The chart on each aperture card lists the effective aperture when the bellows are extended for focusing on closer subjects

The aperture column: The physical diameter of the aperture opening in millimeters.

The f: column: Lists the effective f: number at each focus distance. (This is a simple way to compensate for “bellows draw”)

The Focus column: Lists three typical subject-to-camera distances (Landscape photos, group, and portrait photos).

The Lens-To-Film column: Lists the typical bellows draw when this lens is focused at each distance (for reference purposes).

.....bottom.....

There is nothing new here, it has all been invented long ago...

Je ne cherche pas. Je trouve.   I do not seek. I find, ...Pablo Picasso

Lens Coverage Graphic

120mm f:2.1

135mm f:2.3

190mm f:3.2

250mm f:4.2

285mm f:4.6

Large Format Lenses

4x5, 5x7, etc.

Fall-off
graphicData_files/120%20%3A2.1%20fall-off.pdf

Fall-off

graphic

Fall-off
graphicData_files/190%20Fall-off.pdf
Data
sheethttp://livepage.apple.com/Data_files/190%20f-3.2%20Data%20sht.pdfshapeimage_7_link_0
Fall-off
graphicData_files/250%3A4.2%20Fall-off.pdf
Data
sheetData_files/250%204.2%20-72mm%3F%3F%3F.pdf
Fall-off
graphicData_files/285vlf%20Fall-off.pdf
Data
sheetData_files/285mm%204.6%20Lens%20data.pdf

120mm f:1.6

250mm f:3.4

335mm f:4.6

500mm f:6.9

1000mm 13.7

Very Large Format Lenses

11x14, 16x20++, etc.

Fall-off
graphicData_files/120%20%3A1.6%20Fall-off.pdf
Data
sheetData_files/120mm%20f1.6%2082mm.pdf
Fall-off
graphicData_files/335%3AFall-off.pdf
Data
sheetData_files/335%3A4.6%20data.%207%2717.pdf
Fall-off
graphicData_files/250%3A3.4%20Fall-off.pdf
Data
sheetData_files/250%203.4%20-82mm.pdf
Fall-off
graphicData_files/500%20Fall-off.pdf
Data
sheetData_files/500%20f%3B6.9%20data.pdf

Fall-off

graphic

Data
sheetData_files/1000mm%20f%3B13.7.pdf

790mm f:5.4

Ultra Large Format Lenses

Mammoth Cameras, Camera Obscura, etc.

Fall-off
graphicData_files/790%20Fall-off.pdf
Data
graphicData_files/790%20f%205.4%20data.pdf

120mm f:2.1.RB

Fall-off

graphic

Data

graphic

135mm f:2.3.RB

Fall-off

graphic

Data

graphic

RB67 Compatible Lenses

One of these data sheets will be supplied with each lens.

(click  below to download)

Fall-off graphics approximate how a film format fits within the image circle.

(click  below to download)

Two articles from 1921 regarding the use of soft focus lenses will help if this is your first experience with historic lenses. (click to download)

Surface Mount flange:

For small, thin boards.

(Technika, Speed Graphic, etc.)

Vignetting may be possible.

Hole precision is unimportant.

Recess Mount flange:

No Vignetting.

Stronger, More secure.

For larger, thicker boards.

Hole precision is more critical.

Data
graphicData_files/120mm%20f-2.1%2072mm.pdf
Data
graphicData_files/135mm%20f2.3%2072mm.pdf

Lens boards:

There’s nothing mysterious about a lens board. It’s not a precision part of the photographic process, contrary to marketing hype. A simple 1/4” light trap between the board and the camera is all that’s needed.

I use quality 5 or 7 ply Baltic Birch plywood cut to fit your camera, sealed against warping and finish coated with either a satin black or a clear poly finish.The the backside is painted flat black, the lens is mounted with stainless steel screws.

In the photo are two Entrepid boards (a 96mm Technika size & a 139mm Sinar size). also, a. 6x6” Deardorff, & a custom 96mm Technika board.

ShuttersShutters.html
DownloadData_files/Soft%20Focus.%20Hammond.pdf
DownloadData_files/Neblette,%20Soft%20Focus%20copy.pdf