Ebony Professional View Cameras


  THE USE OF WIDE-ANGLE LENSES ON AN EBONY FOLDING CAMERA, WITH BOTH WIDE-ANGLE AND UNIVERSAL BELLOWS

(N.B. Ebony cameras require no drop-bed to use even the widest lenses)


Ebony are often asked whether our wide-angle bellows are required, or whether our universal bellows will give sufficient movements, with a particular wide-angle lens. This question applies only to Ebony's folding cameras, as the S and more particularly the SW series are specifically designed for use with wide-angle lenses, and their (non-interchangeable) bellows accordingly allow ample movements with even the widest lenses.

We are also often asked whether it is necessary to use the "wide-angle configuration" with a certain wide lens and bellows combination when using a folding camera. The wide-angle configuration involves using base tilts at either the back, or the front, or at both back and front, to move the standards closer together, and then center tilts to return the standard(s) back to the vertical position.

Below is a series of pictures of the Ebony SV45Ti which illustrate various possible lens/bellows combinations and wide-angle configurations. To give an approximate idea of the amount of movement available with each lens/bellows combination, front rise is used as the representative movement: with each combination maximum possible front rise is contrasted with zero front rise. When considering the maximum amount of movements that are possible, however, it should also be remembered that extensive movements are likely to cause vignetting with wide-angle lenses. (This is less of a problem when using reducing backs for smaller formats.)

The minimum extension of the SV45Ti without tilts is 85mm. However with tilts at both front and back (i.e. the "wide-angle configuration") the minimum extension is 55mm, allowing the use of e.g a 47mmXL lens with a flat lensboard. Wide-angle lenses with the following focal lengths have been used for the demonstration: 47mm, 65mm, 75mm, and 90mm. All lenses are mounted on flat boards. With recessed lensboards the bellows do not have to be compressed quite as much, thus allowing more movements, particularly in the case of the universal bellows. Recessed lensboards may also allow e.g. a 75mm lens to be used without resorting to the wide-angle configuration. However the demonstration below covers lenses mounted on flat boards only.

With a 47mm lens, tilts are required at both back and front (figs. 1, 2). With a 65mm lens, tilts are also generally needed at both back and front (figs. 3, 4, 5, 6), however sometimes it is possible to get away with using front tilts only (fig. 7). The advantage of using back tilts is that the standards are pushed toward the front of the camera bed, and there is therefore less chance of the front end of the bed protruding into the picture. With a 75mm lens, back tilts only are generally sufficient (figs. 8, 9, 10, 11) although as with a 65mm lens, front tilts only (fig.12) are also possible. With any lens with a focal distance of more than 85mm, e.g. a 90mm lens, there is generally no need to resort to the wide-angle configuration (figs. 13, 14, 15, 16).

As a general rule, if you are planning to use lenses that are no shorter than 75mm, universal bellows will probably give sufficient flexibility. If you are planning to use lenses shorter than 75mm, and movements are required, Ebony recommend using wide-angle bellows.

 


 
WITH WIDE-ANGLE BELLOWS
WITH UNIVERSAL BELLOWS
 
NO FRONT RISE
MAX FRONT RISE
NO FRONT RISE
MAX FRONT RISE
ALTERNATIVE
WIDE-ANGLE CONFIGURATION
47MM

1) Wide-angle configuration

Back and front, base and center tilts
The image circle of a 47mm lens is very small, so very few movements are possible, or indeed desirable (with 4x5 film).

Very little front rise

2) Wide-angle configuration

Back and front, base and center tilts
The image circle of a 47mm lens is very small, so very few movements are possible, or indeed desirable (with 4x5 film).

No front rise


65MM

3) Wide-angle configuration

Back and front, base and center tilts

4) Wide-angle configuration

Back and front, base and center tilts
15mm maximum front rise

5) Wide-angle configuration

Back and front, base and center tilts

6) Wide-angle configuration

Back and front, base and center tilts
15mm maximum front rise

7) Wide-angle configuration (b)

Front base and center tilts only

75MM

8) Wide-angle configuration

Back base and center tilts only

9) Wide-angle configuration

Back base and center tilts only
42mm maximum front rise
(maximum possible)

10) Wide-angle configuration

Back base and center tilts only

11) Wide-angle configuration

Back base and center tilts only
22mm maximum front rise

12) Wide-angle configuration (b)

Front base and center tilts only

90MM

13) Standard configuration

No base or center tilts necessary

14) Standard configuration

No base or center tilts necessary
42mm maximum front rise
(maximum possible)

15) Standard configuration

No base or center tilts necessary

16) Standard configuration

No base or center tilts necessary
42mm maximum front rise
(maximum possible)