20 September, 2007
Large Format cameras have a complicated array of movements that can be very intimidating and confusing to someone new to or thinking about the format. This is exacerbated by advertising pictures of view cameras with bizarre looking and excessive tilts, shifts and swings – which are never used in the real world. In practice there are a few common movements used to gain the standard effects; the objective of this article is to explain and demystify some of these common situations.
View Cameras have movements that are designed to control two things: the plane of focus and the perspective.
On a camera without movements, the plane of focus is always parallel to the film and lens planes; front to back sharpness is achieved by stopping down the lens aperture to increase the depth of field. The lens is focused to the ‘hyperfocal distance’, the closest it can be focused for that particular lens and aperture combination whilst keeping the background acceptably sharp. How close you can focus the camera and still keep the background sharp is limited to the depth of field of the lens. In reality, there is only one plane of sharp focus - depth of field gives the illusion of sharpness, but this breaks down under enlargement.
Secondly, when a camera (and film plane) without movements is pointed upwards or downwards, the perspective changes. Lines that were parallel begin to converge, causing buildings and objects with straight lines to take on a bizarre shape. Without movements, the only way to prevent this happening is to setup up the camera film plane parallel to the plane of the lines in the picture; in most cases this is dead level which limits the ability to place the horizon anywhere other than the middle of the picture (unless you crop top or bottom of course – which I often do on 35mm – or use a specialist perspective control lens).
A view camera allows you to better control these two limitations of most 35mm and medium format photography; in a nutshell, tilting the back (film plane) of a view camera controls the perspective and tilting the front and or back controls the plane of focus.
There are a range of potential movements found on a view camera, but not all cameras have all the movements. These movements are:
- Front tilt – the ability to tilt the lens forward or backwards which moves the plane of focus
- Rear tilt – the ability to tilt the film plane forwards or backwards which moves both the plane of focus and alters perspective.
- Swing (front and rear) – basically the same effect as front and rear tilt but adjusting the focus and perspective side to side rather than top to bottom.
- Rise and Fall (front and rear) – moving the lens or film plane upwards or downwards allowing the picture to be re-composed without any change to perspective or focus. Typically used when the film plane has been set parallel to the plane of the straight lines in the picture; this has an effect similar to pointing the camera upwards or downwards but keeping the film plane parallel – eliminating converging lines.
- Shift – same as rise and fall, only side to side.
There you have it; sounds complicated and a lot to understand but in practice there are 5 standard situations and effects that account for 99.9% of all practical landscape pictures:
Scenario 1: Front to back sharpness. Tilting the lens forward or the film back backwards causes the plane of focus to move so that it is possible to run the focus plane from the ground just in front of you to the horizon. This means that foreground objects at the bottom of your picture and distant objects at the top are sharp, even if the aperture is wide open. Usually only a small amount of movement is needed to achieve this. See the excellent article on the procedure for focusing the view camera to achieve this effect at the Large Format Photography website. This must account for at least two thirds of landscape pictures, where most of the objects in the picture are on or close to a single plane.
Scenario 2: Fix the perspective. Placing the film back parallel with the side of a building will render the perspective more natural; usually this means getting the film plane vertical to the ground i.e. upright. Most view cameras have spirit levels to help you get the back level. This result is achieved in two ways: either set the camera up so the film plane is level and then use front/rear rise and fall to compose the picture. Alternatively, point the camera upwards or downwards as desired and then tilt the rear and front so that they are upright. It is possible for this movement to be limited by either the camera (not enough fall or rise possible) or lens coverage (running out of glass or getting too much light fall off). These two scenarios (1 and 2) are often combined because tilting the lens whilst keeping the back flat alters the plane of focus but does not alter the perspective. Normally, set up the perspective first, and then focus using front tilt.
Scenario 3: Looming foregrounds. A common large format effect is to exaggerate the size and scale of the foreground in relation to the background. This is most easily achieved by pointing the camera downwards and tilting the film back backwards; this has the effect of altering the perspective so that the foreground seems to loom, and it also alters the plane of focus as in scenario 1.
Scenario 4: Swing. A wall running from foreground left to background right can be rendered in focus by swinging the lens left to right. This adjusts the plane of focus so that it runs from the foreground left to background right. In practice I find this occurs most often in close up or inner landscape photography.
Scenario 5: The large format blind spot. Focusing using movements does not work in one particular, but sadly fairly common, situation: when there is a foreground object spanning both the bottom and top of the picture that needs to be in focus (e.g. a large rock or tree) and the background also needs to be evenly sharp. In such a situation, moving the plane of focus doesn’t help; you will find that part of the foreground object (the top) goes out of focus when you tilt the lens or film back. The only answer is to stop down the lens. In such situations I will stop down up to about F32; the point, on 5x4, at which softness from diffraction begins to overtake the increase in sharpness from depth of field.
Scenario 6: The hole. Alright, this is not another scenario but it is a common occurrence when using movements to focus - getting a sharp result top and bottom of the picture, but a soft result (or hole) in the middle. This can happen because the objects in the middle are not on the same plane of focus running from the bottom-foreground to top-background. The only answer here is to be aware it can happen, check for it, stop down the lens, tweak the focusing and check the result on the ground glass with a loupe.
So what is the downside?
Photography is all about trade offs; and there has to be some downsides and limits to this control, apart from the obvious LF ones of slowness, weight and complexity.
- Movements can be limited by the camera: for example, some cameras don’t have rear tilt. Although it is rare for the amount of permitted tilt to limit what you want to do, sometimes the amount of rise and fall is limited, and limiting.
- Lens coverage can limit the ability to apply movements: either because physically you run out of glass or because of light fall off, particularly with wider angle lenses. Obviously, this varies lens by lens.
- In macro or close-up situations, front or back tilt can cause some light fall off due to bellows factor. This is rare in practice.
- Messing it up; it is easy to make a mistake: leaving movements unsecured, accidentally setting a movement (e.g. swing), leaving a focus ‘hole’ etc.
I find being able to recognise and act on these five scenarios helps to simplify and understand view camera movements. There are some excellent books that explain all of this in more detail; in particular I found Ansel Adams’s book ‘The Camera’ and Leslie Stroebel’s ‘View Camera Technique’ very helpful.
© Jon Brock 2007