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afd

macrumors 65816
Original poster
Apr 12, 2005
1,140
393
Scotland
I just got a Pentax K10 and I have an old Vivitar 283 flash. Can I safely use this with the camera? I have read that the voltage across the hot shoe contacts on an older flash is too much for modern camera and will burnout the circuits? Anyone know if this is true? The manual only mentioned Pentax flashes.
 

afd

macrumors 65816
Original poster
Apr 12, 2005
1,140
393
Scotland
I emailed Pentax and got this (very fast) reply-

Dear Sir/Madam,

Thank you for your enquiry.

The only fully compatible flashguns are the AF360FGZ and AF540FGZ, all other older flashguns do not support P-TTL.
Unfortunately we do not know the specifications of your Vivitar flashgun.
Please make sure the trigger voltage does not exceed the 30 Volts else you might damage the camera.

If the flashgun meets this requirement the flashgun might work. Please keep the following in mind:
(P-TTL stands for Pentax TTL and not Preflash TTL as many people think. This is similar to Nikon's i-TTL and Canon's E-TTL)
When the flashgun meets the requirements of having a trigger voltage below 30 Volts, this flashunit can be used but it's not fully compatible because this is an A-TTL flashunit instead of a P-TTL flashunit.
This means that the camera and the flashunit cannot synchronise properly with eachother.

TTL dedicated flashes for Pentax use a separate metering sensor in the light box to get a reading from the reflection of light from the film (or sensor) plane during the exposure. The problem with this type of system is that the CCD sensor in digital bodies is more reflective than film, so calibration is different. The major advantage is that with only one flash, there is less chance of "droopy" or closed eyes from fast reacting people or animals, and standard slave flashes will work without any problems.

P-TTL dedicated flashes for Pentax use the regular exposure meter to get a reading before the actual exposure using a pre-flash just before the shutter opens. You can actually see the preflash in the viewfinder just before it blacks out.
Because of the pre-flash, only "digital" slaves that fire on the second flash will work correctly with a P-TTL flash unit.

TTL Auto Flash will not work. You have to use manual flash settings and use the flash aperture control.
You also have to set the ISO on both camera and flash to the same value. This way using this flash will still be possible.

I hope that your question has been answered to your satisfaction.
Should you have further questions regarding this matter, please do not hesitate to contact us again.


Will get the voltage measured and if it's a lot less than 30V I'll use it. I also found the Wein Safe Sync referenced on another site, but I think the money ($50) it costs I'd rather put towards a new flash.

Thanks again for the replies
 

M@lew

macrumors 68000
Nov 18, 2006
1,582
0
Melbourne, Australia
It will actually work with your camera, but constant use will definitely fry it. I'm pretty sure it is a higher voltage than recommended if it's old enough for an old film SLR.
 

compuwar

macrumors 601
Oct 5, 2006
4,717
2
Northern/Central VA
I just got a Pentax K10 and I have an old Vivitar 283 flash. Can I safely use this with the camera? I have read that the voltage across the hot shoe contacts on an older flash is too much for modern camera and will burnout the circuits? Anyone know if this is true? The manual only mentioned Pentax flashes.

You want a Wein Safe-Sync Hot Shoe Mounted High Voltage Sync Regulator

http://www.bhphotovideo.com/c/product/245292-REG/Wein_W990560_Safe_Sync_Hot_Shoe_to.html

The older 283's were hot and there's the potential for a lot of voltage drift from spec. Alternately, invest the $50 in a newer flash unit.

The K10D seems to only have a trigger voltage of 6.5V (rumored, not in the specs) and the older 283s will go to 250V, but you could see it up to 260V. My D2x will do 250V, but I'm not sure I'd try the 283 on it, given the reported variances.
 

compuwar

macrumors 601
Oct 5, 2006
4,717
2
Northern/Central VA
It will actually work with your camera, but constant use will definitely fry it. I'm pretty sure it is a higher voltage than recommended if it's old enough for an old film SLR.

Constant use? I think a 243.5V difference is going to show up the first time, the magic smoke is going to escape, and we all know that once the magic smoke escapes, it'll stop working.
 

Father Jack

macrumors 68020
Jan 1, 2007
2,481
1
Ireland
Constant use? I think a 243.5V difference is going to show up the first time, the magic smoke is going to escape, and we all know that once the magic smoke escapes, it'll stop working.

I think 243.5 volts indicates that "constant use" means using it one or more times!! ... :eek:
 

ChrisA

macrumors G5
Jan 5, 2006
12,828
2,033
Redondo Beach, California
Wein Safe Sync referenced on another site, but I think the money ($50) it costs I'd rather put towards a new flash.

I use the Wein Safe Sync between my camera and my Studio strobe system. The strobe power box dates from the 1970's and plugs into wall current and sucks down 15 amps. With this box I used the safe sync even with a mechanical camera to keep the contacts from pitting. This is what the Safe Sync was designed for. But those little Vivitar strobes are powered with 4 AA cells and are controlled with an electronic circuit. The power going to the flash tube does not go through the camera.
 

seahawk09

macrumors regular
Jul 2, 2007
101
0
Canada
Hey AFD,

Thankyou for posting this question I also just bought a K10D I have a Tamaron bounce flash and I am a little concerned about using it on my new camera I think i will check with my camera shop to see if it's compatable if it's not i'll just save up for a pentax flash.:)
 
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