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domaz
10-Jul-2011, 17:28
Ok so we know that uncoated plastmats are not really a good thing- 6 elements to cut down contrast. But is it safe to say that the only uncoated plasmats for LF use is the Hugo Meyer Plasmat Convertible series? I haven't gone through every page of the Vade Mecum but I don't remember ever seeing another reference to an uncoated LF plastmat.

Ole Tjugen
11-Jul-2011, 07:11
It is rarely safe to say anything at all about German lenses based on the Vade Mecum, but I don't know of any others either. But it wouldn't surprise me much if there is a half dozen more.

Louis Pacilla
11-Jul-2011, 08:10
How about the Hugo Meyers Doppel Anastigmat f6 Euryplan?

domaz
11-Jul-2011, 08:32
How about the Hugo Meyers Doppel Anastigmat f6 Euryplan?

Ahh thanks for that one. I did a bit more searching on that angle and it seems the Zeiss Orthometar was also plastmat design and probably uncoated.

David Lindquist
11-Jul-2011, 08:48
Ok so we know that uncoated plastmats are not really a good thing- 6 elements to cut down contrast. But is it safe to say that the only uncoated plasmats for LF use is the Hugo Meyer Plasmat Convertible series? I haven't gone through every page of the Vade Mecum but I don't remember ever seeing another reference to an uncoated LF plastmat.

The Ross Wide Angle Xpres is a Plasmat design, with a British patent date of August 16, 1928, so would have been uncoated.
David

Steven Tribe
11-Jul-2011, 10:06
Pre 1914, there was Schulze and Billerbeck, Gorlitz, Germany with their original Euryplan series and Suter had a licence from Rudolph for their Plasmats.

sinhof
13-Jan-2012, 11:32
Here is the Orthometar 4,5/25cm. Seems to be uncoated. I think this is made year 1941. This thread is the only including the word "Orthometar". Who can tell more about this rare optic? Picture later. Lens # 2729609.

E. von Hoegh
13-Jan-2012, 11:36
If it's the one that looks to be a Plasmat, there isn't much to say that hasn't been said. It's a flare machine. Your link doesn't work, BTW.

Jody_S
16-Jan-2012, 21:14
I have a couple of the Schulze & Billerbecks, they have their uses but I wouldn't try one shooting into foreground light. Can be sharp enough if used in the right manner. No worse to use than a 1930s Summar on a Leica, for example.

Jody_S
26-Jan-2012, 11:42
I'm re-scanning some of my older shots, I came across a lens test of a Schulze & Billerbeck Euryplan-Anastigmat Series I 6in f4.5. I got the cells in a box of stuff, and machined a barrel for them. I never got around to making stops, so this was wide open. I'm posting this for the interesting flare patterns. I focused on the lights about 10ft in front of the church doors, and because it's wide open that's about all that's in focus.

http://i8.photobucket.com/albums/a8/Kingsmeg/ShulzeBillerbeck.jpg

cyberjunkie
26-Jan-2012, 22:37
All these lenses, and a great number of pre-WWII dialytes, not to mention some double gauss wide angles, would benefit from a single coating treatment.
That's exactly what B&J did with their Carl Meyer line.
I tried to contact www.thinfilmcoating.com
No reply so far.
It's a pity because the prices were affordable, and the technology should be, IIRC, a low temperature one, which should not affect cemented groups.
Any experience with their service?
I tried to find somebody in the EU, doing coating/recoating for spectacle lenses, with simple magnesium fluoride technology, but i found none.
I know that there were a good number of small companies doing this kind of stuff, years ago. There also are fewer optical shops doing custom job, grind from glass blanks. When i was a child most optician could make any kind of optical lens, on order.
I guess that the two things are related. There is no need anymore for protective or anti-reflection coatings on non-industrial, custom made lenses.

I have even seen a vacuum coating device on Ebay, a couple years ago, but it was a medium capacity machine, too heavy and expensive even for the most hard core vintage lens enthusiast. :(

have fun

CJ

Jody_S
27-Jan-2012, 11:18
All these lenses, and a great number of pre-WWII dialytes, not to mention some double gauss wide angles, would benefit from a single coating treatment.
That's exactly what B&J did with their Carl Meyer line.
I tried to contact www.thinfilmcoating.com
No reply so far.
It's a pity because the prices were affordable, and the technology should be, IIRC, a low temperature one, which should not affect cemented groups.
Any experience with their service?
I tried to find somebody in the EU, doing coating/recoating for spectacle lenses, with simple magnesium fluoride technology, but i found none.
I know that there were a good number of small companies doing this kind of stuff, years ago. There also are fewer optical shops doing custom job, grind from glass blanks. When i was a child most optician could make any kind of optical lens, on order.
I guess that the two things are related. There is no need anymore for protective or anti-reflection coatings on non-industrial, custom made lenses.

I have even seen a vacuum coating device on Ebay, a couple years ago, but it was a medium capacity machine, too heavy and expensive even for the most hard core vintage lens enthusiast. :(

have fun

CJ


As it happens, I have 2 or 3 of these lenses, and a vacuum coating machine of the appropriate size. Yes it's a low-temp process, I suppose if I set the machine on a higher amperage 'plasma' setting it might heat the target a little but I don't expect the glass would conduct enough to make a difference. All I'm missing is a jar of magnesium fluoride, which I intend to buy as soon as I sell something or other so I can pay for it. I have a couple of rare things I intend to auction off rather soon, including a Yashica Half 14 which should fetch a few $.

I'm still researching lens preparation for this, and wondering what sort of a holder I should make. If I'm coating both sides of a group, a simple arrangement of grooved blocks holding the outside of the group should do it, perhaps with a tie-wrap to keep the whole thing from moving- necessary because the vacuum pump is integrated into the machine and rattles a little. I should also devise a method of estimating the thickness of the coating; I don't believe any of my instruments are able to measure fractions of a micron. I suppose a simple estimate of reflection might suffice for trial purposes, and it's standard procedure with these machines to coat x number of minutes at such a setting for a given thickness. I may be able to get estimates from lab manuals from universities, for preparing samples for electron microscopy (amazing what you can find, with teh google). I will of course test on a few junk lenses before attempting anything serious, but the advantage of the single coating is that it's rather soft and can easily be polished off (even accidentally, for early coatings like on a Medalist).

E. von Hoegh
27-Jan-2012, 11:23
As it happens, I have 2 or 3 of these lenses, and a vacuum coating machine of the appropriate size. Yes it's a low-temp process, I suppose if I set the machine on a higher amperage 'plasma' setting it might heat the target a little but I don't expect the glass would conduct enough to make a difference. All I'm missing is a jar of magnesium fluoride, which I intend to buy as soon as I sell something or other so I can pay for it. I have a couple of rare things I intend to auction off rather soon, including a Yashica Half 14 which should fetch a few $.

I'm still researching lens preparation for this, and wondering what sort of a holder I should make. If I'm coating both sides of a group, a simple arrangement of grooved blocks holding the outside of the group should do it, perhaps with a tie-wrap to keep the whole thing from moving- necessary because the vacuum pump is integrated into the machine and rattles a little. I should also devise a method of estimating the thickness of the coating; I don't believe any of my instruments are able to measure fractions of a micron. I suppose a simple estimate of reflection might suffice for trial purposes, and it's standard procedure with these machines to coat x number of minutes at such a setting for a given thickness. I may be able to get estimates from lab manuals from universities, for preparing samples for electron microscopy (amazing what you can find, with teh google). I will of course test on a few junk lenses before attempting anything serious, but the advantage of the single coating is that it's rather soft and can easily be polished off (even accidentally, for early coatings like on a Medalist).

As for coating thickness. If it's a blueish purple, it's the right thickness. Experiment on bits of glass. I'm very interested to see how this works out. :) Edit - these simple coatings are very delicate.