Non-coated vs. coated lenses misconception?

Discussion in 'Large Format' started by bj_rn_nilsson, Nov 17, 2002.

  1. In a recent thread (about 210mm lenses) I read that someone stated that an uncoated (old) lens would give better shadow detail than a coated lens. The way it was written gave the impression that this was a "feature" of older lenses and that this feature was "lost" with the coating of modern lenses.
    First, this "feature" is hard to control. (Unless you always use the same light in your pictures.) The improved shadow detail comes from the lens flare creating a preflash of the film. As any preflash affects the least exposed parts of the negative the most, the shadow zones are lifted and somewhat compressed. In total the flare gives less contrast, a fact I recon is known to most of us. I don't know whether this preflash caused by lens flare is totally even across the negative, but I assume it is relatively even.
    On the other hand, a multicoated lens, especially with a good lens shade will produce much less flare, which in turn gives you better contrast. The "trick" of getting better shadow detail is indeed simple. Expose for it! (I guess that you all know the rest, i.e. develop for the highlights.) If you want the very same look and feel that uncoated lenses give, i.e. the somewhat compressed and lifted lower zones, preflash the film! You will get exactly the same effect, but now you are in control of it.
    Now, say that you use an uncoated lens the way most of us (including me) do, i.e. maybe possibly with a hat or something as an excuse for a proper lens shade. In certain backlit situations the negatives becomes virtually unusable. (I'm not saying that a coated lens would give you a much better result.) In other situations, like in a dark forrest, noone could tell the difference between an uncoated and a brand new multicoated lens.
    Please don't get me wrong here. I'm not saying that old lenses are "crap", nor am I saying that new lenses all of a sudden will give you better pictures. It's (as always) a matter of knowing the pros and cons of your equipment.
    I will not be able to read or answer any responses to this for a week, but I will sure read any answers and respond if needed.
     
  2. Bjorn: There are a large number of people who just have to have the very latest multicoated lenses, so to a large extent it is hopeless to raise this issue with them. (The people who are shocked to find their G Clarons are not multicoated and swear they have to sell them, I mean people like that.) I use a variety of lenses from the latest multicoated Schneiders to very, very old uncoated lenses. My thoughts on this general subject are as follows:

    1. If you are shooting into the sun, so that the sun is actually going to appear on film or be just slightly off camera, multicoating is a plus over single coating and single over no coating at all. In these situations, multicoating is real progress. Shading the older lens can help a lot unless the sun will actually appear on film.

    2. As a landscape photographer I have VERY rarely taken photos which were made possible by multicoating. At least for me, the need to take photos covered by my first statement is slight and I don't normally have a desire to take a photo like that. Obviously others feel differently about it. And if money is no object (a statement which applies to so many aspect of LF photography) go spend your money for the expensive lenses. Nothing wrong with that if you can afford it and it is what you want to do.

    3. The difference between multicoated and single coated lenses is not nearly so great as many on this forum would have you believe. There are statements in the archive about the lack of multicoating costing a full paper grade for most subjects. This is crazy and will not hold up to an objective test. It isn't nearly that much when comparing multicoated with non-coated lenses. Try it with lenses with shutters of known accuracy and you will see the difference is minor.

    4. Even uncoated lenses can produce contrasty modern appearing results in most situations. Many of these lense are of much simpler designs, with fewer surfaces, and that difference in design offsets some of the benefit of coating. This is true with very contrasty subjects like a white stucco house in full sun against a dark background. Many uncoated lenses will handle this situation well, provided the sun isn't in the picture. That's where multicoated lenses have an edge.

    5. I'm not sure when "contrast" became the holy grail of photography, nor why. Do you print everything on Grade 6 paper? Always use a grade 5 filter to get as much contrast as you can with VC materials? Shoot everything with a deep red filter? I'll bet not. I suspect if you go through the various threads on this forum and compare the number of LF photographers trying to compress their contrast range versus expand it the ratio would be something like 8:1. I think most of us can get more contrast than we want on the print without much trouble, so giving up a small amount of it on a negative to save hundreds and hundreds of dollars seems like a pretty acceptable tradeoff for those for whom saving money is an objective.

    6. Within the print sizes you probably make, multicoated vs. single vs. non coated lenses can (depends on the lens, of course) result in differences in sharpness which are not detectable from normal viewing distances. There are lens in shutter you can buy on ebay which produce very, very sharp prints which would satisfy anyone and cost less than $15. Ludicrous suggestion, many will say, but they haven't tried buying one of those old Kodak folders, throwing away the camera, and using the lens and shutter. I am not saying this is true of all old, cheap, uncoated or single coated lenses, of course, and you have to be selective and try them with film.

    7. Single coated lenses can give great color. You can tell from the posts that large numbers of people think single coating and color are hopeless. I don't think so. I won't say anything about uncoated lenses and color materials until I've tried that, which I'm planning to do soon.

    So I'm not saying Multicoating is useless. I am saying that if you look beyond the knee jerk advice that single coated or uncoated lenses are unacceptable and will only produce odd moody results, then you can save a lot of money and put together a small lightweight kit which will perform.
     
  3. It may be that the classic designs are quite contrasty, even in their uncoated form, but coatings make better corrected lenses possible, which would have had poor contrast originally.

    The Planar is nearly as old as the Dagor, but the Planar did not come into its own until the advent of lens coatings, because it had 8 air-glass surfaces in its original form. And now with multi-coating, the original 4-group, 6-element planar has developed into 7 and 8 element forms to make it faster and better corrected. Before lens coatings, the Dagor was a much better lens, with 6 elements and only two groups (four air-glass surfaces), and old uncoated Dagors hold up surprisingly well today (and I like them for their classic look).

    Likewise the Celor was originally offered as a low-end version of a Dagor, using the airspaces between the two front elements and two rear elements as "lenses." The modern multicoated Fujinon-C is based on this design, though, and is regarded as an excellent lens.
     
  4. "It may be that the classic designs are quite contrasty, even in their uncoated form, but coatings make better corrected lenses possible,"

    My APO process lens predates WWII and I assume it's uncoated. Considering it's APO doesn't that make it reasonably corrected?
     
  5. Yes, your APO process lens is well corrected for chromatic aberration and barrel/pincushion distortion and coma at the reproduction ratio for which it is optimized, but it is also probably comparatively slow. If you wanted a lens of the same focal length to be two stops faster, say, it would probably require a more complex design.
     
  6. Erik said:
    >>>>>>>>>>>>>>>
    There are a large number of people who just have to have the very latest multicoated lenses, so to a large extent it is hopeless to
    raise this issue with them. (The people who are shocked to find their
    G Clarons are not multicoated and swear they have to sell them, I
    mean people like that.)

    On the positive side, this keeps down the price of some superb single-coated lenses such as Kodak Commercial Ektars. I have two (8 1/2 inch and 14 inch) and they were not terribly expensive. They are also excellent colour lenses. I also have an Apo Lanthar which, if I am not mistaken, is only single coated and it is legendary for its colour rendition (I know it is a collector lens but I got it very cheap, less than $200, because of cleaning marks). As you point out, the difference between single-coated and multi-coated is not as great as some would have us think.

    Also, many, if not most, of my favourite photographs were NOT taken with modern lenses that cost as much as my car. This is not a diatribe against modern lenses but simply a reminder that those of us on a budget don't have to give up LF photography because we can't drop two grand or more on a lens.

    Don Wallace
     
  7. The lens is F/9.0 Worse it should be used at F/22.

    I think the following is the important point

    " it would probably require a more complex design."

    The older lens tend to be simpler designs that have a better chance of getting away with less coating. At least that's the way I understand it.
     
  8. Yes, that was my point. Sorry if I was being unclear. The older lenses are simpler with fewer features, and therefore can perform well despite the lack of coatings. Coatings make the advanced features of modern lenses possible (good performance wide open, more speed, wider usable image circle, zoom lenses on smaller formats, etc.), because they make it possible to design a lens with more air-glass surfaces.

    That said, I love the older lenses myself. A beautiful MTF curve doesn't necessarily make a beautiful photograph.
     
  9. I guess I maybe responsible for 1/2 of this ongoing discussion. I orginally said that the older "Dagors" produced the open shadows and was taken to task by another contributor. Mr. Nilsson has enlighten me as to why this happens which is the exact reason that I frequent this site. All that said, I really am not a very technical person about photography. I enjoy learning why something happens, but really all that matters in the end is finding a way to get the results you want. After years of LF Landscape photogaphy with new and old equipment an old saying my father used to use all the time is never more true, "Gentleman it is not the arrow it is the indian"
     

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