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rtrski

Member Since 13 Jul 2007
Offline Last Active Today, 10:23 AM
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Topics I've Started

The world's bulkiest TTL optical trigger....

23 May 2016 - 02:59 AM

So, home-made solution to an antique problem, although variations might be useful in some cases still....

 

I am shooting with a rather old Sony A55 SLT, from the very first generation 'translucent' mirrored series that is currently capped by the A99 full frame (which I use above water).  The SLT series has electronic viewfinders.  I have an Ike housing but elected to use Inon Z240 strobes vs. Ike 125/160/161 for their smaller size.

 

Unfortunately, in these very first SLTs, the A33 and A55, Sony 'helpfully' had the viewfinder mimic predicted exposure results to give the photographer a "what you see is what you get" type intuition.  Unfortunately, in an underwater housing with manual strobe sync, that means it 'helpfully' turns black with settings like ISO200, f11, 1/160th underwater because the camera doesn't know you're getting significant light boost from a strobe.  AF module works fine - but you're shooting blind.  Using the EVF tunnel or the rear screen makes no difference.  UW photogs are a tiny market but this same effect hampered studio photogs with radio triggered flash, so for the next generation SLTs (starting with the A65) Sony offered a 'setting effect off' option in the menu so the EVF brightness is always tied more to ambient light not exposure prediction.  (Same option is available in all the A6xxx and A7 mirrorless offerings now).  Will help me when I upgrade but for now....

 

The only other fix is TTL - as long as the camera knows a strobe is indeed present, f11, 1/160th or so isn't going to black out the viewfinder.  I do have a DS51 which I use when shooting macro (and have a fiberoptic half-ring flash arrangement I printed up posted about elsewhere).  Finally getting a dive trip again this year to a location I want to shoot wide angle with the Inons again, so decided to do something about my dilemma.

 

Hence - a cover plate to use the DS51 as the light source for optical sync to the Inon z240 sensors, but without having the light from the DS51 influencing the shot by just letting it blap out all over.  Printed a cover and 'adaptors' for the sensor caps on the Inon to accept any TOSlink audio S/PDIF cable.  At like $6-8 from Monoprice vs. the much more expensive underwater manufacturer fiber optic cables, I can afford to keep a few spares around expecting the inevitable corrosion around the FO tips (since these were clearly never intended for saltwater immersion).  Cable in the picture is a Monster TOSlink cable I had laying around and look forward to drowning (purchased many moons ago before I knew what a**hats they were as a company....)

 

First pic of connection (two FO links available at the strobe face, only one currently in use) below.


"Newbie" action cam for UW on wrist - Sony or GoPro?

03 February 2016 - 12:21 PM

Wife wants to wrist-mount an action cam of some sort and just point around at stuff underwater while we're diving; I'm usually shooting (stills) with a DSLR rig and strobes (sig).  Can't afford to upgrade my rig for this trip so it's getting a little long in the tooth... but can justify $500ish to keep her happy with my habit for the future upgrade. ;)

 

Don't necessarily care about 4K, do want 1080p (shouldn't be an issue these days), won't likely be providing dedicated lighting or mounting on a tray or whatnot (maybe a reasonable LED flashlight in the other hand), and she's not exactly up to task loading thinking about changing settings and all.  It'll pretty much be preconfigure on the surface and just hit 'start' and 'stop'.  She just wants to show me snippets later on of all the subjects I'm missing while I attempt to get that one dang shot right, and/or post to FB for her friends/family.

 

Read a bit about Sony having WB issues, but perhaps otherwise better stabilization and the like than the GPs; of course Sony you have to buy an extra housing for dive depth while the GP's is already good down to 100ft or more...but I think the net pricing comes out about the same.  (100ft is more than plenty for our purposes; just recreational divers.  Might be nice to have a close-up option if the cameras in the housings don't already allow relatively close focus. 

 

I know this is a way amateur question for most in this forum, but if you had to choose for just a poodling around type filmer...which would be your recommendation, and why?

 

Location of this trip is Dominica, which tends to pretty clear water, somewhat darker on morning dives (sites on western side of island and high slope), but nice subject matter to preserve wider angle if possible.  My preferred DSLR setup is either 8-16mm rectilinear (on APSc) behind a minidome, don't tend to shoot anything between that and 100mm macro.  So that's what's set her expectations of what she might capture with an actioncam.

 

(Open to other brands beyond Sony and GoPro I s'pose, but don't see any need to really go total KIRF...)