Flash advice

Having looked at quite a few ist D cameras when I was buying mine, there seemed to be a high percentage with faulty built in flash. Is this a common problem with the ist D?

If it is, I have an old hot shoe (?) flash from my SuperME. Will this work with the ist D?

If it will, is there any benefit from using this over the built in flash; ie, to prolong battery life and prolong the life of the flash?
It isn't a "fancy" flash unit, just an upright forward facing flash, but then the built in flash is only basic, ( well, compared to some of the other flash units I've seen).

If i am correct in saying the ist*D does not support P-TTL and if this is the case and your old flash is TTL compliant it should work ok. Just check the trigger voltage first.
Someone more in the know than i will correct me if i am wrong.

The problem with using old flash units is their terminal voltage. Some old flashes charge up their hot shoes to truely amazingly high voltages and this can be dangerous for modern cameras with their delicate digital electronics. They simply aren't designed to get 600V put across them. I don't blame them, neither am I.

The only reference I am aware of on this is a reported quote from Pentax saying that their SLRs were safe up to 600V. That quote, if it were true in the first place, is now several years out of date. We don't know what may have changed since then, we don't know if they were refering to DSLRs, film SLRs or both.

The first thing I would do is get a multimeter (if you don't have one, Maplin will usually sell you one for about a fiver and it's a useful thing to have in a drawer somewhere). Charge up the flash and carefully measure the voltage between the main central contact and the secondary contact on the side of the shoe (both on the flash of course!). Be careful doing this, remember that you are not designed to get 600V across your terminals (fingers) either! if you are unsure, find someone who knows what they are doing to help you.

If the terminal voltage is low, of order 10 or 20V, then you should be fine. If it's higher, it's worth doing a google search to see what you can turn up. Pentax seem to be one of the more robust brands when it comes to flash voltages, but you should be aware of the potential risks involved and the fact that the safety margin has never been documented.


Edit: clarky got in first actually the *istD DOES support P-TTL, but it also supports old style TTL so what Clarky says holds true. Still if the flash is ME-Super era, it's probably Auto at best, you'll still only get modes the flash itself can support.

Thanks Mongoose!
I'm a CCTV engineer, so my multimeter is my right hand

I'll check those voltages tonight. Wasn't expecting to hear there may be 600v on the contacts, I thought it would be a transistor switch ( 3-5v )


That'd make my hair stand up ( what's left of it ).

I've never actually seen one as high as 600V myself, but I do have an old Vivitar which IIRC came out at about 360V. I decided not to use that one on camera!

Here's a link to a very comprehensive list of Flash units and their voltages.
http://www.botzilla.com/photo/strobeVolts.html
The 'Yes' means they are suitable for the Canon Eos models (very low voltage acceptance). I've read various figures given for the Pentax DSLR as safe voltages but personally I'm keeping below 10 volts to be safe with my K100d super. Rather be wary than scary. Hope it helps.

Met with Pentax at the LCE camera show on April 2nd - advised to NOT use any old flash guns - even 20V is too much for a modern digital designed for 5V.

Shame as I wanted to use my old Vivitar 283 - they said that would kill a K20D.

where was your viv 283 made?
in japan? (danger) oldest highest voltage model
tiawan, or korea or vietnam? (safe) newer lower (may still be high enough to kill a canon). don't know about the k20, but my vivs work fine on the k10 and ds2.

No bad thing.

Dan

china! my newer vivatars are made in china!

Did the person who gave you that advice have any sound technical reason for giving it, or was he/she a salesman who would prefer you bought a new flash?

Other information, apparantly from a technical source, suggests that Pentax cameras are designed to handle trigger voltages up to 300 volts.

I know Canon SAY 5 volts, but does anyone believe that? They would be crazy to use such a low figure, given that the relevant international standard is 24v, and quite a few reasonably modern guns are between 10 and 20.

I have never heard of anyone frying a camera with a modern flashgun.

Interestingly (according to the quoted site) Wien, who make triggers to protect sensitive little cameras from nasty big flashguns, make triggers with voltages of over 10v.

G

This was quoted on the PDML by somebody who was given that advice by Pentax USA. And it was after the introduction of the *ist D.

All Pentax flashguns for many years have been under 10v (AFAIK), so it is conceivable that Pentax may have made their cameras less robust in recent years.

But I can't remember any specific warnings in Pentax camera manuals about high voltage flashguns - just the usual blanket disclaimers about using non-Pentax products.

G

the problem with asking Pentax is that it's very hard to tell how much of the response you get is actually "we want you to buy a 360FGZ" and how much is "seriously dude, don't do it"

works on my ds2 as well.
not much more to say.....