Using a digicam as a meter/polaroid

Discussion in 'Exposure Discussion' started by Early Riser, Feb 5, 2009.

  1. Early Riser

    Early Riser Subscriber

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    I figured before I started all my testing and synchronizing my digicam to B&W film I thought I'd ask a few questions first and see if others have gone down this road before. Please keep in mind hat I am not talking about the use of the digi cam as the final image capture device, that will be film. But I am trying to replicate the use of polaroid as a test or visualization tool with the digicam.

    Is there any sort of reciprocity failure that digicams get when working at long exposures? Like 1-15 minutes?

    Is the color sensitivity of the ccd's completely linear when used in B&W mode or do they have varying color sensitivities like B&W film?


    Any experience or advice would be appreciated. Thanks.
     
  2. bobwysiwyg

    bobwysiwyg Subscriber

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    On this issue, the digicam's equivalent is "noise." The longer the shutter is open, the greater the likelihood of noise.
     
  3. keithwms

    keithwms Member

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    No, there is no recip. failure. You have to consider that separately. (Of course, recip. failure for polaroid was always quite different form that of the shooting film anyway, so, no big loss...)

    The response is very linear.

    My advice is, to get the most out of your results, learn how to use the histograms and highlight warnings etc. Do a couple of trials to see how much range you can capture in your digicam.

    Do also consider the wonderful fuji instant films for proofing... even for final shots as well, it's great stuff.
     
  4. archphoto

    archphoto Member

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    I have been considering to go that way too, Early Riser.
    With the prices of old stock Polaroid gone through the roof and Fuji getting verry expensive too it will be the best bet.

    Noise will be of no issue as you use a digicam as a measuring instrument to check your exposure and composition, the later a bit hard to see on a relative small screen.
    Last night I did some testing for a different reason and my exposure of 30 sec > f:8 at 100 ISO came out good. (nightscene over town)
    Your best bet would be a camera with an Aperture preferred setting as on 4x5 inch you will be using f:22 .

    Peter
     
  5. L Gebhardt

    L Gebhardt Subscriber

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    The aperture range on the digicams is what killed this method it for me. The digicams I have only stop down to f/8. This makes it very hard to use as a preview of what the image will look like (think moving water). It also required more calculation to translate into the 4x5 exposer than my brain was able to do quickly. And a DSLR is way to heavy to carry around as a light meter. It is just much easier to use the spot meter for me.
     
  6. keithwms

    keithwms Member

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    I use a dslr. For a few hundred bucks you can get something like a d40 that will give you full aperture range to at least f/32, colour matrix metering, histograms... I would not recommend using a fixed-lens, p&s digital for metering. You need full aperture and shutter control, matrix metering, colour temp adjustment, individual channel histograms etc. Sounds a lot to consider at first, but just think of it as a fancy scene meter.
     
  7. OP
    OP
    Early Riser

    Early Riser Subscriber

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    I just bought the panasonic lumix G-1 for this function. It's a micro 4/3rds and it's a dslr without a mirror box so it's tiny. It uses an extreme high resolution digital viewfinder and lcd and it's lens goes to f22. I figured as a meter and polaroid substitute I'd set it to B&W ISO 100 and at F22. Then let it tell me the shutter speed. It also has a spot meter and when I put B&W contrast filters on renders the colors accordingly in B&W. I plan on mounting it to the hot shoe of my Linhof MT3000. (boy will that make the passersby scratch their heads!)
     
  8. David A. Goldfarb

    David A. Goldfarb Moderator Staff Member Moderator

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    I recently acquired a Canon 40D, and I've been thinking about this myself. It doesn't seem to exhibit RLF, and noise isn't an issue if one is only using it as a sophisticated light meter.

    I don't think matrix metering is a necessity if spot metering is an option, but of course, all metering systems work if you know how to compensate for their weaknesses.

    It seems like there's a lot of room to calibrate contrast and color temperature. You could put in a color temperature in degrees kelvin matched to the color balance of your color film, for instance, and see how it looks with different filtrations on the LCD or a laptop with a calibrated monitor and get RGB histograms.

    Ideally, it would be good to be able to match the contrast setting on the camera to B&W or color film, but I haven't tested to see if the range is there to make that work in practice. The spectral sensitivity of the sensor in monochrome mode is more like T-max 100 than Tri-X, and I don't know if there's a precise in-camera way of compensating for that (maybe a filter or two on the lens), so if you shoot T-max, it might be a better visualization tool than if you shoot a film with a more traditional kind of spectral sensitivity curve.
     
  9. df cardwell

    df cardwell Subscriber

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    You mean an Electronic Image Simulator ?

    Works great for me. The Histogram is what you want to use.
    For me, and my negatives, I can skim the edge of the Histogram,
    add a stop, and make a negative. But I set my system to to do that !

    Don't forget that a digital camera is like shooting 'chromes or Polaroid.
    You HAVE to expose for the highlights.

    I use a P&S digicam as well, has a Histogram,
    and it is pretty easy to count up from f/8.
    Good thing, I don't think I could manage from f5.6 !

    A digicam can be a GREAT previsualisation device !
     
  10. keithwms

    keithwms Member

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    David, what you can do is go to the charts on dpreview and look at the range versus contrast settings. These can be used to roughly simulate films with less range (e.g. colour slide) or more range (e.g. b&w print).

    Have a look at this...

    http://www.dpreview.com/reviews/nikond700/page20.asp

    Of course, one is always best advised to go through some standard tests and see for yourself. All I am saying is that some reputable data for most dslrs are out there already.

    One metering pitfall to watch out for: the digitals have way more IR sensitivity and how much that is "removed" by the hot mirror will vary. If you want to use the dslr as an IR meter then you probably need an additional filter (i.e. in addition to the hot mirror). I have a cutoff filter for that purpose.
     
  11. wildbill

    wildbill Member

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    You're all going to digihell:smile:
    Sure its not cheap or easy but that's not why we shoot film. Fuji's iso 100 4x5 pack film will be sold in the U.S. in a month or so.
     
  12. Peter Black

    Peter Black Subscriber

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    My limited understanding of the situation is that digital "iso"(sic) is far removed from being an internationally agreed and recognised standard, and that 200 on a Nikon meter is not the same as 200 on a Canon meter. This will mean that you'll probably have to completely test your digicam against your chosen film, and any result would not be transferable between different digicam manufacturers. Is this going to give you that 1/3 or 1/2 stop accuracy on your favourite transparency film? I'd have thought not, but then I haven't researched it. I did buy a Nikon F80 some years ago to act as a spotmeter for a 4x5, but didn't find it to be accurate enough. If you are talking b&w, then that's a whole lot of testing or just shoot XP2 at 200 or 320 and it'll just about be printable even if the digicam meter is a couple of stops off.
     
  13. df cardwell

    df cardwell Subscriber

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    Instant film should come with a Sharpie, two art directors,
    and a pint of Maalox.
     
  14. df cardwell

    df cardwell Subscriber

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    "This will mean that you'll probably have to completely test your digicam "

    Yup, just like a lightmeter. BUT you can make these assumptions:

    1. The range of the sensor is 7 stops... or less. Like Polaroid, like 'chromes.

    2. You can't judge shadows. Like Polaroids.

    3. You must judge the highlights. Like Polaroids. Like chromes.

    4. The histogram is deadly accurate. The display is helpful, but not accurate. But it is a check on your visualisation.

    Nail the conversion factor in one test roll. Easy. It's just a tool, like a meter, like anything else.

    Let's see, 8x10 film is 4 ~ 5 bucks a pop. You might only get one chance to make the picture. You get to SEE the brightness range, and for some of us visual thinkers, a Digital Image Simulator is handier than a Spreadsheet.

    Life is short, use any tool that helps.
     
  15. markbarendt

    markbarendt Subscriber

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    That's cute.

    Actually, if you are using the digi-cam ONLY as a meter/Polaroid that advice is flawed.

    The idea should be to check the exposure using a technique that maximizes the film in use. The Digi-cam can't capture the same range of stops with detail as Pan F, so why would you bother trying to save the highlights. Trying would lead you away from a maximized exposure.
     
  16. markbarendt

    markbarendt Subscriber

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    Dumb question, context first.

    It took me a year to truly understand my D200, get good with it's white balance, with it's meter, to get the camera set to spit out reasonable images, know it's strengths, idiosyncrasies, and failings, to be able to read it's histogram, and know it's limits. When I drop the shutter with that camera, nailing exposure is not an issue. The shot may have other problems, but if I paid attention, exposure is not one of them.

    If I put the year ahead into my "new" FM2 and my N90s's, with nothing but Delta 400 and Fuji 400H and use nothing but the meters in those cameras I'd expect to be just as good at nailing my exposures because I'd understand those films well, and those camera's meters well, and I'd know my real limits.

    Now the question.

    If you want to shoot film and be good at film, why in the world would I want to waste a year learning a meter?
     
  17. Peter Black

    Peter Black Subscriber

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    Maybe about 12 years ago I started in MF with a Bronica SQ-B. I'd devoured all I could on B&W and "knew" that my lack of satisfaction was down to not finding out my personal film speed for a given film & developer combination. So I took a 1 day college class where the 10 or 12 of us went through the whole painstaking routine of shooting a scene containing a white towel, a black towel and a grey card, then developed and printed the results.

    For my Bronica and Sekonic meter I hit exactly box speed :rolleyes:, yet for some reason could never quite replicate that in a real situation and was never entirely happy with the results. I now have a leaning towards some Pyro developers that have a single time for all films, or for XP2 in 35mm due to its latitude, but I still feel I'm missing out.

    Spend time getting to understand your combo of camera and meter, but don't think it is going to take anything like a year, and if you can score a shortcut using pyro or stand development, then why not?:smile:
     
  18. keithwms

    keithwms Member

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    Everyone will have his/her own opinion about the value of this or any other tool.

    At $5-10 per shot for LF slide, the [~10 minute] time it took me to familiarize myself with my dslr's metering was a very good investment. If I were shooting more 35mm film rather than MF and LF, then I'd simply rely on the in-camera meter and bracket if necessary.

    People have to use what works for them. I recall reading Adams' description of Weston's metering practices (or implied lack thereof). Adams basically painted Weston as a simpleton. That was the beginning of the decline in my respect for Adams: what a complete ass to assume that his way is the only way. Adams did what worked for him. Weston did what worked for him. As we all should.
     
  19. tiberiustibz

    tiberiustibz Member

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  20. markbarendt

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    My point exactly, the "meter" I was referring to was a digi-cam.

    The Seconic can be producing exceptional readings the day you get it. Take the cheat sheet with you and you are good to go.

    If you use a DSLR as a meter, it will take some time just to learn the DSLR.

    Given the standard 400+ page book that comes with modern DSLRs it might be a while before you get reasonable results AND they won't match the results you get from film.
     
  21. df cardwell

    df cardwell Subscriber

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    "Adams basically painted Weston as a simpleton."

    Well, Ansel doesn't need my defense, but I'll offer that you may have misread him.

    Adams revered Weston, and recognized that Weston posessed as a photographer what he, Adams, lacked as a musician and a photographer: an intuitive sense of process and vision, the ability to REACT to a scene and go straight to the image. The Zone System was a remarkable achievement, an EXPERT SYSTEM which allowed Adams to connect his heart to his mind, and make the pictures he saw when he look at the world. He understood he was not Strand, Stieglitz, or Weston: he devised a way to engineer an image that he could not flow naturally from his hands.

    The reason that this is essential for us to understand today
    is that we fall into one of three broadly drawn groups:

    intuitive photographers like Weston, who viscerally makes the process to a singular image, he just responds.

    rational photographers like Adams, who think their way through the steps to achieve an image that resembles the picture in their mind's eye.

    a mix of the two who find their balance someplace between the two extremes, of a Weston and an Adams.

    Today, if we try to work as Weston, and all too often lack both his vision and a simple but masterful technique.

    We try to work as Adams, with our spot meters, densitometers and spreadsheets, but lack Adams' great heart.

    Between these two extremes is the vast world of photography and it is up to us to find the pictures we want to make, learn ourselves, and the necessary way to accomplish what we can.

    Besides sharing their great friendship, they understood their own limitations and devised a personal technique to enable their vision. THAT is the object of their teaching, and yet we float right past it.

    For whatever its worth,
    there is a vast collection of primary sources to support this notion,
    beginning with the letters between them.

    d
     
    Last edited by a moderator: Feb 5, 2009
  22. markbarendt

    markbarendt Subscriber

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    Good reason.
     
  23. Chan Tran

    Chan Tran Member

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    A good idea but does take a lot of testing and calibration. I myself use a film scanner as a way to analyze the negative before I make the print both with color and B&W. Again this method also requires a lot of testing and calibration.
     
  24. Vaughn

    Vaughn Subscriber

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    My feelings also...:wink: But then I use an 8x10 and a spot meter. Can't seem to think of a reason to strain my eyes to look at a low res tiny little screen when I have an 8x10 high res "screen" to look at. And three or four readings with the spot meter gives me the "histogram" of the scene quite quickly.

    But I am also just using very forgiving B&W film. Sounds like a digi cam might make for a good system for getting exposure info...and someone has to buy the latest/greatest digi cameras that are no longer the lastest nor the greatest...sounds like a good use for them.