View Full Version : Busch Pressman Flash Sync: Bi Post Connector on Rangefinder not lens

Jeff Romeo
25-Aug-2011, 14:45
I have the good fortune to have gotten a free and quite good looking
Busch Pressman camera.

I want to sync with strobes, but there is no bi post on the lens. HOWEVER,
there is a bi-post on the Range Finder which is attached to the top
of the camera. What does that mean? What is that ? PHOTO ATTACHED>

If I plug a paramount cord into this and then into a pocketwizard
will the strobes fire? I don't want to order a cord until I figure it out.

Thank you.


E. von Hoegh
25-Aug-2011, 14:56
That's for rangefinder illumination, so you can focus in very poor light. It projects two dots on the subject, when the dots become one, you're focussed.

Jeff Romeo
25-Aug-2011, 14:58
OK so what can I do to hook up the strobes with this lens?


E. von Hoegh
25-Aug-2011, 15:01
If the lens has no synch contact, you're limited to opening the shutter in a darkened room and popping the flash.

Or getting a lens with flash synch..

Ivan J. Eberle
25-Aug-2011, 19:39
If you have a Wollensak Raptar 135mm, which so many of these cameras came with, the Rapax shutter is also available in a Synchromatic model with X synch and two-post terminals (adapters to PC are available or you might cobble one with a spare Norelco razor cord).

Back in the days of flashbulbs, the electric shutter release would first fire the flashbulb, as these had a substantial ramp-up time to reach peak brightness, and then the shutter firing solenoid was mechanically adjusted (lagged) to match this peak time. So in this way shutters like yours without internal sync circuitry could be used with an external solenoid on a board-- but that won't cut it with an electronic flash pop, which syncs instantaneously.

(Alternately, you could find the pieces to use bulbs and go retro. But then Pocket Wizards or other wireless won't make much sense since you'd have change bulbs before the next shot.)

My understanding is that the View Focus doesn't project two dots that converge to focus; it just offers some additional illumination by which to more easily focus in the usual way. (The Kalart Focuspot that fits atop the Kalart Synchronized Rangefinders-- now that does project two converging images of a lightbulb filament. And these are fairly easily converted to an LED laser-pointer dot bright enough for daylight and long distance nighttime use).

E. von Hoegh
26-Aug-2011, 07:23
Thanks Ivan. I've used the Kalart, also the Linhof illuminators. I just assumed the View Focus worked in the same way.

I'd still like to have one of those Busch cameras though.:)

Robert Hughes
26-Aug-2011, 09:12
That illuminator bulb is a 6V or 12V bulb I believe. I blew the one in my Busch Pressman to smithereens when I tried to light it with improper voltage. I'm thinking of replacing it with a white LED.

Jeff Romeo
26-Aug-2011, 10:52
So can I just buy a new shutter?

Jeff Romeo
26-Aug-2011, 11:00
Maybe that is easier said than done...buying a Rapax X Synchromatic
shutter...where does one get these? I have looked on Ebay.

Dan Fromm
26-Aug-2011, 11:29
They're rarely sold loose. Your best bet is to get the lens you want in a working shutter.

By Murphy magic, you're about to be inundated with offers for just the shutter you need.