Tuesday, 1 April 2008

Experiments in 6x9 cameras

Today I got my latest addition to my image making tool set. Its a Voigtlander Bessa I.

For those who aren't familiar with it, this is a 120 roll film camera, which is essentially the same paper backed roll film from the good old box brownie (minor changes).

This film is still popular with professionals today, and has been in use for since around 1900. Unlike 35mm (more or less killed off or at least badly wounded) by digital the larger image area provided by this film means that you can comfortably get 12Megapixels from even a modest flat bed scanner, or as much as 26 Megapixels from higher quality film scanners (like the Nikon LS 9000).

Of course its the lens which makes the image, and while all the other bits of the camera help as well you just can't get a good image with a crappy lens or poor focus.

The lens on mine is the Vaskar, which I'm told is no "killer".

However looking at the image on a ground glass (pressed against the film rails) seems to show images that are quite sharp (as long as you have them in focus that is) but a quite narrow DoF.

This last point (focus) is where this camera suffers in use. Focus is by adjusting the lens with nothing more than some markers on it for predicting the distance.

You can see the distance scale on the black ring around the lens (white numbers), as well as the black arrow just visible over there on the left side.

With no way to preview or confirm your focus this is all you have. I've checked it by making a bit of ground glass and putting it on the film area at back of the camera, and its not very accurate. But what you can see is that when its focused, its quite sharp. Nearly as sharp as anything else in my camera outfit (which includes 90 and 180mm Fujinon large format lenses, as well as Canon EF series lenses).

Worse the depth of field focusing guides (black on the chrome) suggest that when focused on infinity that things as close as 20 feet (6 meters) will be in focus too. Sadly this is quite optimistic, and I'm sure lends to the reasons why these older cameras were dismissed as being rubbish by a generation.

The shutter is a bit sticky on the example I have, so I'm not confident that it will operate consistently at shutter speeds of longer than 1/10th of a second. However, for daylight use I think this will be fine.

Anyway, no pictures yet as I've got no developer at home just now, but watch this space for some soon :-)

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