Hi,
I'm wondering if there is a cheap way of viewing the pits and lands of a DVD disc. The problem is that the data layer is buried 0.6 mm below surface. 40x objective usually doesn't have sufficient working distance. Is there a way other than buying an expensive LWD objective?
DVD, CD and Blu-ray parameters:
https://en.m.wikipedia.org/wiki/Compact ... DVD_BD.svg
Viewing DVDs
Re: Viewing DVDs
it doesn’t answer your question, but I’m guessing you might find this of interest:
https://www.researchgate.net/publicatio ... prints_Too
MichaelG.
.
P.S. I think the answer is … that’s the sort of job that LWD objectives are designed for.
… but you don’t necessarily need an expensive one !
https://www.researchgate.net/publicatio ... prints_Too
MichaelG.
.
P.S. I think the answer is … that’s the sort of job that LWD objectives are designed for.
… but you don’t necessarily need an expensive one !
Too many 'projects'
Re: Viewing DVDs
About 8:30 into this :
https://www.youtube.com/watch?v=GuCdsyCWmt8
(peeled it off with sticky tape).
https://www.youtube.com/watch?v=GuCdsyCWmt8
(peeled it off with sticky tape).
Re: Viewing DVDs
Sticky tape for CDs and Xacto knife for DVDs. Sometimes brute force wins over fine optics I might try that.Chas wrote: ↑Sun May 22, 2022 8:48 pmAbout 8:30 into this :
https://www.youtube.com/watch?v=GuCdsyCWmt8
(peeled it off with sticky tape).
I was wondering that maybe if I shortened the optical tube, I could extend the working distance of a 40x objective a bit to reach 0.6 mm into the DVD. I don't know whether the spherical aberration thus introduced would tend to compensate, or aggravate one caused by the too thick "cover slip".
Too bad I don't have an epi-illuminator. They seem to cost twice what I paid for my entire Alphaphot.