removing lens coating ???

[lightfootwillwalkinthecat]

I'm still in the process of building what I need to shoot wet plate for the first time and started thinking about the coating on my lens. ( Nikon Apo-NIKKOR 610mm f/9 )
I'm wondering if its worth removing the coating to allow more UV light through ? Looks like I would need to remove the front lens element, soak it in warm isopropyl alcohol and gently scrape off with a soft plastic scraper ...

What do you guys think ? Stupid ? worth doing ? Leave it alone ? go for it ?

[Dan Fromm]

Hmm. Why do you think that the lens' coating will be attacked by isopropyl alcohol?

[xkaes]

Hmm. Why do you think that the lens' coatingS -- there are more than one -- removes more UV light than the lens glass itself?

[Vaidotas]

But - lens coating removal works inducing flare and might help to increase middle and dark tones separation.
Kind of collateral gain!

[Peter De Smidt]

Please don't purposely damage the lens. It's unlikely that the coating reduces UV light in any meaningful way. If you want more flare, simply put an uncoated glass filter on it. If the types of glass don't pass enough UV light for you, then get/make a different lens. You can use diopters/meniscus.....with a shutter. There are so many better options than damaging a relatively rare, high quality, and never to be made again lens

[Jason Greenberg Motamedi]

Don't. I and others have done tests comparing lenses with and without coatings, lenses with balsam vs uv-cure cement, and normal vs uv-passing lenses. None of it made a difference in exposure, and lenses with coatings made a large difference in reducing flare.

It wouldn't work anyway, alcohol is not going to remove coating.

[paulbarden]

Don't. I and others have done tests comparing lenses with and without coatings, lenses with balsam vs uv-cure cement, and normal vs uv-passing lenses. None of it made a difference in exposure, and lenses with coatings made a large difference in reducing flare.

It wouldn't work anyway, alcohol is not going to remove coating.

Jason is correct: there's absolutely no point in trying to remove the surface coatings. Attempting to do will likely result in significant damage to the lens (its not coming off in Alcohol, that's for sure), and the lens will not behave any differently when used for Wet Plate work. Like others, I have used many different lenses, from 1850's Petzvals, to uncoated Kodak Anastigmats from the 20's-40's, and Coated Ektars from the 1950s, all the way up to modern Schneider Symmar types. They all transmit "wet plate usable" light to the same degree.

[jnantz]

I know nothing about the lens you are thinking of "modifying" but sometimes great things are done by
doing things people think goes against the grain and common sense ... modifications like lens coating might be something that can be reversed, so .......
you can obviously pay the money to get something "recoated" if you decide that it was a waste of effort and a WTFWIT moment

.. personally...

I would modify the rear element, doing something to the front element is for chumps ... the rear element is what forms the image and people say issues on the rear element t will lead to a ruined lens.
when I say people ... I've friends who are camera repair people (not people that do it to their own and maybe a desperate friend's but people have earned their livelihood from it for 30 years or more
as maybe did their father ) ... in the past when I asked them (friends in this vocation ) about a lens being worth the money asked (random lens with a bubble or a gouge filled with India ink or whatever lens )
I almost bought for pennies on the dollar ) they'd always say ( yes waste that money if the front is fine, rear element never, .. according to them that sort of thing will ruin the lens or to quote this guy rusty's dad who was
a freak brother's fan who drove into a snowbank with us in the back of the car on the way to a mountain in Maine "the whole back end is cooked!" ) like a re-coating "mishap", he got his boat of a car fixed ...
so my advice is if you want images might be unique to your specific lens that people might say "holy crap lightfootwillwalkingthecat, that image is amazing I've never seen anything like it
... how did you do it ( a positive thing) ?" do something to the rear element, not the front .. . but there is always a chance someone might say "holy crap lightfootwillwalkingthecat, that lens can't produce a good image if your life depended on it! sell that piece of cr@p (negative thing )" ...

yes, I've taken sandpaper to a lens before .. but still, good luck ..
John

[Peter De Smidt]

"Might" is a pretty low bar. All it takes for something to 'might be true' is that it doesn't entail a contradiction. I might win the lottery even though I haven't bought a ticket. That's true....but rather unlikely.

[paulbarden]

I know nothing about the lens you are thinking of "modifying" but sometimes great things are done by
doing things people think goes against the grain and common sense ... modifications like lens coating might be something that can be reversed, so .......
you can obviously pay the money to get something "recoated" if you decide that it was a waste of effort and a WTFWIT moment

.. personally...

I would modify the rear element, doing something to the front element is for chumps ... the rear element is what forms the image and people say issues on the rear element t will lead to a ruined lens.
when I say people ... I've friends who are camera repair people (not people that do it to their own and maybe a desperate friend's but people have earned their livelihood from it for 30 years or more
as maybe did their father ) ... in the past when I asked them (friends in this vocation ) about a lens being worth the money asked (random lens with a bubble or a gouge filled with India ink or whatever lens )
I almost bought for pennies on the dollar ) they'd always say ( yes waste that money if the front is fine, rear element never, .. according to them that sort of thing will ruin the lens or to quote this guy rusty's dad who was
a freak brother's fan who drove into a snowbank with us in the back of the car on the way to a mountain in Maine "the whole back end is cooked!" ) like a re-coating "mishap", he got his boat of a car fixed ...
so my advice is if you want images might be unique to your specific lens that people might say "holy crap lightfootwillwalkingthecat, that image is amazing I've never seen anything like it
... how did you do it ( a positive thing) ?" do something to the rear element, not the front .. . but there is always a chance someone might say "holy crap lightfootwillwalkingthecat, that lens can't produce a good image if your life depended on it! sell that piece of cr@p (negative thing )" ...

yes, I've taken sandpaper to a lens before .. but still, good luck ..
John

John, the OP is wondering about improving UV transmission through a lens, not looking to modify the image quality/characteristics. If all he wants is to optimize UV transmission, removing the coatings isn't going to achieve that. If, on the other hand, he just wants to experiment with modifying the lens, then anything goes. (As long as he's willing to accept the possibility that he might just end up with a useless lens)

[Delfi_r]

Coating it's done depositing a thin (sometinmes one atom level) amount of some metallic elements. They are not soluble with any solvent. But you can remove it.

As suggested avobe you don't need to do something so radical. I's even stupid to damage a lens to obtain something that can be easy other ways. You can try another lens more suited to your purpose.

[Tin Can]

I love my 610mm NIKON lens

Lightweight, has built in lens cap and works fine with a Packard

and sharp

Read the past, Apo Nikkor 610 mm f9

https://www.largeformatphotography.info/forum/showthread.php?103587-Apo-Nikkor-610-mm-f9&p=1029246&viewfull=1#post1029246

[jnantz]

John, the OP is wondering about improving UV transmission through a lens, not looking to modify the image quality/characteristics. If all he wants is to optimize UV transmission, removing the coatings isn't going to achieve that. If, on the other hand, he just wants to experiment with modifying the lens, then anything goes. (As long as he's willing to accept the possibility that he might just end up with a useless lens)

well if he removes the coating and it screws up the lens is what I was getting at, then the whole back end will be cooked ! :)

[mhayashi]

If you care about the lens coating, why not buy an uncoated dialyte like an old apo ronar?
You could still ask Jason Lane to remove the coating but 8 surface coating removal is very expensive.
I wouldn’t do that and simply buy an uncoated lens….

BTW, here is the link to apo nikkor catalog. UV sensitivity and the range of spectrums are mentioned.
https://www.savazzi.net/download/manuals/Apo-Nikkor.pdf

[Nodda Duma]

I’m not yet set up to strip coatings after moving.

In any case, knowing what I do about how coatings work and what they get you in the UV, removing them will still result in a net loss of throughput for wet plate. So leave them on, they are helping your total transmission.

FYI bulk transmission loss in the glass itself (esp. lanthanides) is a bigger contributor and even that isn’t really significant.