Omega D-5 negative carrier

Discussion in 'Large Format' started by james_burgess|1, Apr 21, 2017.

  1. I am trying to buy a Omega part#423-319 6x4.5cm. negative for this enlarger. I have tried ebay with no luck any suggestions?
    This part has been discontinued by Omega.
    Thanks,
    Jim
     
  2. Just use a glass 45 carrier and a mask. All enlarging lenses are corrected for a glass carrier. Or, if you don't need optimal results, 645 will easily print in a 66 carrier. But not as well as with the glass carrier.
     
  3. If you have basic metal working skills you can cut masks from aluminium sheet to replace the glass or other masks in an existing carrier. Aluminium isn't as good as brass or stainless steel, but it's much easier to work. A couple.of cheesehead screws can serve as film locators.

    The amount of non-flatness caused by a glassless carrier is trivial IME, and can easily be nullified by stopping the enlarging lens down another stop. The lack of 4 additional dust-catching surfaces more than compensates for the lengthened exposure by reducing cleaning and retouching time.

    No danger of Newton's rings either.

    If you're worried about diffraction - don't be - it's not an issue. Just think of it as an optical grain reducer!
     
  4. Glass carriers do two things that quality prints from quality lenses require.
    First, they hold the film flat.
    Second, they prevent the film from popping during the exposure.

    Film has two dust attracting surfaces, glass has an additional two on each side. If your darkroom is plagued by dust then blasting the four glass surfaces and two film surfaces with a good blower like a Giottos Rocket blower takes virtually no time and will remove all dust.
    However, you should make a concerted effort to track down the cause of the dust and eliminate it. It could be as basic as re painting the room. Or do a thorough dusting of higher shelves and keep then dusted. Lastly an exhasust fan from the darkroom is always a good idea.
    Your goal should be to make the very best prints that your equipment can provide and that includes a properly aligned enlarger, av property exposed and developed piece of film, a quality enlarger lens used at optimal aperture and within it's optimized magnification range.
    Stopping a lens past optimal range does not cure less then flat film or film popping as any gain in depth of field is at the paper side of the lens not at the film side. On the film side you worry about the film being placed within the depth of focus of the lens. Not in the depth of field of the lens. All additional stopping down will do is create diffraction once you are beyond the optimal aperture.
     
  5. Bob, aperture affects depth-of-focus and depth-of-field equally. Especially at the sort of conjugate focii found in enlarging. The angle of the cone of light is narrowed on both sides of the lens by stopping down.

    Negative popping? In 40 years of professional and amateur darkroom printing I maybe encountered it twice or three times. It's one of these overblown mythical issues that's really a non-issue. Most modern enlargers have a sufficiently effective heat filter that the negative stage doesn't get hot enough to "pop" the negative, and a cold-cathode head eliminates the problem altogether. OTOH I've seen plenty of prints ruined by Newton's rings. AN glass really isn't the answer since its textured surface can also be visible in the print.

    All in all, most of the darkrooms I worked in preferred to use well-designed glassless carriers to minimise dust issues. Glass has a far greater static attraction for dust than does a piece of film, so just counting the dust-catching surfaces doesn't divide out quite equally.

    Dusting a darkroom is counter-productive. Dust that's lying on shelves is dust that's no longer floating about in the atmosphere. However, I agree that minimising dust in the first place is a good idea. But unless all darkroom personnel are going to follow cleanroom procedures and change in and out of a bunny suit every time they enter or leave, then dust is almost inevitable.
     
    Last edited: Apr 22, 2017
  6. Joe,
    I am glad that you have had 30 years of experience. I started printing with first a contact print frame and then a Federal enlarger in 1954, so you have a way to go to catch up to my experience. I was a USAF aerial reconnaissance photographer and you have seen many of the prints that I printed. Just look at the 5" roll aerial obliques from the Cuba Crisis. Most of those I printed.i am a graduate of the USAF photo school and was also a by pass photo specialist in photography prior to completing basic training in the Air Force. Before joining the AF I was a photographer for a major university and a stringer for a major newspaper.
    After the AF I owned my own studio doing police, fire, news, commercial, portrait and wedding photography in the NYC metropolitan area.
    After selling my studio I became the Product Manager for Beseler enlargers. After Beseler I was involved with Rollie as a Product Manager, Marketing Manager and a Sales Manager for 7 northeast states. Following that I was involved as a marketing specialist for Durst, Ademco, Sinar , Broncolor, and other pro lines, then I spent 35 years as the Product Manager and National Sales Manager for Linhof, Rodenstock, Rollei, Meopta, Kaiser, Heliopan, Gepe, Gepe Pro, B+W, Novoflex and many other professional photo products.

    Properly installed Anti Newton glass on an enlarger or on a transparency is never a problem as the Anti Newton glass is always placed against the base side of the film while the enlarger or the slide projector is always focused on the emulsion side of the film. So you can not bring the Anti Newton treatment on the glass into focus on the print or on the projection screen. This presumes, of course, that you have properly treated glass for the Anti Newton side of the glass. That normally means that the treatment was etched onto the glass by an acid treatment. Cheaply or poorly treated glass usually has a sprayed on surface and that can create problems.

    As for popping, there are standards for the temperature at the film gate of a projector and the film stage of an enlarger and regardless of your light source film will change position or pop during exposure. After all, film is normally at room temperature and during its time under the light the film will gain heat. And this results in popping. Furthermore film sags or curls towards the emulsion side. Those two reason are why glass is required. There is no substitute for glass, even carriers that stretch film, like the NegaFlat, grip the film and can leave marks on the film.

    So, apparently there is the best of correct way and your way. The OP is going to get his best results with a properly aligned enlarger; film stage to lens stage to baseboard; a quality piece of film in an Anti Newton glass carrier and a quality lens at optimal aperture and within the optimal Magnification that the lens is designed for.

    Otherwise he will never obtain optimal performance, and neither will you. Sorry for being so blunt, but 30 years is really not a lot of experience.
     
  7. I said 40 years, not 30 Bob. I built my own darkroom at the age of 13.

    Anyway, the OP (remember him?) asked about the availability of a glassless carrier for 645. Therefore I have to assume that he considers a glassless carrier sufficient for his needs.

    Also, there is no glass plate holding the film flat in a large format camera, so why should it be deemed essential in the enlarger?

    And BTW: The conditions in enlarging mean that the negative is the subject or "field". Therefore depth-of-field applies to the film, and depth-of-focus to the print.
     
  8. Joe, depth of focus is the distance behind the lens where the film lies. Depth of field is the distance in front of the lens that appears in apparently sharp focus. Diffraction will occur on the paper side of the lens when you stop down too far.
    Sorry if I chopped off 10 years on you. It wasn't intentional.
     
  9. Agree with post #2. You may don`t need a 645 carrier (unless you were using it a lot, for convenience reasons). I have glassless carriers for all formats and just one AN glass for the largest, despite of the enlarger. It is the one I use more. (I also have carriers with glass only in one side). Another fast choice is to use two sheets of glass to sandwich whatever the film you were using. Just buy two photo frames made with 2mm glass. You can mask it at your taste (think that the film should be in contact with the glass).

    FWIW, I still experience popping with some negatives when using hot bulbs. Sometimes I suspect the negative base or age counts, not sure about it. I enlarge negatives either from the 60s (thicker, curved, -another old croc here-) to current ones (thinner, flatter). It was my main reason to switch to LED sources in my smaller enlargers (I also prefer to use glassless negative carriers for 35mm format).
    Also, AN glass is desirable. I can get AN rings quite easily, specially in 120 film, don`t ask me why. Maybe the thickness and surface of the film, again.
    The lens issue; check your lens. It could happen that field curvature force you to close the lens more than you`d like, despite of diffraction. It could make a glass carrier to be desirable, too.
     
    Last edited: Apr 27, 2017
  10. Hmmm, I actually don`t know if older films are thicker, or simply more rigid... or maybe both...
    And BTW, some glassless carriers are badly manufactured, made in a very soft material, so they don`t really hold the film as flat as one would expect. Don`t know the Omega ones, mine (vintage) ones are pretty good. And the glass on the carrier is obvious to be used as a mirror when aligning the enlarger... two more reasons to use glass carriers.
     
    Last edited: Apr 27, 2017
  11. I am using an Omega D5 XL enlarger with the Super D Dichroic II lamphouse so negative popping is not an issue and the Omega glassless carriers have held the film flat up to 4x5 negatives.
     
  12. I've had neg popping problems and though one can use a workflow that minimizes the problem, subtle neg motion will still reduce the quality of your prints. Glass carriers will solve the problem, but I don't have the money to buy them or the patience to keep them clean. Instead, a heat absorbing glass takes care of most of the problem. No doubt you don't get perfect optical quality without glass, but how much is good enough? Another little appreciated thing that kills quality is rolled edges on negative carriers. Some are produced using a sanding process (Timesaver machine) that removes too much metal at the edges, moving the support away from the frame. Same reason I think filed out carriers are stupid. The best carriers I've made myself from aluminum sheet. Whatever you're using, put a grain focuser on center and watch the sharpness as the enlarger warms up. If the focus isn't dead stable, start applying fixes.
     
  13. I've never been a fan of the glass carriers and it never seems to fail, once the negative warms up a bit it will pop, the bigger the negative the more obvious it is but I notice it mostly on medium format. Simple solution is to simply put the negative and carrier in the enlarger and let it pop, then do your fine focus. Be ready to put paper in the easel and expose within a few seconds of completing your focus and there won't be a problem.

    Rick H.
     
  14. Glass carriers do two important and vital things to ensure optimal print quality.
    1 they hold the film flat
    2 they prevent popping

    Your solution only partially accomplish 1 of these and does nothing for the other.
     
  15. I'm pretty sure that I have one. Send me a private message.

    Oops -- I see that this is a fairly old thread.
     
    Last edited: Dec 17, 2017

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