Let me know when you find a source for the isolator. I will look into it. I 
just finished a shoot in my studio. I shot about 50 frames. Again no problems. 
I should check the pin voltage on my monolights. I have no idea what it is.


> I think you're probably right and it would be fine
> on all the flashes I listed and the 400T.
> For $50.00 however I'll get a lot of peace of mind.
> I don't use the 285s on the shoe anyway so it's no
> hassle to use the isolator.
> 
> Don
> 
> > -----Original Message-----
> > From: Paul Stenquist [mailto:[EMAIL PROTECTED]
> > Sent: Saturday, December 18, 2004 10:08 AM
> > To: [EMAIL PROTECTED]
> > Subject: Re: Isolators_Was- "safe" Flash Sync Voltages
> > 
> > 
> > I use my Pentax AF 400T and my Studio Pro mono lights on the *ist D 
> > constantly. I must have more than 1000 firings without incident.
> > Paul
> > On Dec 18, 2004, at 10:49 AM, Don Sanderson wrote:
> > 
> > > Here are the isolators I'm refering to:
> > >
> > > http://www.adorama.com/WNSSPC.html
> > > http://www.adorama.com/WNSSHSHS.html
> > >
> > > Don
> > >
> > >
> > >> -----Original Message-----
> > >> From: Don Sanderson [mailto:[EMAIL PROTECTED]
> > >> Sent: Saturday, December 18, 2004 9:32 AM
> > >> To: PDML
> > >> Subject: "safe" Flash Sync Voltages
> > >>
> > >>
> > >> All the talk about 'safe' flashes to use on the D got
> > >> me a little concerned.
> > >> The last thing I want to do is damage the poor thing. :-(
> > >> I took some measurements from various units that I use.
> > >>
> > >> Here are the sync pin voltages I measured from
> > >> various flash units:
> > >>
> > >> Pentax 200T                4.65
> > >> Pentax 280T                7.18
> > >> Pentax AF-360FGZ           3.01
> > >> Pentax AF-500FTZ           3.55
> > >> Vivitar 285HV              5.80
> > >> Vivitar 285                6.24
> > >> Yake M-110 Studio Flash    8.09
> > >>
> > >> I no longer have an O'Scope so I can't measure any
> > >> 'spike' voltages present at the sync pin when fired.
> > >> These spikes are what could do real damage.
> > >> In a properly designed trigger circuit there should
> > >> be no spikes but I can't prove their presence or
> > >> absence on these units.
> > >>
> > >> As far as I can see the ist D manual only mentions these
> > >> flash models:
> > >>
> > >> 240,330,360,400,500.
> > >>
> > >> The 360 and 500 I measured are the lowest sync pin voltage
> > >> of the lot. This leads me to believe that the newer Pentax's
> > >> are designed to operate at lower, (sub-TTL logic) levels.
> > >> I'm reasonably OK with the 200T but the Yake and the 280T
> > >> really scare me.
> > >>
> > >> There is such a thing as a "flash isolator" available.
> > >> It fits in the hot shoe and protects the camera from
> > >> overvoltage/spikes at the sync pin.
> > >>
> > >> I will be buying one very soon for the 285s and Yake!
> > >> I will also not be using the 280T on the D anymore.
> > >>
> > >>
> > >> Don
> > >>
> > >
> > 
> 

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