There's coatings and there's coatings. You can get an AR coating on your drinking glasses if you use off-brand detergent in the dishwasher.
Early AR coatings were aqueous dip coatings. They rub off easily and were only used on internal lens surfaces.
Everything you never wanted to know: https://brinkerlab.unm.edu/assets/p...cations/dip-coating-brinkerdipcoating2013.pdf
Google to your heart's content. Getting it to work well as a DIY process might be tough.
I just received an old Rolleicord Ia Mod. 1 from 1936-7. All as expected except the taking lens a CZ Triotar 4.5 is coated, both front and rear element of the front group.
I realise that this must have been a later upgrade because not even my then state-of-the-art 1937 Rolleiflex Automat v.1 w. a CZ Tessar 3.5 is coated.
Yet it seems a bit excessive to spend money to have such a relatively modest lens coated, can't have been cheap.
Does anyone here know if the Triotar 4.5 was ever sold coated from the factory?
The 3,5 Triotar came on the market much earlier than that. In fact, the 3,8 Triotar on the second model of Rolleicord from 1934 was actually a 3,5 that was aperture limited due to the size of the shutter that at the time didn't make it possible. That was changed with the Rolleicord II from 1936, that got the full 3,5 Triotar. The factory coated 3,5 Triotars were made in East Germany by Carl Zeiss Jena after the war and can be found on the last Rolleicrd II models. These lenses have a serial number above 3 million.I can see that from 1939 the Triotar 3.5 started shipping, and I would imagine that this would be the obvious candidate for coating when that became a standard feature.
Any thoughts?
Wow, thanks!!
Yeah, well, that paper is all about current techniques and maybe not the best source for information on 'cheap and cheerful' methods.
Early AR coatings were aqueous dip coatings. They rub off easily and were only used on internal lens surfaces.
Thanks JPD!No, they weren't coated at the factory, but a few owners had the lenses coated after the war and it was probably not done by Zeiss. I once had a Rolleicord II from 1938 with a coated 3,5 Triotar and it also had a PC flash contact added. This was probably done in the early 1950's.
The 3,5 Triotar came on the market much earlier than that. In fact, the 3,8 Triotar on the second model of Rolleicord from 1934 was actually a 3,5 that was aperture limited due to the size of the shutter that at the time didn't make it possible. That was changed with the Rolleicord II from 1936, that got the full 3,5 Triotar. The factory coated 3,5 Triotars were made in East Germany by Carl Zeiss Jena after the war and can be found on the last Rolleicrd II models. These lenses have a serial number above 3 million.
The Rolleicord Ia, type 3, with 4,5 Triotar was made until 1949 and these lenses were never coated to my knowledge. I think the 4,5 Triotar on the post 1945 cameras were all made before the war.
Yes, that is how mine would have looked when new - yours is beautiful.Yes, that's the first Rolleicord II. That doesn't look like a PC contact, so I guess the modification was made before the PC connector became standard. It was certainly cheaper to "modernize" the camera with AR coating and flash sync than buying a new Rollei. My Rolleicord II, type 3, had a PC contact on the front plate, not on the shutter itself, and an accessory shoe on the side.
I have one of the same model as yours, but without any modifications:
https://live.staticflickr.com/4106/4971557849_84b164bc92.jpg
I find it fascinating that objects such as these were perceived so valuable at the time, and owners found it worthwhile making costly upgrades. Today, in most cases, we would just dump or sell our used stuff and move on to the next new thing.I have a 1940 Daagor, Goerz AM Opt, that was coated after the war for the original owner, it's not like the softer and easily damaged early Kodak blooming. I've seen a 1938 T coated CZJ 150mm Tessar and the coatings were excellent identical to my 1953/4 CZJ 150mm Tessar.
As Ag has said coatings were used during WWII often for military optics. T., T & H (Cooke) were quite advanced in their coatings but they were deemed a military secret.
Ian
Labour up to sixties and seventies was still much cheaper than materials and brand.I find it fascinating that objects such as these were perceived so valuable at the time, and owners found it worthwhile making costly upgrades. Today, in most cases, we would just dump or sell our used stuff and move on to the next new thing.
I am currently eyeballing a Leica II once modified from a Leica I where basically everything was replaced during the modification.
A few nickel knobs and the serial number may be all that is left from the original Leica I -even the housing of the lens and the shutter was replaced, and yet someone found it worthwhile to upgrade to a camera which basically just added a coupled rangefinder.
I'm thinking; why not just sell the old one and buy a new?
I bet there was even signs for coating programs in store windows in the forties and fifties, where shops would routinely ship disassembled elements of whole cameras off to coating services.
I find it fascinating that objects such as these were perceived so valuable at the time, and owners found it worthwhile making costly upgrades. Today, in most cases, we would just dump or sell our used stuff and move on to the next new thing.
I am currently eyeballing a Leica II once modified from a Leica I where basically everything was replaced during the modification.
A few nickel knobs and the serial number may be all that is left from the original Leica I -even the housing of the lens and the shutter was replaced, and yet someone found it worthwhile to upgrade to a camera which basically just added a coupled rangefinder.
I'm thinking; why not just sell the old one and buy a new?
Yes, but with your indefinite knowledge of magazines, have you ever come aross a respective ad (aimed at consumer or at mechanics) offering coating, or an article hinting at such service ?
I wonder if that may actually be "blooming" on the taking lens? I've had more than a few folders from the 30's, and some of them had that. It acted as a form of coating anyway according to what I've read. This is what gave people the idea of coating the optics in the first place according to some.
All I know is that the Triotar is my very favorite medium format lens. Put a hood on it w/ a yellow filter, load the camera w/ Tri-X, it's a pretty magical thing, especially wide open at close distance and w/ head and shoulder portraits. You can use just the center of the neg to crop it down for almost head shots w/ some pretty neat bokeh. The one below from a 1938 Rolleicord was full frame though.
It's faded, but the brown colour can be beautiful if it's even. I'm not sure about the process they used, I've read that they are etched, but not if they were anodized as well.Yes, that is how mine would have looked when new - yours is beautiful.
Mine does however have a faded brown background on both name plate and the plate around the focusing know, not faded by age but by design - I think.
"Blooming" is very common on the uncoated Triotar, but it has a rainbow sheen.I wonder if that may actually be "blooming" on the taking lens? I've had more than a few folders from the 30's, and some of them had that. It acted as a form of coating anyway according to what I've read. This is what gave people the idea of coating the optics in the first place according to some.
All I know is that the Triotar is my very favorite medium format lens.
The gold rim is just brassing. It looks more even in the photo than it does in real life. The added flash sync looks strange though, I have no idea how it would have worked - of course there is the possibility that it served a completely different purpose.But there's someting that smells fishy here, why the Gold Rim Dagor look to both lenses, I suspect that the lens was coated well after WWII, the whole camera has been timkered with.
Ian
I wonder how it holds up to other well known ≈ contemporary triplets, like Novar and Apotar?The Triotar is indeed a very good triplet, with a character of its own. Longer versions were used as "tele" for small format cameras, and since only the very center of the image circle was used, these lenses vere excellent despite only having three elements. (I don't have any of those, but there are many photos taken with them on Flickr).
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