Making DIY aperture scale for Prontor Prof. Sshutter
Hey folks!
I need a short hint how to do this. I whant to Mount a Rodenstock APO Ronar 300mm/9 into a Prontor Prof. 1S shutter. The shutters aperture scale starts from 5,6 onwards. But the Prontors have clicks in 1/3 f-stops. Normaly I would think that I start at 9 and count onwards to 11, 16...but is this really correct? It is annoying me that the first step from 9 to 11 is only a 2/3 step!
Any suggestions are welcome!
Sebastian
Re: Making DIY aperture scale for Prontor Prof. Sshutter
Now I found the information that the stops (and clicks???) are adjusted by two screws on the back of the shutter. So unfortunately it wont't be as easy as I hoped. At least I found a photograph of exact this lens in this shutter and it seems if the same number of stops is done in nearly the same overall stoppig-distance
https://grossformatfotografie.de/thr...1-9-300-mm-mc/
Re: Making DIY aperture scale for Prontor Prof. Sshutter
Why not call Rodenstock and ask them if they still have scales left?
Re: Making DIY aperture scale for Prontor Prof. Sshutter
I have had similar problems when using old shutters from 120 bellows cameras with homemade lenses on a 4x5 camera. The aperture readings of the shutters bears no resemblance to the amount of light entering the camera. The solution i devised is written up in another blog on this site entitled "through the lens metering"
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Re: Making DIY aperture scale for Prontor Prof. Sshutter
Quote:
Originally Posted by
sdzsdz
Hey folks!
I need a short hint how to do this. I whant to Mount a Rodenstock APO Ronar 300mm/9 into a Prontor Prof. 1S shutter. The shutters aperture scale starts from 5,6 onwards. But the Prontors have clicks in 1/3 f-stops. Normaly I would think that I start at 9 and count onwards to 11, 16...but is this really correct? It is annoying me that the first step from 9 to 11 is only a 2/3 step!
Any suggestions are welcome!
Sebastian
I solved same by printing a vynil sticker, if IIRC cost was 1€.
Re: Making DIY aperture scale for Prontor Prof. Sshutter
300mm is close enough for rock and roll (assuming b&w) to 12". Use a caliper to measure the aperture, setting it to open one inch. This is f12. Work out the offsets.
Re: Making DIY aperture scale for Prontor Prof. Sshutter
If you still have the original shutter (or barrel) for the APO Ronar the all you need to do is measure the diameter of the aperture at each marked f stop. This measurement will be the same for the new shutter at the same f stop.
Re: Making DIY aperture scale for Prontor Prof. Sshutter
Paul, that makes sense except the shutter aperture has fewer blades so measurement won't be precise (irregular hole). However, that may not matter enough to be concerned with. 'Close enough' is often close enough... just not something we OCD folks are comfortable with.