> Foxy,
> What folks are trying to tell you is that the F280 on an OM-2n will not
give
> anything close to conventional FP results.
Agreed. The FP bulb is much brighter. And takes time to turn on.
> When a standard FP bulb is triggered, it takes a while to reach peak
output.
> That is the function of the FP setting.
> When you use this FP mode on an F280, it will simply fire before the
shutter
> opens. Therefore, no flash exposure.
The F280 flash duration in super FP mode is between 1/40 and 1/25 second,
depending upon who's data you read. The shutter speed must be chosen so the
F280 exposure time is longer than the FP prefire time and the shutter speed.
This is about 20 milliseconds. So if the F280 output time is between 25 and
40 milliseconds, I have between 5 and 20 milliseconds to take the photo.
This is 1/200 to 1/50 as my longest shutter speed, again depending upon
who's data is correct.
> I'm not even sure that the FP mode can be triggered on the F280 unless it
is
> triggered off the special contacts that only a 4T has.
The FP is not a computer. It has two terminals and a common. When the FX
trigger terminal is held at one potential (I cant remember, but have his
data somewhere), it will trigger. The other terminal allows a quench, but
who needs it? The 4Ti controls exposure by shutter speed not flash duration
in this mode anyway.
> Buying FP bulbs may be expensive, but they will work. I'm not at all
> convinced your idea will begin to produce usable results.
So by triggering the F280 from the FP socket, I have a limited range of high
shutter speeds. Probably greater than 1/125. By providing a 10 millisecond
delay, no problems. I'll need to connect to the F280 through a modified
hotshoe or lead. An some small elctronics. Easy stuff really.
I would prefer to use bulbs, but exchange rates mean thay cost too much. And
I can buy an F280 locally.
Hey, no laws of physics are violated here. Trigger by some very simple
external electronics.
Foxy
< This message was delivered via the Olympus Mailing List >
< For questions, mailto:owner-olympus@xxxxxxxxxxxxxxx >
< Web Page: http://Zuiko.sls.bc.ca/swright/olympuslist.html >
|