Monday, 15 July 2013

DIY Underwater Video light for my Sony Action Cam

Previously I had mounted a simple dive light to the side of my goodman handle which had the video camera mounted on like this...


But the issue was, the reflector in the torch was creating a hot spot in the images.



So I set out to remove the reflector from the torch and move the LED to as close to the lense as I could, to create a wide angle light. Basically copying the off the shelf video lights on the market.

So, I bought another one of the Cree lights ( as per my blog) and modded it like this...

Disassemble the light and remove the LED module...




The LED pcb on top can be lifted upwards, it has some play in the red and blue wires but not enough to bring the LED to the front of the torch, so these need to be lengthened..



I unsoldered the original wires from the LED pcb, found some new cable of the same colour ( multi-core) and soldered them up like above.. I also put some insulation tape over the connections. New length is only about 1.5 inches..

To hold the LED pcb close the lense, I cut a 40mm length of steel angle line and tie wrapped the LED pcb to it, placing a good squirt of heat sink compound between the two.



The steel strip is only held in place by virtue of it being a tight fit.

Inside the head there is an edge where starts to get narrower, I measured this edge to be 40mm approximately in diameter, so if I cut something of that length it would sit on the edge rather falling in.

I'm working on a neater solution with a 40mm washer instead but it was a good prototype solution.

I was worried that the LED would get too hot given the small piece of metal now acting as a heat sink and relatively low contact area with the side of the torch but its not had a problem.

The next major problem to overcome is, the reflector is used to hold the LED module against the battery to make the circuit. Removing the reflector, basically makes the module and battery fly upwards and out !

To overcome this, I glued the module into the head with J-B Weld.

You need to be very careful here, because glueing the LED module in the wrong position will stop the magnetic ring selector working i.e. no turn on.

To get round this slight issue, mark inside, the position you will want to glue it in. I turned the ring into the ON position, pushed the LED module down and turned it until the light came on constantly. Then I marked on the LED module and the inside of the head like so..



This gives you the correct position.

To fix it in and make the circuit with the battery underneath, I removed the spring on the underside and glued  the mating edges.


Pushing it in, lining up my marks and leaving overnight to set.

Once the glue has set, you can place the LED back in the head, on its new base and tighten up the lense/bezel.



In my 'prototype' the metal plate is a snug fit so once pushed in it isn't going moving too soon. I didn't need to do much else.




Results:

Went diving this weekend, 2 dives to 28m ( 91ft ) and 20m ( 65ft ) , no issues with leaks so happy and the light spot is gone !


Tompot Blenny on the MV Aeolian Sky.  I think this was taken around 23m, vis was 2-3m and distance 1m to subject.

About 1m - 1.5m to subject.

Some observations..

In the first image above, the light is cut off in the very corner, which i think might be the furthest corner from the light, I reversed the image because the Tompot decided he wanted to stay upside down which doesn't make for a good picture so the bottom right in fact the top left in the real life, which at opposite end on the rig from the light. My only thought is to move the LED closer to the lense.

Even a second torch would sort that one out or mount higher up on the handle.

The second image shows some backscatter i.e. the muck in the water. It was pretty bad but maybe positioning the light further away/up would sort that out ?

I like the look of the Light For Me setup for the GoPro with its butterfly/adjustable clamps on the side...If I can find those I might invest in them.

On this dive and those ambient light conditions, the light only had a range of 1.5m approximately, beyond that it, it looses it's effectiveness so you need more power! Maybe a second light on the other side of the rig. But I do like the size/ease of use of this set-up, it fits in a pocket so no special entry requirments.

The light became a bit loose in the clamp, will need to put some inner tube around it to give it some grip.

Further bits:

Remembered the camera was on Underwater scene mode, 120 degrees ( widest angle the SteadyShot works on) and 1920×1080/30P(HQ).

More thoughts:

After 7 dives with the new double light configuration, in varying UK conditions, green/dark good/bad vis, I've observed the following...

1) At Max setting, two lights give an adequate light on the scene at a range of 1m (3ft), this is in darker waters. Night dive might be better further away, lighter / closer to the surface your going to need to get very close to make a difference, say 0.5m ( 1.5ft).

2) Backscatter, the lights are quite close to the camera and like a stills camera its suffering from backscatter. Strangley its ok at the short ranges <1m but as u get further away from the target its pretty awful. Its a shame because the form factor is really neat and not bulky at all. But you can't live with it, its too annoying. Only solution I can think of is to move them off the goodman handle with arms like the Light For Me design. Need to see whether that suffers from the same issue before investing in those arms.

3) Torches slipped in the  brackets. Thicker rubber tubing required.

4) The 3rd torch i purchased, I couldn't remove the pill to make the modification, maybe it needs a little more force but I avoided this by using the ones i can mod for use as video lights..












Cree Dive light - Magnetic Ring...

The mode selector was getting stiff on one of the Cree dive lights I bought. I tried to move back and forth to loosen it up and it jammed completely, oops. Right, apply some more force and the whole assembly fell off.

NB To remove the ring, you need to disconnect the head from the body and turn the ring to the off position as there is a groove for the magnet to slide through. Then slide off with a little force, the magnet might run on the o-rings.

It looks like this :-


On one side there is a small hole to contain a spring and ball bearing ( that sits on top).


On the opposite side of the head is a groove for the magnet.

There were signs of rust around the magnet and the hole so maybe the spring / ball bearing are rusting...

Reassembled the whole thing quite easily. Might take it apart again to oil it.

Update after 30 odd-dives :

The ring now has completely free movement, no notch. The spring has completely rusted up and fell to pieces when I removed it. The ball bearing was fine.



Its too loose underwater like this as it keeps turning itself off, so to provide some resistance to the ring movement, I added a piece of inner tube which seems to work...







Thursday, 27 June 2013

SONY HDR-AS15 Action Cam

My second Canon Ixus 75 flooded again, the plethora of Go-Pros when diving and a recent trip to Scapa Flow seduced me into the world of video... As per usual, instead of following the herd I tried not to go to the default route of a go-pro 3 and choose the Sony action cam. The lense quality, sensor low light capabilities and price brought me to this device. It doesn't have same level of accessories as the go-pro but thats fine...

http://www.sony.co.uk/product/cam-action-cam/hdr-as15


I also bought a spare battery, charger and underwater flat ported door from Sony.. You need a flat port for diving.. google it..
Purchased from John Lewis Stores £199, Amazon £20 and ebay £35 for the door pack.
Action Cam Replacement Doors — 2 Pack
Model number:  AKA-RD1




To  mount it, I used the provided flat surface clip on mount, tie wrapped to a goodman handle. This was in turn secured to me by a retractable lanyard clipped off on my right chest D ring.





Tie wraps (T&B) and not cable ties, are 2mm width for extra strength. Two each side of the mount.




Two tie wraps on each side, going through the holes in the goodman handle and the mount, crossing over to give extra strength.

Retractable lanyard.



To protect it when I jump in, I keep it in a Bowstone pocket on my belt and then remove once in the water. Its always clipped off to the right chest D-ring.. I thought I would need a bolt snap on it for extra security but i've not used it yet.



Its a bit fiddle to get out of the bag but it works. I think thats the bags fault!

Lighting

As my first trip was going to be deep and dark ( like most UK dives tbh) I added a light to the goodman handle.

It was a bit of a lash up and the angle bracket that the light was attached to, seriously rusted... so the mark 2 is shown below. This uses, from ebay...

EPDM Rubber Lined P Clips Hose Pipe Clamp Cable Wiring Metal & Stainless Mikalor, 30mm stainless steel and a M4 X 12 A2 SOCKET CAP HEAD SCREW HEX ALLEN KEY BOLT A2 STAINLESS + Bolt.







I also updated the firmware to the latest version, this gave it more shooting modes but more importantly, introduced the underwater scene mode, essential! 

The biggest issue with this setup is the spot from the light shows up too much on the video, it needs to be diffused. I tried a plastic opaque top from somewhere in the kitchen but it doesn't diffuse enough..





I had the diffuser on a detachable bungey so that I could use it as a general torch but I never did remove it underwater....

This is a frame from the video with the light on full power with the diffuser. As the camera has no viewfinder, its a bit of suck it and see. The torch does have a number of power settings but this didn't seem to remove the spot, just reduce its intensity.




This was my torch shinning from the left ( wrist mounted) which is useful for lighting from the side, its like painting the light..



Here is a picture with mostly natural lighting ( beam from left is faint) , its probably a cloudy day, 26m depth... Its the Hull/Deck of the Dresden...




Next quest is for a better method of diffusing the light. Maybe remove the lense and just have the LED "bare" or another material in front...? Watch this space...

Some initial observations :

I thought the flat port was quite obtrusive and might cause a leak if it were knocked, but so far so good.. after a week of fairly abusive behaviour its ok.

In the 170 degree mode ( wide angle), I noticed I could see the flat port lense and a bit of image distortion at the periphery which annoyed me. I think you need to stick to 120 degrees underwater. Maybe blue water diving would be ok but in green/dark. I also found my primary light caught the edge of the port and caused a flare mark.

Battery life is quite impressive, I did 6 cold water dives without changing the battery, I only changed it after that to be safe at 40% ish. This is one thing I had heard about the GoPro 3 that sort of put me off.

Although I bought mine 3-4 months after the firmware upgrade, the one I purchased from the store was old firmware i.e. didn't have the underwater mode. Its not big deal but just don't get disappointed the mode is not there initially, download and install, easy.

Accessories, well there not as prevalent as the GoPro fittings but it does have a standard tripod mount which opens the door to quite a bit. I used the supplied quick release mounts to attach to the goodman handle.

GoPro humidity pads fit inside fine. In fact there seems to be quite a bit of space around the camera ( 2mm ;).

The wireless feature is a novelty, I don't think I will ever use it, there is a version without wifi which is cheaper so that might be a better bet. 

Price, i like, it cost me £199 from John Lewis and another £35 for the door pack.  Given the environment you takes these devices into and their propensity to flood ever so often, I'm not laying out mega bucks...

I've put some sample videos on my Youtube channel..

http://www.youtube.com/user/johnohuk2

Or 

Vimeo 

https://vimeo.com/user19212157

A new firmware version was released in June which I didn't notice, just loaded it and have yet to get it wet, new version is v3.0.0, previously I was running v2.0.0.

Update:

Just got back from a Red Sea liveaboard..... Northern Wrecks and Reefs... Dual light worked a treat, really brings out the colours on the reef... limited range mind, maybe 1m max in good conditions...but definitely worth it because just a little light is needed to turn from a dull blue into something else..

https://vimeo.com/90581529

I'll try to put some of the wreck penetration videos up soon...



Tuesday, 25 June 2013

Greisinger GOX 100 - Oxygen Analyser for Diving

Found this on the internet and decided to give it a go... Its significantly cheaper that the most common analyser ( Analox O2EII Nitrox Analyser ) and only slightly more expensive that a homebrew kit so it seemed a good idea.



Greisinger GOX 100 T Oxygen Meter with Sensor











Details from their website...

Greisinger GOX 100 T Oxygen Meter with Sensor
Highlights & details
  • For gaseous oxygen
  • Automatic temperature compensation for greater accuracy
  • Inc. thermometer
Description
This compact Greisinger GOX 100 T Oxygen Meter with Sensor measures the oxygen concentration in gas mixtures and air. For the best the results the actual measurement of the oxygen takes place at the tip of the included sensor. The unique design of the sensor the device has to be calibrated at regular intervals to obtain accurate measuring values. When the sensor is used up, the device will detect this at calibration and the sensor element hast to be replaced before the start of the next measurement.
By means of the integrated hold-function, the MOD-Display (max. operating depth) and a specialized sensor, it is optimized for the testing of diving gas mixtures (such as NITROX).
Features
  • Min, max value storage
  • Cheap sensor element very easy to replace
  • Sensor evaluation for assessment of the sensor status
  • Simplest calibration on air
  • Configurable automatic OFF function
  • MOD-display (indicates the maximum permitted depth with the measured oxygen mixture).
Included in delivery
  • Sensor with 1 m Cable
  • Hose adaptor
  • T-item
  • 1battery (9V block)
  • O2 oxygen sensor GOEL 370
  • User manual.
The device corresponds to the essential protection ratings established in the Regulations of the Council for the Approximation of Legislation for the member countries regarding electromagnetic compatibility (2004/108/EG). Device meets EN 61326-1:2006, Additional fault: <1%.
Technical data
Accuracy± 0.1 % O2 (± 1 Digt)
Weight150 g
Power supply9 V battery pack
Resolution0.1 % O2
Measurement rangeOxygen concentration: 0.0 – 100.0 % O2
Dimensions(W x H x D) 67 x 106 x 30 mm

I'm glad i made a handsfree bungy attachment so that I can just attach the sensor to the valve, as I've only got two hands.. 







The case is not waterproof. An otterbox/Peli would be better. It survived as I was on a hardboat and there wasn't a great deal of water on the deck... but I can imagine on a Rhib or wet day it won't do unless you put in the cabin/dry bag. I just left it in my mesh bag on the deck.

A nice feature was a hold reading button and a MOD function, basically tells you the MOD of the current reading.

It worked without issues and I was happy for the price..







Tuesday, 28 May 2013

Review 80M Waterproof Underwater 1800 LM CREE XM-L T6 LED Diving Flashlight Torch

Purchased one of these off ebay...



Put a bolt snap on it and went diving... took it to 24m (75ft)., 8 degrees C ( 46 F)..


Results, well it worked during the dive no problems... nice tight beam and about 20-30% brighter that my old UK Light Canon 10W HID. Going by previous lights it looks like ~900 lumens?

However, after the first dive, it had drops of water in the lense... groan...

Stripped it down, left it to dry, greased up the lense O-ring ( which was bone dry) and went back.. this time no problems... 24m depth again. 

One bonus of the strip down is that i've lost the SOS mode. The pill needs to be rotated to match the magnets in the outside ring...I switched the mode selector ring to ON and then rotated the pill till the light came on, then closed it up..

Here are some pictures...










Some closeups of the o-ring sitting on a "ledge".

The lense sits on the o-ring.



I'm sort of happy with it, I'll go through all the O-rings and grease up, making sure all the pieces are tight. Also make sure all the o-ring surfaces and threads are free from loose metal/dirt etc...

Some more pictures...





Some further observations...

The multimode isn't as bad a I first thought.... you don't have to cycle through all the modes every time you switch it on and off.. For instance, if you have it on Full power and just want to turn it off and on again and retain the full power mode, just wait 5 seconds before turning it back on again. If you do it more quickly, it will change mode and go down to the next lower power setting. 

I measured the current on full power, it takes 2.2A with a fresh battery. So at 4.2V its 9.24 Watts.

I had a look at the control board PCB with a view to remove the modes but I didn't understand it enough to come up with a solution. It has one main controller chip ( 8 pin ) in the centre and 2 hall effect sensors on the perimeter of the PCB. It also has space/PCB tracks for 2 more, these are not populated.

So, 4 sensors, each one has a track going into the controller, with +Vcc and GND, leaves two for outputs..

None of the chips had identification numbers on.

There is another 4 pin power device but without taking the PCB out of the base I can't see it or probe it...  

I suppose I could remove the controller chip and put in an ATTiny chip of my own but as i'm going diving next week I want it to be in one piece.

A bit more..

Take care to hold the body of the torch and not the head when you take off the end cap changing batteries OR changing mode/On/Off underwater, the bezel/body connection are too easily loosened and you could create a leak.

Update...

After 14 dives ranging from 41m to 17m in 8 degrees water, I managed to unscrew the bezels by accident and both flooded. Again, dry out and tighten and back to normal. A suggested solution to this was to use a thread lock type product, so i've ordered some Loctite 243 and will see how that goes..

Another Update..

Applied the thread lock ( Loctite 243) to the bezel threads on the head, like so... Tightened the head up. Dived again and didn't flood but only 9m depth dive.... I'll update some more when I get more depth.

Unscrewing it after the dive was not an issue, maybe put a little more on that the small blob in the photo. < Yep works..>...




£3.50 from Amazon.

Update : Bought a third one for the video light project, noticed a slightly different label on the side and it didn't come with the inner plastic battery adapter, otherwise it looks exactly the same. Need to verify its ok with another dive.

Another Update:

Dived to 4m so suspect its ok. I've not got a deeper dive for a month so will feedback then. Tried to disassemble it and noticed: 

The plastic insert/battery adapter was not there, a 16850 battery will still work it just flops about a bit when your tightening up the end, still makes a connection. I had some plastic tubing which I cut down to the same length ( 8cm length, Outside diameter 23mm) as one of the others and it was fine.



The reflector doesn't want to come out nor the LED pcb either. A gently push didn't dislodge it, so might swap the heads around with my older ones to make another video head or give it a whack with a hammer..!
Otherwise this third one, looks ok...

Beam shot :


More shots of the body, the end cap does fit on the head unit... Not sure its water tight but does make a solid seal... Plenty of beam shots on my Vimeo channel...https://vimeo.com/user19212157




Simple goodman handle for the light, found some webbing from an old dive bag, tie wrapped it on. I clip the bolt snap onto my computer bungee to keep it straight. Usually do this once i'm in the water.

Update:

I have three of these now, 2 have glass lenses and 1 has an acrylic lense. None have flooded since I put the loctite thread lock.

1 glass lense one has done 30 dives to a max of 42m ( 137ft).
Another glass one has done 12 dives to a max of 30m ( 98ft)
The acrylic lense version has done 10 dives to 30m.

Run time on an Xtar 2800ma 18650 battery is around 55 mins continuous , which is two dives for me ( its not on all the time).

Two have been converted to Video lights are per my blog.

The only nasty bit is the rotating control ring, this can either go stiff OR very loose... Still works but the spring and steel ball don't like salt water. See other post on my blog for the control ring issues..

The loctite thread lock will need to be applied again soon as I can feel the bezel coming loose again on one of them.

I've not changed the original o-rings. They look awful but so far they have held out, just greased them up.

Another Update:

Someone noticed there was a current drain when in the off position, I checked it with a multimeter and sure enough, looks like around 50mA. I'd not noticed battery going dead when I left them in but I tend to charge them before every dive trip.

I mentioned in another post that the control ring is completely free now i.e. no notch. This mean it slips around quite a bit. The solution is to place a tight bicycle inner tube around it seems to work ok.

Beam shots in the pool: