Aperture for 9 inch Verito

[Simon Benton]

I have a 9 inch Verito in barrel and there is no aperture present and from looking at the barrel there never was an aperture. One option I have is to have a machine shop cut a slot for a Waterhouse type aperture. I have read that another option is to have a plate made with a suitable opening that could be placed directly over the front element and held in place somehow. For the Verito I would only want apertures of f5.6 and F6.3 as I find anything smaller reduces the soft focus effect. Does any one have any comments about the validity or suitability of putting the aperture over the front element? Any information gratefully received.

[Vaughan]

Thew tricky bit is working out where to place the stop. It matters to optical performance. An aperture over the front element will vignette the image.

The easiest and cheapest option to control light might be to use neutral density filters on the front.

[Dugan]

I would suggest having it mounted in a shutter with an aperture (Alphax #4?), or front-mounted on a larger shutter with an aperture.
Spendy, but much more user-friendly.

[Mark Sawyer]

Thew tricky bit is working out where to place the stop. It matters to optical performance. An aperture over the front element will vignette the image.

The easiest and cheapest option to control light might be to use neutral density filters on the front.

On the Verito, the aperture is used more to control the softness from spherical aberration than for exposure control.

Look at other 9" Veritos for aperture placement. Some Veritos were cut for Waterhouse-style "enlarging stops". Remember, when calculating the aperture diameter, it has to be measured through the front element, which magnifies the size slightly.

[Dugan]

Apparently, Veritos were also used as enlarging lenses 'back in the day'...maybe that's how yours started out?

[djdister]

I would suggest having it mounted in a shutter with an aperture (Alphax #4?), or front-mounted on a larger shutter with an aperture.
Spendy, but much more user-friendly.

Absolutely on point. Look for an plain Alphax shutter or one that comes with some beat-up lens and re-purpose it for your Verito. Like this...

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[Vaidotas]

Cheapest but highly uncomfortable problem solving here is putting round shape diaphragm (cardboard works fine) in the barrel by unscrewing one of the elements.

[Simon Benton]

Thanks for all the comments. A local machine shop is going to cut a slot in the barrel and make me 2 Waterhouse stops and I will give that a try.