Hello folks!
I was looking into estimating lens thickness and I remember that besides the sag height formula, there was another way to estimate it where you can use a constant K-value and...
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Hello folks!
I was looking into estimating lens thickness and I remember that besides the sag height formula, there was another way to estimate it where you can use a constant K-value and...
Hey folks,
Since being furloughed for the foreseeable future I've decided to take a deep dive into optics. I am now stuck on monochromatic aberration (oblique astigmatism specifically) and was...
How detailed is the Advanced Cert test?
Hey folks,
I am taking the ABO-AC test in 3 weeks and I've focused on optical formulas and theories for the longest time. Now I am taking a step back and in rereading the AOT I see that almost...
Hey y'all,
Thanks for all the replies! It definitely helped with clearing up the confusion. It really seems to me that the more I dig into the nitty gritty part of optics, the more confusing it...
Hey folks,
Got a quick questions here. When I was working in a lab a few years ago I remember that that base curve of a lens is always on the convex side of a meniscus lens. And I have only...
Hi Robert,
Oh yes! Sorry for the confusion. I totally forgot that "compensated Rx" have a collection of variables at play. I'm digging through the Optical Formula Tutorials book and their...
Hello folks!
I'm currently studying for the Advanced Test and I want to make sure I have a clear understanding of two different concepts (correct me if I'm wrong please!):
Effective power is...
I've been in this field for about 5 years now and I have worked both in large retailers and private practices. I know from conversation with a lot of my co-workers and some of the posts I've read on...
Hey Robert,
It became much more apparent once I drew out what you said. Thanks!
And further, if I recall correctly, for a plus lens, the closer a lens is to a specified focal point, the more plus power is needed for that lens to achieve the same specified focal point. In that...
ANSI Z80.1 tolerance question
Hey folks!
I'm not sure how I have never, ever noticed it but now as I'm looking at the ANSI Z80.1 2015 tolerance I noticed that the Sphere tolerance is based on Sphere Meridian Power (Minus...