4x5 Delta 100 - 1 month before I can develop negatives

Discussion in 'Black and White' started by dw|1, Sep 24, 2009.

  1. I've moved to 4x5. Shooting Delta 100. Kodak, for instance, recommends
    development within 72 hours - or storing in an airtight, cool environment.
    Well - I'm going on a road trip and won't be able to develop the negatives for
    about 1 month after exposure. The exposed holders will be in a box in my car.
    It is the "cool season" where I'm going, so the negatives won't get too hot.
    Obviously the box is not airtight. I'm considering buying a small food sealer,
    but obviously I prefer to avoid dragging that with me unless really needed.
    My question is about what I can expect from waiting this long, in general.
    Also, is the airtight storage critical or will the cool'ish temperatures suffice.
    I'm using DDX,with the Delta 100 if that is of relevance.
    THANKS
     
  2. Sooner is better, but you should be ok as long as the film doesn't get too hot. Manufacturers are always very conservative in their recommendations, it's a CYA strategy.
     
  3. I think the key is whether the film is kept cool enough. Remember that even in cool weather, the "greenhouse" interior of the car can get pretty hot. How much film are you planning on shooting?
    I used foam picnic cases for 4x5 Polaroid Type 52 film before it was processed in that case; and the film stayed usable, even in the American Southeast in the summertime.
     
  4. The latent image on film begins to degrade as soon as the photo is taken. Films differ in how long after they are exposed before the image is in poor shape. In general it goes like this.
    For best quality (100%) develop within an hour.
    For (99%) develop within 8 hours.
    For (97%) develop with a day.
    For (96%) develop with a week.
    For (95%) develop within a month.
    For (90%) develop within 6 months.
    etc.
    You get the idea. There is not a big change after the first few days as long as the film is stored away from excessive heat and humidity. Normally all of us take a few days to develop our film so you will probally see no problems as long as the car stays cool. You could always mail the exposed sheets every few days for someone to store in their fridge till you get home.
    PS I recently developed a roll of Panatomic-X exposed in 1983 with OK results. See my post on Photo Net.
     
  5. Brian: Where did those numbers come from? I often have to wait months before doing b&w sheet film. Have never noticed any difference between that and the film done within a few days. I don't refrigerate it either.
     
  6. I have 75 holders, so 150 negatives. I can deal with a 5% to 10% reduction since this is
    my first 4x5 adventure -- ie., latency will likely be the least of my headaches. Nevertheless,
    no use burning a strike if I don't have to so I'll keep the box in the trunk, away from windows.
    Thanks
     
  7. The % numbers I gave were just made up by me as I don't have the source in front of me and I haven't been able to find it in the last few minutes of looking. Still I said "in general" and it was just meaning to set an example.
    The idea is there is a an exponential and rapid decline in the first few days after shooting the film. BUT this decline is SMALL. It can be seen in controlled side by side test but WILL NOT be noticed in general use.
    Think about it this way. With roll film it is VERY common to take a week or more to shoot the roll. If there was a big difference we would see a difference in the first negatives vs the last negatives shot.
     
  8. Still no luck finding my print article but I did find this one online about the stability of B&W paper when it is exposed and developed at once or after a wait of up to 4 hours. See here for results.
    http://www.apug.org/forums/forum41/65780-expose-develop-delay-time.html
     
  9. Thanks Brian. I appreciate your effort. Best Regards.
     
  10. The latent image of normally exposed slow and moderately fast speed films is usually very stable. Avoid underexposure and your film should be in good shape.
    Don't delay processing of ultra-fast films (Delta 3200, TMZ, etc.) or pushed films. Ultra-fast films tend to accumulate fog fairly quickly. Underexposed film tends to lose shadow detail very quickly. The worse the underexposure, the more rapidly film will lose what little shadow detail might have been captured. I've seen my own "pushed" film (such as ISO 400 film pushed to 1600) lose significant latent image in less than a month.
    But normally exposed slow and moderate speed films appear to be very stable. If I anticipated a long delay between exposure and developing and wanted the best possible results I'd stick with ISO 400 or slower film and give and re-rate it downward, around 1/3 to 1/2 stop slower than the rated ISO, to ensure good stability of the latent image in shadow areas.
     
  11. Brian, I'd heard quite some time ago that its actually better to wait at least an hour (after exposure) prior to processing - as there are, for at least a few minutes after exposure, some still-excited electrons bouncing around, and that they need some time to quiet down. Any comments?
     
  12. ps... some time ago, I ran across a B+W Tri-X film I'd exposed many years previous, and "normal" processing of this gave perfectly fine results.
    Then there was the 1930's vintage box camera - complete with exposed film.... that I'd bought at a (mid 1990's) yard sale. Upon processing this film, I'd realized, from the surroundings/clothing of the subjects, that the vintage of the photos was about the same as that of the camera. A fair amount of base fog - but printable!
     
  13. There is no big problem with B & W. Avoid excessive heat and humidity. Obviously, it is preferable to develop the film as soon as possible. Think tanks take with you and dry chemical. But unlike color film ( except that Kodachrome is based emulsion BW and receives its colors during development - which explains its success, including National Geographic), the B & W is resistant over time.
    Take great pictures.
    Hoping you have helped
    Regards,
    Jean-Marc "MM"
     
  14. John, as far a waiting at least an hour after exposure before developing the film. I am not sure why you were told this but will guess. I am a scientist and photographer. This is a guess based on my experience and reading but I may be totally wrong. There is a technique I have used for film and paper called pre-flashing. In short you give the emulsion a brief WEAK non-image forming burst of light. If done properly it will increase the sensitivity (ISO if you will) of the emulsion but have little if any effect on the base fog. This effect is shot lived. The emulsion must be pre-flashed and exposed to image forming light in a short period of time or it will behave like regular film. The theory (explained in easy speak) goes like this. When a photosensitive molecule absorbs a photon of light its electrons are excited. If there was enough energy absorbed a permanent chemical change occurs. If not enough energy was in the photon then the electron is only half way to where it needs to be. If nothing further happens in the near future it will fall back to its low energy state and no permanent change will occur. If however the molecule absorbs another photon there is enough energy for permanent change (latent image) to form. It may be there is a similar effect in developing film just after exposure. Tri-x may behave as 800 speed (I donโ€™t know this it is just and example). If this were so and you developed too soon you would get overexposed film. So that is why you may have been told to wait and hour. Where I get this idea is Polaroid film. It is usually fast 600 to 3200 speed. It is always developed seconds after exposure. Perhaps this high speed comes from rapid development after exposure. This is not a problem if you designed the film for this.
     

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