I think this is a great invention. Would something like this be available with a device, that can shift + and - ? I know these (without the isolator) are necessary for some digital cameras. I guess this is why my *ist D won't work with the studio strobe outfit.
Jens Bladt mailto:[EMAIL PROTECTED] http://hjem.get2net.dk/bladt -----Oprindelig meddelelse----- Fra: Don Sanderson [mailto:[EMAIL PROTECTED] Sendt: 18. december 2004 16:49 Til: [EMAIL PROTECTED] Emne: Isolators_Was- "safe" Flash Sync Voltages 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 >
