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  1. #41
    Photo Engineer's Avatar
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    Frankly, this is a non-issue! Without any concern for it, there have been millions of accurate and beautiful photos take over the last 100+ years.

    PE

  2. #42
    RalphLambrecht's Avatar
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    yes, thanks for thesobering words of wisdom!
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  3. #43
    Leigh B's Avatar
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    Quote Originally Posted by Photo Engineer View Post
    Frankly, this is a non-issue!
    Without any concern for it, there have been millions of accurate and beautiful photos take over the last 100+ years.
    Absolutely true.

    - Leigh
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  4. #44
    Bill Burk's Avatar
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    I agree the problems can be totally avoided by incident metering with a touch of judicious spotmetering.

    I don't have a Zone VI modified meter, but I think it is worth estimating the problems the modifications tried to resolve. If I find the problems only cause one stop of issue, I'm probably going to drop it in with other "one stop" issues that tend to cancel each other out.

    The article about meter modification in Zone VI Newsletter Number 37 was written by Paul Horowitz. I have to admit I like Paul's style more than Fred Picker's. He seems impartial and scientific, yet he writes clearly. (Paul gave us the stabilized cold light head. I wish I had one, I undestand those live up to the advertising claims).

    Paul introduces the problem clearly... "Objects placed on Zone V sometimes wound up on the print as Zone III, sometimes Zone VII. There seemed to be some persistent errors -- foliage always underexposed from one to three zones, sky consistently overexposed, typically a stop or more. Late afternoon often seemed to produce underexposure. And shadow areas that metered as Zone II often "dumped" into total black."

    My Sekonic L758-DR is sensitive to infrared. I get EV 12 when I meter the illuminating LED on the ATN-Viper. This is near infrared, but I've tested that it doesn't significantly fog TMY-2 in 15 minutes.

    Foliage is an interesting problem. It's green, but reflects infrared. I hunted the backyard with my first-generation infrared viewing scope looking for illogical examples. Maybe because it's late summer, I didn't find any extremes (except a red apple looked light).

    I tried to find infrared by metering first with my spotmeter (responds to infrared) then with the SEI photometer (it shouldn't respond to infrared - it uses my eye as a sensor). As Leigh points out, the angle of measurement can affect readings and natural subjects are inconsistent. I didn't find any significant departures. Sometimes I'd find one stop difference but other times I'd meter the same.

    Then I got to thinking... What do photographers sometimes do when they want to darken leaves? A red filter of course... What does a red filter do to the infrared. Trick question - it does nothing. What does it do to the visual image of a green leaf? It darkens it.

    This is where I think meters do poorly - through red filters looking at foliage!

    I aimed the Sekonic at a gray target and metered with and without the red filter. Three stops difference. I aimed the Sekonic at a dark green leaf with and without the red filter. Two stops difference.

    If I meter foliage through the red filter, the recommended exposure will be off by one stop. It will be underexposed.

    Now the fun begins. Meter places the leaf on Zone V but I previsualize a bit darker, so I place it on Zone IV. But due to the error it falls on the print at Zone III.

  5. #45
    RalphLambrecht's Avatar
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    after several dissapointing experiences witha pentax spotmete(unmodified and modified)and metering through filters, i gave up on metering through filters and aplly the filter factor sfter metering without filters.
    Regards

    Ralph W. Lambrecht
    www.darkroomagic.comrorrlambrec@ymail.com[/URL]
    www.waybeyondmonochrome.com

  6. #46
    Bill Burk's Avatar
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    Quote Originally Posted by RalphLambrecht View Post
    after several dissapointing experiences witha pentax spotmete(unmodified and modified)and metering through filters, i gave up on metering through filters and aplly the filter factor sfter metering without filters.
    Thanks Ralph!

    And I use the "ISO 2" setting on my L758-DR to apply the filter factor so that may be why I never had the problem!

    Some people deal with this issue by using the "Hutchings" factor after reading through the filter that is written in Steve Simmons' view camera book.

  7. #47
    Mustafa Umut Sarac's Avatar
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    Matt ,

    If you want to dissect and anatomical analysis of old electronics parts , its virtually impossible. Only you can do is to buy several famous lightmeters , disassemble it , look for the light sensor part number , find it at old factory manuals , look for the electronic circuit ....and list goes on.

    You have to know that they bought what is available from catalogs , test them approximately and try to be sure part would be available next few years and cheap.

    They were not NASA and not sending man on to the moon.

    There was no such technology at consumer goods and thats why we hate digital cameras and modern lenses even today

    But Leica was always different from Gossen and others.

    Umut

  8. #48
    Bill Burk's Avatar
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    Umut,

    You would probably appreciate the build quality of the SEI Photometer. The only issue in this discussion is that it has a sensor (the eye) that does not correlate 100% to film. I wonder what sunglasses I would have to wear to approximate the response of Tri-X.

    Probably something pale Magenta to pull down the Green. Next time you see me in the field, I'll be wearing rose-colored glasses.

  9. #49
    Mustafa Umut Sarac's Avatar
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    Hello Bill,

    Neodymium glasses , greatest eyeglasses color, I think you are talking about them. There is a glass studio called Cam Ocagi at Istanbul and when I went there , people were wearing these glasses to protect their retinas from radiation of hot glass.

    Click image for larger version. 

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    I really loved the color ,I think I must find the seller. Second thing is the amber , real natural amber deep yellow glasses.
    I will try to buy it when I visit Russia.
    Click image for larger version. 

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    Thank you reminding me them.

    Umut

  10. #50
    Bill Burk's Avatar
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    Quote Originally Posted by Bill Burk View Post
    I hunted the backyard with my first-generation infrared viewing scope looking for illogical examples. Maybe because it's late summer, I didn't find any extremes (except a red apple looked light).
    Here's the trick that makes IR anomalies visible: Put a black E-6 slide over the lens of a night-vision device such as the ATN-Viper.

    Now I see scenes in broad daylight similar to how they appear in infrared black and white prints.

    I am really enjoying this view of the world. Live IR!

    And I see the extreme examples I was looking for.

    Looking through the infrared viewer, foliage in shade is as bright as foliage in the sun. So I am focusing my attention on shaded foliage.

    Adding the red meter over the Sekonic only reduces the reading of green foliage in shade by one stop.

    By carefully choosing an edge case, I have found a problem that could lead to a two stop underexposure.

    Solution: Meter without filter and apply filter factor afterwards.

    I think I will bring the night-vision device in the field to help me see how much infrared is in my scenes.

    Who am I kidding. I'm bringing the ATN-Viper to have fun.

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