Reciprocity info Kodak Ektar 100

Discussion in 'Color: Film, Paper, and Chemistry' started by /dev/null, Jun 3, 2014.

  1. /dev/null

    /dev/null Member

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    Hi,

    I was looking for info on the reciprocity factor of Kodak Ektar, but some pages seem to have disappeared.

    I want to shoot a landscape picture of an industrial engineering plant just before the sun comes up. The sun comes from the right angle. I will be shooting Cambo Wide 150mm on f/11 with Kodak Ektar. 120 film format (6x12).

    I measured the light at f/11 and ISO 100 and gives me an exposure time of 30 seconds. Do I need to correct these values? Does anyone have a chart for Kodak Ektar?

    Thanks!
     
  2. StoneNYC

    StoneNYC Subscriber

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    If you have the iPhone you should seriously consider getting this app, I use it for all my LF and Long Exposure work.

    Reciprocity Timer App

    https://itunes.apple.com/us/app/reciprocity-timer/id459691262?mt=8

    This is the kodak data sheet but you're right there's not any serious long exposure info on their, strange... It's almost always in the data sheet...

    http://www.kodak.com/global/en/professional/support/techPubs/e4046/e4046.pdf

    The app is almost always spot on for exposure times, I HIGHLY recommend it and it was designed by someone on the LF forum, there's so many options it's almost too full for the screen size if an iPhone but the info for exposure is always correct from my experience.
     
  3. StoneNYC

    StoneNYC Subscriber

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    PS I just looked on the app and it says this...

    ImageUploadedByTapatalk1401799854.911831.jpg

    However at that amount of time I would think that using a color correction filter would be needed which would extend the time further... If I had to guess, an 81B filter? If it's a newer industrial complex with slightly fluorescent / whiter lights and not tungsten?

    ImageUploadedByTapatalk1401800287.848505.jpg
     
  4. /dev/null

    /dev/null Member

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    Thanks. I looked at this app earlier today and wasn't sure about it. But I bought it now, looks pretty cool indeed.

    Just to double check the app' results with you. I selected Kodak Ektar 100 and a 30 seconds exposure time. I don't have any additional variables like bellows, or compensation. So the app shows me 1:08 min. So that would be my exposure time then? That is friggin' cool and simple :smile:
     
  5. StoneNYC

    StoneNYC Subscriber

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    Yep, you just missed my second post (look above).

    Yes if you don't have bellows to deal with just leave those sections alone.

    I know a while ago someone was having trouble with the filter options, to my knowledge the designer has updated the app to fix it, and if you add filters you need to remember to hit the + symbol after highlighting the filters in the filter area or they won't actually apply, so the app is a little quirky but it works well.
     
  6. paul_c5x4

    paul_c5x4 Subscriber

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  7. /dev/null

    /dev/null Member

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    Thanks, very useful info! You think I need a 81B filter then? I was reading about them, have to see where I can pick one of those up. I mean, reading about the color corrections with long exposure times. Have to google around a bit more on that subject.

    The filter thing is indeed a bit quirky, but seems OK once you know how to add them :smile:
     
  8. StoneNYC

    StoneNYC Subscriber

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    I don't shoot long exposure color, except sunsets and sunrises where I want the over saturation and color shifts, so you will have to ask someone who does, but if you're shooting a daylight color film, which tends to go blue in shadows, and shooting an industrial scene with modern lighting (no tungsten) then I would "guess" that a light warning filter would help to keep the lighting more natural, but you would have to so real world tests or have a color spot meter (if one exists) they make color meters just not sure of spot ones, and they are expensive so I wouldn't bother, just use your bear judgement and don't forget if you use a filter to compensate for he filter factor, and HAVE FUN! :smile:
     
  9. Athiril

    Athiril Subscriber

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    Ektar is pretty good for reciprocity if I remember when I used it, I tried correcting for reciprocity in my exposure and ended up overexposing the film badly.
     
  10. /dev/null

    /dev/null Member

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    How did you correct it and what exposure times did you use?