Photos captures memories, but can only do so with sufficient light.
So I decided to build a ring light, a lens mounted flash that distributes light uniformly over the subject. This ensures that the subject is captured with immense clarity. This is certainly a must-have for avid photographers.
Read along and I hope that after this instructable you will have enough knowledge to be able to construct your own one.
Step 1: Design Choice
When starting with this project I remembered someone else's project I saw on a website a few years ago and started my research there. https://www.instructables.com/member/DIYPerks/
Their project sparked my own idea. I saw several things which I wanted to improve on. Firstly the 10W LED's would have generated to much heat and consumes a lot of power. They also looked a bit unstable in the way they were mounted and the manner in which they were connected would would result in total failure if only one LED burned out. My design negates these issues.
I wanted a ring-light which was aesthetically pleasing, lightweight, robust and able to support the LED's sufficiently. I liked the idea of using high powered LED's but didn't want to risk 10W LED's so I went with 3W LED's as they are easier to power and will produce less heat but still provide ample light for the photograph. Battery power was a given as portable photography is important so I went with a SLA battery but this could easily be changed to LI-PO or LI-ON which would work better.
My first design was base around a hardwood base with sufficient airflow to help cool the LED's. I then decided to look into aluminium as substrate and in the end settled on it as a base. The aluminium proved to be lightweight and will help dissipate the heat from the LED's sufficiently.
Connecting the light to the camera posed a problem as you cannot just attach it around the lens of the camera and have it fit nicely. So the solution I used was to glue a clear lens filter to the ring light and have that screw on to the front of the lens.
Step 2: Part List
18 x 3W White LED's
1 x LM2596 Volateg regulator
6 x 3W led driver circuits (each one powers 3 LED's)
1 x 10Kohm Potentiometer
1 x 12V 2.3aH Sealed lead acid battery (could be any other 12V battery pack)
2 x Pairs of 5.5mm Male and Female connectors
1 x Clear lens filter (choose a size which fits onto your camera, just remember to change the CAD models accordingly)
Some M3 bolts and nuts
Step 3: Manufactured Parts
1 x Laser cut 2mm thick aluminium base plate
1 x 3D printed back ring
1 x 3D printed back cover
1 x Controller box (hand made or 3D printed)
Step 4: Mechanical Assembly
The ring light:
Start by adding a tiny bit of thermal paste to the bottom of each LED and the placing them onto the aluminium base as seen in the first picture.
Fasten them to the base with M3 nuts and bolts using the slots provided and the notches in the LED's. Then use a sharp pointed object to score the aluminium all around the LED specifically in the notches to ensure the epoxy has something to grip onto(refer to the photos to see the final product).
Mix up some 2 part epoxy, be careful as it sets very quickly so mix only enough for a few spots at a time. Place small blobs of epoxy in the notches with the scratched aluminium and allow it to dry overnight. In the morning you can remove the bolts, the LED's are now fixed to the base.
Next mount the filter to the aluminium base. You will notice that there are some notches in the base to ensure it mounts well with the filter. So firstly line up your filter with the hole in the base and mark off the notches onto the sides of the filter. Then sand the filter on those spots so that the epoxy will have something to grip onto. Place the filter into the hole and ensure that it is flat with the front of the base and that it is the right way around (the threads of the filter should be facing backward). Apply epoxy to the notches and all around the filter, be careful not to get any epoxy onto the filter or its threads. To ensure this didn't happen, I used some duct tape to mask off the threads and filter before applying epoxy. Let it dry overnight and the filter will then be securely connected to the base.
The Controller: (This can be built any way you desire)
I constructed the controller box by layering some acrylic on top of each other and the drilling out the center before making a bottom and top to keep everything inside. This could also be 3D printed or made out of wood. It must just be big enough to fit the voltage regulator and the potentiometer but still be small enough that it is easy to carry around. Drill a hole into the bottom to fit the potentiometer though and a hole in either side for the wiring to connect it to the battery and light.
Step 5: Electrical Assembly
The ring light:
This part is quite tricky as it requires you to keep track of the polarity of the LED's and doing so in a cramped workspace. The LED's are wired in series in pairs of 3 to a LED driver as can be seen in the image. All the drivers are wired in parallel to each other and a connector is then added to the parallel inputs of the drivers. (You will have to modify the CAD sketches or just drill a hole in the side of the 3D printed part for the connector to go to the outside of the casing)
Wiring the LED's are done by pushing 2 wires through the holes in the aluminium base and then soldering it to the front of the LED. Try to keep as much of the wiring at the back of the base and inside the 3D printed enclosure to ensure tidiness. Screw on the 3D printed back-plate and that is the ring light done.
Put a connector's wire through one of the holes in the controller box and solder the leads to the inputs of the voltage regulator. Take a 1m piece of wire and put it through the other hole and wire that to the output of the regulator and solder a connector to the other end. Desolder the potensiometer on the board and use pieces of wire to solder the bigger potentiometer to the board instead. The Potentiometer is then glued through the hole in the box and all the electronics stuffed inside and closed up.
Solder the remaining connector to a piece of wire and crimp some connectors to the other side of the wire which fit the battery terminals and connect them to the battery.
NOTE: Ensure that you keep track of connector and wire polarities throughout the system so that they all fit together without blowing everything up.
Step 6: The Finished Product
Admire your product.
Step 7: Results
These are just some of the photos I took with the ring light.
Step 8: Improvements
Interchangeable lens mount so that the light can fit onto other cameras with different sized lenses also.
A different type of battery which is smaller but still capable of delivering the power needed.
3D print the entire light base with clip in hooks to hold the LED's.
3D print the controller housing.