Deep Depth of Field in Low Light
If the light is dim, how are we able to get good depth of field if we don't want to use flash? We need to stop down for more depth -- but then the shutter speeds get too slow and we need a tripod. Or do we?
I learned this lesson backwards while-attending the Naval Training Center at Bainbridge, MD in 1955. I was using an older black dial Leica lllf equipped with a brand new 50mm f/1.4 Nikkor I'd bought for my fledgling freelance photo business in New England, just before bring drafted following college deferment. I had sent for the camera, Weston meter, and some film from home. I knew the great speed of that lens would be needed for the interior of the barracks buildings and the drill hall. But a problem arose when trying to get a large group along with the company commander all in focus inside the cramped and dim interior barracks space. How did I solve it? Simple: I couldn't. Instead, I had to concentrate on pictures of the commander and others singly, as well as the graduation ceremony in the drill hall, all nearly wide open at f/2 on the all-purpose ASA 80 Plus-X film I had at the time. How I would have liked some extra width and depth in those situations! The only wide angle I then possessed was a 35mm f/3.5 Summaron which I hadn't asked to be sent because I knew it would be way too slow for the dim interior light. The wide angle would have provided the needed extra width and depth, even wide open, but the shutter speed required would have been way too slow to handhold.
However, with those experiences came the realization of a lesson I had missed when I admired some of the spectacular wide and deep shots made by famous photographers of the time. They used the same slow 35mm f/3.5 Elmar and Summaron lenses, but with inventiveness that I had yet to learn and practice. One picture I remembered in particular appeared in the Leica Manual of 1951, page 141, made by Peter Stackpole. It shows the mayor of Paoli on the main street, facing the camera while reading a newspaper. The picture has extreme depth from the newspaper page in the foreground all the way back to the town hall's clock tower at the top of the frame several hundred feet away. In the book reproduction you can read some of the larger print in the newspaper a little overthree feet away near the bottom of the frame, and you can also three feet away near the bottom of the frame, and you can also read the clock on the tower at the top of the frame. I remember being impressed with it. But what I should have remembered was the photo data! It was made with a 35mm Elmar at a 20th at f/16. A 20th! He used that slow a shutter speed, even in daylight, yet the picture was very sharp!
The small aperture provided that great depth, but at a slower shutter speed than I would have thought reliably sharp at the time. The major part of the lesson I had missed was that rangefinder wide angle lenses (not retrofocus, as for a reflex camera) can be handheld at much slower speeds due to the very short distance between the optical center of the lens and the film plane. With that factor minimizing any effects of shake, and combined with the very smooth braking action on the leading shutter curtain in all Leicas, the camera can make pictures very steadily at quite slow speeds - even a 10th or an 8th can show little or no visible shake - where a longer handheld 50mm lens can start to show a little shake even at 30th. That was the "secret" I hadn't absorbed. The facts are that a wide angle has more depth at any aperture than a normal lens, and it can be handheld at very much slower shutter speeds, therefore it can be used in the same low light as the 50! An exposure of 30th at f/2 with the 50 is exactly the same as a 10th at f/3.5 with the wide angle.
I could have gotten those whole groups in the dim light of the barracks with the wider angle combined with good depth of field quite easily handheld using the 35mm Summaron wide open. I would have been able to get more of the graduation ceremony through the upper floor window. And the photo of the group outdoors would have looked just about the same as with the 50. After my time at NATC Bainbridge was over, the lllf and Summaron and Nikkor and some other gear - including the use of these new techniques - went on to provide good service during a tour of duty as a Naval aviation photographer. (For a story about that tour, see Viewfinder Vol. 27, No. 2, 1994, Shooting the "Blues" with Leicas, 1956-57).
Nowadays press photogs are using even shorter focal lengths like 14 to 18mm on digital sensors at astronomical ISOs to get their deep depth in low light, but it all started as early as 1930 with those first 35mm f/3.5 Elmar lenses taking advantage of the Leica's smooth 1/20th shutter speed!