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ralph_barker

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Posts posted by ralph_barker

    which transparency films have greater latitude, especially to under exposure?

    in Leica and Rangefinders

    Posted

    I usually use Provia or Astia for chromes, depending on the subject, because of their different color palette (less saturation and contrast, in particular). With less contrast, they appear to have greater tolerance. But, in truth, I think most slide films have about the same luminence range. Negative films have a stop or two of additional range, but I'm of the opinion that "tolerance" is a fiction. Although some compensation can be done in printing, tonal values at one end or the other are still lost if the exposure isn't accurate.

    Getting bounce fill from an SF20. Any ideas?/Calling Mr. Konermann.

    in Leica and Rangefinders

    Posted

    I have an SF20, too, Mani. I'm not convinced that it has enough "oomph" to do ceiling bounce, though. Lutz's SFILL is a good step in the right direction, but it doesn't provide enough diffusion (or, a large enough light source) for close quarters. Putting the SF20 on a handle mount, and using a larger diffuser, such as one of the small, inflatable "soft boxes", might help. With an M6 TTL, that should still work for flash control at close distances. The other alternative would be to attach a small chrome rectangular plate that would direct half or some other portion of the light toward the ceiling, and then add diffusion to what's left.

    Why do you love Leica?

    in Leica and Rangefinders

    Posted

    Douglas - I agree with the first part of your comment, but not the second - particularly if one happens to marry them. ;-)

     

    Ben - I don't "love" my Leica Ms, but, like others have commented, I certainly appreciate the size, precision and optical qualities they provide. I'm too old to benefit from the "chick-magnet" aspect of the cameras, so I have to settle for the fact that they contribute to good photographs.

    Leica provenance

    in Leica and Rangefinders

    Posted

    <p>You can make an inquiry about the status of a camera at <a href="http://www.leica-camera.com/cgi-bin/overview.pl/en/snstatus">this link on the Leica site</a>. Obviously, it only covers items having been reported as missing to Leica through the other page on their site. Leica requires a copy of the police report to register an item.</p>

    <p>There is also a <a href="http://www.photo.net/registry/">stolen equipment registry</a> here on ohoto.net.</p>

    Why do I get this?

    in Leica and Rangefinders

    Posted

    Even though you said not to, I'm going to do it anyway. Try re-scanning, John, but try scanning as a color positive transparency, and then invert and convert in Photoshop. That's how I scan most of my B&W film, and it seems to keep the grain more in line with what's actually present in the negative.

    gallery more perplexing than usual

    in Leica and Rangefinders

    Posted

    Roger - while I agree that the actions of photo.net participants are often mysterious, I only partially agree with your assessment of the image. Aside from being a cute "family snap", I also see more universal elements being represented: the innocence of children, along with their endearing ability to multi-task by taking in the world around them while still being intent on enjoying a tasty beverage. For those purposes, the background seems essential to providing the needed context, and the soft lighting seems consistent with that mood.

    Film Speed Setting

    in Leica and Rangefinders

    Posted

    John - I'm not saying that all films actually work well at their rated ISO, but that's the fault of the tests required by the standard, not the film. The old ASA and DIN standards were much closer to realistic shooting conditions, I think. That said, I've actually had good luck with shooting Delta 3200 at that speed, and developing it "normally" with DD-X.

    Film Speed Setting

    in Leica and Rangefinders

    Posted

    Barry said, "Ralph, in developement, do not the shadow elements develope first and then the highlights?"

     

    That is certainly true for prints, but I think the reverse is true for film. It may also depend to an extent on the nature of the developer being used - conventional vs. "compensating", etc. Never having been inside the developing tank, I'm not sure which actually develops first. But, the highlights (the darkest areas in the negative) are getting the most exposure, so it seems logical to me that those silver halide crystals would be the quicker to respond to the developer than the less photon-affected shadow areas. Hence, I believe the opposite of what you said is true for film, that is, that highlights develop first, and shadows later.

     

    Barry also said, "I think we were taught to 'shoot for the shadow details, and develop for highlites'. The theory being that the first portion of developing brings in the darks and after a certain point, most of the action is just bringing in the highlites. In other words, extending developement time past a certain point won't really bring you much except in the light areas. Is this correct?"

     

    Partially, but it depends on the part of which one is speaking. ;-) The old saying, "Expose for the shadows and develop for the highlights" is essentially the basis of the Zone System, and is more related to controlling the contrast in the negative than to the sequence of shadow/highlight development. Longer development time (up to a point) increases the contrast, while shorter development time reduces the contrast. So, one way of looking at it would be if you "expose for the shadows" (essentially, over-expose the film), you reduce development correspondingly to compensate, keeping the overall density of the negative "normal" and adjusting the angle of the contrast curve accordingly. In Zone System terms, this can be viewed as either "compressing" the contrast of the scene into the response range of the film, or effectively "expanding" the contrast range of the film to accommodate a wider range of luminence values in the scene. Depending on the number of stops the luminence range in the scene exceeds the range of the film, you reduce the development a corresponding number of effective stops (N-1, N-2, etc.). Conversely, if the scene is "low contrast" or has fewer stops difference between dark and light than the film is capable of rendering, exposure id decreased and development is increased (N+1, N+2, etc.) to bring some life (contrast) back to the shot.

     

    But, the Zone System approach is only practical for large format sheet film, where individual exposures can be developed according to their individual needs. For roll film, one must either go for an average, or have reasonably consistent exposures and contrast ranges for all of the images on the roll.

     

    Another way to look at the question is from the perspective of "pushing" film - essentially, up-rating the ISO. If one up-rates an ISO 100 film to ISO 400, for example, the result is essentially a two-stop under-exposure. So, development is increased by two stops to compensate. That brings additional detail (often meaning some image) to what are effectively the shadow areas, and makes the highlights quite dense on the negative. That's why "pushing" film increases the contrast - because the film is developed longer to compensate for what is effectively an under-exposure. (Note how this relates to the question of which develops first, too.) Increased development also tends to increase grain, hence making "pushed" negatives more grainy.

     

    Most of the "old sayings" about exposure and development are over-simplifications of the physics, and are often applied to situations where they don't really fit. Thus, it is often better to think through the whole process to gain a better understanding of where best to apply the wisdom these sayings represent. "Going forth and multiplying," for example, is much quicker with an electronic calculator than having sex, but it probably doesn't increase the seating density in the church much. ;-)

    Looking for LF Soft Focus Lens, Anything like the Cooke PS945??

    in Large Format

    Posted

    Don't forget that you can also create a variety of soft focus effects by using a wide variety of diffusion filters - anything from silk stockings (or panty hose) to Zeiss Softars, or even smearing petroleum jelly on a UV filter. The filter approach also gives you more control. Black mesh versus white mesh, for example, gives you a decidedly different effect, blurring shadows into highlights rather than highlights into shadows.

    OT: PLEASE Remind ME Why MF Delivers More Tonal Range Than 35mm

    in Leica and Rangefinders

    Posted

    "Mmmmm," says the blue, furry creature, rolling his eyes, "More cookie!" ;-)

     

    I agree with Jack - it's all about the volume of image data that the film size provides for a given display size. More data (larger film) provides smoother tonal transitions, so the image looks "richer". A musical analogy might be comparing the sound of a quartet to a band to a symphony orchestra, where 35mm is the quartet, MF is the band, and LF is the orchestra. (Minox would be a Pan flute in that comparison.)

    Film Speed Setting

    in Leica and Rangefinders

    Posted

    I wouldn't call the ISO ratings "optimistic", as that suggests a marketing ploy. The ratings are actually quite accurate - for the specific tests required by the ISO standard. It's just that the ISO tests don't always equate directly to conventional picture-taking situations.

     

    The conventional wisdom is to give negative films (both B&W and color) a bit more exposure to increase shadow detail, allowing highlights to fall where they may. The assumption in doing so is that one can always burn-in the highlights during printing, if necessary. The reverse is true with transparency (slide) films, where precise exposure is far more critical, and highlights are usually watched closely, if not given precedence. How one "rates" a film, however, is best determined by extensive testing. The testing results are influenced strongly by developing technique and the chemistry being used. Unless distilled water is used, regional variations in tap water can also have an effect.

     

    The key factor in determining how one "rates" a film/developer combination is to standardize the processing as much as possible, and then compare results. So, while exposing an ISO 400 film at 200 would, in theory, result in a 1-stop over-exposure, that may be partially or completely offset by processing technique - how one agitates during development, for example. In doing this, it is handy (even if not altogether accurate) to think in terms of exposure controlling density of the negatives, and development as controlling contrast.

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