The birth of a Lensboard

by Jo Lommen.

It all started with

the search for the image circle of the 7" Kodak Aero Ektar.

The easiest way is to do that is to go into a dimmed room with a window,  take your Aero in the hand, point it to the window and ask your assistant to hold the sheet of paper some 20 to 30 centimetres behind you. By moving the Aero until the image is sharp on the sheet of paper, your assistant has one hand free to take the ruler and measure the circle. By using a 30x30 cm cardboard with  the Aero in the centre, the image would even be better.

But of course this can be done better and with more accurateness. One of my colleague web site "4x5 camera" publishers John de Vries was curious to know how big the image circle would be of a Kodak 7" Aero lens, by using  his huge Wisner camera, assuming that the Aero image circle would fit on the ground glass of the 8 x 10 camera. To do that experiment, he needed a lens board to hold the heavy Aero lens and emailed the photo below with the necessary measures of the Wisner's camera standard.

Please join me on the way to realize a research which turned out to be a very good idea for further creative photographic

Wisner light trapped lens standard.


               Design n & Drawing                                          Selection of wood


              Sawing & Milling backside to fit the standard light trap.                       Front site waiting for 78 mm lens hole


      First fitting                                  General rehearsal 


          Special tools for making the aluminium lensboard
          needed for extra strength and support on the backside of the lens board


                                    To prevent  internal reflections the backside has to be painted flat black.
The aluminium lens board gives extra strength.


   The lensboard need to be varnished in several layers to let it shine like the first violin in the orchestra.


Photos Jo Lommen

it all ends up in a 

rediscovery of the second life of the Kodak Aero 7 " lens.


The dramatic metamorphosis from a former war machine into a classic "work of art".  


Photo by John De Vries.

The result of John's search for the usable COGD (Circle of good definition) is 16cm square (7.8").


Mounting the Aero Ektar

Any Questions         The Speed Graphic and The Aero Ektar          The Speed Graphic and The Aldis lens

Adjusting the Kalart Range Finder to accept the aero lens                 Double light-trap lens-board    

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Photos Jo Lommen