Heliar: coated or uncoated?

[Ari]

So that's what the P stands for; thanks, Dan!

[CCHarrison]

The acronym D.R.P. with or without punctuation stands for Deutsches Reichspatent which literally means 'German imperial patent'.

FROM http://www.assistedknife.com/index.c...subcatid/80975

[Ari]

Thanks, CC.

[Steven Tribe]

I don't whether this has cleaned recently - if not, it is worth doing.

The threads get a little difficult if they haven't been moved for decades - it is amazing how much black oxide appears in the thread groves. In addition, the interior of the barrel is not usually painted (black) and loads of decomposition products settle on everything, including the back of the central lens and the inside surface of the rear lens.

[Ari]

I'll certainly clean it when it gets here, thanks Steven.
I'll take it to my machinist's if there are any serious problems with threads.

[cowanw]

and there's this on Mr. Harrison`s site
http://www.antiquecameras.net/heliarlenses.html
Which shows this lens as an original recipe

[Ari]

Saw that; thanks, Bill.