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  1. #31

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    I suggest these steps:

    1. Hold your negatives up to a light and look for detail in the shadow areas. If they lack shadow-detail, increase exposure.
    2. Look at how dense the highlights are. To make them denser, develop longer. This increases contrast.
    3. Scanning has its own contrast-control, so a high-contrast negative can give a low-contrast scan. If your negative is good (steps 1 and 2), then you need to apply an S-curve to the scan.

    Mark Overton

    Quote Originally Posted by daniele_vittorio View Post
    Wow, thanks a lot for all the answers!

    As some of you have correctly suspected (Bill Burk, Gerald C Koch, pdeeh, and Fabrizio Ruggeri, just to name a few), I am rather new to the analogue world, and I am really not familiar with the details of the Zone System. (Adopting Fabrizio's catchy words, please don't "overkill" me!) I definitely plan to dig deeper into the technical aspects of analogue photography, including reading the suggested classics by Ansel Adams, but for the time being, I am just looking for some basic guidelines.

    Speaking in layman's terms - and I apologise for doing so -, what I often experience is that I pick up the developed negatives from the lab and the scans lack in contrast to my eye/taste. What I do than, as a layman, is resorting to Photoshop and adjusting the gradation curve until the contrast pleases me. This almost always involves brightening the highlights and darkening the shadows, i.e. giving the curve an S-shape.

    However, I feel like tweaking curves in Photoshop is not what analogue photography should be about, and I would like to achieve the desired contrast by purely analogue means.

    Now, referring to the instructive answers by Doremus Scudder and smieglitz, and hoping I understood them correctly, here is what I came up with: If I under-expose, I will get strong blacks. (This is what I want.) However, I also want strong whites: In order to get these, I must over-develop the negatives. While the light grays will turn white (this is what i want), my blacks will still stay black, because - quoting smieglitz - "increased development doesn't change the shadow tones very much but has a great effect on the midtones and highlights."

    In brief, this boils down to pushing, i.e. under-exposing and then over-developing.

    Ok, experts out there, please tell the layman if he got it right.

  2. #32
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    Quote Originally Posted by Leigh B View Post
    Exposure controls shadow detail. If underexposed, there is none.

    Development controls highlight density. More development = greater highlight density without changing shadow density significantly.

    - Leigh
    One should not even start exposing film, let alone set foot in a darkroom without understanding those basics. Of course if everyone followed that advice the "I'm a noobie and my pictures look bad..." posts will stop appearing and we will have to create sub-forums in the "Lounge" to manage all the new threads on non-photography topics...

  3. #33
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    Quote Originally Posted by Gerald C Koch View Post
    Whether you find the ZS easy or hard depends on the book or teacher you use. In this case one must remember the Zen proverb, "When the student is ready, the Master appears."

    It's not really LF per se but whether you have control of individual negatives. In order for the ZS to work you must be able to adjust development for each negative individually. This is just not practical with roll film.

    With the development of VC papers that are just as good as graded papers the ZS has really lost most of its raison d'etre.
    The core concept of the Zone System is pre-visualisation (deciding how you wish to depict the scene rather than how it actually is) and this is at the heart of achieving the images that you want. This is essential for people starting out as those with more experience have usually acquired darkroom skills that let them cope with less than perfect negatives. Making an interesting image that is marred by poor technique can be hugely off-putting for people starting out with photography as can years of fumbling about 'experimenting' and never reaching consistent results.

    I agree that the pseudo-scientific and pseudo-philisophical aspects attached to the Zone System by various teachers are a distraction, and often a numbing stumbling block, for people wanting to learn good technique (in reality, and with a good teacher, good technique can be learnt in a couple of days). However, at the heart of the Zone System is the very simple concept that you, as quickly as possible, pin down your technique to achieve consistently well exposed and well developed negatives that renders an average scene to your personal liking (in reality only a few boring hours of testing are needed to achieve this). This gives you a great starting point whereby all of your negatives print reasonably well and then you can set about the fun part of altering the image in the darkroom to meet your own creative vision.

    As you progress from this grounded starting point, you will quickly learn that varying exposure (placement in Zone System terms) will enable you to realise your pre-visualised concept for how you wish the image to appear in its final print form. The need for significant adjustment in the processing of individual negatives is only a very small part of the Zone System (for most scenes it is not needed) most suited to a time when there were only fixed grades of paper. These days increasing/decreasing the contrast of the final image (N+1 / N-1, etc parlance in the Zone System) can be achieved with VC papers/different devlopers.

    The core concept of the Zone System remains particularly relevant today because it is all about understanding how to render any particular scene in the final print in a manner that matches your own particular artistic vision. One should never forget that much of what Adams achieved in convincing the USA to protect it's wildernesses was through majestical photographs of majestical scenery that were a very long way away from how the scenes would appear if a straightforward technical representation of the scene had been presented. The photographs that he presented to Presidents, wealthy supporters, etc were hugely manipulated personal interpretations of what he saw and felt when in the field photographing. That for me is the key to photography - taking a scene that I find interesting, interpreting it and then transforming it into a print that matches my vision.

    Best,

    David
    www.dsallen.de

  4. #34
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    Daniele,

    The Zone System is quite easy to understand. It's the explanations of the ZS that are confusing.

    Let's start with a spot meter... what it is and what it does.
    The spot meter looks at a small area of the subject (usually 1° but some are larger),
    and tells you what exposure to use TO MAKE THAT AREA MIDDLE GRAY.

    This is the key point to the whole system, and one that's frequently not even mentioned.
    If you shoot at the metered exposure, whatever you pointed the meter at will end up middle gray on the print.

    If you want that spot to look brighter, you increase the exposure (slower shutter speed or larger aperture).
    Increasing by one stop will make the spot noticeably brighter; increasing by two stops makes it much brighter, approaching white.

    Similarly, decreasing the exposure by one stop makes the spot darker; decreasing by two stops makes it much darker but with some detail.

    So how does this relate to a real scene?

    If the spot you select is the white shingles on a church, obviously you want that brighter than middle gray,
    so you use an exposure that's two stops greater than what the meter says.

    If the spot is in the bushes next to the church, you want that darker than middle gray, so you decrease the exposure by two stops.

    As you become more familiar with the system, mainly by metering various tones in the subject and keeping notes,
    you'll start to learn what a real middle-gray looks like in the subject, and be able to select your metered spots more accurately.
    But initially, concentrate on the two ends of the tone range that have details you want to retain.

    There's a lot more to ZS than I covered here, but this provides a good starting point.
    The ±2 stop range that I suggested is average for black&white film with normal processing.
    There are several factors that will influence your exact values, but this range will yield good printable negatives in most cases.

    - Leigh
    Last edited by Leigh B; 07-18-2012 at 05:39 AM. Click to view previous post history.
    “Wise men talk because they have something to say; fools, because they have to say something.” - Plato

  5. #35
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    Quote Originally Posted by daniele_vittorio View Post
    Now, referring to the instructive answers by Doremus Scudder and smieglitz, and hoping I understood them correctly, here is what I came up with: If I under-expose, I will get strong blacks. (This is what I want.) However, I also want strong whites: In order to get these, I must over-develop the negatives. While the light grays will turn white (this is what i want), my blacks will still stay black, because - quoting smieglitz - "increased development doesn't change the shadow tones very much but has a great effect on the midtones and highlights."

    In brief, this boils down to pushing, i.e. under-exposing and then over-developing.

    Ok, experts out there, please tell the layman if he got it right.
    Well, you are getting closer. What you need to be cautious of with underexposure is that adequate exposure must be given to ensure shadow detail regardless of how you develop the negative. If you overdevelop, you can expect to gain a tiny bit of density in the shadow areas of the negative. If you underexpose too much, the development will not be able to compensate for the underexposure and detail will be lost in the shadows forever. You'll get the deepest black tone you desire, but it will be void of any detail and look unreal.

    As a sweeping generalization, here's the deal: If you "push" a negative one stop in the midtones or highlights you will probably only gain 1/3 stop in the shadows. A 2-stop push in the midtones & highlights might only give 1/2 - 2/3 stop increase in the shadows and beyond that, most modern films aren't pushable without losing shadow detail. What this means is if you push a film to get something like a middle-gray card tone (Zone V in Ansel's ZS) to show up as a light skin tone (Zone VI density from Zone V exposure) you can probably safely rate a 400 ISO film at ISO 500 and the overdevelop and your contrast will increase without sacrificing the shadow detail because the overdevelopment does move the film's threshold to light back up the tonal scale a little bit. It is very important to note that what I've described here is a 1-stop push in the midtones, not in the shadows or highlights. If the midtones are shifted 1-stop (aka 1-zone) via more development, the shadows are probably shifted only 1/3-stop while the highlights probably would move about 2-stops simultaneously. You have to choose where on the scale you want the push effect to be optimized with everything else perhaps being a compromise. Most photographers look at a highlight tone (Zone VII or VIII) when pushing (or expansion in ZS).

    If you were to attempt a 1-stop push by rating your ISO 400 film at ISO 800 which results in a full 1-stop underexposure of every tone in the scale, the reality is you will lose shadow detail and there won't be anything to print if an important shadow value was pushed back under the film exposure threshold. The overdevelopment might bring back the highlights to where you desire them to be, but the shadow values will experience irreparable loss. Hope that makes some sense.

    Here's the deal part II: for a quick and dirty zone system try the following. If you are under cloudy bright conditions with shadows having a fairly sharp edge but not fully razor-sharp, you have a normal contrast lighting that requires normal exposure (shooting your film at the Exposure Index [EI] you have determined to be "normal") and normal development. If the shadow edges are crisp and razor-sharp as in a bright sunny day, you have high-contrast lighting which will require pulling the film, probably by 1-stop in the highlights. To do this pull, set the EI lower to slightly overexposure the scene (e.g., rate the ISO 400 film at ISO 320), then underdevelop (maybe 10% with T-Max or 15% - 20% with other films). If the shadows are diffuse with soft edges your scene is a candidate for pushing. In that case set the ISO 1/3-stop higher (ISO 400 film @ ISO 500 setting) and overdevelop (perhaps 10% for TMax and 25% as a starting point for other films.) If it is foggy, you are probably looking at a 2-stop push (ISO 400 film at ISO 640 exposure) with perhaps 25% overdevelopment for TMAX and 50% for other films. (BTW, all these times should be tested for beforehand.)

    It seems paradoxical, but a bright sunny day and a night scene are both candidates for pulling because they are high-contrast lighting situations. Foggy or overcast conditions are the opposite and require pushing.

    If you plan to read up on the Zone System, I'd recommend John Schaeffer's book, Ansel Adam's Guide... (I think book I), as a compilation of excerpts from Ansel's 4 or 5 ZS books.

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