How to focus a soft focus lens

[djdister]

These instructions for the Verito from 1916 says to simply focus at whatever f stop is most pleasing for the effect...

[Mark Sawyer]

Here in ENGLISH are Heinrich Kuhn's instructions for using his Imagon invention: https://www.cameraeccentric.com/stat...s/imagon_2.pdf

Russ

It should be noted that the technique for focusing the Imagon with h/stops is very different than for other soft focus lenses with conventional f/stops. With the Imagon, you focus on the sharp image with the h/stops closed, then open the h/stops to add the glow of spherical aberration. With conventional f/stops (including when using the Imagon with a conventional diaphragm), just set the aperture for the desired degree of softness and "focus to taste". With a panchromatic emulsion, what-you-see-is-what-you-get.

[Bob Salomon]

It should be noted that the technique for focusing the Imagon with h/stops is very different than for other soft focus lenses with conventional f/stops. With the Imagon, you focus on the sharp image with the h/stops closed, then open the h/stops to add the glow of spherical aberration. With conventional f/stops (including when using the Imagon with a conventional diaphragm), just set the aperture for the desired degree of softness and "focus to taste". With a panchromatic emulsion, what-you-see-is-what-you-get.

No, there is a focus shift when you change H stops on the Imagon. You must focus it at the desired H stop.

[Mark Sawyer]

No, there is a focus shift when you change H stops on the Imagon. You must focus it at the desired H stop.

Not according to Kuhn, and his method makes sense if you want a sharp image with a soft overlay. Focus for the sharp image for the central aperture, then add the soft effect from the peripheral h/stop apertures. The out-of-focus shift IS the soft effect. If you focus with the h/stops open, they may compromise the sharp image from the central aperture, which throws the dominant image.

In practice, we do what we want.

From Kuhn, in the link Russ posted:

[Bob Salomon]

Not according to Kuhn, and his method makes sense if you want a sharp image with a soft overlay. Focus for the sharp image for the central aperture, then add the soft effect from the peripheral h/stop apertures. The out-of-focus shift IS the soft effect. If you focus with the h/stops open, they may compromise the sharp image from the central aperture, which throws the dominant image.

In practice, we do what we want.

From Kuhn, in the link Russ posted:

Why not quote Rodenstock’s instructions? Then you would avoid the focus shift.

[Mark Sawyer]

Why not quote Rodenstock’s instructions? Then you would avoid the focus shift.

Having the soft image from focus shift overlaid on the sharp image is the whole point of the Imagon.

To quote from the Rodenstock's instructions online at: https://www.cameraeccentric.com/stat...s/imagon_1.pdf

[xkaes]

That's exactly what Fuji says as well -- focus stopped down on the most important feature. Then open up to get the softness you want. I posted that six weeks ago.

Around and around we go.

[russyoung]

Having the soft image from focus shift overlaid on the sharp image is the whole point of the Imagon.

To quote from the Rodenstock's instructions online at: https://www.cameraeccentric.com/stat...s/imagon_1.pdf

Later instructions, written by Joseph Foldes for IMAGON also note to focus with the peripheral holes closed then open up: https://www.cameraeccentric.com/stat...s/imagon_1.pdf
russ