70 replies to this topic

[aeromole]

[tamas970]

Thanks for sharing the pics, Pete!

 

What is the benefit of Hedvig's design vs the simple MOSFET version?

(Is there a circuit published somewhere? single LED would be fine for me...)

Only thing I can think of if the LED may not shut off in time and force the

 strobes to keep firing...

 

First I'll try replicating rtrski's design with an IR LED and some beefier batteries.

 

Tamas970

 

Sorry for the delay  in replying - been away for a few days.

 

The example of Hedwig's unit that I have seen was nice - much more sophisticated than the MOSFET version.  I did make it work by firing the LED directly into the fibre optic bulkhead connector, but did not fit it to the camera as it mounts on the hot shoe....and mine is already used by the camera pressure lead detector.

 

The MOSFET circuit I am using has 2 x 12V LR23 batteries in parallel, with the 4 high power LEDs mounted in series.  Hedwig uses 2 CR button cells of 3V each, and his LEDs appear to be in parallel.

 

Herewith pictures of my version.  One shows the batteries and circuitry mounted under the camera tray, the other shows the hot shoe connector with the wiring break for the flash, and you can see the 4 LEDs mounted on a board directly under the bulkhead connector.  Units are connected with computer plugs.  Wiring is rather untidy - I will make another one when I have a minute and tidy things up.

 

Pete

 

 

 

 

 

Ah, the photos failed.  I will try again.

Edited by tamas970, 24 June 2013 - 01:13 PM.

[aeromole]

Tamas970

 

You probably ought to ask Hedwig about the features of his design.  As far as I can see, the flash comes when the switch (ie camera hot shoe) is broken rather than when it is made, but this happens so quickly there is no problem.  The LEDs are also mounted in terminal blocks and are in parallel, so you can use more (or less) and adapt them easily.

 

The circuit I have used is the same as rtrski's instructions, though I didn't get it from him.  I've just used veroboard, rather than try to etch a circuit board.  It also just produces a single short pulse as the hot shoe circuit is made, so there is no problem with making the strobes continue firing.

 

Pete

[tamas970]

How much banding do you get at 1/320 and 1/400?

[aeromole]

The D90 will only sync up to 1/200 with a non-Nikon flash, though it will sync at faster speeds with a proper Nik flash.  Can't afford one of them....in an underwater housing as well!

 

At 1/400th, the shutter is covering perhaps 10% at the bottom of the image.  1/320th, it will be less but still visible at 1/250th.  

 

Pete

[tamas970]

My E-PL5 is similar or somewhat better. Stock fastest sync is 1/250 and using a non-communicating flash 1/320 is clear, 1/400 gives <10% loss with my inons, which is not necessarily a concern underwater. (I might even risk 1/500 with 40% loss in certain scenarios)

 

What kind of LEDs are you using? I am planning to order a couple white ones just in case the infared wouldn't work.

[Uli Kunkel]

Is anyone still making these? I would love to get my hands on one!

[thomas0686]

me too!!

[maxteo98]

Me too.

[owfotograaf]

I have them in stock but reading this topic first is a must before contacting me.

grts, Hedwig.

[006fazer]

Hi,

 

Did some one use it with a Canon 600D into a Sea&Sea RDX-600D ? Did i have some modification to integrate it ?

 

I have a Sea&Sea flash YS27-DX .... will i have troubles...

 

Best regards

Edited by 006fazer, 11 October 2013 - 06:55 AM.