The craft of photography

Recently I have been reading an interesting book called the Craft of Photography, by David Vestal. This is an old school black and white film photography book (published in 1972) about developing and printing techniques. Mr Vestal has some interesting things to say about exposure calculations, repeating the ancient photographic adage 'Expose for the shadows, develop for the highlights'. He encourages making some test shots to identify the best exposure for a particular film and development combination. He talks about using a separate exposure meter, which for most of my older cameras is what I use as they don't have built in meters. The technique works like this.
1) Choose a high contrast subject with both dark and light parts to it.
2) Using the light meter measure the exposure reading from the darkest part of the subject that you want to be able to see detail.
3) Make a test shot at this exposure.
4) Open the lens 1 stop and make another test shot
5) Open the lens another stop and make another test shot
6) Make a test shot with the lens 1 stop closed down from the meter reading.
7) Develop the film in the normal way and view the results.
These are my results (taken with my Olympus OM-2 in manual mode - film is Legacy Pro 100 - a Fuji film, developed in Rodinal, stand development 1+100 for 1 hour) ):

1/60th at F5.6 - this was the meter indicated setting from the dark areas of the camera body 

1/60th at F8 - this is +1 stop from the meter reading

1/60th at F11 - this is +2 stops from the meter reading (bit dark - under exposed)

1/60 at f4 - this is -1 stop from the meter reading and was the exposure indicated by the camera's own internal meter.

Which one is best?? 

Well interestingly the camera's own meter overexposes the shot, perhaps because of the white paper under the camera. What we are looking for is the best rendering of the dark tones. If you compare the shot taken at the meter reading and the one taken +1 stop side by side:

You can see that the one on the left, which is +1 stop gives the best shadow detail and the best contrast. The conclusion is therefore to get the best exposure, take a meter reading off the darkest part of the subject then open the lens 1 stop. Which is exactly what Mr Vestal recommends in his book!.

Exakta progress

Further to the problems I had with the shutter curtain on my Exakta Varex IIa I purchased another body from ebay at a bargain price. This one has a new shutter curtain. I still have the problem of the fungus on the Zeiss Biotar lens, however the test pictures show the camera works perfectly and the lens is very sharp.

This is an enlargement of a test shot.

Here is another test shot I often do of a fern, detail is very sharp:

Its quite interesting to compare this with the test shot I did to try out stand development. Same film, same developer (Rodinal) but different camera and different developing technique, While the picture below was developed using the stand method 1+100 for 1 hour, the one above from the Varex was done 1+25 for 7 mins.

The fungus on the Zeiss Biotar looks like this. It does not seem to effect the performance of the lens.

Interestingly I also tried the Zeiss Pancolor lens I originally got with my Exakta Varex IIb and I discovered why the photos from that camera were so poor. The lens does not stop down so all the shots were at f2. Next I should try the Biotar on that camera.

Exakta repairs

Bad news I'm afraid :-(
I tried to repair the shutter curtain on my Exakta VXIIa with the liquid electrical tape. I painted it on OK.

But to cover all the holes so no light showed through I needed several coats of the stuff. Eventually no light showed through but the paint ended up quite thick and uneven.

Having left it to dry over night, as I suspected, the shutter now sticks as the paint is too thick. When I have time I will try to dismantle the shutter to see it I can fix it. Replacing the shutter curtain is possible but its pretty complex.