Hasselblad H2 Depth-of-field calculation, Stop down /depth-of-field, Infrared focus settings

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Lens focus setting too far beyond the distance of the subject framed by the central section in the viewfinder

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Focus setting too close for the distance of the subject framed by the central section in the viewfinder

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Focus setting correct

Depth-of-field calculation 7

There are two distance scales (in feet and metres) visible through the focus distance window on the upper part of the lens barrel. There is also a central lens index mark and a depth-of-field scale. The focusing distance is read off the chosen scale from the central lens index.

Depth-of-field can be calculated as follows:

1.Focus the lens as required.

2.Make an exposure reading (auto or manual) and note the aperture setting.

3.Find the markings on either side of the central index that cor- respond to the chosen aperture.

4.From these two markings, read off on the required lens dis- tance scale the two corresponding distances.

5.The depth-of-field (at that particular aperture and focus set- ting) will be the area included between these two distances.

In the example given here, the focusing distance is set at nearly 3 metres. At an aperture of f/22, the depth-of-field would therefore extend from just over 2 m to approx... 4.5 m.

Stop down /depth-of-field 8

A visual depth-of-field preview can be made by depressing the STOP DOWN button while viewing the image on the viewfinder screen.

Infrared focus settings 9

As infrared rays form an image at a different plane to that formed by visible light, the normal focus settings do not apply. Proceed as follows in manual focus mode:

1.Focus the lens in the conventional manner until satisfied.

2.Note the distance setting against the central lens index.

3.Re-align this distance setting against the infrared mark (coloured red) instead of the central lens index.

Alternatively if you have already calculated the required distance, you can make a manual distance setting by using the distance scales together with the infrared mark instead of the central lens index.

Focus aid

As well as the conventional view on the focusing screen to ensure a sharp image, the H2 also features LED focus aid appearing as two arrowheads to the right of the viewfinder display (except for lenses with a maximum aperture of f/6.7 or smaller). The arrowheads provide confirmation of a precision focus setting and are a useful aid when making a setting with eyesight alone.

Manual focus setting

When the left arrowhead alone appears it means the focus setting is too far beyond the chosen distance (the area framed within the central zone in the viewfinder) and when the right arrowhead alone appears it means the focus setting is too close. Focus is cor- rect when both arrowheads appear together. If the focus cannot be established, then both arrowheads flash.

Automatic focus setting

Focus is correct when both arrowheads are visible together. Focus

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