epeace wrote:
sitting here in the office looking at it i have no earthly clue . . . .
There are two principles that will inform nearly every decision you make with a large-format camera:
Perspective correction: If the film back is vertical, there will be no vertical perspective convergence. Using shifts or combinations of shifts and tilts, move the lens sideways with respect to the vertical film back to get the composition you want. But eliminating vertical perspective starts with a vertical film back.
Scheimpflug Effect: The planes that include the film back, lens board, and plane of sharp focus all intersect. When the film back and lens board are parallel, that intersection is at infinity and the plane of sharp focus will intersection there, too (which means it will be parallel to the lens board and film back). But if the lens board and film back are tilted with respect to each other such that their planes intersect, the plane of sharp focus will intersect along the same line.
Thus, if you want a picture of a forest, with the leaves on the forest floor all in focus, then start with a vertical film back (to keep the trees vertical without perspective convergence). Then, note where the film back plane intersects the ground. This will be right under the camera at ground level. Tilt the lens board so that it lines up with that point. Voila! The ground will be sharply focused at all apertures. Then stop down to get the tops of the trees in focus.
The trick is deciding where the plane of sharp focus needs to be. I once photographed a tree stump with the front of a mission chapel as the background. I wanted the chapel bell tower to be sharp, and I wanted the tree trunk to be sharp. The problem was that the tree trunk was about two feet in front of the camera, and the chapel was about 150 feet away. No depth of field will ever accommodate that. So, I imagined a plane between the chapel tower and the stump, and if that plane was a wall, it would have extended from two feet to the right of the camera, with the camera lookingg basically down the length of it. I tilted the lens to the right so it pointed to the intersection of the film plane and that "wall", and the chapel was sharp along with the center of the stump. The only thing in the picture not in focus was a root at lower left projecting from the stump, and I cropped that off.
Get a 10X loupe (a cheapie plastic one will do fine, and cover everything but the lens with black photographic tape. Use is to view your ground glass to check focus.
Use the open corners of your ground glass to check for lens coverage. If, looking through the open corner through the lens, you see anything but the diaphragm blades, the lens is beyond its movement capabilities and needs to be backed off. It's much easier to see it that way than by looking for vignetting on a fresnel ground glass.
Get a good focusing cloth. It needs to be opaque. Velcro around the lens board will help keep it in place.
Don't forget a lens shade.
Keep a notebook and be rigorous about how you metered the scene and your exposures and focusing strategy. That's the only way you'll be able to do a post-mortem if something goes wrong. Mark your film backs rigorously and make sure your notes are descriptive enough to match negative to notes.
Everything else is just a matter of practice.
Rick "Cambo 4x5 with regular and bag bellows; 47, 65, 90 and 121 Super Angulons, 160 Geronar, and 210 Ilex Paragon; Pentax and Minolta spot meters; compendium shade; 6x9 rollfilm back; Peak loupe; home-made focus cloth; and no desire to do the necessary darkroom work" Denney
