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blakedoyle
2-Oct-2020, 13:41
Hello all,

I have encountered a very odd problem that leads me to believe that my Speedotron flash is firing before my camera shutter.

Gear:
Sinar F2 – Rodenstock Sironar-N 210MM F5.6
Speedotron D802 pack with M11 head
*Direct PC cable from lens to power pack*


A few days ago, I tested out this newly borrowed strobe kit to sadly receive blank film. This was unexpected as I did digital tests before shooting film and the strobe hit on each exposure. I was able to successfully capture a digital exposure up to the maximum flash sync of the 5D Mark 3. With the confidence from the digital test, I shot two sheets of Portra 400 in my Sinar F2 that came back blank.

4x5 Settings:
F22 1/60th Iso400

What happened?

Upon reshooting, I decided to do a Polaroid test with FP100C, assuming that my strobe may be firing late, I tried an exposure at 1/8th of a second, all to see a blank frame. The only other factor I could attribute this issue to is the flash firing early, although the flash is triggered by the shutter itself? I’ve never heard of this, but it was my only option. My next Polaroid test, I opened the shutter on Bulb Mode and manually fired the shutter. It was a success.

My questions is, why is this happening? I was able to use this Bulb Mode work around in this case, but I can’t do this with every picture.

I thought it could be the lens, but I had recently shot with Speedlights with this lens, remote triggered by Paul C Buff Cybersyncs with no issue. Additionally, the same exact set up worked perfectly with the 5D Mark 3.

Any ideas why I’m having this problem and how to solve it?

Thank you.

-blake



Lens Shutter Details:
208246208247208248

Dugan
2-Oct-2020, 13:50
Is there a switch on the shutter for M/X?
If so, it needs to be on X.

blakedoyle
2-Oct-2020, 13:56
Is there a switch on the shutter for M/X?
If so, it needs to be on X.

This lens has options of shutter speeds from 1/400th - 1sec, B and T mode. I have used this lens with Speedlights and Paul C Buff Alien Bees, both remotely triggered. I have used this lens with flash at shutter speeds between 1/125 and 1/8th successfully. This is what's so strange to me. Maybe a Speedotron quirk?

John Olsen
2-Oct-2020, 14:08
If the trigger input to the Speedotron is a two prong household plug, try reversing it in case it's a floating ground problem. Most of my optical slaves work one way but not the other on my Speedotrons. Otherwise?

reddesert
2-Oct-2020, 14:28
This lens has options of shutter speeds from 1/400th - 1sec, B and T mode. I have used this lens with Speedlights and Paul C Buff Alien Bees, both remotely triggered. I have used this lens with flash at shutter speeds between 1/125 and 1/8th successfully. This is what's so strange to me. Maybe a Speedotron quirk?

Are you sure that the shutter doesn't have an M/X switch and that you haven't accidentally bumped it to M since the previous time you used a flash? Because M sync will cause exactly what you're describing, flash fires before shutter opens.

ic-racer
2-Oct-2020, 14:36
Can you just look at the ground glass to see what is going on?

blakedoyle
2-Oct-2020, 14:54
Yes, I wish that was the issue. I've been told that my lens may need a CLA and that this can be the issue. I have attached images to the post showing the lens. Thank you for your response.

blakedoyle
2-Oct-2020, 14:55
It is a two prong household plug. It's strange because this problem does not exist on the digital camera. I'e also been told that the trigger voltage can be dangerous for the digital. Are there are cables to adapt the two prong to mini jack to I can use remote triggers?

Pieter
2-Oct-2020, 14:59
I think Flash Zebra might have what you're looking for. https://www.flashzebra.com/products.shtml

Neal Chaves
2-Oct-2020, 15:27
You have an X sync shutter. Aim the strobe to light up a wall with the strobe. Hold the lens in your hand and look through it at the wall while you trip the shutter 1/60 sec. at wide open aperture. If the strobe syncs correctly, your eye will retain an image of the shutter blade position at the instant of strobe burst. The shutter blades should be seen wide open. If not, you have a shutter problem.

Bob Salomon
2-Oct-2020, 15:52
You have an X sync shutter. Aim the strobe to light up a wall with the strobe. Hold the lens in your hand and look through it at the wall while you trip the shutter 1/60 sec. at wide open aperture. If the strobe syncs correctly, your eye will retain an image of the shutter blade position at the instant of strobe burst. The shutter blades should be seen wide open. If not, you have a shutter problem.

Do it at any speed. A properly synced shutter and flash will result in a bright white circle. It is best to do this at a high shutter speed as synch is more critical there then at low or middle speeds.