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Thread: Ir Photography

  1. #11
    jim kirk jr.'s Avatar
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    Quote Originally Posted by Robert Hall
    I hear you on that first one!

    But this is an interesting point on the new film. The huge difference that some folks are getting used to is that MACO is panchromatic film (unlike the orthocromatic characteristics of HIE). I wonder, exactly, how much difference another 20nm of sensitivity will change the "look" of the IR.

    Kodak "works" with the red 25 because its orthochromatic. It might be nice to have less visible light sensitivity instead of more IR light sensitivity. I would think that MACO film may see more success if one could hand hold the camera. My exposures are 30 seconds to 1 minute at f/64. There are times I would like non-blurry clouds.
    Tell me about it-I've had exposures as long as 4 minutes at f/19.Not fun when your outside hoping that no breeze comes along and blows something on the front of the filter.
    "An object never performs the same function as its name or its image"-Rene Magritte

    "An image of a dog does not bite"-William James applied to photography

  2. #12
    Robert Hall's Avatar
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    Quote Originally Posted by jim kirk jr.
    Tell me about it-I've had exposures as long as 4 minutes at f/19.Not fun when your outside hoping that no breeze comes along and blows something on the front of the filter.
    My wife has a hard time understanding why a "perfect day" is no wind when its above 95 in the high desert. (she shoot tri-x and doesn't quite get the multi minute exposure thing.)
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    Technology is not a panacea. It alone will not move your art forward. Only through developing your own aesthetic - free from the tools that create it - can you find new dimension to your work.

  3. #13
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    This may be a dumb question but, I think it's related...

    Does IR film require special handling?

    I ask because, I have a changing bag that says "Not safe for IR film" on it (actually on the box it came in) and always wondered what that meant.

  4. #14
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    Quote Originally Posted by GaussianNoise
    This may be a dumb question but, I think it's related...

    Does IR film require special handling?

    I ask because, I have a changing bag that says "Not safe for IR film" on it (actually on the box it came in) and always wondered what that meant.
    The short answer is, "Yes."

    In most cases, it is recommended to load/unload the camera in "total darkness", with emphasis on the "total" part. Many seemingly opaque materials are essentially transparent to IR. That includes many changing bags, and some plastic cameras, too.
    [COLOR=SlateGray]"You can't depend on your eyes if your imagination is out of focus." -Mark Twain[/COLOR]

    Ralph Barker
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    Quote Originally Posted by Ole
    I was under the impression that chlorophyll fluoresces in IR, and that's why healthy foliage is bright, while dead and diseased is dark?
    Odd... this is the first time I've heard of ANYTHING fluorescing under Infra Red light. Ultra Violet, yes, certainly ... but IR?

    Come to think of it ... fluorescence is - or would be - the conversion of "Ultra" - or "Infra" into visible light ... so no specialized film would be necessary, anyway.
    Carpe erratum!!

    Ed Sukach, FFP.

  6. #16
    jim kirk jr.'s Avatar
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    Quote Originally Posted by GaussianNoise
    This may be a dumb question but, I think it's related...

    Does IR film require special handling?

    I ask because, I have a changing bag that says "Not safe for IR film" on it (actually on the box it came in) and always wondered what that meant.
    Depends on the film.Kodak IR I would say yes-in darkness.With Maco 820,konica 750 shade is good enough in my experience.Shade being under a tree or the non-sunlit area in the back of my car(tinted windows)or in a
    building with no lights on(only the light to see with).I've even heard of some
    who do "nothing different with Maco 820 than they do with TRi-X")Most warnings for IR film apply at present only really to Kodaks films(BW and false
    color)at least in my experience.
    "An object never performs the same function as its name or its image"-Rene Magritte

    "An image of a dog does not bite"-William James applied to photography

  7. #17
    Ole
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    Quote Originally Posted by Ed Sukach
    Odd... this is the first time I've heard of ANYTHING fluorescing under Infra Red light. Ultra Violet, yes, certainly ... but IR?

    Come to think of it ... fluorescence is - or would be - the conversion of "Ultra" - or "Infra" into visible light ... so no specialized film would be necessary, anyway.
    Eh, no, lots of things give out IR light when irradiated with visible light. Fluorescence is the "conversion" of light to light with a
    longer wavelength. What we usually think of as fluorescence is absorbtion of UV light followed but emission of visible light. So when visible light is absorbed, some of it may be emitted as IR light. I thought I read somewhere that this is what happens in chlorophyll, so that "reflects" what amounts to more than 100% of infalling IR light.
    -- Ole Tjugen, Luddite Elitist
    Norway

  8. #18
    Robert Hall's Avatar
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    This excerpt is from the text I use:

    "The explanation of the white appearance will be clear from a consideration of Figure 55, which is taken from the work of Willstaetter and Stoll, and which shows how light is reflected internally in a leaf. The light passes through the epidermis and the palisade cells, but is scattered diffusely and even reflected back towards its source in the spongy parenchyma, the interstices between which are filled with air. Mecke and Baldwin pointed out he similarity of behaviour between the leaf and freshly fallen snow (!!!), the bright reflection of which is due to the presence of air between the small ice crystals. If snow is pressed or tamped, it becomes darker and transparent. The same occurs in case of a leaf. If the air is removed by the leaf being placed in a vacuum, and if it then placed in water to fill the air spaces, no difference results which is visible to the eye, since the chlorophyll absorbs most of the light. In the infrared, however, to which chlorophyll is transparent, the bright reflection of the leaf is almost completely lost, and the leaf becoms relatively transparent."

    Many things are opaque to our eye but to different wavelengths it is transparent or partially so. X-rays are and example.

    As to using a light meter, the variable in IR light and visible light is the make up of the light itself. If one uses a meter and measures 4EV, it doesn’t say how much of that is IR light. As the sunlight passes through our atmosphere, blue light is blocked and IR passes. That's, of course, what makes the mountains glow red in the evening (Alpen Glow). For those without mountains, I'm truly sorry. Therefore if we rely upon an instrument to measure something it's not calibrated for, one is basically guessing as to what the exposure really should be.

    Personally, I my experience has shown that our highlights (such as the ir highlights we look for in IR film) get enough exposure, perhaps, overwhelmingly so. It's the shadow areas that need more exposure, hence, "Expose for shadow, and develop for highlights". I expose as I do in order to bring up shadow areas in my images to I don't end up with entirely non printable shadow area.

    Blue light fills shadow areas. Those who shoot color film may use a filter to compensate for that. So if the light in the shadow areas is mainly blue light, then measuring the light with a light meter in the shadow areas is folly due to the utter lack of IR in the shadow areas. Blue light bounces a little better than ir due to it's wavelength, hence it fills shadow areas where IR does not.

    This is what I use to determine my exposures. YMMV.
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    Technology is not a panacea. It alone will not move your art forward. Only through developing your own aesthetic - free from the tools that create it - can you find new dimension to your work.

  9. #19

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    :o Darn, Next time I have to stay up and follow the post's.
    Thank you all for your answer and explanations.
    Ralph, Nice Picture. But stopping down ? You gave 8 stop's less exposure than metered ?
    Ole and Robert your explanations about Cells and flourescence was some usefull reminders. Mr Noise brought up a good point. I know that maco recommends subdued light in the 35mm case but as I recall the 120 films are not as critical because of the paperbacking.
    Ole I would like to know more about materials flourescensing IR radiation.
    And last, will my Rodinal do as developer
    Regards Søren

  10. #20

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    I am going to make myself very unpopular here, but I have had better IR results with a D.....l camera than I did with film. Sorry, I guess the things had to be useful for something. Apparently, it only works with some models. I have an Olympus C8080 which is particularly good in this role.

    David.

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