Camera Flash

BeeJ

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Sep 24, 2012, 8:30:00 PM9/24/12

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I have two Nikon camera flash units that are old but working fine.
SB-24
SB-20

Need help with

1) flash shoe pinout functions?
i.e. how to trigger manually through the falsh shoe?

2) how to open the units without damage to clean interior dust?

3) compatibility with Canon EOS Rebel series cameras?
i.e. will not damage either if attached/used?
will flash on camera shutter release. say in M or A mode?
will provide TTL capability?

If not compatible with Canon, then I will do the math and use a
wireless radio trigger to trip.

Speculations do not help.

I could not find newsgroups that are more specific. If you know of
any, please let me know.

Thanks!

Cydrome Leader

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Sep 24, 2012, 10:33:31 PM9/24/12

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In sci.electronics.basics BeeJ <nos...@spamnot.com> wrote:
> I have two Nikon camera flash units that are old but working fine.
> SB-24
> SB-20
>
> Need help with
>
> 1) flash shoe pinout functions?
> i.e. how to trigger manually through the falsh shoe?

to fire the flash short the ground terminal of your hotshoe to the center
pin, or use the pc sync terminal if they have them. The SB-24 does have a
3 pin terminal for sure on the side.

> 2) how to open the units without damage to clean interior dust?

they're a real pain to to open and put back together again. It's not going
to be worth the effort. You said they work fine, leave them alone.

> 3) compatibility with Canon EOS Rebel series cameras?

no, if you just attach it to a canon.

> i.e. will not damage either if attached/used?

no damage

> will flash on camera shutter release. say in M or A mode?

This is questionable. With a plastic shim that insulates the other pins on
the flash, you'll be OK in manual modes.

> will provide TTL capability?

no. Canon digital bodies don't speak old-day nikon flash language. Those
flashes won't work on most nikon digital camera either.

> If not compatible with Canon, then I will do the math and use a
> wireless radio trigger to trip.

just use a stupid pc sync cable, or get a hot shoe to pcsync cable. this
will bypass the nonsense pins that will not communicate between a century
old nikon flash and a canon body. If you're comfortable with guide numbers
fiddling with settings, they'll still work fine.

> Speculations do not help.
>
> I could not find newsgroups that are more specific. If you know of
> any, please let me know.
>
> Thanks!
>
>

manual for the sb-20

http://www.lensinc.net/manuals/Nikon_SB-20.pdf

BeeJ

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Sep 27, 2012, 2:50:43 PM9/27/12

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Thanks for the info. I was able to clean without opening and the unts
are fully functional.

Is there a commercial shoe isolator that will provide the center
terminal only for connection? Or do I have to build one?

Any suggestions on wireless? Cowboy?

William Sommerwerck

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Sep 27, 2012, 3:57:48 PM9/27/12

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> Is there a commercial shoe isolator that will provide the center
> terminal only for connection? Or do I have to build one?

A well-stocked photo store should have one. The shoe and central terminal
connect to a short lead with a PC connector. (I bought one a few years ago.)

I'd recommend covering the bottom of the shoe with two or three layers of
Magic Mending Tape, then cutting out the area over the central terminal. The
tape keeps the extra pins from contacting anything.

BeeJ

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Sep 27, 2012, 4:26:30 PM9/27/12

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Afraid of the glue goo.
Maybe some thin polycarbonate.

I'll look for that shoe, I think I actuall hd one at one time so it is
probably in the camera cabinet.
But my flash does not have the standard PC connector I think.
It is a unique Nikon connector.
I have a cable for it but I hate to cut it up to use it.

Thanks for the input.

qrk

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Sep 28, 2012, 2:39:24 PM9/28/12

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Be sure that the voltage at the trigger contacts is 5 volts or less
(as measured from the center pin to common). Canon cameras can only
handle a trigger voltage of 5V, or less. Use a Hi-Z meter as the high
voltage triggers have a many megohm resistor in series with the
trigger terminal. Or, see
http://www.botzilla.com/photo/strobeVolts.html for trigger volages.

You can buy trigger cables for $15 and cut out the evil control wires.
Better yet, sick some Ethernet keystone connectors on the trigger
cable and you can extend the cable with a simple Ethernet cable.

If you go with radio triggers, either get good ones like Pocket
Wizards (many hundreds of dollars) or on the cheap side the Calumet
triggers get good reviews.
http://www.calumetphoto.com/eng/product/calumet_pro_series_2_4ghz_4_channel_wireless_trigger_kit_optimized_for_canon_flash_systems/cf0090
They are 2x the price of Cactus, and similar really bad Chinese
triggers. These Calumet Chinese triggers are more reliable.

Growl

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Nov 28, 2012, 8:23:48 PM11/28/12

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"BeeJ" <nos...@spamnot.com> wrote in message
news:k42cpl$sma$1...@dont-email.me...

If you do manage to open it up, WATCH out, the Capacitors in those things
store around 400 volts charged and even if they are discharged first, a
charge will build on the capacitors afterwards. If you short them out it
could damage the capacitors and will give a loud snap and a bright flash -
not recommended. Discharge them with a suitable resistor.

Shaun