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  1. #201
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    I've never reduced exposure more than 2/3 of a stop in an effort to counteract flare density in the low zones (nothing earth shattering), the notion that it causes problems is simply not realized in my experience. The very few times I have done it, only necessitated a quick re-evaluation of the important high value and planned developmet time.

    Stephen points out that flare is always present to some degree, I simply do print through it as suggested, it's precisely why I rarely have ever made any attempt at compensation for it. But in the case of "excessive" flare possibilities, I have reduced exposure to no apparent problems----I would rather have a negative that minimizes it to some degree (which I believe that it does), while also printing through what remians. So, if after the shadow placement is made, it is believed that there is added density to it due to flare, then reduce exposure slightly to counteract it, re-evaluate the important high value, maybe adjust the planned development time, maybe not, make the exposure and move on. Some point of theory may suggest that this is detrimental, but I have some instances of photographing that suggests it is not.

    Anyway, good or bad, that' how I do it, off to work now.
    Chuck

  2. #202
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    Also, let's not forget the loss of local contrast and reduced log-H range can be compensated by printing on a higher grade of paper. The increased slope of the higher grade of paper should help restore the local shadow contrast to a pleasing level.

  3. #203
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    Quote Originally Posted by AndreasT View Post
    Sorry I have to get back to this, if the shadows are more flat beacause of a pre-exposure the rise in the film is more gentle and surely you would have to travel more down the curve to the right to reach the speed point.
    You have more density and theoretical speed increase over the unexposed film where there is no additional light.
    Now if you want soft shadows like mentioned before thats fine but if I want to keep the contrast in the shadows I would have to eventually expose more.
    There's a difference between film speed and EI or personal taste. Different interpretation of terms plays a major roll in much of the miscommunication on these threads.

    The ISO film speed standard incorporates a stop flare into the equation. The contrast parameters for development is to make the fixed density method correspond to the results from the fractional gradient method which bases speed on the shadow gradient. So gradient is a factor with ISO film speed. I'm not really sure what effect additional flare would have on the ratio between the fractional gradient point and the fixed density point of 0.10. Increased processing will reduce the ratio, which is why the fractional gradient method and Delta-X Criterion have effective film speeds that tend not to move with increased processing (a likely action with excessive flare).
    Last edited by Stephen Benskin; 01-30-2013 at 11:16 AM. Click to view previous post history.

  4. #204

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    The frightening thing for me is the more I think about flare as pre-exposure, the more my view (expressed in the "challenge" to Chuck's reduced exposure with high flare) seems consistent with Barnbaum's take on pre-exposure of the negative (ie that it doesn't really help)

    Perhaps a decent way to think about it is consider paper flashing. This effectively increases the "speed" of the paper in the highlights (analogous to what happens in the shadows when exposing the negative under flare conditions), so that it takes less image-forming exposure to get some highlight detail onto the paper. But while it is easier to get that first hint of highlight tone, local contrast in the highlights is compressed, which can end up looking a little muddy. When exposing the negative this is what we have in the shadows. The effective "speed" is increased which means less image-forming exposure is required to get the first hint of density above FB+f, but local contrast in the shadows is reduced.

    So I suppose I can summarize my view by saying that an increase in "effective" film speed due to non-image forming light should generally be ignored. This is because for me speed (or exposure index) is little more than a means to an end - ie getting contrast in the shadows as close as I can to the contrast of the rest of the curve. If the extra speed caused by flare/pre-exposure decreases shadow contrast, I'd argue it isn't "effective" speed at all.

  5. #205
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    There's another factor that hasn't been address and that is the perception of the scene. The viewer expects a certain look from a backlit scene and that usually includes a flattening of the shadows. If the object of the photograph is to be natural looking, then snappy shadow contrast may not be appropriate. Personally, one of my favorate photographic approaches is to play against these kind of conventions.
    Last edited by Stephen Benskin; 01-30-2013 at 01:09 PM. Click to view previous post history.

  6. #206
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    Quote Originally Posted by Stephen Benskin View Post
    There's another factor that hasn't been address and that is the perception of the scene. The viewer expects a certain look from a backlit scene and that usually includes a flattening of the shadows. If the object of the photograph is to be natural looking, then snappy shadow contrast may not be appropriate. Personally, one of my favorate photographic approaches is to play against these kind of conventions.
    Yep.

    There are also the considerations of imparting mood. The compression in the low end can impart an old time look or a boudoir look or in color photography a pastel look....
    Mark Barendt, Beaverton, OR

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

  7. #207
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    Quote Originally Posted by Stephen Benskin View Post
    Fun fact about flare and shadow compression. Ever wonder why Tri-X professional, with it's long toe, is considered a "studio" film? There's less flare with interiors and the ability to control lighting. In theory, regular Tri-X shot in daylight would have similar tonal distribution in the toe as Tri-X Pro shot in the studio.
    A friend of mine pointed out something interesting that is practical application of this. Normally shooting portraits using Tri-X and HC-110, and switching to TMax 400 and Xtol, all of a sudden shadows were problematic due to flare. Solution? Expose TMax 400 at 1,000 to 1,200 and Xtol is still efficient enough in the shadows to get enough shadow detail - all while burying most of the flare. In fact, it looks a whole hell of a lot like Tri-X this way, and the advantage is of course that it gets easier to shoot medium format or large format with almost two extra stops of light. Just an aside, but it's a practical example of what you're saying.
    "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

  8. #208

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    Quote Originally Posted by Stephen Benskin View Post
    There's another factor that hasn't been address and that is the perception of the scene. The viewer expects a certain look from a backlit scene and that usually includes a flattening of the shadows. If the object of the photograph is to be natural looking, then snappy shadow contrast may not be appropriate. Personally, one of my favorate photographic approaches is to play against these kind of conventions.
    Obviously, but I don't think that's what was being proposed as theoretical support for reduced exposure under high flare conditions. Flare flattens shadow contrast on its own. The only reason to reduce exposure (assuming of course the highlights fall within the scale of the film) is to flatten them even more. If that's the intent of the artist, I have absolutely no problem with it.

  9. #209
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    The book of Henry is worth a read, what would it bring me?

  10. #210

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    Some of the theory is good, and many myths are debunked. In my opinion the first half of the book which deals more with printing (paper etc) is perhaps the better part of the book - although the materials themselves are all outdated except Dektol. I find the second half a little more difficult to follow. Exposure theory, K factors and meter calibration etc - these are not the clearest parts of the book. And the film/developer testing data on granularity, sharpness etc are of relatively little practical use.

    To me, the most important "learning outcome" from reading Henry is a healthly skepticism. It reminds us much of what we read about photographic technique and materials has little in the way of evidence to back it up. And as Stephen has said many times, even when we are presented with data it is important to be given information on the testing procedures, otherwise it is difficult to conclude anything. Sometimes you read an article in a magazine and it looks really sound because is has tables and charts and curves. But what if there were all sorts of errors or sources of error, mistakes etc in the test? As we know there are many variables to manage, and as I've come to learn, designing a proper photographic test is not so easy.

    At the same time though, once we realize how much of what people say is wrong - including some very fine photographers/printers - we must then reconcile this to the fact they still end up with great prints. This tells me there is quite a bit of lattitude in the photographic process, from metering to exposure to development to printing. It means people can be wrong about what is going on at a scientific level but still make things work, because the lattitude provided by our materials allows them to work around the "data" they present with practice - usually without them knowing it. Often, people, even great photographers are not getting what they think they are getting from their process when it comes to film speed, curves etc, but it doesn't really matter because with practice they've simply developed their technique around what they are actually getting.

    Stephen has written about all this before, so I'm not saying anything new. I just like Henry's book because it presents many practical examples.

    To sum things up, there is a lot of bad information out there. Just because someone on APUG, or the author of a book says something is so, doesn't mean it is so. When somebody makes a statement, you might ask them to prove it!
    Last edited by Michael R 1974; 02-01-2013 at 07:20 AM. Click to view previous post history.



 

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