Jump to content


Photo

Why are there so few housing / strobe combo with hotshoe connection?


  • Please log in to reply
8 replies to this topic

#1 JDelage

JDelage

    Triggerfish

  • Member
  • Pip
  • 48 posts

Posted 18 January 2014 - 09:10 PM

I know, the answer to "why" is always "money".

 

Let's rephrase that: what makes it so expensive for housing and strobe makers to develop combos that would allow true TTL via a camera's hotshoe?

 

Thanks,

 

Joss



#2 Stoo

Stoo

    Wolf Eel

  • Member
  • PipPip
  • 162 posts
  • Gender:Male

Posted 18 January 2014 - 09:16 PM

It's partly that, but in my limited experience TTL just doesn't work very well in the water. I don't know why, but shooting in manual, really isn't very hard and offers much more opportunity to be creative...



#3 Cerianthus

Cerianthus

    Tiger Shark

  • Member
  • PipPipPipPip
  • 653 posts
  • Gender:Male
  • Location:Hasselt, Overijssel, Netherlands

Posted 19 January 2014 - 11:39 AM

Sorry but are you both forgetting that one of the least expensive brands Ikelite gives TTL ( via hotshoe) on all dslr housings and their strobes. TTL works fine for macro.
Gerard

My photo's on flickr
Crop the world ! (Using Canon 20D, 60mm, 100mm, 10-17mm FE, Ikelite)

#4 Cary Dean

Cary Dean

    Sting Ray

  • Member
  • PipPipPip
  • 277 posts
  • Gender:Male
  • Location:Southern California

Posted 19 January 2014 - 11:48 AM

Sea and Sea is releasing in housing TTL for the newer cameras.

It is camera specific Canon/Nikon - various models, and the unit

is slightly different depending on the housing model.


"The sea, once it casts its spell, holds one in its net of wonder forever."
Jacques Yves Cousteau

#5 bvanant

bvanant

    Giant Squid

  • Team Wetpixel
  • 1571 posts
  • Gender:Male
  • Location:Los Angeles (more or less)
  • Interests:Science, photography, travel

Posted 21 January 2014 - 09:56 AM

Digital TTL is quite different than film TTL. The technology of film TTL (at least Nikon's version) was simple to implement via a simple connection. Modern eTTL and iTTl are very different with much of the electronic bits in the flash, not in the camera. If you are willing to house a name brand strobe then getting true eTTL or iTTl is quite simple but Nikon and Canon (correctly, I think) consider their TTL protocols as proprietary.  That is why there are converters (Matthias) and sTTL emulations of TTL.

 

Bill


Bill
Canon 7d, Nauticam, Lots of glass, Olympus OMD-EM5, Nauticam, 60 macro, 45 macro, 8 mm fisheye, Inon, S&S, Athena Strobes plus lots of fiddly bits.
www.blueviews.net


#6 rtrski

rtrski

    Great White

  • Member
  • PipPipPipPip
  • 1001 posts
  • Gender:Male
  • Location:Texas, USA
  • Interests:Slowly learning digital photography and underwater digital photography. Like drinking from a salt-water firehose... ;-)

Posted 21 January 2014 - 11:27 AM

It's not necessarily that it's expensive - as someone else already posted, Ikelite provides it as a rule on all DSLR housings, providing conversion circuitry to interpret / provide communication from the camera for TTL out to their strobes.  The question is one of getting the same TTL functionality without the hotshoe connection.

 

Inon strobes provide optically-slaved TTL mimickry - they'll perfectly match a camera's onboard lamp in terms of preflash, mainflash, and quench.  So...why have the electronic cabled connection (which must penetrate the housing, thus provides an extra potential leak path) to the flash?  If the camera "thinks" the lighting is being provided by its own onboard flash and is still able to 'control' the external unit by saying "got enough light- quench now!" the user hasn't lost anything aside from perhaps some battery life in the camera since you are firing the onboard flash (and the need to provide good internal light protection in the housing so the onboard light doesn't illuminate the interior of the port, etc.)

 

Factor in whether or not TTL really "helps" in many cases and manual can be quite good enough, and you have your answer.  Different vendors have picked different paths to the end requirement - adequate control of external lighting - and only a few have decided to pursue a wired TTL route.


Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 105mm f2.8 DC Macro w/ Ike 5505.58 flat port or Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs triggered with DS51 for TTL mimicry, or DS51 alone with home-made ringflash assy for macro.

 

Topside, unhoused: Sony SLT-alpha99, Sigma 150-500mm + 1.4TC (Saving for Sony 70-400 G2), Sigma 15mm diagonal fish, Sony 24-70mm f2.8 CZ, Tamron 180mm f2.8 Macro...all the gear and nary a clue...


#7 JDelage

JDelage

    Triggerfish

  • Member
  • Pip
  • 48 posts

Posted 21 January 2014 - 12:39 PM

Relying on the internal flash means that we're using the camera's battery for nothing, as well as slowing down the maximal rate at which one can take pictures. Might not be that big a deal - I don't know, I'm new to UW photo.

 


So...why have the electronic cabled connection (which must penetrate the housing, thus provides an extra potential leak path) to the flash?

Edited by JDelage, 21 January 2014 - 12:40 PM.


#8 rtrski

rtrski

    Great White

  • Member
  • PipPipPipPip
  • 1001 posts
  • Gender:Male
  • Location:Texas, USA
  • Interests:Slowly learning digital photography and underwater digital photography. Like drinking from a salt-water firehose... ;-)

Posted 23 January 2014 - 07:49 AM

You've got it right - that is a trade-off.  You're still going to be limited by the external strobe unit recycle time if not using onboard flash, although admittedly those have much bigger caps and batteries and can fire off pretty darn fast when not doing full dumps.

 

To me the 'ideal' approach would be a mini, TTL-capable, hotshoe-connected unit internal to the housing that just flashes an LED in fast enough sequence to provide preflash, flash, and quench information optically to an external strobe, which provides optical mimicry of that sequence/duration.  Since that unit would only be firing off very small LEDs with enough light to illuminate a well positioned fiberoptic sensor, it shouldn't have a slow recycle at all and prevent firing off the camera as fast as your main strobe recycle allows, at least.  But no one has marketed something like that yet.  (A few of us have built very simple little LED-strobes that just use the 'sync' signal to trigger, but that means no TTL or preflash, just manual triggering.)  Wouldn't even have to mount "on" the hotshoe - Ikelite's TTL electronics baseplate probably has room for a couple coin batteries, a few more caps and a FET to fire off a couple small LEDs, and their clear housing would let you mount an external fiberoptic fitting almost anywhere without a penetration.

 

But right now there seems to be a few TTL circuit options (Ikelite housings cabled to their own strobes, TTL adaptors by 3rd parties), a few optical-TTL options (Inon and others mimicking onboard flash),  and a lot of manual options (both electronically and optically triggered).  It may not seem like many choices, but we're a pretty small market overall...


Current rig: Sony SLT-alpha55 in Ikelite housing, Sigma 105mm f2.8 DC Macro w/ Ike 5505.58 flat port or Sigma 8-16mm f/4.5-5.6 DC HSM behind UWCamStuff custom 5" mini-dome. Dual INON z240 Type IVs triggered with DS51 for TTL mimicry, or DS51 alone with home-made ringflash assy for macro.

 

Topside, unhoused: Sony SLT-alpha99, Sigma 150-500mm + 1.4TC (Saving for Sony 70-400 G2), Sigma 15mm diagonal fish, Sony 24-70mm f2.8 CZ, Tamron 180mm f2.8 Macro...all the gear and nary a clue...


#9 dpaustex

dpaustex

    Lionfish

  • Member
  • PipPip
  • 62 posts
  • Gender:Male
  • Location:Central Texas
  • Interests:Scuba. Photography. Mountains.

    What else is there?

Posted 10 February 2014 - 08:58 PM

Ikelite housings for Canon cameras have TTL.

 

The 5D Mk III housing has the newer TTL, also.

 

Works like a charm, WA, macro, supermacro.