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

[DrTang]

I were referencing the post regarding 'semi circle' vs 'full circle' - yes..I'll be able to see the flash coming thru..but if there is a difference between part open and fully open..the big blast of light coming thru the back of the lens might obscure that



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

[Bob Salomon]

Not if you point the flash at a wall and point the camera towards the same wall. All you will see is a circle of light or a partial circle of light. If necessary sunglasses can be optional. But in over 55 years of doing this I have never found that they are necessary.

[DrTang]

Not if you point the flash at a wall and point the camera towards the same wall. All you will see is a circle of light or a partial circle of light. If necessary sunglasses can be optional. But in over 55 years of doing this I have never found that they are necessary.



SWEET

I'm on it tonight


thanks so much

[Leigh]

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?
That's not exactly true.

The only way to really check flash sync is with an oscilloscope and photodetector.

The problem is one of speed and intensity.

The strobe is quite bright. If it fires too early, before the shutter is fully open, you'll still see the flash when looking through the lens, but its intensity will be low, as though you used too small an aperture.

- Leigh

[Two23]

I have some lenses in Compound shutter. Where can I get one of these release cords? What are some brand names, exactly what is it called?


Kent in SD

[John Koehrer]

If the sync is off and you're looking through the lens, the flash is right if you see the full circle. If it's close you will see an area obscured by the edges of the shutter blades. IE: A number of pointed shadows.

[DrTang]

One is a Kalart Automatic Symchronizer - it is a shutter release cable with a deal at the top with a flash PC socket - I have one that is adjustable I think..with a screw on the back, and another that is adjustable via the length of the plunger deal on the camera side


also..I have a russian device that screws into the cable release socket and a cable release screws into it..it has a pc socket on it too


I got mine from ebay...was just browsing around and found them

the first one I mentioned..I just tested and it seems to work... I'll have to shoot some film to really find out though


I have some lenses in Compound shutter. Where can I get one of these release cords? What are some brand names, exactly what is it called?


Kent in SD

[SergeiR]

One is a Kalart Automatic Symchronizer - it is a shutter release cable with a deal at the top with a flash PC socket - I have one that is adjustable I think..with a screw on the back, and another that is adjustable via the length of the plunger deal on the camera side


also..I have a russian device that screws into the cable release socket and a cable release screws into it..it has a pc socket on it too


I got mine from ebay...was just browsing around and found them

the first one I mentioned..I just tested and it seems to work... I'll have to shoot some film to really find out though

If its not too much trouble - can you post picture or two? :)

[DrTang]

here's the Russian do-dad

http://www.ussrphoto.com/UserContent/synch%202.jpg

here's the other one for sale right now:

http://www.ebay.com/itm/Vintage-KALART-Speed-Flash-Synchronizer-and-bracket-/251019575086?pt=LH_DefaultDomain_0&hash=item3a71eebf2e#ht_500wt_1057

[Barry Kirsten]

A somewhat related question... Older lenses like the Optars have a so-called bi-post flash connector, two terminal posts that the sync cord connects to. Is it possible to obtain a compatible connector plug? or what do people do to get flash synch? Thanks,

Barry.

[Bob Salomon]

Use a television cheater cord or an electronic shaver cord.

[atlcruiser]

A somewhat related question... Older lenses like the Optars have a so-called bi-post flash connector, two terminal posts that the sync cord connects to. Is it possible to obtain a compatible connector plug? or what do people do to get flash synch? Thanks,

Barry.

It is called a bi post to PC cable. You can also use a standard PC to PC and cut one end off and attach a butt terminal.

http://www.delcity.net/store/Butt-Connectors/p_189077.a_1.r_IS1012?mkwid=s2IjLrWYC&crid=9950891309&mp_kw=butt%20terminal&mp_mt=e&gclid=CLTz08Ck-q4CFcNa7Aod6nSPxg

You can get them at any auto part store. You might need to mess with it a bit to get it to contact correctly but it will work perfectly once you get it right.

[rdenney]

Paramount makes and sells a nice bi-post-to-PC cable.

Rick "who has used a shaver cord for connecting to a Speedotron, but shavers and flashes ain't the same these days" Denney

[premortho]

To the OP; If you have a Kalart deluxe compak speed flash, the two nuts on the threaded end that goes into the cable release control when the flash goes off. It's called the synchroniser head. The flash assembly originally included a test bulb that was supposed to be used to set the delay. The instructions make a big deal about pressing the shutter release slowly to get everything working at the right time. I don't know if you can get it to zero delay or not, but it is worth a try. Further out is longer delay, in shorter.:cool:

[E. von Hoegh]

Use a television cheater cord....

Does anyone know where to even find a store that knows what this is?

[Bob Salomon]

Any electronic supply store will have them. If you are in the USA Radio Shack will have them.
Or look here
http://www.google.com/search?client=safari&rls=en&q=tv+cheater+cord&ie=UTF-8&oe=UTF-8

[Sevo]

The strobe is quite bright. If it fires too early, before the shutter is fully open, you'll still see the flash when looking through the lens, but its intensity will be low, as though you used too small an aperture.



Looking through the ground glass you'd only notice a underexposure for reasons unknown (besides sync issues, the flash might not be up to original specifications).
Looking directly through the back, as suggested, you'd see the partially opened shutter - which will be obviously small for sync issues that cause a underexposure of a stop or more, but which might be hard to recognize if it is only a third or half stop.

If you have film to blow, one method to check for slight sync errors would be to expose a flash series with increasingly smaller aperture - if the sync is off, exposure will stay identical for some steps from fully open, as the aperture is hidden behind the partially opened shutter.

[Barry Kirsten]

Thanks for ideas on bi-post connectors. :)

[Bob Salomon]

If you see a bright, round circle of light you are synched. Period. If you don't see a clear bright, round circle of light you are not synched. X synch is at the instant the shutter is fully open. No variable in exposure other then a not fully charged flash unit.

[John Koehrer]

If you see a bright, round circle of light you are synched. Period. If you don't see a clear bright, round circle of light you are not synched. X synch is at the instant the shutter is fully open. No variable in exposure other then a not fully charged flash unit.
Or mis-shaped contact. He's trying to go from M to X so will have to fiddle a bit "reforming" the contact.
Reforming= bending but you get to charge more for it!

[DrTang]

UPDATE


after more testing with less whiskey


the Kalart (mine anyway) works intermittently... it is the Russian one that is now doing the trick