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Thread: HP5 at ISO1600

  1. #31

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    Quote Originally Posted by StoneNYC View Post
    the films natural "habits" HP5+ is designed to be pushed, so it's designed to be slightly lower in contrast at box speed ...
    The film speed standards for B&W pictorial negative films specify a certain "contrast," so one cannot assign an ASA or ISO speed without meeting this. (Need I say more?)

  2. #32

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    This is true. But Stone may or may not also be correct (from a practical perspective, even though his wording is incorrect).

    If a group of films have a rating of ISO 400, by definition they exhibit the same specified densities at the ends of a specified exposure range. In other words, over that exposure range, they have the same total contrast as measured by a straight line. However:

    -The exposure range specified is only 4 1/3 stops, and does not extend beyond what we would call mid tone densities
    -The shape of the curve is not fully considered, and highlight contrast is ignored
    -The conditions are met given exposure to a light source of a specific colour temperature
    -The conditions are met given a specified developer and process

  3. #33
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    Quote Originally Posted by Michael R 1974 View Post
    This is true. But Stone may or may not also be correct (from a practical perspective, even though his wording is incorrect).

    If a group of films have a rating of ISO 400, by definition they exhibit the same specified densities at the ends of a specified exposure range. In other words, over that exposure range, they have the same total contrast as measured by a straight line. However:

    -The exposure range specified is only 4 1/3 stops, and does not extend beyond what we would call mid tone densities
    -The shape of the curve is not fully considered, and highlight contrast is ignored
    -The conditions are met given exposure to a light source of a specific colour temperature
    -The conditions are met given a specified developer and process
    Thanks, yea it's all relative, but still, pushing 2 stops is going to give more contrast than pushing 1/2 a stop (technically 5/8ths?)
    ~Stone | "...of course, that's just my opinion. I could be wrong." ~Dennis Miller

  4. #34

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    There is a safety factor in ISO of 1.25 stops...

    So pushing speed by 2 stops may be undesirable.

    But this is rattys first venture into available darkness as well as bracketing he should have tried crepescule first.

  5. #35

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    I am wrestling with low light conditions too. I'd like to share some thoughts on the subject.
    If in normal conditions I take abreflected light reading, the meter integrates all light reflected from deepest shadows to the lightest highlights. If I am lucky the subject range does not exceed the taking capability of my film and I get all, no blown out highlights and fine details in the shadows. If not, I probably loose on both ends.
    If I am exposing a film with box speed 400 at 1600, I am underexposing it by two stops. I will have to narrow my reading down to the regions of my subject which I can realistically get within that range. Otherwise my meter will integrate into its reading regions which the film does not get anyway and the reading will be biased. So I will have to deliberately exclude deep shadows and the highest highlights from my reading. The easiest way to do so, is to spot meter the scene and take the readings on the midtones. For instance take a reading on a face , increase the exposure by one stop and and let all other tones lie where they may fall(applies to caucasian faces only obviously). I will probably get pitch black shadows and pure white highlights - from lamps for instance. But I will get my main subject about right. Is this correct so far?
    Last edited by Ulrich Drolshagen; 03-09-2014 at 08:20 AM. Click to view previous post history.

  6. #36
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    I like HP5 particularly in large format however it does build up contrast when it's pushed to 1600 EU. I used to use it in 35mm to shoot live performances but switched to XP1 and later XP2 pushed to 1600 or 3200 as they gave a better tonal range as they were much less contrasty and much finer grain.

    It's not widely realised that XP2 can be push processed, the main reason is when Ilford switched from XP1 (which had a non standard colour dev time in C41) to XP2 they dropped the recommended push processing times. This was because commercial labs hadn't liked processing XP1 as they couldn't be run alongside C41 colour films, XP2 uses the standard C41 dev time.

    If you do your own C41 developing then push processing XP2 is a viable proposition.

    Ian

  7. #37
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    Quote Originally Posted by Ulrich Drolshagen View Post
    I am wrestling with low light conditions too. I'd like to share some thoughts on the subject.
    If in normal conditions I take abreflected light reading, the meter integrates all light reflected from deepest shadows to the lightest highlights. If I am lucky the subject range does not exceed the taking capability of my film and I get all, no blown out highlights and fine details in the shadows. If not, I probably loose on both ends.
    If I am exposing a film with box speed 400 at 1600, I am underexposing it by two stops. I will have to narrow my reading down to the regions of my subject which I can realistically get within that range. Otherwise my meter will integrate into its reading regions which the film does not get anyway and the reading will be biased. So I will have to deliberately exclude deep shadows and the highest highlights from my reading. The easiest way to do so, is to spot meter the scene and take the readings on the midtones. For instance take a reading on a face, increase the exposure by one stop and and let all other tones lie where they may fall. I will probably get pitch black shadows and pure white highlights - from lamps for instance. But I will get my main subject about right. Is this correct so far?
    Most reflective meters have an angle of view and or they "weight" one part of the scene more than the rest, they don't necessarily see or consider the whole scene. To get a reliable reading we need to understand what the meter is seeing and how it is "weighted".

    If you can beg, borrow, buy, or hang out with someone that uses an incident meter you can use the incident meter reading as a reference to learn from.

    With most any reflective meter if you fill its view with your main subject, say a head, you can get a reliable reading.

    That reading then needs to be offset to get the camera setting because heads don't necessarily average to the middle tone the meter expects.

    For a blond caucasian Scandanavian that hasn't seen much sun since last October you might increase camera exposure by 1.5-stops from the meter reading to keep their face bright in the final photo. In that situation the meter thinks the subject is too bright. For a Spanish construction worker late in August the adjustment might be just a half-stop. The average light skinned, dark haired German head might be somewhere between those two. Dark skinned subjects may provide you a reading that requires a reduction offset because the meter thinks, wrongly, that the scene is too dark.

    This same principle applies to whole scenes. Judging a whole low light scene with a variety of subjects is a real challenge. It is typically easier to pick one subject, meter it and apply an appropriate offset.
    Mark Barendt, Beaverton, OR

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  8. #38
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    Quote Originally Posted by Ian Grant View Post
    I like HP5 particularly in large format however it does build up contrast when it's pushed to 1600 EU. I used to use it in 35mm to shoot live performances but switched to XP1 and later XP2 pushed to 1600 or 3200 as they gave a better tonal range as they were much less contrasty and much finer grain.

    It's not widely realised that XP2 can be push processed, the main reason is when Ilford switched from XP1 (which had a non standard colour dev time in C41) to XP2 they dropped the recommended push processing times. This was because commercial labs hadn't liked processing XP1 as they couldn't be run alongside C41 colour films, XP2 uses the standard C41 dev time.

    If you do your own C41 developing then push processing XP2 is a viable proposition.

    Ian
    XP2 is a film that consistently amazes me.
    Mark Barendt, Beaverton, OR

    "We do not see things the way they are. We see things the way we are." Anaïs Nin

  9. #39
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    Quote Originally Posted by markbarendt View Post
    XP2 is a film that consistently amazes me.
    Me too! It's really special.
    "Often moments come looking for us". - Robert Frank

    "Make good art!" - Neil Gaiman

    "...the heart and mind are the true lens of the camera". - Yousuf Karsh

  10. #40

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    Quote Originally Posted by Thomas Bertilsson View Post
    Me too! It's really special.
    +1

    Is it fair to say that it ought to be slightly less sensitive when processing as there are no colours that can go off? I'm asking because I have started to hand process my C41 films and it's not easy to be within 1/3 of a grade Celsius without a tempered processor.

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