High Voltage (ancient) flash on modern DSLR - Sync Speed mystery

[DennisS]

I just resurrected an old SunPak Autozoom 3000 flash unit and use it on a Nikon D5100 DSLR. I am using it with the Wein Sync Safe device (on the hotshoe) so as not to fry the flash circuitry on the camera. It appears that although the flash fires (via the hotshot - not PC cord), when shutter is activated, the camera does not appear to recognize that a flash is present. The IPTC information does not show it. In addition, the camera allows me to bump up the shutter beyond the Sync Speed of 200 in Manual mode. I have validated that the flash is in Sync and correctly lights the subject although I have to use the manual settings on the flash.

What gives? Would bumping up the Shutter actually be an advantage here? I have tried going to 1/300 and I do not see any black bands show up yet - maybe they would at higher speeds - plan to test that out soon.

I understand I do not have the ability to use the CLS system with the Sunpak (no i-TTL or i-TTL-BL) but that is a sacrifice am willing to make until I have the budget for something like the SB-700 with an additional Nikon SU-800 since the camera does not have commander mode (nor PC Sync slot).

[Manfred M]

You have a plain old "dumb" flash that does not communicate with your camera; it does not have all the pins (or electronics) to do that. As there is no communication, the camera has no way of identifying it is there, so you are in a position to do just about anything, as none of the "safety" interlocks that modern cameras have will restrict what you do. On the other hand, you won't be able to do things like shoot rear shutter flash either.

At 1/300, the black bands would likely only appear at the very top or bottom of the image and would be fairly small. I assume that synch speed is around 1/200 or 1/250 on that model. Eventually you will find that there is banding from the moving shutter curtains; you might even want to try to see if this creative effect does something for you. Personally I would not shoot faster than the synch speed for any serious work, but experiment away, as it isn't going to cost you anything.

I think you are going to learn a lot about flash shooting on manual and this will do you good once you get an integrated flash. Remember that studio flashes are manual flash, and not everyone uses CLS in their work.

[jcuknz]

The next step is to remove the flash from the camera and use it as a studio 'key' light. Triggering it with the camera's onboard flash, if it has one, either lighting the subject or shielded from the subject, or some trigger device. It can be great fun
See http://jcuknz-photos.com/LIGHTING/ONELIGHTEXERCISE.html for what I did with my old Sunpak and reflectors.

[Steaphany]

Just know what you are doing, possibly testing the voltage at the strobe's contacts, and read this page for compatibility:

Strobe Trigger Voltages
Is your old strobe safe to use on your new camera?

[loosecanon]

Great if old flash unit. I have three of them for a portable studio. In manual mode the variable power was a revelation when the unit was new. There is a kit of adaptors to modify the flash output, more diffuse, or coloured filters which fit into a clip on holder. They have the auto flash on them (where use set the aperture and the flash it cut at the right exposure) or full manual. There is also an auxiliary sensor that plugs in to the flash and then sits on the camera hot shoe, measuring fllash at the camera, and this is a low voltage hotshoe unlike that on the flash.

[DennisS]

So after I reviewed the link that Steaphany posted, I checked the voltage with a multi-meter across the PC Sync contacts of my Sunpak Autozoom 3000 and I get only 2.85 Volts...!!!!! Oh boy - if that is the trigger voltage then I just blew $50 on something I may not have needed in the first place. I just assumed since this was an old flash (35-40 years for sure) that the voltage would be high.

I do see an entry for this model at 246V so am going to play it safe and use the Wein.

The manual does not mention anything about the trigger voltage.

[DennisS]

Remember that studio flashes are manual flash, and not everyone uses CLS in their work.

Glad to hear that - opens up so many more possibilities from something that I almost got rid of on Ebay...!!!!

[DennisS]

The next step is to remove the flash from the camera and use it as a studio 'key' light.

Yes - I plan to invest in a cheap radio trigger (Cactus V5???) to fire it off camera.

[William W]

In addition, the camera allows me to bump up the shutter beyond the Sync Speed of 200 in Manual mode. I have validated that the flash is in Sync and correctly lights the subject although I have to use the manual settings on the flash. What gives? I have tried going to 1/300 and I do not see any black bands show up yet - maybe they would at higher speeds - plan to test that out soon.

Maximum Flash Sync Speed is not an exact science and is dependent (also) upon the Flash Unit being used.

Your Nikon’s specs are 1/200s (if I recall OK), so 1/300s may actually be quite ‘safe’ with that old Sunpak Manual Hotshoe Unit: but if you connected your camera to some old Elinchrom Studio Flash heads, you would likely get bands when using a Shutter Speed of around 1/160s.

+++

Would bumping up the Shutter actually be an advantage here? . . .

Yes it could be, depending upon the shooting scenario.

Unlikely that a shutter speed of 1/300s (or 1/400s if you can make it) would be useful to you in Studio Setting –but if you are using Flash as Fill in Sunlight then that extra bit of Shutter Speed can be translated to using a Larger Aperture, which can be used to make a smaller DoF, which could be very useful.


WW

[OldFrank]

So after I reviewed the link that Steaphany posted, I checked the voltage with a multi-meter across the PC Sync contacts of my Sunpak Autozoom 3000 and I get only 2.85 Volts...!!!!! Oh boy - if that is the trigger voltage then I just blew $50 on something I may not have needed in the first place. I just assumed since this was an old flash (35-40 years for sure) that the voltage would be high.

I do see an entry for this model at 246V so am going to play it safe and use the Wein.

The manual does not mention anything about the trigger voltage.

For what it is worth some of the old firing circuits would cause a high voltage pulse at flash. Since the camera only closed a mechanical contact it didn't matter, but with an electronic firing circuit in the camera it could be disaster.

I'm an electronic engineer and used to play around with this sort of stuff.

frank

[DennisS]

For what it is worth some of the old firing circuits would cause a high voltage pulse at flash.

I believe I may have measured the voltage without simultaneously firing the flash with the test button. I will attempt to do that tonight and see if I get a higher voltage.

[jcuknz]

So after I reviewed the link that Steaphany posted, I checked the voltage with a multi-meter across the PC Sync contacts of my Sunpak Autozoom 3000 and I get only 2.85 Volts...!!!!! Oh boy - if that is the trigger voltage then I just blew $50 on something I may not have needed in the first place. I just assumed since this was an old flash (35-40 years for sure) that the voltage would be high.

I do see an entry for this model at 246V so am going to play it safe and use the Wein.

The manual does not mention anything about the trigger voltage.

I gather that some multi-meters do not measure the voltage correctly but you will need to ask somebody who knows about these things ... I do not

EDIT Frank's answer might be the reason ... it was not explained or maybe known by my source

[Loose Canon]

Great if old flash unit. I have three of them for a portable studio. In manual mode the variable power was a revelation when the unit was new. There is a kit of adaptors to modify the flash output, more diffuse, or coloured filters which fit into a clip on holder. They have the auto flash on them (where use set the aperture and the flash it cut at the right exposure) or full manual. There is also an auxiliary sensor that plugs in to the flash and then sits on the camera hot shoe, measuring fllash at the camera, and this is a low voltage hotshoe unlike that on the flash.

I apologize because I may be jacking your thread Dennis.

I just wanted to say hello to my namesake and welcome Mr or Ms. canon to the Board!

I'll try not to embarrass us such that we are mistaken for one another!

[Manfred M]

I believe I may have measured the voltage without simultaneously firing the flash with the test button. I will attempt to do that tonight and see if I get a higher voltage.

You will need some specialized metering equipment to figure out what the actual voltage is. Your multimeter was never designed to measure voltage spikes with such a short duration.

[DennisS]

Yep - you may be correct. I tried measuring while hitting the test button - did not make a difference.

I also verified that I do get banding but only above 1/320 secs..!!!

In any case, I am happy with my present setup and like you said, in a Studio environment, CLS is not a big deal. My "studio" is my basement and have had fun with this flash - so far all good...!!!

Thank you all for the great suggestions/tips/advice.

[photoguy]

Regarding trigger voltage of the 3000, I have tested many units and they generally range between 160-180v. I have never seen one with a trigger voltage over 200v. I have also used them directly on a D50 and D90 for many years with no problem as they and later models are rated conservatively at 250v. The trigger voltage when using an attached sensor is around 30-40v. When used with a Nikon D50 and some other Nikon DSLRs with electronic/mechanical shutters there is no limit to the sync speed, it will sync at all shutter speeds without having to resort to an FP mode. There were also two different versions of the 3000, the later model has a button to illuminate the dial and different aperture choice selection and ranges. The earlier model had a constantly illuminated dial and no gaps in its 4 stop aperture range. There was also a bounce flash attachment which let you fit a large silver card to the flash and the flash could also be run from the mains via an adapter. The sensor also came with an extension which allowed the flash to be mounted on a stand with an umbrella and still be used in auto mode (as long as you didn't trip over the cable).

[loosecanon]

Hello fellow Canon. All the family doing well, though F1 getting old now so doesn't get out much. All the siblins doing ok, though A1 died some years ago, but AE1P still perky, and F1N still likes the occasional film through it.

My voltage for the autozoom 3000 was about 260 if I recall right. The ultimate accessory is of course the long extension for the remote sensor, think it is about 5 metre.

[photoguy]

Hello fellow Canon. All the family doing well, though F1 getting old now so doesn't get out much. All the siblins doing ok, though A1 died some years ago, but AE1P still perky, and F1N still likes the occasional film through it.

My voltage for the autozoom 3000 was about 260 if I recall right. The ultimate accessory is of course the long extension for the remote sensor, think it is about 5 metre.

I would think there would be a fault with that flash if its trigger voltage is anywhere near 260v as i've never seen any sunpak flash with a trigger voltage of much over 200v and I have tested many including those in the autozoom range such as the 3000, 3600, 4000 and 5000. The extension cable that comes included with the sensor for the 3000 is 1.5 metres in length which is added to the cable already attached to the sensor. Often people break off the locking bar for the sensor in the flash because they forget to press the release button on the flash. In USA the 3000 is known as the auto 411.