Hi Jean-Louis, I will quote from myself. This is something I just sent to Murray. We were discussing his aerial film that he got on Ebay. He sent me some and I made an exposure with a newly made film box 5x7 50mm pinhole camera: http://www.???????/discussion/upload/gallery2002.php?pic=rheathermurysfilm1.jpg
He asked about contrast and I tried to explain the difference between "global contrast" (the total luminance difference from highlights to shadow) verses "local contrast" ( the appearance of exetnded detail within the light and/or dark areas of the print): " "High contrast" is a double edged sword. We all like to see a brilliant image with full tonal range, deep blacks with detail and bright whites with detail. When you see a print like that you say "high contrast" as compared to "flat" or "muddy". However the job of the film is to record all the available detail and allow a brilliant print. High contrast in film often means little latitude for over and under exposure. Some scenes have a tremendous range in luminance, bright sky, dark foreground. For that you need a film that tolerates heavy exposure. Expose for the shadow detail and curtail development enough to use the highlights. In darkroom printing you will then dodge and burn to get an "even" print with the illusion of high local contrast but actually greatly contracting the tonal range. This is easily done digitally by selective masking and manipulating of tonal range but it is the main "magic" and "alchemy" of a darkroom printer. Don't get too obsessive about Zone system details but try to see the big picture that you want a usable negative not a perfect one. Most modern film has a tremendous latitude to provide a usable image as long as you don't underexpose." Richard Heather Jean-Louis Thiry wrote: > I wish to thank every person who gave some attention to my dwarf picture, and > their nice comment. > I promise to put on line some photos and descriptions of my cameras on an html > page on my site. > > some comments brought me to some considerations about sharpness in pinhole > photography. In the lensphoto area, sharpness is essential, it is what gives > the > price of a lens. You may have blur by the use of a soft focus filter or lens > to > get an atmospheric image but even in this case your image has to be sharp > whatever the contrast of the image is (lo key, hi key are two contrasts > possible > of a lens image). > Sharpness in pinhole photography is not the first aim, you wish to get closer > to > YOUR eye's vision (the most precise description of what you see), which is not > as sharp as a lensphoto, which can't cover all of a lanscape at a glance for > exemple. Eye's vision is sharp only at one point : what you're looking at - > very > small. > What is more difficult to get in pinhole photography is contrast. A good > exposure gives good contrast as a good film development gives good contrast > and > you ahve only one contrast (no lo key or hi key). Am I wrong when I think that > good contrast gives more sharpness to a photo? and that the atmospheric feel > of > a pinhole photography is due to a lack of contrast as much as a bad relation > between focal length and diameter of the hole? I think there is a border > between > sharpness and contrast so thin that it is there that all the magic of pinhole > works to help us to create those "pictorialist" images : painted by fingers of > light. > > Jean-Louis (Montauban - France) > > -- > > Galerie Béla Fleck > http://perso.wanadoo.fr/multimage/sessionbanjo/outbound/index.htm > __________________________________________________________ > > MULT'IMAGE > Applications graphiques - 41, rue Voltaire - ZI Nord > F-82000 MONTAUBAN > Tél 05 63 63 54 54 - Fax 05 63 63 11 18 - ISDN 05 63 63 11 18 > > _______________________________________________ >
