flash synch testing shutter???

[DrTang]

I have a couple lenses in shutters without flash sync. Since I need to use them with my strobe system, I bought a couple devices I'm hoping will do the trick

one is a kalart deal that is also a cable release..I think it was built for bulb synch..so hopefully I can tinker with it to make it sych to flash


the other is a russian device that also uses the cable release to achieve synch - this one looks to have flash synch setting


I need a way to check to see if these things are synching correctly (firing flash when shutter is open)

if I fire the flash towards the lens with the device/shutter and simply look thru the back of the lens..if I see light - then it's synched..right? I know all about too high a speed with focal plane shutters and the band one gets, but with leaf shutters..if it syncs too early or late.. I wouldn't see any light..correct?


also..I suppose the device - once set - will only work for that shutter (given differences in cable release throw needed for different shutters)

[Steve Smith]

if I fire the flash towards the lens with the device/shutter and simply look thru the back of the lens..if I see light - then it's synched..right?

I think so. If you can get it so you can see light through the lens (or shutter) at its highest speed then it should be about right. I think I would then try to delay it very slightly and use a slower speed.


Steve.

[E. von Hoegh]

I'm willing to bet your widgets are for synching flashbulbs, not strobes. They might be adjustable for a strobe though.
Yes, if you can see light from the strobe through the shutter, it's synched.

[Bob Salomon]

Point the flash at a light colored wall. Look through the back of the camera. Fire the shutter. If you see a round circle of light when the shutter fires you have X synch. If you only see a partial circle then you are not X synched. Change shutter speeds and keep repeating. When you find a full circle of light you are synched. That speed, and all slower shutter speeds, will be X flash synched at that shutter speed.

X synch fires the flash once the shutter is fully open.
M synch fires the flash as the shutter starts to open so the flash bulb would be a full peak once the shutter is fully open.

With X synch the guide number for a given film speed is constant regardless of shutter speed (at the X synch speed and slower. Leaf shutters are synched at all speeds).
With M synch the guide number changes with film speed and shutter speed.

[rdenney]

With a leaf shutter, it's easier just to point the flash into the lens, since you can see the shutter blades easily through the glass. Release the shutter. If you see the shutter blades (or any portion thereof) in the light of the strobe, the synch is not right.

Rick "who checked his flash synch before every wedding gig" Denney

[DrTang]

I wonder if there is a way to photograph - with a digital camera - the lens/shutter - from the back so I don't have to rely on my eyesight?? maybe I'll get some cardboard and rig something up tonight

[E. von Hoegh]

I wonder if there is a way to photograph - with a digital camera - the lens/shutter - from the back so I don't have to rely on my eyesight?? maybe I'll get some cardboard and rig something up tonight

You're joking, right? Point your flash at your face. Pop it. I bet a lot of "blind" people could see that.

[rdenney]

I wonder if there is a way to photograph - with a digital camera - the lens/shutter - from the back so I don't have to rely on my eyesight?? maybe I'll get some cardboard and rig something up tonight

Just try it before wasting time rigging something up. It does not require magic seeing or special eyesight.

Rick "who never spent more than about 3 seconds checking the synch on his wedding rig" Denney

[E. von Hoegh]

I wonder if there is a way to photograph - with a digital camera - the lens/shutter - from the back so I don't have to rely on my eyesight?? maybe I'll get some cardboard and rig something up tonight

A camera won't work. Look for an app. They have apps for everything these days.

If you don't want to look into the flash (not a bad idea) point it at the wall. You still can't miss it.

[rdenney]

A camera won't work. Look for an app. They have apps for everything these days.

If you don't want to look into the flash (not a bad idea) point it at the wall. You still can't miss it.

I find it easiest to point it at the lens, and look at the lens from behind the flash. Leaf shutter blades are easy to see in the light of the strobe if they are in view. If they are not in view, the synch is working. Make sure the lens aperture is wide open.

Rick "who---once---aimed the flash through the lens at his eyes" Denney