Practica flash


Link Posted 15/04/2012 - 08:33
Hello there,
Could anybody tell me what sort of voltage the hotshoe on a k-x will accept.
I have a Praktica BC2400 which has auto settings, which seems to vary the output according to the distance (light reflected back). This was bought in a job lot from a car-boot with camera and lenses by mistake. I thought that they were were using the same bayonet fitting but B--lsed up.
Measuring the hotshoe fitting I get a reading of 11.9 - 12 volts pos centre peg. I seem to remember reading about high voltage on the hotshoe NOT being usable.
If it is usable according to what I read on the back it should be good for up to 30ft at 400asa with camera at f5.6 I think. Or f11 from 3-15 ft.
I don't want to just stick it on to see what might happen just in case!!

Any help or advice would be appreciated.



Link Posted 15/04/2012 - 10:21
This sort of question comes up quite regularly.
The Pentax trigger voltage is quite low, and I would not want to take a chance; particularly when there are a lot of genuine Pentax flashguns around. When I asked the same sort of question a year or two back, I was told that any Pentax flash is safe on any Pentax DSLR.
If I want more power than the built-in flash, I have an AF240Z that slips straight on and works. Alternatively, I use an old Vivitar flash that connects through the PC socket (but I don't know if the K-x has one).
The Pentax AF240Z seems not to be a particularly sought-after flash, so for a cheap unit, it could be worth looking out for one.
For a definitive answer, search the forum for posts by mattmatic.

Water can wear away a stone - but it can't cook lunch
Lenses Digital: 50-200, 18-55 KAF: 28-80.
Lenses KA & K: SMC-KA f2.0, SMC-K f1.4, SMC-K f1.7 Tokina KA 28-70 , SMC Pentax 70-210 F4, Sigma KA 75-300 , Hanimex 500mm Mirror, and the Tamron Adaptall-2 stuff.
and then there's all the M42 kit, and the accessories ...



Link Posted 15/04/2012 - 11:24
12v should be absolutely fine. I think when people talk of dangerously high voltages, they mean units that produce hundreds of volts. Up to 24v should be safe (and probably a bit more - on the other forum several people reported advice from Pentax customer service on safe voltages- the advice varied but the lowest figure I saw quoted on the thread was 30v.)

Apparently Nikon have published the fact that their hotshoe takes up to 250v. Not sure why Pentax haven't officially confirmed their maximum voltage - presumably not doing so helps them sell flashguns.



Link Posted 15/04/2012 - 11:38
Me again,

I actually got it wrong on the voltage. I measured the small pin to centre, which seems to be a flash ready signal. Centre to the side contact, which touches the shoe mount was 6.5 volts.

Decided to try it as I'm sure I remember this sort of voltage is safe.
Wahey, seems okay, tried it in manual settings and looks to work as I thought.

Probably will buy secondhand Pentax flash all the same though.

How about the Pentax AF400 FTZ. If as you say any Pentax AF flash is ok then this is probably more powerful than the AF240z for a similar price.

Any thoughts on this model on my K-x would be grateful.



Link Posted 15/04/2012 - 20:58
Some older Pentax flashes have a trigger voltage of 100v,I haven't fried a dslr yet.
“We must avoid however, snapping away, shooting quickly and without thought, overloading ourselves with unnecessary images that clutter our memory and diminish the clarity of the whole.” - Henri Cartier-Bresson -


Link Posted 20/04/2012 - 20:21
Hi all,

As I had said probably go for a Pentax flash, well I got a AF240Z.

Pleased with it on my K-X . It works ok in P mode on both, communicating with camera and setting aperture and if shutter set too fast it brings it down to max flash setting. Bounce off ceiling in my front room works nicely so yes pleased with it, real improvement over pop-up flash and at £10 well worth the money.

Reading what I could seemed that the 400ftz would have been okay but just in total manual settings, could have coped as that is all I had on 35mm Chinon and National Panasonic cheapo.

Thanks Pat


Link Posted 20/04/2012 - 20:47
I once got an answer from their tech support guys on this topic, they told me not to go above 12V (K7)
... just another middle-aged guy with a hobby. I have an extreme macro learning site at - Pentax-centric, your feedback and comments would be appreciated!
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