[keithpeter]

Well I did say fantasy - a sheet of 10 x 8 film is the same cost as a roll of 35mm (similar area if you think of a contact sheet).

A 35mm camera on a tripod with shutter release would allow experimentation and allow you to decide about weight and carrying for hiking. I used the long exposures mainly in buildings in a city.

My images are not on Edwin Smith's level by any means, but the movement of the Sun direction over an hour does make a sort of smoothing of the light.