This is a sequence of test shots on Harman Direct Positive Paper.
The paper was rolled up in a 120 rollfilm backing and exposed in a Zeiss Ikonta.
The first shot (this camera winds right to left) on the right is without filter at my best calculated exposure, ISO 3 and paper preflased to just short of a tone.
The prints were developed in a soft developer for 90secs and Ilford MG for about 30 secs (note warm tone).
As you can see it is still too contrasty.
Moving to the left, the first shot has a yellow filter, with 1 extra stop exposure. Obviously this filter factor is not valid as it is over exposed. Next shot is one stop less (F5.6 @ 1/2 s) and the last shot (on the left) is F8 @ 1s. Note that the contrast is a bit higher - and the depth of field a bit greater.
Both of the last two shots are, for me, in a 'normal' tonal range for pictorial photography-but it was hard work getting there. I next tried to take some 5 X 4" pics using the same methods - and failed completely. Like ultra critical slide photography, there isn't much latitude available and not much you can do to save the situation in the darkroom afterwards. Moving to a different camera / lens / shutter and with a few little things thrown in such as bellows extension and slight change in lighting conditions by the time I was ready... and back to the drawing board.