Vivitar 283

My trusty old Auto Thyristor 283 has ASA settings from 25 to 400. Is there
a way to adapt this flash unit to ASA 800?

Camera is (now) a Nikon FM3a (used to be a Spotmatic). The simple answer
is to shoot 400 and below and be happy. I have been using a Nikon SB28
with this camera but would like to go back to the 283.

Ralph

pumper hinkle wrote:
My trusty old Auto Thyristor 283 has ASA settings from 25 to 400. Is
there a way to adapt this flash unit to ASA 800?

Camera is (now) a Nikon FM3a (used to be a Spotmatic). The simple
answer is to shoot 400 and below and be happy. I have been using a
Nikon SB28 with this camera but would like to go back to the 283.

Close one stop compared to what the flash set at 400 says (i.e. close
lens to f/11.0 if the flash is set for f/8.0)

pumper hinkle wrote,on my timestamp of 28/12/2008 5:38 PM:
My trusty old Auto Thyristor 283 has ASA settings from 25 to 400. Is
there a way to adapt this flash unit to ASA 800?

Camera is (now) a Nikon FM3a (used to be a Spotmatic). The simple
answer is to shoot 400 and below and be happy. I have been using a
Nikon SB28 with this camera but would like to go back to the 283.

Ralph

You might burn the ttl flash circuits in your FM3A with a
Vivitar 283:
http://www.botzilla.com/photo/strobeVolts.html
Watch out, I did fry the TTL flash in my fe2 with a Metz
that had incorrect voltage...

Noons wrote:

You might burn the ttl flash circuits in your FM3A with a
Vivitar 283:
http://www.botzilla.com/photo/strobeVolts.html
Watch out, I did fry the TTL flash in my fe2 with a Metz
that had incorrect voltage...


The 283 started out life as a high voltage sync strobe. Sometime during
production, they were switched to low voltage sync. I expect it was when
the 285 was produced, they were all low voltage.

The way to tell if you have one new in the box and am sure that
the box belonged to the flash in it, is to look for a black dot on the
label (I think it was an end).

The only way to be 100% sure is to measure the voltage with a voltmeter.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

Well, unfortunately I don't have the original box, just a vinyl case. I
had bought this unit used at a camera shop several years ago after my
original 283 had developed an incurable problem. The serial number of this
unit, if that is any sort of indicator, is 1948082.

How does one measure the voltage? A volt meter across the flash terminals?
This is something I've never considered before.

I would like to use the 283 but not if there is any possibility of damaging
the camera.

By the way, what is high voltage and low voltage considered to be?

Ralph

"Geoffrey S. Mendelson" wrote in message
...
Noons wrote:

You might burn the ttl flash circuits in your FM3A with a
Vivitar 283:
http://www.botzilla.com/photo/strobeVolts.html
Watch out, I did fry the TTL flash in my fe2 with a Metz
that had incorrect voltage...


The 283 started out life as a high voltage sync strobe. Sometime during
production, they were switched to low voltage sync. I expect it was when
the 285 was produced, they were all low voltage.

The way to tell if you have one new in the box and am sure that
the box belonged to the flash in it, is to look for a black dot on the
label (I think it was an end).

The only way to be 100% sure is to measure the voltage with a voltmeter.

Geoff.
--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM

Duh. I think I was just tired when I posted my question. Sure. Halve
the f-stop. Duh again.

Ralph

"That Rich" wrote in message
...
On Sat, 27 Dec 2008 22:38:50 -0800, "pumper hinkle"
wrote:

My trusty old Auto Thyristor 283 has ASA settings from 25 to 400. Is
there
a way to adapt this flash unit to ASA 800?

Camera is (now) a Nikon FM3a (used to be a Spotmatic). The simple answer
is to shoot 400 and below and be happy. I have been using a Nikon SB28
with this camera but would like to go back to the 283.



What up Ralph,

Just half (2X the f stop) the setting on your camera relative to the
flash.
A little experimentation goes a long way.

Cheers,

RP©

pumper hinkle wrote:
Duh. I think I was just tired when I posted my question. Sure.
Halve the f-stop. Duh again.

The convention in this NG is to not top-post. Please post your replies
below other replies.


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In article , pumper
hinkle wrote:


By the way, what is high voltage and low voltage considered to be?

Ralph

IIRC, my 283 was over 200 volts, maybe almost 300 between the centre
post and the outside. Switch it on, and wait for it to say ready, then
measure the voltage. A safe level for the cameras is considered to be 5
or 6 volts max.

--
Jim

pumper hinkle wrote,on my timestamp of 1/01/2009 3:34 AM:

How does one measure the voltage? A volt meter across the flash
terminals? This is something I've never considered before.

A voltmeter is not enough, you need to measure
a spike and normal voltmeters don't usually do that.
Use either a sampling voltmeter or an oscilloscope.
If in doubt, just use one of the known safe flashes.



By the way, what is high voltage and low voltage considered to be?

If you read the site I posted below, it's noted there
what the safe voltage is for all Nikon ttl-flash cameras.


"Geoffrey S. Mendelson" wrote in message
...
Noons wrote:

You might burn the ttl flash circuits in your FM3A with a
Vivitar 283:
http://www.botzilla.com/photo/strobeVolts.html
Watch out, I did fry the TTL flash in my fe2 with a Metz
that had incorrect voltage...

Noons wrote:

A voltmeter is not enough, you need to measure
a spike and normal voltmeters don't usually do that.
Use either a sampling voltmeter or an oscilloscope.
If in doubt, just use one of the known safe flashes.

Not really. If the flash uses direct triggering, high voltage will be
present on the sync contacts when the ready light is lit.

If it stays low (3-6 volts), then there is some sort of triggering
circuit inbetween and it is safe.

It's always wise to check out the documentation on the camera, many cameras
that have sync contacts on the hot shoe can only handle low voltage,
but can handle high voltage on a PC socket.

It's not 100% sure because sometimes you find a camera with a PC socket that
was added later. They are NOT high voltage safe.

One thing to keep in mind is that they way to find out is NOT!! to try it.

Geoff.


--
Geoffrey S. Mendelson, Jerusalem, Israel N3OWJ/4X1GM