I just started collecting Emisars because they’re awesome. I’m new to light-lust.
I recently bought a D4SV2 with a stainless steel bezel.
When replacing the pre-installed bezel with the stainless, I discovered that the glass lens is cinched down by the bezel directly against the plastic optic.
Does this glass-against-plastic interface result in tiny scratches or wear-hazing over time as they slide against each other through everyday life? Is glass against optic the norm for flashlights, or do they usually have a separating O-ring or something to keep the two apart?
This is the first light I’ve disassembled in any way. Please pardon my hobbyist OCD!
The other thing I frequently notice in this design construction, is that Glass (lens) pressed directly against Plastic (TIR) often results in that ‘rainbow’ oil effect at the contact points. A slight air gap would prevent that in addition to the rubbing wear that you mention…
This happened to me a lot. But if carclo is good plastic and there’s no AR coat on glass, one can try adding a tiny drop of mineral oil to merge the air gap too
Did that to both my FW3A and Astrolux S41 but can’t guarantee if mineral oil will melt the plastic
You could probably get a shim. Probably wouldn’t need more than 0.05mm. cut out of shim stock or you might be able to find something in the right size to be unnoticeable.
That is the same design as my KR4. I think as long as you keep it very clean when taking it apart you won’t get scratching between them. BUT now that I think about it, unless that TIR is really flat you might get a high spot that puts pressure on the lense. So it would probably be a good idea to not tighten it down too much without an air gap.
The optic won’t be moving around at all, and I highly doubt the glass lens will be either. It’s being pushed down pretty hard, and has friction against not only the optic but also the oring which should keep it in place very well.
I am assuming that the glass lens tends to protect the plastic optic from getting scratched up. Being carried in a pocket or bag could introduce debris directly to the unshielded optic and cause many scratches and gouges.
Just my opinion. I would rather replace a glass lens than a plastic optic.
They don’t slide against eachother, the friction between them essentially holds it together as one piece.
Unless you’re constantly disassembling and reassembling the flashlight they will not be sliding against eachother or getting dirt in between.