Measuring trigger voltage

xandy · 01-17-2008, 07:09 PM

A few days ago I've read an article in this Forums about measuring trigger voltage but cannot find it now, sorry for being poor with search, would you please reply with that link.

Or if anyone uses Vivitar-Electronic Flash-1900 or Vivitar 252 please tell me if it is safe to use them on K100D. Just found those two in friends garage and both are in working condition. I did found and downloaded manuals but no info in them re trigger voltage.

With appreciation
andy

Clem Nichols · 01-17-2008, 08:32 PM

Andy:

The info you are looking for can be found here: Photo Strobe Trigger Voltages

It shows the 1900 to have a trigger voltage of at least 90 volts. It doesn't list info for the 252, but shows that the 253 model has a trigger voltage of 200 volts. I would not want to use either flash on camera, but either could be used off camera in manual mode using wireless triggers.

CN

P.S. I don't know about everyone else, but I find the search engine for this forum to be pretty much useless.

xandy · 01-17-2008, 08:44 PM

Originally posted by Clem Nichols

Andy:

The info you are looking for can be found here: Photo Strobe Trigger Voltages

It shows the 1900 to have a trigger voltage of at least 90 volts. It doesn't list info for the 252, but shows that the 253 model has a trigger voltage of 200 volts. I would not want to use either flash on camera, but either could be used off camera in manual mode using wireless triggers.

CN

P.S. I don't know about everyone else, but I find the search engine for this forum to be pretty much useless.

Wireless means more accessories to purchase, would i need a deep pocket ;-) ?

Thank you for the link, bookmarked!

George Lama · 01-17-2008, 08:47 PM

If you have a multi-meter handy, you can measure your own trigger voltage easily. Just make sure both your meter and flash have fresh batteries.

If I remember correctly, on that website it gives you instructions on how to measure your own.

I would do multiple measurements to be sure.

Mike Cash · 01-18-2008, 07:29 AM

Wireless means about thirty bucks and is very well worth the investment.

If you do the voltage test yourself, be sure to use a digital multimeter as many analog meters can't do the job properly, for reasons beyond my meager ability to comprehend.

**Lowell Goudge** · 01-18-2008, 07:49 AM

Originally posted by Mike Cash

If you do the voltage test yourself, be sure to use a digital multimeter as many analog meters can't do the job properly, for reasons beyond my meager ability to comprehend.

Analog meters can put a load that causes voltage reduction, depending upon the input resistance of the meter, this mens you may measure a lower voltage than the camera circuitry may see. Additionally on an analog meter the input resistance changes as a function of voltage range.

Jodokast96 · 01-18-2008, 08:55 AM

How much of a difference may be expected? I only have access to an analog meter, and when I tested the Vivitar 283 it consistently measured around 5v, though still less than 10v using a higher range. Is the difference enough that I should still be concerned and retest with a digital meter?

**Lowell Goudge** · 01-18-2008, 09:07 AM

Originally posted by Jodokast96

How much of a difference may be expected? I only have access to an analog meter, and when I tested the Vivitar 283 it consistently measured around 5v, though still less than 10v using a higher range. Is the difference enough that I should still be concerned and retest with a digital meter?

The digital meters all have a constant input resistance greater than 1 million ohms.

Analog meters usually state, the impedance per range. the actual value is a function of the current required to generate full scale deflection. in a 10 volt range this could be as low as 10,000 ohms.

this could greatly impact the measurement. as a minimum, you could make measurements on one or two ranges, and look at how the measurement changes providing you have two ranges that you are confident you can make an accurate measurement.

a digital meter would be better, and is relitively inexpensive today, but by the time you do this, you may have spent more than a good flash,

Mike Cash · 01-18-2008, 09:21 AM

The cheap anagog meter I initially tried wouldn't give consistent results on different ranges and I took it back and exchanged it for a digital. Some analog meters may work fine, but as Lowell said, if you're not getting consistent readings on at least a couple of ranges, do it on a digital.

Jodokast96 · 01-18-2008, 09:42 AM

I tested it at all the ranges and it never went above 10v so I should be safe then right? The numbers I'm getting do seem consistent with what I saw listed on that site for my exact model.

**Lowell Goudge** · 01-18-2008, 12:06 PM

Originally posted by Jodokast96

I tested it at all the ranges and it never went above 10v so I should be safe then right? The numbers I'm getting do seem consistent with what I saw listed on that site for my exact model.

Just to let you know, I checked my Sunpak autozoom 3000 with an analog meter, which had a resistance of 20,000 ohms per volt (of full scale voltage)

On 15 volt scale (300,000 ohms) , I measured 14 volts
on 60 volt scale (1,200,000 ohms) I measured 48 volts
on 300 volt scale (6,000,000 ohms) I measured 140 volts
using a digital meter I measure 198 volts!!!!!!!! (edit note)

When I touch the flash rerminals with my finger IT HURTS, therefore the voltage is real.

With the off camera attachment, trigger voltage 30 volts (still too high) (Edit note)

all I can say is Be careful. I have the schematics for my flash, and for the remote sensing head/cable for off camera flash, I will look to see what they have done on this unit to protect the remote sensing electronics.

one final word, my Af500FTZ has a trigger voltage of 3.8 volts (edit note)
a second last word, my AF540FGZ has a trigger voltage of 2.5V (edit note)

xandy · 01-18-2008, 09:21 PM

Thanks for all answer on this topic.
Now additional question: what exactly is a trigger voltage?

**Lowell Goudge** · 01-19-2008, 07:47 AM

Originally posted by xandy

Thanks for all answer on this topic.
Now additional question: what exactly is a trigger voltage?

trigger voltage is the foltahe at the center contact of the flahs shoe, relitive to the metal mount, which is present to the contact or in new cameras the electronics that fire the flash

xandy · 01-20-2008, 04:25 PM

Originally posted by Lowell Goudge

trigger voltage is the foltahe at the center contact of the flahs shoe, relitive to the metal mount, which is present to the contact or in new cameras the electronics that fire the flash

I have put my question upside down , sorry.
What I want to know is if it's possible to find what is a minimum voltage to fire a particular flash. How can I measure this value. This came to my mind as I noticed that battery in the flash maybe depleted a bit but it still fires however with much less of a power. I know it may be not worthy to pursue such technical details but curiosity ....

**Lowell Goudge** · 01-20-2008, 05:57 PM

Originally posted by xandy

I have put my question upside down , sorry.
What I want to know is if it's possible to find what is a minimum voltage to fire a particular flash. How can I measure this value. This came to my mind as I noticed that battery in the flash maybe depleted a bit but it still fires however with much less of a power. I know it may be not worthy to pursue such technical details but curiosity ....

This will vary from flash to flash. I tried to get thid from pentax on the AF540. Not so much the actual voltages, but the difference between maximum charge voltage on the flash's capacitor (assume new batteries) and the minimum charge voltage, where the flash ready light comes on, which usually is also the minimum charge voltage that will permit the flash to fire. I got no good response.

You could, using a DSLR, photo editor, and flash, get a measure of this.

Set up on a tripod, with a subject like a uniform wall as the subject, and simply take a photo with fully charged batteries. Let the flash run for 2-3 minutes to insure maximum charge on the capacitor, then take a shot in manual calculated to give you correct exposure, or set it up with some trial shots. The discharge the batteries, by taking multiple flashes, and take an exposure perhaps one every 20 flashes. Keep doing this until the flash will no longer fire.

Using a photo editor, measure the grey scale value of each photo. it will slowly drop as exposures continue.

With all exposure settings set to neutral, 1 F stop is a change in grey scale of about 40-50. (providing you are in the range 25-230)

The final shot where the flash fires will be the dimest, the first shot the brightest. Measure the greyscale, and calculate the difference. This will give you the change in exposure which will also be approximately equil to the difference in flash energy, and voltage.

01-17-2008, 07:09 PM	#1
xandy Senior Member Join Date: Sep 2007 Location: Regina,Sask.,Canada Photos: Gallery Posts: 103	Measuring trigger voltage A few days ago I've read an article in this Forums about measuring trigger voltage but cannot find it now, sorry for being poor with search, would you please reply with that link. Or if anyone uses Vivitar-Electronic Flash-1900 or Vivitar 252 please tell me if it is safe to use them on K100D. Just found those two in friends garage and both are in working condition. I did found and downloaded manuals but no info in them re trigger voltage. With appreciation andy

01-18-2008, 12:06 PM	#11
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by Jodokast96 I tested it at all the ranges and it never went above 10v so I should be safe then right? The numbers I'm getting do seem consistent with what I saw listed on that site for my exact model. Just to let you know, I checked my Sunpak autozoom 3000 with an analog meter, which had a resistance of 20,000 ohms per volt (of full scale voltage) On 15 volt scale (300,000 ohms) , I measured 14 volts on 60 volt scale (1,200,000 ohms) I measured 48 volts on 300 volt scale (6,000,000 ohms) I measured 140 volts using a digital meter I measure 198 volts!!!!!!!! (edit note) When I touch the flash rerminals with my finger IT HURTS, therefore the voltage is real. With the off camera attachment, trigger voltage 30 volts (still too high) (Edit note) all I can say is Be careful. I have the schematics for my flash, and for the remote sensing head/cable for off camera flash, I will look to see what they have done on this unit to protect the remote sensing electronics. one final word, my Af500FTZ has a trigger voltage of 3.8 volts (edit note) a second last word, my AF540FGZ has a trigger voltage of 2.5V (edit note) Last edited by Lowell Goudge; 12-04-2008 at 05:26 PM.

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01-17-2008, 08:32 PM	#2
Clem Nichols Veteran Member Join Date: Mar 2007 Location: Munfordville, Ky. Photos: Gallery Posts: 370	Andy: The info you are looking for can be found here: Photo Strobe Trigger Voltages It shows the 1900 to have a trigger voltage of at least 90 volts. It doesn't list info for the 252, but shows that the 253 model has a trigger voltage of 200 volts. I would not want to use either flash on camera, but either could be used off camera in manual mode using wireless triggers. CN P.S. I don't know about everyone else, but I find the search engine for this forum to be pretty much useless.

01-17-2008, 08:44 PM	#3
xandy Senior Member Join Date: Sep 2007 Location: Regina,Sask.,Canada Photos: Gallery Posts: 103 Original Poster	Originally posted by Clem Nichols Andy: The info you are looking for can be found here: Photo Strobe Trigger Voltages It shows the 1900 to have a trigger voltage of at least 90 volts. It doesn't list info for the 252, but shows that the 253 model has a trigger voltage of 200 volts. I would not want to use either flash on camera, but either could be used off camera in manual mode using wireless triggers. CN P.S. I don't know about everyone else, but I find the search engine for this forum to be pretty much useless. Wireless means more accessories to purchase, would i need a deep pocket ;-) ? Thank you for the link, bookmarked!

01-17-2008, 08:47 PM	#4
George Lama Veteran Member Join Date: Jun 2007 Location: Buffalo/Rochester, NY Photos: Albums Posts: 1,133	If you have a multi-meter handy, you can measure your own trigger voltage easily. Just make sure both your meter and flash have fresh batteries. If I remember correctly, on that website it gives you instructions on how to measure your own. I would do multiple measurements to be sure.

01-18-2008, 07:29 AM	#5
Mike Cash Veteran Member Join Date: Jan 2007 Location: Japan Photos: Gallery Posts: 6,950	Wireless means about thirty bucks and is very well worth the investment. If you do the voltage test yourself, be sure to use a digital multimeter as many analog meters can't do the job properly, for reasons beyond my meager ability to comprehend.

01-18-2008, 07:49 AM	#6
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by Mike Cash If you do the voltage test yourself, be sure to use a digital multimeter as many analog meters can't do the job properly, for reasons beyond my meager ability to comprehend. Analog meters can put a load that causes voltage reduction, depending upon the input resistance of the meter, this mens you may measure a lower voltage than the camera circuitry may see. Additionally on an analog meter the input resistance changes as a function of voltage range.

01-18-2008, 08:55 AM	#7
Jodokast96 Veteran Member Join Date: Oct 2007 Location: Erial, NJ USA Photos: Gallery \| Albums Posts: 2,134	How much of a difference may be expected? I only have access to an analog meter, and when I tested the Vivitar 283 it consistently measured around 5v, though still less than 10v using a higher range. Is the difference enough that I should still be concerned and retest with a digital meter?

01-18-2008, 09:07 AM	#8
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by Jodokast96 How much of a difference may be expected? I only have access to an analog meter, and when I tested the Vivitar 283 it consistently measured around 5v, though still less than 10v using a higher range. Is the difference enough that I should still be concerned and retest with a digital meter? The digital meters all have a constant input resistance greater than 1 million ohms. Analog meters usually state, the impedance per range. the actual value is a function of the current required to generate full scale deflection. in a 10 volt range this could be as low as 10,000 ohms. this could greatly impact the measurement. as a minimum, you could make measurements on one or two ranges, and look at how the measurement changes providing you have two ranges that you are confident you can make an accurate measurement. a digital meter would be better, and is relitively inexpensive today, but by the time you do this, you may have spent more than a good flash,

01-18-2008, 09:21 AM	#9
Mike Cash Veteran Member Join Date: Jan 2007 Location: Japan Photos: Gallery Posts: 6,950	The cheap anagog meter I initially tried wouldn't give consistent results on different ranges and I took it back and exchanged it for a digital. Some analog meters may work fine, but as Lowell said, if you're not getting consistent readings on at least a couple of ranges, do it on a digital.

01-18-2008, 09:42 AM	#10
Jodokast96 Veteran Member Join Date: Oct 2007 Location: Erial, NJ USA Photos: Gallery \| Albums Posts: 2,134	I tested it at all the ranges and it never went above 10v so I should be safe then right? The numbers I'm getting do seem consistent with what I saw listed on that site for my exact model.

01-18-2008, 09:21 PM	#12
xandy Senior Member Join Date: Sep 2007 Location: Regina,Sask.,Canada Photos: Gallery Posts: 103 Original Poster	Thanks for all answer on this topic. Now additional question: what exactly is a trigger voltage?

01-19-2008, 07:47 AM	#13
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by xandy Thanks for all answer on this topic. Now additional question: what exactly is a trigger voltage? trigger voltage is the foltahe at the center contact of the flahs shoe, relitive to the metal mount, which is present to the contact or in new cameras the electronics that fire the flash

01-20-2008, 04:25 PM	#14
xandy Senior Member Join Date: Sep 2007 Location: Regina,Sask.,Canada Photos: Gallery Posts: 103 Original Poster	Originally posted by Lowell Goudge trigger voltage is the foltahe at the center contact of the flahs shoe, relitive to the metal mount, which is present to the contact or in new cameras the electronics that fire the flash I have put my question upside down , sorry. What I want to know is if it's possible to find what is a minimum voltage to fire a particular flash. How can I measure this value. This came to my mind as I noticed that battery in the flash maybe depleted a bit but it still fires however with much less of a power. I know it may be not worthy to pursue such technical details but curiosity ....

01-20-2008, 05:57 PM	#15
Lowell Goudge Site Supporter Join Date: Jan 2007 Location: Toronto Photos: Gallery \| Albums Posts: 17,888	Originally posted by xandy I have put my question upside down , sorry. What I want to know is if it's possible to find what is a minimum voltage to fire a particular flash. How can I measure this value. This came to my mind as I noticed that battery in the flash maybe depleted a bit but it still fires however with much less of a power. I know it may be not worthy to pursue such technical details but curiosity .... This will vary from flash to flash. I tried to get thid from pentax on the AF540. Not so much the actual voltages, but the difference between maximum charge voltage on the flash's capacitor (assume new batteries) and the minimum charge voltage, where the flash ready light comes on, which usually is also the minimum charge voltage that will permit the flash to fire. I got no good response. You could, using a DSLR, photo editor, and flash, get a measure of this. Set up on a tripod, with a subject like a uniform wall as the subject, and simply take a photo with fully charged batteries. Let the flash run for 2-3 minutes to insure maximum charge on the capacitor, then take a shot in manual calculated to give you correct exposure, or set it up with some trial shots. The discharge the batteries, by taking multiple flashes, and take an exposure perhaps one every 20 flashes. Keep doing this until the flash will no longer fire. Using a photo editor, measure the grey scale value of each photo. it will slowly drop as exposures continue. With all exposure settings set to neutral, 1 F stop is a change in grey scale of about 40-50. (providing you are in the range 25-230) The final shot where the flash fires will be the dimest, the first shot the brightest. Measure the greyscale, and calculate the difference. This will give you the change in exposure which will also be approximately equil to the difference in flash energy, and voltage.