www.9000.org - controlling depth of field

Controlling depth of field

When a lens is focused on a subject, there is a certain range behind and in front of the subject that remains sharp, as mentioned in the part "the aperture". This range is called "Depth Of Field" or DOF. The photos show how depth of field varies with the aperture selected.

Large apertures (e.g., f/1.7) yield a shallow field of sharp focus, rendering the background and foreground unsharp
Small apertures (e.g., f/22) yield greater depth of field with more of the scene in focus

At a given aperture and focal length, depth of field also varies with subject distance: When the lens is focused on a close subject, depth of field is less; when focused on a distant subject, depth of field is greater. Focal length does also affect DOF; a wide angle lens will give a large DOF, while a tele lens gives a shallow DOF.

DOF preview lever

The preview lever can be used in all exposure modes to close down and lock the lens' aperture. This enables you to determine whether depth of field is sufficient. The lever is hinged and folds up against the handgrip when not in use. To use:

Focus on the main subject.
In A or M mode, set the desired aperture. In P or S mode, meter in the usual way.
With film advanced, press the preview lever partly down and release it. Lens aperture will now be locked at the setting displayed in the data panel. "F" blinks in the data panel while the preview lever is used.
Look through the viewfinder to determine DOF. When the lens is closed down, autofocusing does not operate and it is not possible to adjust the aperture setting. Also, the viewfinder image may appear dark, but this has no effect on exposure.
To cancel the preview operation, press the preview lever all the way down and release it. The aperture setting can now be adjusted by using the up/down controls as usual. The DOF preview is also cancelled if the shutter is released with the lens stopped down.

NOTE

When pressing the DOF preview lever down just a bit, the camera will stop down the aperture to the desired aperture. When pressing a bit more, the camera will stop down to the minimum aperture available on the lens (e.g., 22). The viewfinder gets very dark, but that's normal. Just press the lever all the way to the bottom and the viewfinder will be normal again.
The camera won't stop down the lens with the DOF preview lever if the film is not advanced.

Click to see descriptions of the different parts.

The self timer LED blinks for ten seconds after you have pressed the shutter release button. After that, the shutter fires.

The shutter speed up/down control allows you to change the shutter speed.

The depth of field preview lever stops down the aperture to let you see the actual range of sharpness in the picture.

These contacts transmits information between the camera and the lens.

The aperture up/down control allows you to change the aperture.

The lens release button is pushed when you want to unlock and remove the lens.

Focus mode switch. It selects between autofocus (AF) and manual focus (MF).

The remote control terminal, here covered by a sliding door, is used when you want to release the shutter without touching the camera. A special cable is needed.

The image is projected on the matte screen inside the camera. Several different screen types exists.

These contacts are used for external bottom-mounted accessories, for example the CG-1000 Control Grip and the winders.

The battery compartment takes two AA size (R6) batteries.

You must always use the rewind release button prior to rewinding the film manually.

This coupler is used for motorized film winding.

This coupler is used by the MD-90 Motor Drive for rewinding film.

The handgrip.

A PC socket allows you to attach external flashes, for example studio flashes.

Minolta cameras (up until Dynax 9 and later with SSM lenses) have the motors driving the focusing inside the camera body. The focus drive coupler transmits the rotational force from the internal motor to the lens.

The mirror reflects light from the lens on the matte screen. It is swung out of the way when taking a picture.

Use this socket to mount the camera on a tripod for long exposures.

Take note of your serial number for security reasons. Some countries (and some private initiatives) keep lists of stolen equipment's serial numbers.

This small window provides lighting for the viewfinder LCD panel. If it's dark outside, the camera will activate an amber LED inside the window to provide additional lighting.

The diopter adjustment dial is used to adjust the viewfinder for near- or farsighted photographers.

This lever controls the eyepiece shutter.

The AEL (Automatic Exposure Lock) button locks the metered exposure value.

Attach flashes, the optional remote release IR-1N, or other compatible accessories to the accessory shoe.

Look in the viewfinder to compose the picture and see exposure values.

The film window shows if film is installed, and which film it is.

Operate this lever to manually advance the film.

This is the main power switch. It has three modes; OFF, ON, or ON w/beep (audible).

The multiple exposure button permits the shutter to be cocked without film being advanced between exposures.

Mount a strap through two of the three strap eyelets. A strap can be mounted for either horizontal or vertical camera carrying.

The exposure mode selector determines the type and amount of automation of the camera's exposure. In the center of the selector a LCD data panel displays exposure values and camera operation details.

The shutter release button focuses and/or takes a picture, depending on the camera settings and type of pressure.

Self timer switch.

The exposure adjustment button can be used to compensate for certain conditions, such as backlit scenes.

The frame counter keeps track of how many pictures you have taken. Standard film lengths are printed in red.

This rotary selector acts as a metering selector, but also as a rewind crank and back release.

The ISO adjustment button allows you to manually set film speed.

The film is pressed against the guide rails by the pressure plate in the back. They should never be touched.

This lever is used when removing the back, for example if changing a standard back into a Program Back or vice versa.

The take up spool rotates clockwise (seen from the top of the camera) to collect wound film.

The shutter controls the duration of the film's exposure to light. Never touch the shutter curtains.

The film sprockets wind the film. See to it that the holes in the edges of the film are aligned with the sprocket teeth.

These contacts are used for communication with an optional back, for example one of the Program Backs.

This latch locks the back shut.

This prong rotates when film is rewound. It can be manually operated with the rewind crank, or motorized with the Motor Drive MD-90.

DX contacts provide the camera with information about the type of film used and its sensitivity. Never touch the DX contacts; if dirty, they may report the wrong film speed.

The mounting index (a red dot) provides visual guidance for inserting the lens into the mount.

The bayonet type lens mount (Minolta "A" type) allows the lens to be mounted on the camera. It is not compatible with older manual focus Minolta lenses of type "SR", "MC" or "MD".

This pin is used by the camera to stop down the aperture inside the lens to the value set on the camera.

This pin locks the lens inside the mount. It is withdrawn when the lens release button is pressed.

(Obscured) The back release lock prevents you from opening the back inadvertently. Slide it in the direction of the arrow and pull up the metering selector to open the back.