Need help to make UW Photo - FOCUS light (Flood/wide Angle) with auto off sensor

Hi

I want to make some sort of focus light for underwater photography - NOT a focusable light , basically a lamp with a wide beam (min 60˚ but upto 120˚+ is fine) doesnt need a long throw so much as usually used pretty short range.
something like this http://www.bigblue.com.hk/ff-1x5-afo.html or http://www.backscatter.com/sku/fe-ledfl.lasso with maybe bit more lumens/power
needs a sensor or auto shut off so when underwater flash (strobe) fires then this actually turns off for a second or two.

Or Suggestions of a Lamp i can buy and simply add a sensor ?

Does anyone have any ideas where to start - where I can buy a sensor or this parts and what bulb (Led) is best that does not have a hotspot and a wide beam - and any ideas with driver wiring etc.
Can either mod a existing dive torch or make a drop in module change something but need l need help really with the electrics other bit i should be able to sort out ..
I have had a really good search online and here also but couldn't find much on DIY Focus lamps with the auto Off feature ..

Thanks in Advance all
cheers Mark

An XML with an aspheric lens can give you exactly the flood you require.
You could fit a light dependent resistor/transistor setup to turn the light off, though I'm not sure how quickly it would do it. What camera are you using? Do you have a pre-flash that could be used with a simple microcontroller and sensor to turn off the light for a preset time?

I was wondering, can you make multipe LEDs produce a smooth beam with a single aspheric?

350xfire said:

I was wondering, can you make multipe LEDs produce a smooth beam with a single aspheric?

Click to expand...

Haven't succeeded yet

matey - not really sure if you need to go to the trouble of switching it off....
if it is dark enough to warrant a flash and a focus light, i'm tipping the light from the flash
will swamp whatever the focus light can produce...
(i have a focus light made with one of these http://dx.com/p/10w-7000k-700lm-white-led-emitter-metal-plate-9-11v-65692?item=39 which is not visible in any flash pictures)

cheers,

sharkbite said:

matey - not really sure if you need to go to the trouble of switching it off....
if it is dark enough to warrant a flash and a focus light, i'm tipping the light from the flash
will swamp whatever the focus light can produce...

Click to expand...

+1 to that.


I'd just use bare LED's with no optics. With a XR-E this will give you about 90 degrees coverage. XP-G,XM-L or most of the others will give you about 120 degree. Either should be wide enough. Also it would produce a nice even beam of light which is going to make it hard to notice under all the light from the flash.

Also unless the camera has some sort of pre flash signal, getting the light to turn off before the flash goes on will be an issue.

Use enough LED's and you can also use it as a macro light, video light or focus light!

Hi All

Thanks for the suggestions so far - I actually posted a Question about needing this sensor in Underwater Photography and some people say dont need as the Flash/strobes cover all the light other people say maybe , But really if using a Snoot on the strobe for example (which limits and focuses the light) or very low power to just get enough light on whats needed ! then will get to much light and over exposure ?
I was just trying to see if it was Feasible to make, Can you buy those sensors ?? as the Fisheye Fix (2nd link on first post) is only about a $40 retail torch ?

No Camera does not have a Pre-flash , I just have a Olympus E-620 in olympus Housing and X2 Inon s-2000 strobes connected with Optical Fibre , with a fisheye Fix focus light (which is sometimes not enough which is why i want to upgrade it) - But cuts out when Strobe fires for 1 second !

I was thinking that the sensor must be a cheap part that you can wire in with Led's in the head of the torch ?


Sharkbite and Packhorse - Can i ask what Torch did you use(for the Base) and where you got it to make your focus light ??? (or did you make from scratch?), as Have a couple of Chinese Led dive lights and took out reflectors and worked ok but as they had Quite deep reflector the sides of the torch made still quite a spot , (no hotspot without reflector though) so i would imagine you need a Torch with a Very shallow reflector in which you can take out or where the LED is close to the Glass ??

Thanks Mark

Matey - i made mine from scratch as a video light -

heatsink is a spent deodorant can housed inside a bit of plumbing

- it has no reflector - no hotspot - LED is right up against the glass so quite adequate coverage.

The light is very helpful for focussing, but is not even close to the flash for brightness - there is no chance of over exposure,
especially if you have a TTL flash, which will reduce the flash output anyway.

Well I have made several....

http://www.candlepowerforums.com/vb/showthread.php?324078-6000-lumen-video-light-set-up
https://www.candlepowerforums.com/threads/227965
http://www.candlepowerforums.com/vb...0-Video-light&highlight=packhorse+video+light

But just about all the other lights I have made could be modified for the same purpose by simply removing the optics and moving the LED's closer to the front lens.
http://www.candlepowerforums.com/vb...ive-LIghts-By-Packhorse&p=3248146#post3248146

Thanks packhorse and Sharkbite

Given me a Lot to think about , Unfortunately where I am living at the moment I don't have many tools to build stuff (just few hand bits and dremels) So cannot really get into Making stuff from scratch , thats why was asking about converting something else .

Packhorse _ your lights Look great But all a bit big for what I class as a Focus light as Mainly Umbilical , where I need a small compac light i could mount on the hot-shoe of the Camera Housing - All your lights would be great when Videoing and I have a Couple HID niterider videolights Bought back in 2001 but still work great and I made a Mount system that holds the Battery under the housing, Also Have a Hartenberger Umbilical Light which use when Nightdiving (one day that needs converting to LED)

Anyway Thanks for help Guys
Cheers Mark

Matey - i don't even have a dremel! (luxury)

made this one with a hacksaw, , a file, a soldering iron and a hand drill....

http://www.youtube.com/watch?v=2Z-AS-gtQ2I&feature=plcp (nice clear view of it at 2:40

all bits except the LEDs and driver bought at bunnings and woolies.

This was a fair to middling torch when i made it, but is now stomped on by a magicshine,
so i replaced the LED withe the one from DX mentioned above...

This one is large, due to the fact i have to use 8 alkaline AA's to get the requisite 12 volts....
but you could use 4 18650s and make it half the size....
having said that this one is lighly positive, so no drama mounted next to a flash...

Lesson learned from the aussie plumbing screw on inspection caps - replace the o-ring with something a bit larger - the standard one will leak eventually.

You could also get one of those magicshine jobbies for around $80 and remove the reflector.....thats a "no tooling" option which could work...

Hi sharkbite

Thanks for that , great torch - to big for a camera focus light (just need smallest and fairly bright without hotspots and wide beam) - great to know you can build a torch with simple parts though. I have actually ordered a couple chinese ebay dive torch's now going to see if can play with. trouble is most small lights have long reflectors ,
Dremels - cheap Chinese copy bought in India 12 years ago , still works like a charm (probably buy on ebay these days or Bunnings)

What parts did you buy in Wollies for the torch ..??

anyway Thanks Mark

Promise you wont laugh?

the heatsink.

I found that the spent can of a certain brand of gents spray deodorant fits almost exactly into some 50mm Aussie drain pipe.
The bottom part is indented almost perfectly to fit the DX LED....
the can is very thin, and has a large surface area to dissipate heat, even though its completely enclosed in plastic.
Some heatsink compound between the case and the can also helps, as well as stopping it moving around.

i know what you mean about the reflectors being a bit long...
If you are getting some cheapo drop-in type lights - try this....
a little bit of wet-and-dry to rough up the surface of the reflector...(i removed the shiny bits and went back to bare aluminium for one of mine)
reduces light output somewhat, but provides a much more even and dispersed beam...
or if you dont want to damage it - sticky tape a pringles lid over the front...

You have got me thinking though - the first home made torch i ever built is Juuust big enough for 4 AA's and a p60 drop in....
given for a focus light you only really switch it on while focussing, heat dissipation wont be an issue....
might build one meself!

cheers,

Hi Sharkbite

No Laughing , have used many household items over the years to fix or make things still puts a smile on my face ..
Sorry took a while to come back ... Have a Couple cheap Chinese Dive lights from ebay and from those and research Best thing i can fathom is you just dont need a reflector and actually put the LED very very close to the from Glass - without a reflector LED's give a very even bean with no hotspots (thanks to people on this forum for info) Inc Packhorse above. wish I had a Lathe now as could just make a Longer Heatsink for the chinese dive torch, resolder the LED to front and leave rest as is .
tried taking reflector out but most cheap torch's have a Longish reflector so just by removing makes a wider beam with no hotspot but the LED is to far back in the torch head still not making wide enough..
Mark

globalmark said:

Hi Sharkbite

wish I had a Lathe now as could just make a Longer Heatsink for the chinese dive torch, resolder the LED to front and leave rest as is .
..
Mark

Click to expand...

Matey - how about just extending the length of the original heatsink....

A trip to jaycar will get you some heatsink adhesive (quite strong )
http://www.jaycar.com.au/productView.asp?ID=NM2014

and an aluminium control knob....

http://www.jaycar.com.au/productView.asp?ID=HK7020

a 16mm diameter one is 14mm "long" and should bring the LED forward quite a bit....

Just take the LED off, glue it to the knob, and glue the knob where the LED used to be....
wire it up - and bobs yer aunties live in lover!

cheers,