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DIY Housing ideas


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#1 rrodex99

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Posted 03 March 2012 - 08:00 AM

Hi.

I am new hereso first let me introduce myself. I am a diver first and a photographer second,and have been very pleased with the modest results obtained from my now ancient Olympus mju 400, but now see the need of updating.

Key requirements to improve on the shortcomings evident to me are, I think, bettermacro-focusing,( the visibility in Scotland, where I do most of my diving lends itself to shooting nudibracts etc); a lighting system to illuminate macrosubjects; RAW format to allow post shooting white balance adjustment, and imagestabilising for good measure.

All to beproduced on an affordable budget.

I have a minilathe and small milling machine and love to dabble so my first thought was tobuild my own housing. I have successfully built and modified led dive torchesand fancy a built-in ‘ring of light’ and shown by Packhorse here and on CandlepowerForums.

My initial thoughts are to follow a well trod path with a piece of aluminium tube, round or square, say 120mm dia with Perspex end plates and O rings.

Sitting 15mm behind the front cover I will fix a sheet of aluminium to act as a diaphragm and heat sink for a collection of LED’s and AMC 7135 regulators.

A hole willbe needed for the camera lens. To avoid all the reflected light the lens would be extended through a hole in the front Perspex sheet to a separate lens cover,with an aluminium cover tube.

All this should be straightforward to produce in a watertight manner.

About now youshould be saying, yes, but the tricky bit is waterproofing the controls.

By using a CanonPowershot camera and CDHK I can get all of my requirements for a camera and the ability to control all the functions via the usb socket.

By using a PICAXE microprocessor I can generate control pulses, using ‘schoolboy’ Basic programming.

To interfacethe picaxe I propose to use Hall effect chips. I have used these very successfully in my torches. A small 3mm magnet can precisely activate it through 3-5mm of aluminium without bother and can generate an input signal to the chip.

At its simplest I am thinking of having the magnet on a small finger ring and having 4 recesses on the outside of the housing. By placing the magnet in each of these in the required sequence I can run through a full menu of camera and light controls. An additional display screen could be added to aid navigation.

A bonus will be that the leds can be at a low power level and ‘flash’ at full power for focus and shooting

I hav ealready bought a cheap A590IS off ebay so can afford to experiment without fear.

My questions are

How thick do the end plates need to be?

How big does the lens cover need to be, should it be glass or acrylic and how thick?

How much illumination do I need? I am thinking in terms of say 4 Cree XM-L giving me around 1000lumen each. (quite often there will be zero ambient light)

Anyone see any insurmountable pitfalls?

Anyone already been down this route and can offer any short cuts?

Thanks

Rod


Edited by rrodex99, 04 March 2012 - 06:52 AM.


#2 Dupsbear

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Posted 07 March 2012 - 10:07 AM

Hello Rod,

I think your lack of response is because you have not given any parameters. You say, "How thick does XYZ need to be...." Maybe if you gave some working depths, then maybe we can help.

I would suggest that you find a good o-ring company where you can purchase the size o-rings you might need. Knowing the sizes of o-rings available will help you with your sealing design.

You mentioned that you have a milling machine. If you can mill an o-ring groove in your tube, you might find that the easiest way to make your housing seal. Check out retail housing manufacturers to see how they seal their housings; my Nexus housing has an o-ring groove on the front part of the housing and the back housing plate is flat. This type of seal is dependable and easy to make.

Your end plate sizes will determine how thick your end plates need to be. I made a housing for a Coolpix 990 with a back plate of 3/8" acrylic that proved to be too thin since I had a hairline crack develop at 90 ft. depth. My next housing had 1/2" plates that proved successful.

Knowing the expected size of your housing will also help determine the thickness of your end plates.

For ports, I would suggest purchasing a ready made port and adapting your housing to fit that brand of ports. Port production is hard, and just because the port seals, does not mean you will have good, much less, great images.

Good luck,
Barry

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#3 rrodex99

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Posted 07 March 2012 - 03:23 PM

Hi,

Thanks for you comments. I dive open circuit air so 45m is all I need.

My major dimension will be 120mm as that seems to be readily available and a reaonable size. I am not too worried about the O ring as I plan to get cord and make them up to suit. I have not done this before, but it seems do-able for this application where it is really just a gasket rather than a moving seal. Interested that 3/8" was not enough, this is just the information I need, I will look for 1/2" or next size up.


It is the port that concerns me most. Presumably it is easier to get the strength from acrylic vs glass , but will be be good enough optically, or are ther special grades?

I am afraid my budget will not stretch to one of your nice domed models, so I am just planning a flat port for now, but if everything else goes to plan I may look at upgrading in the future.

Cheers

Rod

Edited by rrodex99, 07 March 2012 - 03:24 PM.


#4 Dupsbear

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Posted 08 March 2012 - 12:45 PM

Hi,

My major dimension will be 120mm as that seems to be readily available and a reaonable size. I am not too worried about the O ring as I plan to get cord and make them up to suit. I have not done this before, but it seems do-able for this application where it is really just a gasket rather than a moving seal. Interested that 3/8" was not enough, this is just the information I need, I will look for 1/2" or next size up.


It is the port that concerns me most. Presumably it is easier to get the strength from acrylic vs glass , but will be be good enough optically, or are ther special grades?

I am afraid my budget will not stretch to one of your nice domed models, so I am just planning a flat port for now, but if everything else goes to plan I may look at upgrading in the future.

Cheers

Rod


I have tried to splice o-rings before and found the process hard to get perfect. Why mess around with a splice when you can get o-rings already made for very cheap? My thought is that you would be wasting your time and efforts to save $8, and if you flood your camera, you spent much more.

If you are going with a flat port, then use glass; a glass shop should be able to cut a piece to size and get you the strength you need. For domes, I stay with acrylic because of cost, being able to easily polish out scratches, and acrylic is closer to the refractive index of water.

Barry
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www.keywordworkflow.com

#5 RossNortier

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Posted 14 March 2012 - 03:41 AM

Hello there, for the Lens port, acrylic works very very well, it is unbelievably clear and more so, much stronger than glass... I have build a fibreglas surf housing before and I used a piece of 10mm acrylic for the port...

#6 tamas970

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Posted 27 December 2012 - 10:28 AM

Hi everybody! I am very new to this forum, thus cannot start a new topic. I am designing acrylglas housings for my land-use strobes. I just started to set up my underwater gear, based on an Olympus E-PL5 and being stunned by the price of underwater TTL strobes or housings for land-strobes. (I have two land-use strobes, capable of remote TTL anyway) Therefore, I am considering building my own housing based on the idea of a videographer fellow: http://www2.mrc-lmb....al/pdh/housing/ .

I modified the design a bit:

Posted Image

Long story short:
Material: Acrylglas, wall strength: 10mm (Lid: 20mm)
Semidome front profile (->the illumination angle of the flash doesn't shrink)
Communication: Toslink cable, I already tested, my Metz 50 fires perfectly using them.
Material weight ~1.2kg -> approx. 1kg lead is needed for neutral bouyancy.

I'll check the local workshops If they can make the shapes for me. Regarding leakage,
I am optimistic: The video housing I've just linked started to leak at 160m...

Edited by tamas970, 27 December 2012 - 10:29 AM.


#7 FanchGadjo

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Posted 28 December 2012 - 03:00 AM

Have a look at this french topic regarding building a flash housing :
http://forum-photosu...php?f=38&t=8167

#8 tamas970

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Posted 28 December 2012 - 06:21 AM

The topic for the first version looks more informative: http://forum-photosu...php?f=38&t=1317

However, this also needs a custom made dome (=need a workshop anyway). I would keep the design simple
and minimize the number of glued/sealed interfaces. Ouch, forgot to mention: The housing would consist of only
two parts, a "bell" or "dome" including its skirt and a lid. Only the lid-side needs sealing.

I just need to find a workshop, that can cast the "bell".


Have a look at this french topic regarding building a flash housing :
http://forum-photosu...php?f=38&t=8167



#9 FanchGadjo

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Posted 28 December 2012 - 09:54 AM

Thanks for the tip ! I had not seen it as I am quite new to this forum.

#10 tamas970

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Posted 28 December 2012 - 01:41 PM

My french is limited, what I decoded they use a PVC tube for the cylinder, claiming it is stronger than Acryl - true, but there is
the hassle fitting the acrylic dome to the front.

Regarding material I am considering plexiglas or lexan (polycarbonate) - I have to do some more research on the materials.
Transparent PVC is slightly blueish (counterproductive for uw photography).

For me, the most problematic part is the sealing: I would like to produce something, that is safe between 100 and 150m.
As a first thought I designed the lid contact surface to be conical to distribute the sear force a bit - here I don't have any
example from the UW photo business, just some experience from the university. However, there we had special conical
O-rings too, unfortunately they are not available in such a large size.

#11 rrodex99

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Posted 12 February 2013 - 01:58 PM

Hi guys,

As this thread has been brought back to life and ‘ring flashes’ are a regular topicI thought I would post the results of my endeavours.

I have now built and used the camera housing I proposed, with a few refinements but quite a change to the housing.

The housing now is based on a 10mm aluminium sheet on which the camera and leds are mounted and forms the base for an acrylic sandwich.

The front cover is acrylic, recessed to make space for the leds and drivers; the camera lens passes through a black Perspex tube (to prevent light pollution) with a flat port of 4mm Perspex.

The back of the housing is made of two sheets, 25 and 20mm thick. All the sheets are sealed by 4mm O rings made to measure from cord, and the whole thing clamped together with 5mm bolts. By milling out of solid sheet the only glued joint is the lens port for which I used super glue.

Camera and light control is via four ‘hall effect ‘sensors activated by a small (3mm) magnet within the white bobbin which runs within a cruciform guide. The signal from the hall sensors is processed by an 18M Pickaxe chip which controls the lights and also the camera using the usb socket and CHDK hack. At present the lights come on for a second to allow the camera to adjust, once focus is achieved 5 shots are taken in a burst before the lights go off. In low light dives the leds can be set on but at a low level as a general purpose torch.

The 4 XM-L leds are driven at 2.8A by AMC7135 boards, each board has 8 x AMC 7135 and by having both leds and batteries as 2S2P only two driver boards are needed.

The only penetrations are for one diy conventional push button to turn on/off the camera, and a hole to operate an on/off switch for the micro processor with a matchstick which is sealed with an o ring and screwed plug.

The whole thing has been designed ‘on the hoof’ as proof of concept and working test bench so is still undergoing development before I make a more polished and smaller Mk 2. Current development plans are to replace the sprung battery holder (4 no 18650 Li-on) with a soldered Li-Po battery pack and fit some optics to the leds to gather the light better.

I have taken it down to 30m without problems and also confirmed the design of some of the components to be good for 100m by finite element analysis.

If anyone want to try finite anaysis, it can be done for free with Z88Aurora. I modelled the back cover in SketchUp (free) and used a plug-in to export in .STL.

My photography skills still need polishing but the camera is up to the job it was designed for.

At present I have used the Powershot in P Mode, the camera seems to chose f2.6 and exposures between 1/1000 at iso400 and 1/125 at iso 125, depending on the subject, so there seems to be just about enough light being generated and it is nice and even.

Since last diving I have fitted some 60 deg optics which appear to give me extra stop or two but the light does not cover the full field of view in wide angle. I have also extended the programme to give full control in Aperture priority or any other mode.

February is not a good time to dive in Scotland so it will be a few weeks before I can test it further.

Rod
Posted Image
Posted Image

#12 Ronyx

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Posted 12 February 2013 - 03:25 PM

That is a nice piece of design. Congratulations