SB105 electronic scheme

I didn't say you needed to turn the laser off before the strobe received the
trigger
signal, only that it needed to be turned off very quickly thereafter, and
that just
disconnecting the power source from the laser might well not be quick
enough.

The SB-105 has a much wider beam (20 mm w/o diffuser, IIRC) than the lenses
typically used for macro
photography (28mm to 105 mm, occasionally 200 mm), AND the strobe is usually
farther from
the subject than the film plane, so, for macro, the strobe only needs to be
pointed in generally the right
direction, especially if you put the diffusers on (15 mm coverage), which
gives a nice sof t light.
Also, with macro, it's really easy to see where the strobes are pointed
because the whole
rig is in your field of vision (not true for wide-angle with nice long
arms).

One more thought: If you have two strobes, different colored lasers would be
a good idea.
Red on the left, Green on the right, would match boat running lights.

"James Connell" <jconnell@gci.net> wrote in message
news:11cj19vj7cjmaa7@corp.supernews.com...
> Chuck Tribolet wrote:
>> If you trigger on the "FIRE" signal, you better be able to shut down the
>> laser immediately (10-50 us max), and if you
>> just turn off power to the laser, that's probably not good enough because
>> it may continue to run for a bit
>> on power stored in in its caps.
>
> Well I'll tell you what - if you can tell me a way, from inside the
> strobe, to figure out when to shut off the laser BEFORE the strobe
> receives the trigger signal, I'll by you a boat dive.
> It takes a little while for the strobe to fire too you know, Likely enough
> to get the laser shut down, and even if it's on for a micro sec. or two
> after the shutter opens it won't show on the image. Many people make a
> Remote TTL trigger that works fine both tiggering and shutting a strobe
> off remotly and keeping well inside exposure limits, I see no reason the
> same can't be done with a solid state laser.
>
>
>
>>
>> The "READY" signal won't work because it may not go off at all when
>> closeup in TTL mod, and
>> even if it does go off, it won't be until the strobe has already been on
>> for a while.
>
> the ready (or 'Confidence' signal) would be (maybe, this is simply
> speculation) for turning the laser back on, not off. I don't think it'll
> work, I prefer a timer, but it's an option that can be explored.
>
>>
>> But once again: If you point the strobe right at the subject, your
>> wide-angle shots will hve
>> excessive backscatter.
>>
>
> so we have decided it won't work for wide angle, big deal, turn it off
> manually Before you shoot WA or ignore it, this is just you pissin on the
> idea and has no real merit in the discussion.

Chuck Tribolet wrote:

> I didn't say you needed to turn the laser off before the strobe received the
> trigger
> signal, only that it needed to be turned off very quickly thereafter, and
> that just
> disconnecting the power source from the laser might well not be quick
> enough.
>
> The SB-105 has a much wider beam (20 mm w/o diffuser, IIRC) than the lenses
> typically used for macro
> photography (28mm to 105 mm, occasionally 200 mm), AND the strobe is usually
> farther from
> the subject than the film plane, so, for macro, the strobe only needs to be
> pointed in generally the right
> direction, especially if you put the diffusers on (15 mm coverage), which
> gives a nice sof t light.
> Also, with macro, it's really easy to see where the strobes are pointed
> because the whole
> rig is in your field of vision (not true for wide-angle with nice long
> arms).
>
> One more thought: If you have two strobes, different colored lasers would be
> a good idea.
> Red on the left, Green on the right, would match boat running lights.
>

I built a laser system in 1998 for macro use. It wasn't for aiming the
strobes however, it was for NonSLR cameras to find the correct focus
/center point. ( I got the idea from someone who built a similar rig
that used the small 2 AAA pen lite flashlights, that never worked
becuase of beam spread). The sytem worked pretty well, on dry ground, I
never got it out of the crude prototype stage and sealed up for
underwater testing. And yes it is more than possible to shut the lasers
off in time.

It didn't frame the shot for you like a wire macro framer will but it
didn't scare the hell out of the subject either. It would also have
given better choices of composition than a wire framer could. Another
concern at the time was shining 2 lasers into a fishes eyes from that
small distance.


I must admit I don't see the need for this strobe aiming system - that's
why they have modeling lites in strobes.
If a SB105 doesn't have a modeling lite than scrap it for one that does.
IMHO the SB105 is not that great a strobe as it is.