Camera Movements for Dummies like Me, Pt.1 by Jason Fung
Jason Fung is back with what will be a Large Format series on the JCH website! The first installment will be Increasing your depth of field. *Note this is a long one. Recommend bookmarking it or getting a coffee and sitting down with it.
Scenario 1: Increasing your depth of field
Ansel Adams wrote three definitive guides about photography. The Camera was about how to use the camera. Chapter 10 dealt specifically with camera movements. The Negative taught photographers how to pre-visualize the exposure and develop your film consistently using the Zone System. The Print dealt with mastering darkroom techniques. These books were too technical for me to synthesize the information in the field. It took me many years and a number of awkardly worded questions on reddit and the largeformayphotography forum to figure it out. I am breaking down what I’ve learned into a series of scenarios to better understand individual components so that a photographer can use a variety of concepts laid out in the different scenarios and apply it to their own photography.
Applicability
This will also be applicable with 35mm cameras if you are using a lensbaby or a tilt-shift lens. This will be more obviously observable as the image gets bigger, medium format to most 4×5 field cameras, and most pronounced on 8×10 cameras. The reason for this is that a shorter focal length lens will have a smaller depth of field; and larger formats require longer focal lengths. For example, a normal lens on a 35mm camera (50mm shooting at f/8, focused on a subject that is 2 meters away) will have a depth of field, about, 80cm – everything from 1.6m to 2.4m will be in focus. However, if you were to use a normal lens a 8×10 camera (300mm shooting at f/8, focused on a subject that is 2 meters away), you would have a depth of field less than 12cm. Therefore, when you are shooting large format, the photographer needs to effectively apply the depth of field to their advantage.
The Scenario
In this scenario, choose a landscape and two subjects. In the far distance, I’ve chosen the mountains. The second subject are some people on kayaks on the water. I’ve place the mountain around the top third of the frame and the boat on the bottom third. They should not be on the same level, otherwise you might need a different kind of movement, such as swing.
If the boats are too close to the camera, I would require extreme front tilt and a bunch of stuff in the middle will be out of focus. On the other hand, if the people are far away from the horizon, I would barely need any front tilt at all. Therefore, it is important to understand the relationship of space. The space between the camera and the near subject, approximately 20 meters away. The space between the near subject and the far subject, approximately 200 meters away (in a camera, it might as well be infinity). I didn’t require much front tilt. Or in this case, I could have tried to not use any front tilt and get away with stopping down to f/64. If the boats were closer, I would require more front tilt, and the more aggress the front tilt, the more I would need to stop down to keep everything between the two subjects in focus. With a bit of experience a photographer will pick up the sense of where the limits of front tilt.
*This is the most front tilt I’ve ever needed. I actually used less front tilt than this.
*This is the maximum front tilt that this camera is capable of. It is too much front tilt for normal use.
The Process
The process of focusing begins on the near subjects using the focus knob. After the mountains are in focus, loosen the knob on the front standard and swing the front standard forward (as if the standard is falling forward) until the mountains fall into focus. By now the kayak has fallen out of focus but the mountains are in focus. Don’t worry, this is all part of the process. Lock down the standard and start again. Focus on the nearer subject. Then, tilt the front standard again until the mountains are in focus. Each time this is repeated, you get a little closer to matching the plane of focus with the two chosen subjects. I am usually able to achieve critical focus on both subjects after 3 or 4 attempts.
*Focus on the near, then the far. Note that the image is inverted because there is no mirror or prism to reverse the image. Therefore the sky is on the bottom of the ground glass and the ground is on the top edge of the ground glass.
Conclusion
Two clarifications. Depending on the circumstance, the camera movements and
personal preference, some photographers advocate focusing on the far object first, then
the near object. To this day, I don’t fully understand the difference. I am pretty sure I’ve
done both at some point, and in both circumstances it has produced an image I was
happy with.
Secondly, in the title, it was very wrong of me to describe this scenario as
increasing the depth of field. It was clickbait. However, to the layman that I once was,
“increasing depth of field” was the only way for me to understand the function of front
tilt. In actuality, you are not increasing the depth of field. It is being moved and is pivoted
in such a way that the depth of field you already have covers the two points that you
have chosen. If you are looking for something more technical that explains all the math
and charts and circle of confusion, I am not the guy, but a much more comprehensive
analysis of the physics can be better explained by googling scheimpflug.
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You can see Jason’s Twitter here and his website here as he will build a collection of Large Format articles on JCH.
– JF
Maybe an even simpler way to understand this, especially with a view camera, is to first focus on the far distance, in this case infinity requiring 300mm bellows extension with a normal 300mm lens, and then the near object, requiring, say 330mm extension. To bring both into focus, one needs to focus halfway, at 315mm extension and then tilt the front standard so that the bottom of the lens board is at 300mm and the top at 330mm. Now the mountain is in focus at the bottom of the focusing screen (image being upside down) and the nearby objects are in focus at the top of the screen. Looking from the side, it is easy enough to understand the principle of it, combining both focusing distances into one image.