Design and making of a scale model (Scheimpflug Line, Hinge Line, kinematics, translation, rods, sliders, linkages)

[Jos Segers]

Harold M. Merklinger argues that view camera focus may be considered to be governed by just two basic rules: the Scheimpflug Rule and the Hinge Rule. After reading his articles I decided to make a scale model.

 

[David M]

Astonishing. May we have a little more explanation, please?

 

[Jos Segers]

Thanks for being interested David! What you see in the pictures consists of a three-dimensional mechanism that allows all movements to be carried out. The part on the right with the coloured rods is a 1:10 scale imitation of the Merklinger image. The left part of the mechanism is a parallelogram like the ones that used to be found in drawing machines. Its function is to allow the film plane to translate in space, i.e. to move it parallel. The accuracy of the model is remarkably good. At my chosen fixed focal length of a lens of 150 mm and a self-set J of 175 cm, the lens tilt (alpha) is indeed about 4.9 degrees. Focusing is done by moving the film plane. This rotates the plane of sharp focus around the Hinge Line.

 

[thronobulax]

Harold M. Merklinger argues that view camera focus may be considered to be governed by just two basic rules: the Scheimpflug Rule and the Hinge Rule. After reading his articles I decided to make a scale model. View attachment 5294View attachment 5295View attachment 5298

This is really nicely done. Among its many virtues, it creates a new application for old, unused draftman's drawing equipment

 

[John]

Thanks for being interested David! What you see in the pictures consists of a three-dimensional mechanism that allows all movements to be carried out. The part on the right with the coloured rods is a 1:10 scale imitation of the Merklinger image. The left part of the mechanism is a parallelogram like the ones that used to be found in drawing machines. Its function is to allow the film plane to translate in space, i.e. to move it parallel. The accuracy of the model is remarkably good. At my chosen fixed focal length of a lens of 150 mm and a self-set J of 175 cm, the lens tilt (alpha) is indeed about 4.9 degrees. Focusing is done by moving the film plane. This rotates the plane of sharp focus around the Hinge Line.
View attachment 5299View attachment 5300

That is pretty damn cool ! Any chance of a pocket version for use in the field ?

 

[John]

That is pretty damn cool ! Any chance of a pocket version for use in the field ?

There was an emoji wink after that but got lost in translation !