Bessa R and Flashbulbs...

[George Bonanno]

Another recent post got me thinking about this. When I use an electronic flash unit on the hotshoe or PC terminal on my Bessa R it fires fine. However when I use a flashbulb unit (known to be in good working order on other cameras) the Bessa R will not fire any flashbulb. I use mostly No.40 & 5 type flashbulbs when I need a lot of light in big rooms and outdoors at night. The hotshoe and PC terminal is just a contact closure... right ? I just don't get it.

 

[payasam]

Strange. The flash should fire, even if it synchronises only at a slow shutter speed. It seems we can rule out a defect in the lead and the plug...

 

[BillBingham2]

Are you sure the flash gun and cord are working? (tried it on another camera)

B2 (;->

 

[newspaperguy]

Dunno George... but hell, if you're using 40s, forget the sync.

Just pop the flash manually and then shoot. That room will stay lit up.

 

[Dwig]

...The hotshoe and PC terminal is just a contact closure... right ? ...

Quite possibly not.

The bulbs could be failing because the internal resistance is too high or because the contact closure time is too brief. The latter often occurs with modern electronic shutters that don't use mechanical contacts on the shutter to fire the flash, instead using a semiconductor "switch" to trigger the flash a predetermined length of time after the first curtain is released. These electronic "switches" are more reliable.

 

[George Bonanno]

Ya know Dwig, ya might be right.

I just tried two other units. My Baby Speed Graphic 3 cell flashgun and a Honeywell Tilt a Mate which uses a 15 volt B-C circuit. No cigar on either however they both work on other film cameras. I'm going to bring the Bessa R to Essex Camera this week and show them. Maybe it's something stupid or maybe it's just not meant to be.

I did use open bulb a few times but boy does that get old quick.

Thanks everyone for your input. I'll keep ya posted if and when it's resolved.

 

[BillBingham2]

Do you have an older (but not too old) camera that has either two sync ports (x and mf or fp or something) or one that has a switch between flash bulb and x to test it on? An old Nikkormat (FT, FTn, FS) lots of different one too many to mention. Got a friend with an older camera you could barrow to test with?

Another approach would be to wrap electrical tape around one end of a paper clip (to insulate it) and short out the circuit on the flash gun as a test.

Open bulb is real fun for painting with light. Flash bulbs have such a long light that you can can actually paint with them. Very cool stuff.

B2 (;->

 

[George Bonanno]

Just tried the flashbulb unit on my Nikomat FTn. The flashbulb fired. Tried it again on the Bessa R, nothing happened. A strobe unit on the Bessa R hotshoe or PC terminal works perfectly. It seems the Bessa R contact closure is resistive or too short in duration to fire flashbulbs.