Tested Vivitar 2800 for Optical Triggering

C_Jones · 01-21-2017, 11:07 AM

I have been testing my Vivitar 2800 Thyristor off camera to see if it triggers with an optical sensor, and have discovered that it "does not". I am not going to use it on any of my Pentax dslr camera bodies to avoid voltage effects. I was using my K-5IIS to test it off camera, and supposedly the flash does not have an optical sensor. I suppose some radio triggers would trigger it, but I do not want to expose radio triggers to a possible voltage problem either. So, my conclusion is, the flash did do well on my K-1000 which I still have, but I do not want to expose my newer dslr oriented equipment to it in the interest of being safe. If anyone is curious, I bought the flash about 1989.

One more comment. I noticed also that rechargeable AA batteries fit a little bit more snug in the battery compartment, calling for a little bit more pushing the batteries down when trying to get the compartment cover on.

Last edited by C_Jones; 01-21-2017 at 11:13 AM.

joe_leg · 01-21-2017, 03:52 PM

If you like your Thyristor you can keep (still use) your Thyristor...

Wein Safe-Sync Hot Shoe to Hot Shoe with PC 990-560 B&H Photo
I use this one with my Sunpak Thyristor bracket flashes with no problem. I recall having an optical trigger made by them that could handle the high voltage but that was some time ago.

C_Jones · 01-21-2017, 06:59 PM

I don't want to use the flash on my dslr's. Thanks for the product mention though. For off camera optical triggering I saw the following product. It costs about as much as a modern, less expensive flash that could be used on a dslr directly, or off camera in manual mode though.

Wein HS Hot Shoe Slave 940-030 B&H Photo Video

Class A · 01-21-2017, 10:46 PM

Originally posted by C_Jones

I have been testing my Vivitar 2800 Thyristor off camera to see if it triggers with an optical sensor, and have discovered that it "does not".

Did the Vivitar not flash at all, or did it issue a flash without contributing to the exposure?

In the latter case, it responded to the pre-flash of your K-5 IIs and you would need to make the latter not issue a pre-flash.

You did use the pop-up flash of the K-5 IIs for attempting to trigger the Vivitar, right?

Originally posted by C_Jones

I suppose some radio triggers would trigger it, but I do not want to expose radio triggers to a possible voltage problem either.

Good radio triggers do not have an issue with voltages up to 300V. You would not have a problem triggering this flash at all.

Not a Number · 01-22-2017, 02:57 AM

The flash is not going to slave as it has no slave circuit. The optical sensor on the flash unit is used to sense the amount of light bouncing back from the subject to quench the flash when the proper amount of light is received.

To slave the flash you need an optical slave adapter such as the Wein unit. The price of similar slave units run from $6 to 40.

The flash trigger voltage on the 2800 has been measured from 170v to ~4v. Typically the newer the production date the lower the trigger voltage. Measure the trigger voltage or use the Wein safety thingy or wireless triggers. The optical slaves shouldn't care about the trigger voltage either.

C_Jones · 01-23-2017, 02:42 PM

Originally posted by Class A

Did the Vivitar not flash at all, or did it issue a flash without contributing to the exposure?

In the latter case, it responded to the pre-flash of your K-5 IIs and you would need to make the latter not issue a pre-flash.

You did use the pop-up flash of the K-5 IIs for attempting to trigger the Vivitar, right?

Good radio triggers do not have an issue with voltages up to 300V. You would not have a problem triggering this flash at all.

Thank you.

---------- Post added 01-23-17 at 04:42 PM ----------

Originally posted by Not a Number

The flash is not going to slave as it has no slave circuit. The optical sensor on the flash unit is used to sense the amount of light bouncing back from the subject to quench the flash when the proper amount of light is received.

To slave the flash you need an optical slave adapter such as the Wein unit. The price of similar slave units run from $6 to 40.

The flash trigger voltage on the 2800 has been measured from 170v to ~4v. Typically the newer the production date the lower the trigger voltage. Measure the trigger voltage or use the Wein safety thingy or wireless triggers. The optical slaves shouldn't care about the trigger voltage either.

Thank you.

01-21-2017, 11:07 AM	#1
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084	Tested Vivitar 2800 for Optical Triggering I have been testing my Vivitar 2800 Thyristor off camera to see if it triggers with an optical sensor, and have discovered that it "does not". I am not going to use it on any of my Pentax dslr camera bodies to avoid voltage effects. I was using my K-5IIS to test it off camera, and supposedly the flash does not have an optical sensor. I suppose some radio triggers would trigger it, but I do not want to expose radio triggers to a possible voltage problem either. So, my conclusion is, the flash did do well on my K-1000 which I still have, but I do not want to expose my newer dslr oriented equipment to it in the interest of being safe. If anyone is curious, I bought the flash about 1989. One more comment. I noticed also that rechargeable AA batteries fit a little bit more snug in the battery compartment, calling for a little bit more pushing the batteries down when trying to get the compartment cover on. Last edited by C_Jones; 01-21-2017 at 11:13 AM.

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01-21-2017, 03:52 PM	#2
joe_leg New Member Join Date: Dec 2015 Location: Near the Cape Cod Canal, MA. (Onset) Photos: Gallery Posts: 23	If you like your Thyristor you can keep (still use) your Thyristor... Wein Safe-Sync Hot Shoe to Hot Shoe with PC 990-560 B&H Photo I use this one with my Sunpak Thyristor bracket flashes with no problem. I recall having an optical trigger made by them that could handle the high voltage but that was some time ago.

01-21-2017, 06:59 PM	#3
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084 Original Poster	I don't want to use the flash on my dslr's. Thanks for the product mention though. For off camera optical triggering I saw the following product. It costs about as much as a modern, less expensive flash that could be used on a dslr directly, or off camera in manual mode though. Wein HS Hot Shoe Slave 940-030 B&H Photo Video

01-21-2017, 10:46 PM	#4
Class A Pentaxian Join Date: Aug 2008 Location: Wellington, New Zealand Posts: 11,251	Originally posted by C_Jones I have been testing my Vivitar 2800 Thyristor off camera to see if it triggers with an optical sensor, and have discovered that it "does not". Did the Vivitar not flash at all, or did it issue a flash without contributing to the exposure? In the latter case, it responded to the pre-flash of your K-5 IIs and you would need to make the latter not issue a pre-flash. You did use the pop-up flash of the K-5 IIs for attempting to trigger the Vivitar, right? Originally posted by C_Jones I suppose some radio triggers would trigger it, but I do not want to expose radio triggers to a possible voltage problem either. Good radio triggers do not have an issue with voltages up to 300V. You would not have a problem triggering this flash at all.

01-22-2017, 02:57 AM	#5
Not a Number Moderator Join Date: Mar 2012 Location: Venice, CA Posts: 10,526	The flash is not going to slave as it has no slave circuit. The optical sensor on the flash unit is used to sense the amount of light bouncing back from the subject to quench the flash when the proper amount of light is received. To slave the flash you need an optical slave adapter such as the Wein unit. The price of similar slave units run from $6 to 40. The flash trigger voltage on the 2800 has been measured from 170v to ~4v. Typically the newer the production date the lower the trigger voltage. Measure the trigger voltage or use the Wein safety thingy or wireless triggers. The optical slaves shouldn't care about the trigger voltage either.

01-23-2017, 02:42 PM	#6
C_Jones Pentaxian Join Date: Sep 2012 Location: NY Photos: Gallery \| Albums Posts: 6,084 Original Poster	Originally posted by Class A Did the Vivitar not flash at all, or did it issue a flash without contributing to the exposure? In the latter case, it responded to the pre-flash of your K-5 IIs and you would need to make the latter not issue a pre-flash. You did use the pop-up flash of the K-5 IIs for attempting to trigger the Vivitar, right? Good radio triggers do not have an issue with voltages up to 300V. You would not have a problem triggering this flash at all. Thank you. ---------- Post added 01-23-17 at 04:42 PM ---------- Originally posted by Not a Number The flash is not going to slave as it has no slave circuit. The optical sensor on the flash unit is used to sense the amount of light bouncing back from the subject to quench the flash when the proper amount of light is received. To slave the flash you need an optical slave adapter such as the Wein unit. The price of similar slave units run from $6 to 40. The flash trigger voltage on the 2800 has been measured from 170v to ~4v. Typically the newer the production date the lower the trigger voltage. Measure the trigger voltage or use the Wein safety thingy or wireless triggers. The optical slaves shouldn't care about the trigger voltage either. Thank you.