Focal length Selection of view camera lenses is simple, because you will most likely
find that two lenses, a wide angle and normal, will cover most of your field
or studio camera needs.
Normal lenses For a standard lens, a 150mm lens is the most versatile for 4x5 camera
work. It gives a natural perspective, and is useful for any subject from
landscape and portraiture to still life. It is also an excellent choice
for close-up and macro photography in the field, because you can achieve
life-size reproduction (1:1) without any accessories. The slightly longer
210mm focal length, common in 4x5 studio camera work, is also widely used
with field cameras. In 8x10 format, the normal focal length is about double
of 4x5, or 300mm to 360mm.
Wide angle lenses The 90mm lens is the most popular and versatile 4x5 wide angle lens,
useful for a wide range of subjects from capturing vast landscapes, and
both architectural and table top subjects. In 8x10 format, the 200mm is
equivalent to the 90mm in 4x5 for a basic wide angle.
Field Camera Considerations
When using focal lengths longer than 210mm with a 4x5 field camera, you
may consider choosing a telephoto design lens (usually designated with a
"T") rather than a regular design lens of the same focal length.
For example, a 360mm "telephoto" lens may require only 260mm of
bellows extension to focus at infinity, where a 360 "normal" lens
will be require a full 360mm of bellows extension. Using only 260mm of extension
for infinity focus will allow the use of additional extension for closer
focusing. Telephoto lenses are ideally suited for field camera use because
they require less bellows extension, are more compact, and lighter than
equivalent focal length non-telephoto lenses.
Approximate equivalents of lens focal length
35mm
4x5
8x10
20mm
65mm
120mm
24mm
75mm
155mm
28mm
90mm
200mm
35mm
115mm
240mm
45mm
150mm
300mm
52mm
180mm
360mm
63mm
210mm
420mm
90mm
300mm
600mm
105mm
360mm
720mm
135mm
480mm
900mm
Maximum aperture
Most large format camera lenses have maximum apertures of f/4.5 or f/5.6,
which are excellent for viewing and focusing brightness. In some instances
you will have a choice of the same focal length lens in two different maximum
apertures. The f/4.5 lens will be brighter and easier to focus than a comparable
lens with f/8.0 maximum aperture, but will be larger, heavier and more expensive.
In actual picture taking, you will probably be using either lens at f/16
and image quality should be comparable.
Image Circle and Format Coverage
To get the greatest use of any view camera, camera movements are employed
for adjustment of composition, or correction of converging vertical lines.
When using camera movements, the image circle projected by the lens on to
the film must be large enough to cover the film area without vignetting.
The same concern holds true for coverage of larger film formats. For example,
a 210mm lens designed for the 4x5 format may not project a large enough
image circle to cover the 8x10 format. Conversely, a lens designed for the
larger 8x10 format would easily cover the 4x5 format, and allow for generous
camera movement in any direction.
When selecting a large format camera lens, check the lens manufacturer's
specifications regarding image circle and recommended maximum format to
see which lens best suits your needs. The image circle is usually expressed
in a millimeter diameter, at infinity, and at a specific aperture of f/16
or f/22. Note these specifications when comparing lenses from different
manufacturers, as standards may vary.
Usually, lenses that cover large image circles are larger, heavier and more
expensive. For field landscape photography, a minimum of camera movement
is typically required. For table-top photography, where extreme camera movement
may be employed, a lens with wide image circle coverage is preferred to
avoid vignetting.