darin_depew

Here is a cheap, easy way to view large negatives: go to your local

used camera dealer, buy a junky, damaged zoom or telephoto lens,

remove the outer part (remove the focusing portion and mount), and

screw some diopters onto it. I have an old Sigma zoom that leaked oil

all over the inside. I can almost view an entire 6x6 negative. It

gives a great image, even standing over it, looking down from 3 feet

above the thing.

For street photography, you can't beat a folding camera, like a Zeiss

Ikonta-A. You have to preset focus, but if the lens standard is rigid

enough, you can press a button, out pops the lens, click, then fold it

back up again. Very candid.

I have a Mamiya Super 23 press camera. The lenses are great, but the

camera is sometimes unwieldy. Make sure you get one with a good

rangefinder. By far the best aspect is the "S" roll film backs. very

flat film plane, very cheap and very easy to put on and take off. By

far the worst aspect is trying to mount ANY type of flash unit to the

pistol grip or the shoe on top. It looks like you just built a camera

from an Erector set. It's pretty heavy fully loaded. You could kill a

buffalo with it.

You're almost there. the reason light falls off at the edges is simply

because the effective aperture is smaller when approached from an

angle than when approach directly, as anyone can tell by looking at a

donut hole straight on, then at an angle. As the camera aperture opens

or closes, the percentage increase or decrease is greater when

viewed directly than viewed at an angle. For example, F16 is 1/8 the

diameter of F2 when viewed head on, but maybe only 1/3 when viewed

from a 45 degree angle. A pinhole diamater varies slightly from all

angles.

A standard focal lenth for a given negative size is supposed to be the

diagonal of the exposed area. A 35mm negative is 24x36mm, which is

43.5 diagonally. However, only 24x30mm is actually used for an 8x10

print. So based on that, here are the standard focal lengths for the 4

film sizes:

for an 8x10 aspect ratio:

===========================================

35mm (24x30mm useable area) 38mm

6X4.5cm(43x54mm useable area) 69mm

6x6cm (45x56mm useable area) 72mm

6x7cm (54x67mm useable area) 86mm

<p>

for a 9x16 Pythagorean "Ideal" aspect ratio:

============================================

35mm (20x36mm useable area) 41mm

6X4.5cm(32x56mm useable area) 64mm

6x6cm (32x56mm useable area) 64mm

6x7cm (38x67mm useable area) 77mm

<p>

You can do the math from there.

I have a Voigtlander Bessa I with a Color Skopar lense which I have

used to make some exceptional pictures. It's a guess-focus lens, and

the lens standard is very sturdy (something you definitely want to

look at before making a purchase). The camera prevents double

exposure, but requires you to cock the shutter. Aperture size is a

large 88x55 millimeters, and there is available (or you can make your

own) an insert that reduced its to 6x4.5 format. The viewfinder has

the option for 6x9 or 6x4.5. NOTE: This is the Bessa "I" model, not

the original Bessa.

I believe you mean the 150. The 180 was for the TLR series. The 150

will focus down to 7ft. Of course, you could get a focusing back and

some extension rings.