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  1. #11

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    These are some results I got from my controlled very long aperture priority AE exposure with Kodak Gold 100. These are unretouched straight-up neutral scans. Background and base are white foam core boards so you can easily adjust colors as needed. Of course this film has so much latitude that meter can be off by -2 or +6 stops and still be automatically recovered with no problems so I should try it with slide film.




    Link to larger version -> Gold 100 long exposures.jpg

  2. #12

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    FWIW The Luna Pro's calculator goes to 8hrs. Accurate? At least as a SWAG.
    Heavily sedated for your protection.

  3. #13

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    Quote Originally Posted by Les Sarile View Post
    These are some results I got from my controlled very long aperture priority AE exposure with Kodak Gold 100. These are unretouched straight-up neutral scans. Background and base are white foam core boards so you can easily adjust colors as needed. Of course this film has so much latitude that meter can be off by -2 or +6 stops and still be automatically recovered with no problems so I should try it with slide film.




    Link to larger version -> Gold 100 long exposures.jpg
    Thank you for the post Les, that confirms what I heard and read. At least for negative film.
    Have you done color correction on your samples? I was thinking it may cause color shift.

  4. #14

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    Quote Originally Posted by MFstooges View Post
    Have you done color correction on your samples? I was thinking it may cause color shift.
    All my scans from the Coolscan are neutral - all color settings off, with no pre or post anything.

  5. #15
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    When you hit reciprocity failure, the exposure becomes a function of how an individual emulsion responds, so what may work with one emulsion may not work with another. IME building a knowledge base with bulb exposures is the way to go. Les Sarile's test is very impressive, but it isn't a sky scape. Also, depending on subject and emulsuion, you may get an expansion effect, because some parts fail and others don't, particularly if your exposure times/exposure levels for some parts of the comp fall somewhere near the point of failure. For star trails with a dark sky you probably aren't seeing much effect because the dark part isn't exposing enough to fail, and the stars are exposing plenty while they track through the frame. Using AE probably isn't going to trip the shutter until enough photons have added up to wash out the sky, what the camera would see as a proper middle of the road exposure, so works great for the bridge shot and the crayons but not as well for something when you want the predominant part of the composition to be black, or at least dark sky. I used to paint foreground objects with a flashlight, and sometimes it worked out pretty cool. If you have a somewhat light polluted sky reciprocity failure is your friend, helping to hold back the sky while the brighter stars expose, but of course some of this is negated by the stars being apparently dimmer, and dimmer stars being drowned out all together. All in all light pollution sucks, destroys the night sky for astronomers, photographers, and lovers alike, wastes energy on a vast scale, and should be seriously against the law. Ask me about my real opinion on it sometime. I have noodled using a filter that blocks the wavelengths common to city light so I can shoot from my current location, but I haven't noodled what that filter/s might be. One thing I can tell you is that you will likely be amazed at the difference a truly dark sky can bring out, and beyond having no moon in the frame, having no moon in the sky at all can bring out several magnitudes more of stars. In my experience if you have a truly dark sky, you almost can't screw it up. (and if someone could, that would be me)

    If you are feeling particularly exotic you can hyper your film: http://www.astropix.com/HTML/I_ASTROP/FILM/HYPERING.HTM

    I think I still have some hypering junk laying around somewhere.

    Nowadays I use the imaging technique that shall not be mentioned for my astrophotography. Funny this thread has come up, I've just started getting back in to it. I have been thinking of piggy backing on of my fim cameras onto my EQ mount and doing some wide field MilkyWay exposures, but I'll have to get a ways out of town for that.
    Last edited by JBrunner; 12-04-2011 at 08:57 PM. Click to view previous post history.

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