Tuesday, 3 November 2009

Make a DIY Macro Ring Light

One thing about macro photography especially in its extremes, is that you are always pressed for light.  At high magnifications, the depth of field becomes very narrow(very little of the subject is in focus). The only way to overcome this is to close down your lens aperture. A smaller lens aperture results in a greater depth of field allowing more of your subject to be in focus. However, the con of this is obvious, a smaller aperture means that less light can get in and your images will be dark.

So, how do you overcome this? The most obvious way is to have artificial lighting, the most common of which is to use a flash. The built in flash of cameras become quite useless in macro photography as the subject is very close (often just millimetres) to the front of the lens, and the light from the flash is completely blocked out by the lens itself.

One can resort to using external flashes which mount on to the camera, but once again, the lens is likely to get in the way. Also since light is being cast on the subject from one direction, causes the formation of deep shadows which are undesirable in images.

The best option for artificial lighting for macro photography is using a ring flash. A ring flash, basically mounts on to the front of the lens, thereby providing the optimal lighting placement and also, since the light is coming from all around the lens, it does not cast huge shadows in any one direction.

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Unfortunately for me, my budget does not stretch to cover a ring flash such as the Sony HVL-RLAM which can cost more than £300. I therefore decided to make my own.

While searching the net for instructions and ideas, two projects caught my imagination and I decided to borrow from them. Check them out here and here.

Firstly, I bought a camping light from ebay. This product is available from china and is usually shipped in 4-5 days. They come incredibly cheap and can be had for under £5 including shipping cost.

 ring light 123 

These lights have 48 white LEDs and take 4 AA batteries. They operate with a built in press switch.

ring light 125 ring light 126

The housing lifts off to reveal the insides. Inside is basically two printed circuit boards with the LEDs, connected to the battery terminals, via the switch.

ring light 127

If it fit, it would have been simple enough to put the lens through the central hole and use it as a ring light. However, the hole is too small. I therefore decided to widen the hole. The problem was that that if i widened it, the switch was in the way.

ring light 135

The switch was a flimsy piece of kit which almost fell apart as I removed it, so I decided to get rid of the internal switch entirely. I therefore unsoldered the wires and connected the wires to a new piece of wire, which was then taken out though a hole (that i made) in the back housing.

   ring light 131

ring light 143

The wire was then connected to an external battery box (also available on ebay) which also housed a built in switch.

ring light 132 ring light 133

finally, the central hole was made wider.  Although I initially, very clumsily hacked my way though, I soon discovered that the easiest way to cut though the plastic was with a hot soldering iron. (be careful not to have melting plastic over your carpets and burn you house down – if thats your talent it would just be better to invest in a genuine branded ring light).

Finally, while the plastic was still molten from the cutting, I squeezed a 55-55mm reversing ring at the front., so that when the plastic cooled, it would sit tight. This would allow me to screw the light into the front of the light.

ring light 134   ring light 137

finishing sculpting was then accomplished with the hot soldering iron. Although it doesnt look pretty, it sits exactly how i wanted it to and works perfectly fine.

 ring light 139   ring light 142 

Finally the hole in the back housing was widened. This was made larger than the front one, in order to accommodate the wider area of the lenses which include the focus and aperture dials.

ring light 144

Here is the ring light in testing stage off the camera.

ring light 145

Finally, the light gets mounted onto the lens by screwing it into the front lens thread.

ring light 146 ring light 147 

…and here it is in action:

ring light 149 ring light 150 ring light 151  ring light 153

The above images were taken at night and hence don’t look too bright, but it is really quite bright. I find it is adequate in supplying a fair bit of extra light, especially in poor light where any bit of extra light is a boon. However, in average lighting, it doesn’t make much of a difference. The LEDs are bright but ideally I would have preferred something brighter but softer. I think it might be worth adding some sort of diffusing material to soften the sharp glare of the white LEDs

Another con is that, the LEDs seem to be set back fro the periphery of the lens by a fair bit.Thereby, there is still scope for a bit of shadow to be cast. However, I had fun making it and it is cheap as chips compared to an expensive macro ring light, and worth having for indoors macro lighting.

I hope this post might inspire other to try their own builds. Do drop a comment on your opinions.


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