Large Format, Instant Fuji, Night Exposure.

Discussion in 'Large Format Cameras and Accessories' started by James MCA, Aug 12, 2009.

  1. James MCA

    James MCA Member

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    Last night i tried to shoot the Perseid meteor shower on my Fuji instant back (iso 100), One Exposure for 30mins at f11, And another at 15mins at f5.6, looking back at this now that was quite silly of me! Both exposures turned out very little indeed.
    So i was wondering what i should do about this? Does instant film have a fall off point where it stops working? am i not exposing for long enough?
    Any help would be most welcome.
    James.
    (my first post so be kind)
     
  2. TheFlyingCamera

    TheFlyingCamera Membership Council Council

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    I'm not sure about the Fuji, but back when Polaroid still made instant film, reciprocity began somewhere around 1/10th of a second, and anything beyond 1 second was an abysmal mess if not an outright failure. Fuji's materials may have a similar threshold.
     
  3. david_mizen

    david_mizen Member

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    ive done a bit of this sort of thing reciprocity is an issue i have no idea what spec your polariod is but it sounds like part of the problem you dont say where your shooting from ive done some similar type of shots from my home location (metro perth western australia) and some from rural areas the rural shots have largely been ok but those take near home have ended up with a brown sky and little else which as i understand the problem it cause by light pollution the other thing is that ive generally only used faster film (400-800 1600) 100 iso will struggle no matter what the circumstances
     
  4. James MCA

    James MCA Member

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    I Live in Canada, I went out to a friends house who lives in the bush, There was no light pollution. I guess the whole 100 iso will be the main problem.
     
  5. Ralph Javins

    Ralph Javins Member

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    Good morning, James;

    Lucky you. You got to see them. Out here in Latte Land, we had our usual cover of clouds.

    The slow speed reciprocity failure effect with the old Polaroid film equivalent is something that I have experienced also, although I am not sure about short term transient phenomena in long exposures. It is not clear that the Fuji film is the same, but I also suspect that it is.

    Out here in Latte Land, the light pollution from the metropolitan area has limited my efforts to a maximum exposure time of about 5 minutes with ASA 400 35mm film, before noticeable fogging begins to develop. With that film and a 58mm f:1.2 lens wide open, I have recorded some trails in the past. My results with a 16mm f4.0 lens were not as productive, but they did show that there is merit in using a wider lens. Taking some ASA 1600 or 3200 film out to a dark sky site in Eastern Washington or Eastern Oregon some time is still on my list of things to do. Perhaps for the Leonids this year.
     
  6. keithwms

    keithwms Member

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    To shoot stars, remember that they are point sources of light and so you need a big ratio of focal length to aperture # and a quite high ISO.

    The perseids put you at a disadvantage because they can happen over a big piece of sky, so you will be tempted to use a wide lens. That is a mistake. Remember that the f/# is the ratio of focal length to pupil diameter, so it basically defines the cone angle of a light funnel. So... for shooting stars, resist the temptation to go super wide, you'll actually get better results from a longer lens with a wide max aperture than you will from a wide lens with a wide maximum aperture. E.g. a 100/2.8 will kick the butt of a 35/1.4 when trying to shoot stars, especially if you are limited to lowish ISO. Somewhere you will find a star 'magnitude' discussion in the context of photography that may help understand this. It is not immediately intuitive so be patient.

    And remember that the perseids are so named because they seem to radiate from that constellation, so you might try cropping in a bit on the constellation and hope for the best :wink:

    Also, you cannot expect good results with ISO 100, I think. I expect that you really want ISO 400 at least, and I'd be more inclined to go much faster but it depends on the lenses available and what field of view you're after.

    So.. overall, this doesn't strike me as something to tackle with 100 speed instant film. If it must be instant then the fuji 3000b would be a more interesting choice.
     
  7. keithwms

    keithwms Member

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    P.S. I just re-read your post and saw that you tried f/5.6 and f/11 at ISO 100. That is not going to cut it, not even close. You need to shoot wide open and with much higher ISO if possible. Bear in mind that astro-photographers go to extremes of ISO by hypering, and not because the like playing with hydrogen :wink: ISO 100 is a nonstarter at those apertures unless your focal length is reaaally long.