How to remove coating from front lens element?

[dslater]

Bjorn Rorslett has a section on his website where he describes removing the coating from a Nikon Series E lens to improve its use for UV and IR photography. I have not tried this so have no idea how well it works.

The design of his website http://www.naturfotograf.com/index2.html makes it difficult to paste a link directly to the page. Use the link above, scroll down below the photo "mission accomplished" to the link "all about D#$#^* UV and IR Photography" Once at the UV/IR article, go to page 7 "Which Lenses?" for his description of removing the lens coating. The last page (13 - final cut) has a photo taken with a 28mm Series E lens.

Good luck and let us know what you decided to do.

Here's a direct link to the page:

http://www.naturfotograf.com/UV_IR_rev05.html#top_page

Martin,
Bjørn uses frames on his site. If you have the Firefox browser, you can right click on his page and choose "This Frame" ==> "View Frame Info" to get the frame's address.

Dan

 

[dslater]

Since when is MgF metallic?

Well - magnesium is a metal

 

[acroell]

Well - magnesium is a metal

By the same logic, table salt (NaCl) would be a metal, since sodium (Na) is a metal.....ouch!

And its MgF2, by the way, not MgF.

 

[dslater]

By the same logic, table salt (NaCl) would be a metal, since sodium (Na) is a metal.....ouch!

And its MgF2, by the way, not MgF.

Well if it's (NaCl) not a metallic salt, then what is it?

 

[acroell]

Well if it's (NaCl) not a metallic salt, then what is it?

Its a metal salt, not a metallic salt. I may be out on a limb here languagewise since I am not a native speaker and I infer it from German, but "metallic" is an adjective and when used with a noun would ascribe the properties of a metal to the object named by the noun; properties like electric conductivity, heat conductivity, reflectivity etc. Table salt certainly has no metallic properties.
A salt is ionic.
The sentence starting this was
"Later photographic lens coatings are very thin metallic deposits which are deposited onto the lens by sublimation methods (Putting the lens in a chamber with a blob of alloy and zapping it with a huge current so is vapourises and re-condenses on the lens, for example...)."

Steven clearly meant metals here because he talks about an alloy, not a compound. Metallic coatings are sometimes used but not as AR coatings; mirror coatings are the obvious use. Dan pointed that out by mentioning magnesium fluoride as the tradiitional AR coating material.

 

[steven_e007]

Steven clearly meant metals here because he talks about an alloy, not a compound. Metallic coatings are sometimes used but not as AR coatings; mirror coatings are the obvious use. Dan pointed that out by mentioning magnesium fluoride as the tradiitional AR coating material.

Actually, Steven meant no such thing.
Steven was merely being careless, because, being new to the forum, Steven wasn't quite prepared for how intricately every post is picked apart for errors such as these!

Steven has since wised up

Most modern techniques involve evapourating the metal *halide* in a vacuum. Not the metal. And yes I did confuse the method with coating a mirror as I had been involved with a problem involving damaged front silvered mirrors that week...

...but, point was, there are several types of lens coating. Magnesium flouride is usually used for all modern camera lenses. Years ago manufacturers, especially in the US (MgF2 was an exclusively German technology in WW2, wasn't it?) used other techniques, including chemical glass etching and soft coatings.

Soft coatings are still used today for spectacles and consist of dunking the lenses in coloured goos and cooking them onto the surface. Some WW2 vintage Kodak lenses were coated in this way.

Soft coatings are going to be faily easy to remove, I suspect.
Hard coatings are going to be extremely difficult.
Etched glass is probably impossible, since it isn't really a coating...

So, knowing what type of coating you have would seem to be essential before attempting any of the suggested techniques for removal, I think.

Steve

 

[dslater]

Its a metal salt, not a metallic salt. I may be out on a limb here languagewise since I am not a native speaker and I infer it from German, but "metallic" is an adjective and when used with a noun would ascribe the properties of a metal to the object named by the noun; properties like electric conductivity, heat conductivity, reflectivity etc. Table salt certainly has no metallic properties.
A salt is ionic.

I am a native speaker and I believe you're mistaken here. I have read many things being referred to a metallic salts. While it is true metallic is an adjective, it does not metallic as in something with properties like electric conductivity, heat conductivity, reflectivity etc. - it refers to the periodic table of the elements where every element is either a metal, a non-metal, a halogen, or an inert element.

here's a link to the table:

http://images.google.com/imgres?img...Fp2PMYl1MvuRjQNw&sa=X&oi=images&ct=image&cd=1

Dan