PC sync socket on K20D

Anya · 05-15-2009, 10:28 AM

I am thinking about getting a K20D. One of the attractive feature is the PC sync socket. I have a couple of Vivitar 283 flash. Will I be able to use these on the K20D safely?

SOldBear · 05-15-2009, 10:40 AM

Originally posted by Anya

I am thinking about getting a K20D. One of the attractive feature is the PC sync socket. I have a couple of Vivitar 283 flash. Will I be able to use these on the K20D safely?

I don't think Pentax has ever published the trigger voltage specs for the hot shoe contact and for the PC sync socket. Many people think the PC sync socket can accommodate high trigger voltage but I believe it when I see something in black and white from Pentax.

I have a 283 with 8.4V trigger voltage and another with 184V! The latter does not get anywhere near my K10D without a Safe-Sync or the like.

I also use a Sunpak 522 (22V) and a Metz 45 CT-4 (24V) without any problem. But I'm taking risk here, not knowing about the long term effect of it.

Measure the trigger voltages of your flash units and decide for yourself.

Wheatfield · 05-15-2009, 10:49 AM

Originally posted by SOldBear

I don't think Pentax has ever published the trigger voltage specs for the hot shoe contact and for the PC sync socket. Many people think the PC sync socket can accommodate high trigger voltage but I believe it when I see something in black and white from Pentax.

I have a 283 with 8.4V trigger voltage and another with 184V! The latter does not get anywhere near my K10D without a Safe-Sync or the like.

I also use a Sunpak 522 (22V) and a Metz 45 CT-4 (24V) without any problem. But I'm taking risk here, not knowing about the long term effect of it.

Measure the trigger voltages of your flash units and decide for yourself.

FWIW, I've used my K20 in the studio with a Norman P200D power pack that dates from before autofocus cameras with no problems. I don't know what it's trigger voltage is, but it is a brute of a power pack (no transformer, just diodes seperating the lights from the mains).

Mikeru · 05-15-2009, 12:02 PM

^^ Braver than I would be!

It brings me to a thought though. Are there many real reports of people damaging their cameras from high trigger voltage? While I certainly don't disbelieve it could be very bad for your camera, I don't think I've heard of it actually happening out of all the stuff I've read about it.

**AlexM** · 05-15-2009, 12:11 PM

I've read in previous publications that the Pentax hot shoes have a trigger voltage limit of 25 volts, but I have not read anything about what the max trigger voltage is on the PC sync socket, however, another user in this forum stated that the sync socket is protected from older hi-voltage flashes...

https://www.pentaxforums.com/forums/275337-post3.html

Alex

Anya · 05-15-2009, 08:02 PM

How do I measure the voltage on my 283? On of them I bought new and the other one was from a flea market for 4EUR. I think my brother had a digital voltmeter but he is aboard at the moment.

**DAZ** · 05-15-2009, 08:28 PM

In the K20 manual on the page about the X-sync socket it gives the same caution about high voltage high current flash units.

To test a flash you need a DC voltmeter that can meter up to about 350 VDC and down to about 1 VDC. With a new set of batteries turn on the flash and charge to full power. On the side of the hotshoe of the flash you will see a little metal contact in the groove. This is the ground contact. It is a little hard to get at and you may have to find a small peace of metal that can get in the groove. You need to meter the VDC from this contact to the center pin of the flash. If you get no voltage you are not making contact or the flash is broken. If you short the ground contact to the center pin the flash should fire. If not the flash is bad or you are not making contact. 3.5 VDC is about what you get on a good Pentax flash.

A flash with high voltage may work on the camera but may slowly damage it. It could burn out the first time or the 1000 time. It just depends.

DAZ

05-15-2009, 10:28 AM	#1
Anya Inactive Account Join Date: Apr 2009 Posts: 10	PC sync socket on K20D I am thinking about getting a K20D. One of the attractive feature is the PC sync socket. I have a couple of Vivitar 283 flash. Will I be able to use these on the K20D safely?

05-15-2009, 12:11 PM	#5
AlexM Site Supporter Join Date: Mar 2008 Location: Prescott Valley, AZ Photos: Gallery Posts: 171	I've read in previous publications that the Pentax hot shoes have a trigger voltage limit of 25 volts, but I have not read anything about what the max trigger voltage is on the PC sync socket, however, another user in this forum stated that the sync socket is protected from older hi-voltage flashes... https://www.pentaxforums.com/forums/275337-post3.html Alex Last edited by AlexM; 05-15-2009 at 12:24 PM.

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05-15-2009, 10:40 AM	#2
SOldBear Veteran Member Join Date: Feb 2009 Location: Alameda, CA Posts: 3,206	Originally posted by Anya I am thinking about getting a K20D. One of the attractive feature is the PC sync socket. I have a couple of Vivitar 283 flash. Will I be able to use these on the K20D safely? I don't think Pentax has ever published the trigger voltage specs for the hot shoe contact and for the PC sync socket. Many people think the PC sync socket can accommodate high trigger voltage but I believe it when I see something in black and white from Pentax. I have a 283 with 8.4V trigger voltage and another with 184V! The latter does not get anywhere near my K10D without a Safe-Sync or the like. I also use a Sunpak 522 (22V) and a Metz 45 CT-4 (24V) without any problem. But I'm taking risk here, not knowing about the long term effect of it. Measure the trigger voltages of your flash units and decide for yourself.

05-15-2009, 10:49 AM	#3
Wheatfield Moderator Join Date: Apr 2008 Location: The wheatfields of Canada Posts: 15,991	Originally posted by SOldBear I don't think Pentax has ever published the trigger voltage specs for the hot shoe contact and for the PC sync socket. Many people think the PC sync socket can accommodate high trigger voltage but I believe it when I see something in black and white from Pentax. I have a 283 with 8.4V trigger voltage and another with 184V! The latter does not get anywhere near my K10D without a Safe-Sync or the like. I also use a Sunpak 522 (22V) and a Metz 45 CT-4 (24V) without any problem. But I'm taking risk here, not knowing about the long term effect of it. Measure the trigger voltages of your flash units and decide for yourself. FWIW, I've used my K20 in the studio with a Norman P200D power pack that dates from before autofocus cameras with no problems. I don't know what it's trigger voltage is, but it is a brute of a power pack (no transformer, just diodes seperating the lights from the mains).

05-15-2009, 12:02 PM	#4
Mikeru New Member Join Date: Dec 2008 Posts: 22	^^ Braver than I would be! It brings me to a thought though. Are there many real reports of people damaging their cameras from high trigger voltage? While I certainly don't disbelieve it could be very bad for your camera, I don't think I've heard of it actually happening out of all the stuff I've read about it.

05-15-2009, 08:02 PM	#6
Anya Inactive Account Join Date: Apr 2009 Posts: 10 Original Poster	How do I measure the voltage on my 283? On of them I bought new and the other one was from a flea market for 4EUR. I think my brother had a digital voltmeter but he is aboard at the moment.

05-15-2009, 08:28 PM	#7
DAZ Loyal Site Supporter Join Date: Sep 2006 Location: Everett, WA USA Photos: Gallery Posts: 744	In the K20 manual on the page about the X-sync socket it gives the same caution about high voltage high current flash units. To test a flash you need a DC voltmeter that can meter up to about 350 VDC and down to about 1 VDC. With a new set of batteries turn on the flash and charge to full power. On the side of the hotshoe of the flash you will see a little metal contact in the groove. This is the ground contact. It is a little hard to get at and you may have to find a small peace of metal that can get in the groove. You need to meter the VDC from this contact to the center pin of the flash. If you get no voltage you are not making contact or the flash is broken. If you short the ground contact to the center pin the flash should fire. If not the flash is bad or you are not making contact. 3.5 VDC is about what you get on a good Pentax flash. A flash with high voltage may work on the camera but may slowly damage it. It could burn out the first time or the 1000 time. It just depends. DAZ