Shooting in 4×5 – Focusing Difficulties

In this modern age of digital photography you probably wouldn’t think anyone would be looking to buy a 4×5 field camera. Given the convenience of digital SLRs, why would anyone be interested in a cumbersome, slow, expensive, and difficult to operate fully manual camera? But just over two years ago that is exactly what I bought rather than a digital SLR. My reason was simple: I had wanted a 4×5 since around 1993 when I first learned that my favourite American landscape photographer, Eliot Porter had used a 4×5.

Way back then I learned some important things about 4×5 cameras. They were just as expensive as a very good 35mm SLR; they were slow to set up; and the film was expensive. Nevertheless, I knew that with a 4×5 camera I would be able to capture landscapes on film that was the size of a postcard, much more impressive than film the size of a postage stamp. The larger format is impressive because it leaps out from a light table and can be enlarged to very big prints while maintaining pinpoint clarity. If you enlarge a 35mm print to 16”x20” you have to increase the original image by doubling the size roughly 4 times (about 1 x 1 ½, 2×3, 4×6, 8×12, 16×24), severely testing the clarity of detail in the photograph. A 4×5 transparency only has to be enlarged by doubling it 2 times (4×5 to 8×10; 8×10 to 16×20) allowing for sharpness to be maintained. Enlarging it by doubling the size four times would give us a 64”x80” size print or 5’1/3”x6’2/3”. It is for this reason that photographers still use large format cameras, particularly 4×5, and some 8×10 or larger.

Some of my favourite British photographers shoot in 4×5: Peter Watson, Joe Cornish and David Ward. Many American photographers I admired in the 90s used 4×5 like Pat O’Hara, William Neill and Carr Clifton. Canadian photographer Graham Osborne also shot in 4×5 (and I think he still does), and many other photographers in countries such as Japan, New Zealand and Australia shoot in 4×5 as well. So I was not as much of an oddball as you might think when I chose to buy a Tachihara 4×5 technical field camera.

A 4x5 transparency and two 35mm transparencies on my light table

A 4x5 transparency and two 35mm transparencies on my light table

Admittedly, it has not been easy. The learning curve has been slow to reach the bend in the elbow. For the most part I have found it easy and fun to use the camera but very difficult to produce the desired results. Composing the image is not as difficult as I had imagined. You view the scene reversed and inverted on the ground glass, but because the view is large enough to be like a small window in most cases I have not found this an obstacle in composing the scene as I wish to capture it. But focusing has proven to be the biggest issue, even much more than proper exposure, which I can get right about 80% of the time using my Minolta spot meter and then deciding the shutter speed from there.

The first reason why focusing is a challenge for me is because I have to think carefully about the focal length of the lens I am using. The standard lens for a 4×5 is a 150mm, and I had to buy a 180mm since there were no 150s available that were used. For the 35mm format, a 150mm lens is a telephoto lens. But even though it is a standard lens for the 4×5 it still has the same depth-of-field. The reason being I’ll explain below.

Each focal length of lens has an image circle that is the circular image of the scene before the lens which is reversed and inverted behind the lens. The smaller the focal length, the smaller the image circle. Therefore it stands to reason that larger film sizes need larger focal lengths in order for the image circle to be larger than the film. A 35mm frame of film is small and captures only the centre of the image circle of a 90mm lens, thus the 90mm works as a short telephoto lens. A 6×7(cm) camera’s film is actually 5.5x7cm and captures a larger area of the 90mm lens image circle. This lens is the standard lens for 6×7 format. A sheet of 4×5 film captures most of the 90mm lens image circle and thus the lens is a wide angle lens in 4×5. We can see that any focal length can be a wide angle, standard, or telephoto lens depending on the size of the camera. A 300mm is a nice telephoto lens for the 35mm format but it’s the standard lens for 8×10.

So I discovered that shooting a landscape with a 180mm lens meant that I had to consider the limitations of depth-of-field. I was surprised to find out that shooting a mountain scene with a large aperture cost me focus because the mountain ridge off to one side that I assumed was in focus at infinity was actually too close and outside the range of the depth-of-field and hyperfocal distance. I blew a number of photos by not realizing this. You may figure that it can’t be so hard not to notice something out of focus but it’s actually quite easy.

First, there is no green light when your subject comes into focus. You view the image on the ground glass and try to focus by turning knobs that move the lens back and forth along rails on the camera bed. The light behind the camera must be darker than the light before the lens otherwise it is difficult if not impossible to see the view on the ground glass. That’s when you need a focusing cloth under which to hide and view the composition on the ground glass. Some experienced 4×5 users claim they can tell if their subject or scene is in focus simply by looking at the ground glass. But some people advise using a loupe to check for clarity. For a straight-forward scenic this is not too difficult. The challenge comes when shooting objects on different focal planes. You have to move the aperture closing lever to make the aperture smaller but then you have less light in the camera and the image will fade into darkness unless you have a focusing cloth to put over the camera and your head.

Sometimes, however, you can’t keep everything in focus the standard way (using a small f/stop like 22 and smaller) and you need to move the lens from its relative position to the film by tilting the lens board back and forth, swinging it left and right, raising it up and lowering it down, and by shifting it to one side or the other (something that can’t be done with a field camera with the lens board on rails). By tilting or swinging the lens you change the normal parallel relationship of the focal plane and the film plane. The most common and easy to understand example is tilting the lens to keep a subject near the lens and one far from the lens in sharp focus simultaneously.

Let’s say there’s a bunch of flowers right in front and a mountain peak in the distance. Normally the depth of field required to capture both in focus would be too great for any lens but one with a very short focal length. But by tilting the lens forward slightly the focal plane can be set across the tops of the flowers and the peak of the distant mountain. With the right focusing adjustments the flowers and the peak of the mountain can both come out sharp with even a large aperture. But if the flowers sit at the edge of a cliff and the valley between the flowers and mountain is in the composition, then the valley will appear out of focus unless and small enough aperture is set to maintain focus throughout the scene because the depth of field now extends out across the scene and the regions out of focus are above and below instead of in front and behind. Furthermore, the normally parallel parameters of the focal plane become wedge-shaped when the lens is swung or tilted, with the point of the wedge nearest the lens. The concept is simple enough to comprehend but I find I have continuous problems with focus nonetheless.

One reason I know for focusing problems is when I set up the camera but don’t check that all settings are at zero before I start making adjustments. Once I shot a sunrise scene of Yarigatake in the Japan North Alps where only the left side was in focus because I had accidentally failed to be sure the lens board was also set at zero. It was actually still set with a slight swing to one side thus throwing out of focus half of the scene spread out before the camera. I wasn’t in the habit of using a loupe at the time either.

Though I still try my best to pay the utmost attention to focusing details with my loupe mistakes occur, and even on my most recent outing to Shiroumadake I failed to set the focus just right and ended up with almost useless shots because some of them, when viewed through the loupe, went out of focus near the bottom or on one side. Again, the foreground rocks and background mountains were in focus but the valley in the lower left was out of the hyperfocal distance.

Focusing can be time consuming and painstaking work, especially when trying to tilt and swing at the same time. You have to be able to see how the focal plane range and limits on the ground glass and imagine how it changes as you adjust the lens position, then meticulously examine the scene through the loupe to verify whether or not you have focused properly. With lots of practice I am sure I will get better but the film is expensive so I cannot shoot as often as I’d like. But that’s a topic for another post.

Me on the way up Oku Hotakadake, shooting the view back towards Yarigatake

Me on the way up Oku Hotakadake, shooting the view back towards Yarigatake

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2 responses to “Shooting in 4×5 – Focusing Difficulties

  1. I’m in utter awe! You, sir, are a photograher. I can’t think of a better way to put it than that.

  2. Well, thank you very much. However, if you mean I am a photographer because I attempt to shoot in large format then… well, you can see the implications. Whether I shoot in 35mm, medium format, large format or digital I still face basically the same challenges: achieving techinical excellence (exposure and focus), good composition, and an overall attractive and pleasing image.

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