate it if you could clarify that for me.. I always thought there's only one principle of measuring and never knew it depends on the target etc.. should it be really different?
Thanks for any info...!
Ben:cheers:
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