Blank negative with Nikon flash and Mamiya 6, What went wrong?

[imyself]

Hi Everyone,
Not long ago I bought a Mamiya 6 camera with all three available lenses from Ebay and had the body CLA'd by Bob Watkins with body/lens calibration also performed. I ve exposed over a dozen rolls of film without incident and I thought Id try taking some portraits with my 150mm lens. First I took two outdoor natural light exposures then I went inside for flash lit portraits using my Nikon SB-900 flash set to manual mode connected to my Mamiya 6 hotshoe via a nikon hot shoe extension cable. I metered the scene with my sekonic light meter and set the aperture accordingly (shutter speed was set to 1/500 to suppress ambient light). I took two exposure and could see the flash was set off in both cases (and I didn't leave the lens cap on!). I developed the film (acros 100) as per usual ( Pyrocat HD 1+1+100 for 12 minutes @ 70 degrees) and was disappointed to see that my flash exposure were all blank! Every other frame on the roll developed fine. So I went back to my flash set up and opened the back of the camera and positioned the flash in front of the lens to see if the shutter was syncing with the flash when I dry fired, and indeed it was. SO Im at a loss with the outcome of the flash exposures. I have no experience with film flash photography but my set up seems very straightforward, so what am I doing wrong?
Cheers
Adam

 

[summicron1]

the flash synched when you dry fired, was that shot at 1/500 like yu did the actual exposures?

because, obviously, the synch was off for your actual pictures. If the camera has a synch switch, make sure it is set on X. If it is, or the camera only has X-synch, then it is possible your synch is off. The synch for X should be so the flash fires when the blades are fully open -- if it is delayed even a titch, at 1/500 the blades will already be closed when the flash goes off.

So check that it is synching at 1/500. If not, then the tech needs to adjust that. Or you could just shoot flash at slower speeds.

 

[imyself]

Thank you for the clarification. Ill try the dry firing again and double check.
Heres what the manual says about flash:
"The Mamiya 6 MF features an X synchroflash terminal and its lens shutter system permits flash synchronization at all shutter speeds.
Shoe-mounted flash units can be attached directly to the hot-shoe, while flash brackets can be attached to the tripod socket for larger flash guns."
So theres no sync switch, but I did use the hot shoe rather than the PC socket, would that make a difference?
Cheers
Adam

 

[imyself]

I just checked again and confirmed that at 1/500 dry fire, the flash pulse is getting through the lens. Not sure what else to try now..

 

[John Koehrer]

The shoe and contact are wired in parallel so both should work. If there's a wire broken or bad connection it would separate them.
Is there any way you could check it using the PC connection? It could have been damaged when the cover(s) were removed.

Depending on how long ago the camera was worked on could it still be in warrantee? If not, it's off to the repair guy

 

[imyself]

Thanks for your help, John. The camera PC to flash PC triggering works fine, too. My final theory is perhaps there's a slight but significant delay in triggering the flash when it's in standby mode. The flash batteries were low when I was shooting last night and so the flash was switching to standby mode quite quickly and so there might have been another delaying element in the system. In any case I've recharged the flash batteries and will try again.
I was just wondering, though, if the shutter sync is at fault , why does my retina perceive the flash pulse when looking through the back of the camera but the film emulsion doesn't register the selfsame pulse of light when in the same position in the camera? Pardon the technically naive nature of this question...[emoji6] Just trying to figure it out.
Cheers
Adam

 

[RalphLambrecht]

Hi Everyone,
Not long ago I bought a Mamiya 6 camera with all three available lenses from Ebay and had the body CLA'd by Bob Watkins with body/lens calibration also performed. I ve exposed over a dozen rolls of film without incident and I thought Id try taking some portraits with my 150mm lens. First I took two outdoor natural light exposures then I went inside for flash lit portraits using my Nikon SB-900 flash set to manual mode connected to my Mamiya 6 hotshoe via a nikon hot shoe extension cable. I metered the scene with my sekonic light meter and set the aperture accordingly (shutter speed was set to 1/500 to suppress ambient light). I took two exposure and could see the flash was set off in both cases (and I didn't leave the lens cap on!). I developed the film (acros 100) as per usual ( Pyrocat HD 1+1+100 for 12 minutes @ 70 degrees) and was disappointed to see that my flash exposure were all blank! Every other frame on the roll developed fine. So I went back to my flash set up and opened the back of the camera and positioned the flash in front of the lens to see if the shutter was syncing with the flash when I dry fired, and indeed it was. SO Im at a loss with the outcome of the flash exposures. I have no experience with film flash photography but my set up seems very straightforward, so what am I doing wrong?
Cheers
Adam

I don't think the Mamiya 6 has a hot shoe.It's just a cold accessory holder.It won't synch your flashproperlyI believe but I could be wrong.

 

[imyself]

Hi Ralph,
The Mamiya 6MF manual and my own observations suggest that the hot shoe is nice and toasty [emoji6]
Cheers
Adam

 

[Jim Jones]

Perhaps the sync speed is slightly off, permitting a little of the flash to pass through the shutter, but not enough to expose the film. They eye is a poor judge of the intensity of flash brightness. Try looking at the flash through the back of the camera with lower speeds.

 

[andrew.roos]

I would try with a slower shutter speed (say 1/60") in a dark room to see if you get flash exposure. If you do, try faster and faster shutter speeds to see at what point it loses sync. If you can sync at say 1/250" then that may be adequate for many scenarios. At least it would give you an idea of what the problem is.

Andrew