Industar-37

[Murgo]

Thanks for the answers. So I'll probably just see how close a focus distance I can get with a moderate extension when the lens arrives, obviously there's no sense making an extension tube much longer than maybe 100mm as that would bring the weight of the lens too far forward for the front standard to comfortably support and probably also cause vignetting.

The reason I want to try this lens is they are available cheap and I like to experiment and tinker with weird old things (which is, after all, why I started film photography again after 20 years of shooting just digital and why I got into large format). If I can't get it to focus closer than a few meters then so be it, I'll use it at longer distances. Or maybe I'll build an 8x10 or maybe a big paper negative camera if I can't use the lens for the Speed Graphic.

I know the longest "sensible" focal length for a Speed Graphic is around 250 mm but I think that would not make a huge difference from the 180 mm I already have. A smaller, shuttered 300mm would on the other hand have the same problems with maximum bellows extension. Also shuttered 250mm lenses tend to be quite expensive (the cheapest I could find on Ebay is about 260€+40€ shipping from Japan+25% tax and maybe 20€ declaration fee if the seller chooses to use DHL as the Japanese sellers these days quite often do as postal services have become kind of erratic lately). The Industar I got for about 100€ from Ukraina. And as the camera has a focal plane shutter I'd like to experiment with a barrel lens.

Also I think the camera would look even more cool and crazy with a huge hunk of a lens sticking out at the front.

[maltfalc]

Thanks for the answers. So I'll probably just see how close a focus distance I can get with a moderate extension when the lens arrives, obviously there's no sense making an extension tube much longer than maybe 100mm as that would bring the weight of the lens too far forward for the front standard to comfortably support and probably also cause vignetting.

The reason I want to try this lens is they are available cheap and I like to experiment and tinker with weird old things (which is, after all, why I started film photography again after 20 years of shooting just digital and why I got into large format). If I can't get it to focus closer than a few meters then so be it, I'll use it at longer distances. Or maybe I'll build an 8x10 or maybe a big paper negative camera if I can't use the lens for the Speed Graphic.

I know the longest "sensible" focal length for a Speed Graphic is around 250 mm but I think that would not make a huge difference from the 180 mm I already have. A smaller, shuttered 300mm would on the other hand have the same problems with maximum bellows extension. Also shuttered 250mm lenses tend to be quite expensive (the cheapest I could find on Ebay is about 260€+40€ shipping from Japan+25% tax and maybe 20€ declaration fee if the seller chooses to use DHL as the Japanese sellers these days quite often do as postal services have become kind of erratic lately). The Industar I got for about 100€ from Ukraina. And as the camera has a focal plane shutter I'd like to experiment with a barrel lens.

Also I think the camera would look even more cool and crazy with a huge hunk of a lens sticking out at the front.

A 2" top hat lens board will get you close enough for head and shoulders portraits.

[ridax]

I needed a 300mm fast lens for my 5x7 for Wet plate head shots in studio. I don't need a shutter but need it to be 4.5 or faster since I am using ALL my available flash power just to get an image (tested and proven with a borrowed lens. f5.6 doesn't do it).

I feel I must warn those who want to use the I-37 as a fast lens for wetplate (or blue-sensitive film). Tessars are not the best choice for the task; the most of them, especially in longer focal lengths like 300mm and fast speeds like f/4.5 or more, are considerably yellowish due to the sorts of glass used in them and the thickness of that glass. That is most probably indifferent for modern films like HP5+ and just a little bit noticeable for older type panchromatic emulsions like Fomapan but it may well make the exposures about 2x to 4x times longer for blue-sensitive materials. So an f/4.5 on a tessar may turn out to be less fast then an f/5.6 on a non-APO plasmat like a Convertible Symmar or a Componon or a Rodagon, etc. Those plasmats are made of glass way more transparent in the violet and UV zones of the spectrum to which the blue-sensitive materials like wetplate are actually much more sensitive than to the visible blue light. The 19th century Aplanats / RR's are still more transparent in the UV (as the feature was highly valued the days before orthochrome emerged).

And for the Industar-37, there is more to it. A lot of Industar-37's have 2-layer coating that drives the situation from bad to worse, giving the lens still more yellowish color. That type of coating is most often purple in reflected light and always much brighter than the classic single coating. Better choose the ones with the pale bluish coating similar to the CZJ one.

The 210mm f/4.5 Industar-51 that comes from the 13x18cm FKD model is not as yellowish and is way more usable. It is better stopped to f/5 for a really nice background blur (which is quite fast as the vast majority of f/4.5 tessars need stopping to f/7 or at least f/6.3 to get rid of the very unpleasant mess in the out of focus background).

And by the way I've almost never seen beaten Industar-37's offered for sale here in Russia. I owned several, and all of them were like new. I guess that's because a faulty one would just never sell for a penny locally, where they are so plenty. Go give it to kids as a toy - or ship it abroad....

P.S.: $20 is the realistic price of a mint I-37 here in Russia. It's still cheaper in the Ukrain.

[Mark Sawyer]

I feel I must warn those who want to use the I-37 as a fast lens for wetplate (or blue-sensitive film). Tessars are not the best choice for the task; the most of them, especially in longer focal lengths like 300mm and fast speeds like f/4.5 or more, are considerably yellowish due to the sorts of glass used in them and the thickness of that glass. That is most probably indifferent for modern films like HP5+ and just a little bit noticeable for older type panchromatic emulsions like Fomapan but it may well make the exposures about 2x to 4x times longer for blue-sensitive materials...

And for the Industar-37, there is more to it. A lot of Industar-37's have 2-layer coating that drives the situation from bad to worse, giving the lens still more yellowish color. That type of coating is most often purple in reflected light and always much brighter than the classic single coating. Better choose the ones with the pale bluish coating similar to the CZJ one.

I disagree. I've shot hundreds of wet plates using coated and non-coated Tessars (including a 300mm Industar), and none have ever shown reduced speed due to either AR coatings or the type of glass. As far as I know, the types of slightly-radioactive rare earth glass that yellow (used in lenses like the Aero Tessar and Super Takumar) was never used in Tessars, whose design far pre-dated the existence of such glass.

[ridax]

I don not mean the Thorium glass (which is actually less a problem as it can be brought back to full transparency by UV treatment); I mean the 'ordinary'/old glass types that are also quite different in their UV transmission. Tessars are usually made of glass types less transparent in the UV then non-APO plasmats and RR's, and most of the RR's have much thinner glass elements than the f/4.5 and faster tessars of the same focal lengths.

Another nuance is the glass quality. The same type of glass can be quite transparent when produced with a high quality control level but considerably more yellowish when there are impurities in it (less refined materials for the glass itself, less suitable materials the glass melting pot is made of, etc.). So a Zeiss Tessar copy may turn out to be not as transparent as the Zeiss original. In fact, 19th century advertising often pointed out the glass quality problem to convince the buyer to purchase from reliable manufacturers.

And as for the coating types, you probably have not experienced the bad luck of dealing with a lens like this:

http://www.photohistory.ru/Pictures/...ran-27-big.jpg
https://www.largeformatphotography.i...=1#post1157867

- as you are on the other side of the Globe.... Most of the Industar-37's have coating far better than the above but the I-37 coating types also changed during decades of the lens production, and not all the versions are the same.

Nevertheless, I am really glad your abundant experience is reassuring, and you were a success with long enough and fast enough tessar type lenses and wetplate. And by the way that reminds me of another factor - the light. When the light itself contains very little UV, the lens transparency in the UV part of the spectrum becomes irrelevant. So all that really depends....

[Havoc]

I have a feeling that there is some confusion about the perceived color of a coating when looked at in reflection and what this does in transmission. But my physics are to rusty (and it is too hot) for me to bother looking into it.

[ridax]

To be more precise - with less speculation and more scientific facts - here is the spectral sensitivity of a typical blue sensitive emulsion, the Kodak Aerographic RA Duplicating film type 2425/4425, from the Kodak publication ti2284:

http://web.archive.org/web/200210080...84/ti2284e.gif

As the scale is logarithmic, 1 unit of difference between the 450nm visible blue and the 365nm near ultraviolet actually means the film is 10 times more sensitive to the UV then to the visible light.

And here is the spectral transmission of some lenses, compiled from different official publications:


.................................................. Spectral transmission at ..........|. total
.................................................. 365nm 405nm 435nm 546nm ..|. glass thickness
Zeiss Sonnar 50mm f/1.5 .............. 0.05
Ross Express 250mm f/4 uncoated . 0.09 .... 0.36 .... 0.5 ... 0.66 .......|. 60 mm
GOMZ(LOMO) Ortagoz 135mm f/4.5 0.18 ..... 0.54 ... 0.6 ... 0.64 .......|. 14 mm
(celor type)

Industar-10 50mm f/3.5 uncoated .. 0.40 ..... 0.68 ... 0.73 . 0.74 ........|. 10 mm
Industar-7 105mm f/3.5 uncoated .. 0.25 ..... 0.63 ... 0.72 . 0.72 ........|. 19 mm
Xenar 105mm f/4.5 pre-1960 ......... 0.37
Industar-2 135mm f/4.5 uncoated ... 0.31 .... 0.67 .... 0.70 . 0.70 .......|. 11 mm
Industar-4 210mm f/4.5 uncoated ... 0.20 .... 0.56 .... 0.70 . 0.71 .......|. 25 mm
Zeiss Tessar 300mm f/4.5 uncoated . 0.20 .... 0.52 .... 0.66 . 0.71 .......|. 38 mm

................................................... 365nm 405nm 436nm 544nm 673nm
Xenotar 80mm f/2.8 1967 (5/4) ...... 0.17 .... 0.65 ... 0.80 ... 0.93 ... 0.89
Xenotar 150mm f/2.8 1967 (5/4) .... 0.53 ..... 0.72 ... 0.81 ... 0.93 ... 0.82
Xenar 180mm f/4.5 1967................ 0.59 ..... 0.79 ... 0.85 ... 0.91 ... 0.89
Xenar 300mm f/4.5 1967 ............... 0.58 ..... 0.80 ... 0.85 ... 0.91 ... 0.88
Tele-Arton 350mm f/5.5 1967 (5/4) . 0.33 .... 0.69 ... 0.76 ... 0.86 ... 0.82

D-Claron 40mm f/4 1968 ................ 0.55
D-Claron 60mm f/5.6 1968 ............. 0.70
D-Claron 105mm f/5.6 1968 ............ 0.58
D-Claron 210mm f/5.6 1968 ............ 0.54

G-Claron 150mm f/9 1968 (Dagor) ... 0.73
G-Claron 210mm f/9 1968 (Dagor) ... 0.64
G-Claron 240mm f/9 1968 (Dagor) ... 0.53
G-Claron 270mm f/9 1968 (Dagor) ... 0.59
G-Claron 305mm f/9 1968 (Dagor) ... 0.43


It's hardly believable that an Express transmitting just 9% of the near UV radiation would need the same exposure for the same f-stop as a 150mm Dagor-type G-Claron that transmits 73% of the near UV - if the picture is taken in sunlight not pre-filtered by the common greenish window glass....

At least my own experience confirms the above measured figures.

P.S.: In practice, any tint in a lens is pretty visible when one looks through the lens on a sheet of bright paper in an overcast day's light (or in a shade under the blue sky on a sunny day). Other light sources may be misleading; and as the human eye is excellent in comparing color shades but not too good in making any measurements, it's important to watch two or more lenses at once to judge which of them is really faster.

[Bernice Loui]

Data sheets from Schneider.
Note the light wave length transmission curve.

210mm APO symmar, Transmission of light wavelengths below 420nm drops off real fast.


360mm Tele Xenar, Transmission of light wavelengths surprising good from 400nm to 700nm.


480mm APO artar, Transmission of light wavelengths surprising good from 400nm to 700nm.
Another illustration of what these "Process Lenses" achieve for optical performance.


Correlates with data from the chart previously posted.


Bernice

[Sean Mac]

[Mark Sawyer]

The same type of glass can be quite transparent when produced with a high quality control level but considerably more yellowish when there are impurities in it (less refined materials for the glass itself, less suitable materials the glass melting pot is made of, etc.). So a Zeiss Tessar copy may turn out to be not as transparent as the Zeiss original...

I have yet to see a visibly yellowed Tessar, Zeiss or otherwise. Or one that suffers from light loss on wet plate compared to other lenses at the same aperture.