Germanium or ZnSe lens for DIY hobbiyist projects...

[Vipitis]

A single lens element doesn't make a useable lens. The best you probably get is close focus.

Your best chance is to get one from Bill and please handle with more care than me.

[Bill W]

But for me it is not clear what is the difference between a "ZnSe" lens and a "II-VI ZnSe lens" ?

But at the end, do you think that nevertheless, this lens would be a good candidate for general imaging application (landscape monitoring, night vision spotter hand held with low magnification, for night walking, and used with a low resolution core 160x120)?

II-VI might simply be a reference to the periodic table.

I'd be more concerned that someone who cannot spell 'focus' is capable of anything more than copying a lens specification from somewhere else and the actual parts could be quite different.

An otherwise perfect single spherical element would still exhibit all the classical spherical aberrations if used for imaging.
https://en.wikipedia.org/wiki/Spherical_aberration

Bill

[Lambda]

II-VI might simply be a reference to the periodic table.

Ok Bill. indeed you right:
https://en.wikipedia.org/wiki/Zinc_selenide

"ZnSe can be made in both hexagonal (wurtzite) and cubic (zincblende) crystal structure.
It is a wide-bandgap semiconductor of the II-VI semiconductor group (since zinc and selenium belong to the 12th and 16th groups of the periodic table, respectively)."

I'd be more concerned that someone who cannot spell 'focus' is capable of anything more than copying a lens specification from somewhere else and the actual parts could be quite different.

My bad, i was copying by hand under Paint the title from this announce.... typo mistake in my hurry to post between two job tasks....

Stéphane

[Fraser]

II-VI Incorporated are a lens manufacturing company. I have some of their lenses.

Sadly the usual risks of fakes apply to eBay purchases.

https://ii-vi.com/optics/

Edmund Optics are an agent fir II-VI

https://www.edmundoptics.co.uk/company/brands/ii-vi/

CVD (Chemical Vapour Deposition) lenses are the better quality or “Hi-Q” CO2 lenses but remain a laser beam manipulation lens rather than being intended for high quality imaging.

Fraser

[Lambda]

Thank you Fraser.

Indeed, the fake aspect is sadly obvious, when looking closer at your references and the E Bay offers...

An other example from Thorlabs.

https://www.thorlabs.com/thorproduct.cfm?partnumber=LA7542-E3

to compare to the offer from E-Bay:

https://www.ebay.com/itm/II-VI-CVD-Znse-GaAS-Focus-Lens-for-CO2-Laser-12-15-18-19-20-25mm-FL-1-4/332449376632?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908105057%26meid%3D70cf8b002f924d4bb3eb36d71d045977%26pid%3D100675%26rk%3D2%26rkt%3D15%26mehot%3Dnone%26sd%3D321078811086%26itm%3D332449376632%26pmt%3D0%26noa%3D1%26pg%3D2380057&_trksid=p2380057.c100675.m4236&_trkparms=pageci%3A13a95051-8d52-11eb-8cc4-129e13dfe8ce%7Cparentrq%3A68db8c8a1780aaf48975e176ffce72b2%7Ciid%3A1

The gap between prices from apparently similar lenses in term of features (diamètre, FL, surface state...) is simply to high for being explainable differently (true high quality product vs cheap fake/low grade product), i guess.

Cheers.

Stéphane

[angelortega]

hi lambda
 i just got this these shots using a recycled dual field of view lens assembly from a thorn emi dfov camera. you can see my shots of the lens used  posted as  recycling a dfov lens for other projects. i have three flir 25mm lenses and one lens has a znse element on backside, two of my cameras are 9hz  one is 30hz, the lens with the znse element came from the 30hz camera.maybe the znse lens helps the 30hz camera see better. finding used lenses at real low price is easy the thorn emi camera cost 30k i got mine on ebay for just $255.00 and pulled the lens out. my setup was a tau2 640x480-50mm lens a 75mm extension tube to the lens assembly. so keep trying to reach for the moon with your projects i do and look how far its taken me.