236
THE HASSELBLAD MANUAL
most of these cameras are smaller than the 35 mm fi lm format that is familiar to most photog-
raphers. Most of these cameras have a sensor in the APS size of about 15
23 mm, (some are
even smaller), and therefore cover a smaller area that would be the case on 35 mm fi lm. In other
words, a lens of a specifi c focal length becomes equivalent to a lens of longer focal length. The
lens factor for the APS size is about 1.5
, which means that a 50 mm lens in the 35 mm fi lm
format becomes the equivalent of a 75 mm lens when used with the APS size digital sensor.
I consider the term lens factor an unfortunate choice and misleading as it may give the impres-
sion to the photographer that the focal length of the lens is changed. This is not the case as
focal length can be changed only by adding optical elements or moving elements within the
lens. A 100 mm lens on a Hasselblad keeps its 100 mm focal length and records the image as a
100 mm focal length whether it is used for the 2¼ fi lm format or any one of the smaller sen-
sors in a digital back. The change is only in the angle of view and the area coverage, which is
smaller on a digital sensor than it is on the 120 fi lm format. As a result the so-called lens factors
also must be considered in digital imaging with Hasselblad and are as follows:
36.7
49.0 sensor: 1.1
compared to 6
4.5 fi lm format
33.1
44.0 sensor: 1.25
compared to 6
4.5 fi lm format
36.7
36.7 sensor: 1.5
compared to 2¼ square format
With Hasselblad in some cases you may compare a rectangular format to a square or vice
versa, so you also must take the format shape in consideration. For example, the lens factor
Figure 14-2
Angle of view. (2) The diagonal angle of view of different lenses for the 2¼ fi lm
format from top to bottom: 40, 50, 80, 150, and 250 mm focal length. (3) The angle of view
can be expressed in relation either to the picture diagonal or to the horizontal or vertical
side. The three are different in a rectangular format. (1) On the 30 mm full-frame fi sh-eye lens,
the 180-degree diagonal angle of view is completely out of proportion to the 112-degree
horizontal or vertical angle. (4) The covering power of a lens is the diameter of the circle
within which satisfactory image quality and illumination are obtained.
Содержание Digital Camera
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Страница 165: ...Heidi Niemala Editorial photograph made with a 50mm lens in the basement of a pre Civil War building ...
Страница 166: ...Heidi Niemala Photographed for clothing designer with a 150mm lens ...
Страница 167: ...Heidi Niemala Editorial portrait with a 150mm lens ...
Страница 168: ...Heidi Niemala Photographed with a 50mm lens during a sand storm at White Sands ...
Страница 198: ...Jonathan Exley An attention creating image of mult time Indianapolis 500 winner Helio Castroneves ...
Страница 200: ...Jonathan Exley Lifestyle Designer Kathy Ireland Courtesy of kathyireland com ...
Страница 243: ...Marco Grob Singer Alvin Chea from theTake 6 band photographed with an HC 2 8 80mm lens on an H camera ...
Страница 244: ...Marco Grob A make up test shot made with an HC Macro 4 120mm lens on an H camera ...
Страница 247: ...Marco Grob The Stairs photographed in CapeTown for Glamour magazine with an HC 3 5 50mm lens on an H camera ...
Страница 312: ...Raya High jewlery photograph produced with an HC 3 2 150mm lens on an H camera Raya Photographer ...
Страница 381: ...366 THE HASSELBLAD MANUAL Chart A2 Area coverage in inches with single extension tubes for the 6 4 5 film format ...
Страница 383: ...368 THE HASSELBLAD MANUAL Chart A4 Area coverage in inches with single extension tables for the 33 1 44 2 sensor ...
Страница 385: ...370 THE HASSELBLAD MANUAL Chart A6 Area coverage in inches with combinations of tubes for the 6 4 5 film format ...
Страница 387: ...372 THE HASSELBLAD MANUAL Chart A8 Area coverage in inches with combinations of tables for the 33 1 44 2 sensor ...
Страница 397: ...Chart D Close up charts for 80 to 250mm Hasselblad lenses an 503 and other V system SLR cameras based on the film format ...
Страница 398: ...Close Up Photography on Film or Digital 383 ...
Страница 400: ...Jonathan Singer ...
Страница 401: ...Jonathan Singer ...
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