Have to expose for 1 hour in daylight...

Discussion in 'Exposure Discussion' started by George Papantoniou, Nov 2, 2005.

  1. George Papantoniou

    George Papantoniou Member

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    I want to make pictures in plain daylight (cloudy day) with my Linhof 4x5 but I need to have REALLY long exposure times... (1 hour). I need normal contrast negs for printing...

    One thought was to expose Ilford ortho film with a red filter. Do you think this would allow me to expose for an hour with say, an f16 or f22 ? I guess the red filter for the ortho film will be much stronger than an ND for a panchromatic one...

    On the other hand I can put several ND's one on top of the other, but then I risk vignetting (too many screw-on filters) and they will cost me a fortune to buy...

    I could use an IR filter but I don't know if there will be anything on the film (even if I use a pan film).

    Are there any more ideas ??
     
  2. Ole

    Ole Moderator Staff Member Moderator

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    When we had a partial solar eclipse a few years ago, I shot it with APX100 and an IR filter (Lee gel). 1 second at f:8 was spot on - for the sun itself.

    But it all depends on the spectral response of the film, the spectral transmission of the filter, and... It's almost impossible to predict. Especially if you don't have APX 100, which I have used that way once.

    Very slow film and dense ND filters are the best bet.
     
  3. FrankB

    FrankB Member

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    Hi George,

    You don't say what you're trying to achieve. Could you get an acceptable result via multiple exposures over a period of time?

    All the best,

    Frank
     
  4. Mongo

    Mongo Member

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    Any particular reason you don't want to stack ND filters? I'd think that would be the easiest way to get where you want to go...not, perhaps, the best way optically, but in a 1 hour exposure even shadows will move significantly so a little optical degredation shouldn't be awful.

    Best of luck.
    Dave
     
  5. matt miller

    matt miller Subscriber

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    You can buy sheets of ND material pretty cheap and make your own "stacked" filters. It will save you money, avoid vignetting, and allow you to experiment without too much cost.
     
  6. Early Riser

    Early Riser Subscriber

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    Don't stack too many filters. There are very dense ND filters made, B+W makes 10, 13 and 20 stop ND filters. They may be special order items but they are available.
     
  7. jimgalli

    jimgalli Subscriber

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    I have a photo of waves coming in around rocks that I did at 7 minutes with 100 asa film in daylight with just a 29 red and a polariser. With Efke 25 film that could have gotten up in the hour range pretty quicly with reciprocity. If the ortho film is true ortho you could leave a red filter on forever and get a blank sheet. There's always pinhole.
     
  8. pentaxuser

    pentaxuser Subscriber

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    Sorry no ideas.Just curiosity really but what are you taking a photo of? I have never been to your latitude in Winter or this late in Autumn but would have thought that even on cloudy days light intensity would mean that an exposure of an hour would be nearly impossible without gross over exposure even with high ND filters. I have seen a photo of a U.K. motorway with a high ND filter which looked to have no traffic because it was several minutes exposure and the vehicles didn't register but this was only a few minutes not anything like an hour.

    Pentaxuser
     
  9. Loose Gravel

    Loose Gravel Member

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    If you are using slow film and can stop down to f/45 or better, then use ND4.0, which is 13 stops. This should get you pretty close if you add the reciprocity. Sure hope your camera doesn't leak.
     
  10. Mongo

    Mongo Member

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    After posting my earlier reply, I thought about this some more. I've had exposures go up to 15 minutes without even trying...bright days, but slow films with very small apertures. Shooting an APO-Nikkor 480mm f/9 at, I believe, f/45 with some bellows extension thrown in, I got into the land of reciprocity failure and was shooting for 15 minutes. (More like 20 minutes to complete the shot, as I would cover the lens whenever a car drove by to avoid any chance of reflections in the pond I was shooting into...almost certainly being too anal, but feeling I'd rather be safe than sorry.) It wouldn't have taken much of an ND filter to push me up to an hour given the reciprocity characteristics of the film I was using.

    My point is, if you can get bellows extension thrown into the equation along with a small aperture and slow film, you might not be far from getting out to an hour for an exposure. Without the bellows extension, it might be worth figuring out which films would give you the greatest reciprocity failure. (I know that Efke films aren't particularly forgiving in this regard.)

    Again, best of luck with your project.
    Dave
     
  11. waynecrider

    waynecrider Member

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    What about using a pinhole and some ND's.
     
  12. George Papantoniou

    George Papantoniou Member

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    Thank you all for your interesting suggestions.

    I just want to shoot in busy city streets and have the traffic out of the picture and the shadows blurred. As you suggest, maybe a quarter of an hour is enough. Yes, the light (even in winter) is quite strong so it'll be more difficult than in Norway (this time of the year)... The winter daylight in Athens is beautiful, on the other hand... especially some days when the smog is not present...

    I have to order some Efke 25 in 4x5, since there is no way to find it here in Athens.

    I don't want to stack NDs because of the vignetting (I might be using a wide angle) and the price. I don't want the pinhole "look" and I am afraid the cheap ND in sheets will degrade the picture quality even if I place them behind the lens (as diffraction when using f45 will, too).

    I cannot have a bellows extension when not shooting close-up...

    I know that reciprocity failure will help, although I am not aware of the degree (with Efke film)... does someone have a fact sheet with the necessary reciprocity correction with the Efke 25 ?

    I will make some tests to see what exp. times I get with an ISO 25 film and a red filter (or maybe just ONE ND filter) and see how it goes...
     
  13. Mongo

    Mongo Member

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    See http://www.jandcphoto.com/index.asp?PageAction=Custom&ID=1 for everything you need to know about the Efke films, including reciprocity data. I think with one decent 3-stop ND filter (remember, if you mount the filter on the back of the lens the coatings aren't nearly as important since you're not exposing the filter to direct light from the sides), a small aperture, and Efke 25, you should be able to get your exposure pretty long without resorting to any other "tricks".

    Good luck with your experiments. I'd love to see the results when you're done.

    Be well.
    Dave
     
  14. Samuel Hotton

    Samuel Hotton Member

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    The easiest way I know to do this exposure is to use 2 polariser filters. When they are dialed one way you have moderate ND which makes focussing easy, when dialed the other you get virtually no transmission of light. Combine this with f stops and you will have your 1 hour exposure. Experiment with some P-roid films or by mounting the P-roid filters on a 35mm or 2 1/4 camera. Do a few tests, mark your filters with a dot of typewriter white out on the filter rim. Not a problem. Let us know if this solution works for you.
    Sam Hotton
     
  15. Wally H

    Wally H Member

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    Hi George,

    I've done what you are trying to do a couple of different ways, 1) with long exposure as you were eluding to (and it seems you know how the get those now) and 2) by multiple exposures. If you have a given base exposure, divide it by at least four. An exposure for 1/4 of the base exposure time is about the point where the subject will not register on film and/or will become very ghost like. Note that reciprocity failure can be introduced in some films when doing multiple exposures (in particular color films).
     
  16. Helen B

    Helen B Member

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    Why not use a speed reducing developer, like PPD, possibly in addition to the other methods described above?

    Best,
    Helen
     
  17. Christopher Colley

    Christopher Colley Member

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    for a 1 second exposure (at f/1 for example), 12 steps away brings you to 60minutes (or f/64), well within the range of ND filters

    a photographer you might already be aware of, who could be of some interest as they produce photographs similar to what you seem to want, long exposures of the street with a large format, in this photographer, Tokihiro Sato's case an 8x10

    http://photoarts.com/gallery/SATO/87.html dont know if the top right corner is due to movements or not..

    http://photoarts.com/gallery/SATO/106.html

    http://photoarts.com/gallery/SATO/satoexh.html

    http://www.tonkonow.com/sato.html
     
  18. photobackpacker

    photobackpacker Advertiser Advertiser

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    Hi George;

    As you may be aware, John Sexton works very effectively with long exposures - enjoying the quality of emerging or dwindling light. He has provided a guide to reciprocity departure using TMax film which may be of interest to you. I have used his guide with good results.

    His recommendation for TMax 100 (EI 64) at a meter indicated exposure of 15 minutes should actually be exposed for 60 minutes. With this exposure, the negative will yield an N+2 contrast. To achieve normal contrast, you would want to plan for contracted development by derating the film speed by 1/3 to 2/3 of a stop to preserve shadow detail and giving N-2 development.

    All of this would work toward your desired longer exposure.

    Bruce
     
  19. George Papantoniou

    George Papantoniou Member

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    Thank you all again for your help.

    I've thought about the two polarisers already, it's a somewhat expensive solution (if I want to get two good ones)...

    This Sato guy is great, I didn't know about him... he goes around with a flash or a torch and creates those strange light spots, huh ?

    Thank you for the info on Tmax film, although I'd never use it...

    I am afraid that I heve still not found the time to experiment with this thing, but I will soon, and I'll let you know how it has come out...
     
  20. George Papantoniou

    George Papantoniou Member

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    Hi guys and girls, I finally found the time to make some tests and here are the results:

    Shot Fortepan 200 with an IR filter (the one that is too dark to see anything but the sun through it) at f8 and an exposure of 3.25 hours gave excellent results (rodinal 1+50, 11 min).

    Shot Ilford Ortho with a deep red filter and f32 for 30 minutes and the results were OK too. Developed it toghether with the Forte, but it actually needed less time in the soup (8 minutes would have given great highlight detail, now they are dense).

    All tests were made at bright sunlight, outside.

    Already posted this in a more recent relative thread, but I just wanted you to know I haven't forgot about this one :smile: