Help with strange problem with my Camera and Phase Back...

[jeff_singer]

Here is a strange one…

I have a Contax 645 that I use with a Phase One P25+  I’ve been using this setup for 6+ years.  It worked perfectly as of my last shoot with it a couple weeks ago.  Nothing has changed with this setup... no knobs on the Contax have been changed and no settings on the Phase have been changed.  The Phase as not come off the camera.

So today at a shoot the camera/back would not register my Profoto strobes (also, the same strobes I’ve been using with no problems for 6+ years).  What do I mean by that… well, I was setting up the shot using my Canon 5d II to test the lights.  The Canon was at ISO 100 F16 @ 125th.  All looked as I wanted it so I was ready to switch to the Contax.  I set the Contax to f11 @ 125th and set the P25+ to ISO 50.  I took a shot and… nothing. 

I know what you’re thinking, I was thinking the same thing too: the strobes didn’t fire.  Took another shot making sure the strobes fired and they were firing fine.

Still, nothing (I was shooting against a black backdrop so it was literally nothing).  Was the lens cap on?  Of course not, I could see through the lens… but I check just to make sure.

So, I double and triple check all the settings.  All the shutter speeds, apertures, ISOs… all where they should be.  Made sure every knob and switch on the Contax was exactly where it should be.   Fire a shot… nothing.  Tried a different lens. Fire a shot… nothing. Took the back off the camera.  Fire a shot… nothing.

But at one point I happen to face the camera at a different angle and noticed the reflection of my silver C-Stand which was reflecting the light from the outside because it was next to a window.

So, I change the aperture on the Contax to f2.0 and change the shutter to 1 second.  With these settings the images should have been full white filling the image since the strobes would have blown everything out.  What I see is a shaky picture of my assistant lit with the (low) available light in the room BUT NO STROBES ARE REGISTERED AT ALL.

At this point we’re both at a loss.  We’re thinking it has to do with the fact that the flash is firing before the for Contax is taking the photo but not sure how that would be possible.  Looking for settings on the Phase there is a shutter lag setting and I switch it from “Short” (where it’s always been and has always worked) to “Long" but the back gives an error saying "the Contax needs to be on Short" so I switch it back.  There are no settings on the Contax that I can change. 

We can't figure out what's happening.  The subject arrives and I do the shoot with the Canon (always have a backup!).

So, any ideas on what’s going on and how to fix it?

[gazwas]

Will the flash fire hard wired from the camera PC sync?

Will the flash fire hard wired to the PC sync on the Phase back?

[bcooter]

At this point after 6 years you know the Contax.

But just a few suggestions.

Did you try a different lens, prism, do you have an extra body?

If not and the kit you have is one lens, one body, one back, take the camera apart, (be very careful with the shutter curtain as on the Contax it's very easy to punch your thumb through it.

Look to see if anything is amiss.   Like the shutter curtain, mirror, check the lens to see if it stops down. (Actually try a few frames with available light and see if the shutter works, the lens stops down throughout the range.)

Also put in fresh, new batteries and if you tether try the camera tethered and un tethered to a cf card.

If you have the 90 degree grip, only use the AA batteries to get you through a session, then at your first break put in a new 2cr5 battery in the vertical part of the grip.

The 2cr5 battery should always be your main power source.

Then disassemble the camera,  take a lint free polishing cloth, and polish every contact on the Contax.  Prism, lens, body, (both ends) and back.

The one downside of the contax is every contact point has to be secure as they work in sync.  The prism only partly connected will throw everything off.

When you polish the contacts, do it like your polishing a jewel, making sure they are complete clean and shiny and once you think you've got it, do it again.

Another weak point of the contax is the prism mounting brackets.  They're made of some kind of composite material and easily crack if the camera is transported with the prism on or if you lift the camera with force by the prism.

It's hard to see the cracks, but a way of check this is to mount the camera on a tripod, set up your flash sync, and when you fire firmly press down on the front center of the prism to make sure it's making contact.

Everything I've mentioned I learned the hard way.   One on high pressured shoot, I couldn't get the 140mm lens to work, just wouldn't fire with regularity.  Luckily the studio had one in rental and I bought it, thinking my lens was down.

Turned out all the lens needed was a good polishing of the contacts.

You might have more serious issues, than what I've outlined and It may seem like I'm making the contax look vulnerable, though I've shot a trillion frames with my contax' and never had one go down, other than the contact cleaning and the prism clips got cracked, but other than that I'd be totally shocked if a P series back or the contax actually broke, though I guess anything can break.

I actually think the Contax is the best medium format camera ever made for digital.

Good luck.

BC

[eronald]

Changing the subject line to
"P25 and Contax flash sync issue"
might attract comments from more people.

Edmund

[yaya]

Have you tried setting the camera to X?

Are you using a sync cable or a remote trigger on the hotshoe?

[jeff_singer]

Well, the story of my life... When I got home this weekend I pulled out the camera and a strobe and gave it a try;  no problems.

One thing did change though (and I know I should have tested before making the change):  I had just purchased the battery grip for the Contax so I installed that (although I was using the same battery as before).  I'm not really sure how the battery grip would make a difference with the strobe syncing, but it's working... for now.  I'm sure it will crap out again on my next shoot.