Introducing the ProdMod Night Vlogger 160!
The following project is a neat way to make your own high powered video light to attach to your digital camera or camcorder. I called it the NightVlogger 160 after I read the term on this article of someone willing to use this type of light to allow him to take paparazzi style video at night. Vloggerazzi if you will. At 160 lumen it is very bright, in fact it is brighter than a 10W Halogen! It also fits in a slim AAA battery holder using only 3 AAA batteries. It projects a wide angle flood as opposed to a focused spotlight so you don’t have to zoom in to avoid the dark circle effect.
If you have followed my previous camera light projects you might have guessed this was the logical next step. I have made a 1W LED camera light before without showing you the details, but I think this latest one is a little easier to assemble and uses a very powerful yet very small Endor Rebel from luxeon to produce 160 lumens of light at 700mA. I also swapped the battery holder switch with a 3 position switch so that I can have two brightness levels, Low and High.
First take a look at this video to see what it can do and then lets discuss the How To.
Here is my classic bathroom video demo you may already be familiar with. Click directly on the video so you can choose to watch in high quality because normal quality is pretty bad. The clicking sound you hear is me switching from 90 lumen to 160 lumen. The camera will automatically close the iris when the light is too bright. But you can see the difference when the camera points to the ceiling which is farther away.
I like using the 4xAAA battery holder as my project enclosure because batteries are the biggest component and its convenient to have a cover and switch built in. I need to make room in the holder to fit my 1W LED, a heat sink, and resistors. So I sacrifice one of the battery chambers and re-wire it so that it now only accepts 3xAAA batteries. There is more than one way to do this. In a previous tutorial I moved the positive terminal with red wire over to the opposite end to complete the 3 battery circuit. But this time I decided to just cut off the negative spring which would be next to the last battery and solder a red wire to it. This tab and red wire is now your positive terminal that you will connect to your LED. You can also completely remove the positive tab with the red wire shown at the bottom of this photo. You should also cut a slot in the side of the holder for the LED lens.
Next I prepared my high powered LED. For this project I chose the Endor Rebel 7007-pwc-09-1 from Luxeon because it is very powerful but has a very low profile. I wanted to see if I can hide the lens of my LED inside the battery holder so I don’t have to worry about touching it or scratching it when its in my pocket. This also allows me the freedom to add a small piece of filter to soften the light or change its color temperature. I chose to buy the Cool White version because it is the brightest available and I can always color correct it using the white balance setting of my camera or place a CTO gel or filter over the lens.
Unlike standard 1W or 3W LEDs, this LED is so small that I highly recommend getting it pre-mounted onto an aluminum base so you have easy to use solder pads to connect your wires and know the LED is properly connected to the aluminum base for proper heat dissipation. You must use a heat sink with these high powered LEDs. In fact you need more heat sink than what comes with the LED which I will show you later.
The typical aluminum base is circular and about 1 inch diameter, usually called a star. It’s too large to fit inside our battery chamber so I had to cut it down to size. Another advantage of the luxeon rebel is that it is mounted off center, so I only have to make one cut and keep the LED down to one edge.
See the photo to get an idea of where I made the cut. I used a hacksaw and a miter. This is definitely tedious and a little dangerous. But take your time and keep moving the hacksaw until you are more than half way through. Then you can take a pair of pliers to bend the aluminum along the cut back and forth until it snaps off. Keep the piece you cut off, you can use this later.
You DO NOT need to solder wires to the LED’s heat sink at this point, I only did that for testing.
Low and High Switch Settings
This LED is rated for 90 lumens at 350mA and 160 lumens at 700mA. I thought this would be a great opportunity to create a video light with two settings 350mA and 700mA. To do that you need a 3 position switch. This feature is optional. You could just wire the LED directly to the built in switch of the battery holder and use the proper resistors to limit the current to either 350mA or 700mA or anything in between. But I can’t guarantee that the heat sink you are about to create and the way this light is designed will allow for the light to be powered with 700mA continuously without risking overheat. So a 3 position switch at least gives you the option to choose the minimum level of light you need. A 3 position switch I bought from mouser fits perfectly in the battery holder. I’ll list the part # at the end.
To use the 3 position switch you obviously have to remove the built-in one. If you remove the plastic surrounding it you should be able to lift both the switch and negative spring terminal out of the holder. You can cut the switch off the negative spring terminal but cut as close to the switch as you can. You will still need this spring terminal and the metal extending off of it to solder to your new switch.
The switch lever should pass through the hole in the battery holder, but it will need to travel more than the original so you have to cut a longer slot for this 3 position switch lever. About 1/8 inch in each direction should be enough.
This photo will show you how I oriented my switch in the case and which part of the switch I soldered to the negative terminal. The switch has 4 tabs. A group of three on the right and one on the left. The one on the left is not used at all. I attach the negative terminal to the first tab of the group on the right.
Wire the Switch and resistors
This next photo should show where to attach the other black wire and the pair of resistors. Through some testing I found that fully charged AAA NiMh batteries just barely generate 700mA of current when connected to the LED. So I decided not to use any resistors for the high setting.
**Caution!! this only worked out because I used 900mAH AAA NiMh rechargeable batteries. If you use different batteries or alkaline it will likely draw more than 700mA without resistors and you will burn out the LED prematurely. So if you use different batteries you should check the current with a multimeter to determine what resistors you need to limit current to 700mA for the switch’s highest setting.
For the low setting I wanted to limit the current to about 350mA but you can choose anything under 700mA. To select the proper resistor value for the low setting or high setting you can start with these calculations:
Resistor Value = Battery Voltage – LED Voltage / LED Current
Remember fully charged NiMh are 1.4V each. So for me it was 4.2V-3.5V=0.7V, 0.7V/.350A = 2 ohm
Power Rating of Resistor = Battery Voltage – LED Voltage X LED Current
For me this was 0.7V*.350A= .245Watts. You should use a resistor with a higher power rating for a safety factor.
Some LEDs will actually have forward voltages anywhere between 3.5 and 4V, so the calculation above wont always give you the value you want. It is best to test the current in the circuit with different resistors. Or use the above equation like I did with the worst case scenario, highest battery voltage and lowest LED forward voltage and consider you might end up with too high of a resistor value.
I ended up using two 2.2 ohms 1/4 Watt resistors twisted together which should yield 1.1 ohms but I measured 1.5 ohms. This might be the tolerance stack up? not sure. But it did limit the current to 350mA so I guess its a good reason to use a multimeter to double check actual values.
Attach the resistor group to the second switch tab on the right. You should also attach a long black wire to the third switch tab on the right.
Now you need to connect that long black wire to the other end of the resistor group. This will essentially leap frog over the resistors and provide maximum current to the LED for the high setting. This electrical connection is only made when the switch is pushed all the way to the end of its travel.
Now tuck the resistors into the holder and snip off the excess resistor legs. This is also a nice close up showing the switch connections.
Connect the LED
You now have one red wire and one black wire to attach the appropriate solder pads of the LED.
The manufacture of this LED and all high current LEDs clearly advise that you need to use additional heat sinks to protect the LED from overheating. I especially need it here since I plan to close the cover of this holder and not have much ventilation. You could use another piece of aluminum or copper as the heat sink, and you can use a thermal compound to link the LED heat sink to your extra one.
One convenient way to get a good heat sink is by using a VGA or RAM heat sink found in computer stores.
I found this CompUSA combo pack for only $8. It includes 8 square aluminum heat sinks which I can use for the LED, but it also has a cooling fan with copper heat sink and a tube of thermal compound. So I get to use those other parts for future projects. What is really great about the heat sinks is they come with thermal adhesive on their flat side. So you just peel off the paper an stick it to your LED.
Although the square heat sinks look like copper they are in fact aluminum which you will soon discover for yourself. In order to use the square heat sink you will have to cut it in half. You can use a hacksaw just like you did for the LED heat sink. You should only cut on the side with the fins opposite the adhesive tape. This prevents aluminum particles from sticking to the tape. Cut more than half way through with the saw. Then slice the paper and tape with a knife. And use pliers to carefully bend the heat sink along the cut back and forth until it separates.
If you cant find this CompUSA brand of heat sink you can also try looking for RAM heat sinks like this brand shown below. A little more expensive at $10 for 8 pieces. They are blue and a little smaller but you still have to cut them to fit.
Apply the heat sink to the LED
Before applying the heat sink you should use rubbing alcohol to clean the aluminum plate (heat sink) of LED. Then peel the paper off the heat sink tape and press firmly onto the LED.
When you push the LED module into the holder you’ll notice a bit of space behind it. Well it so happens that the piece of aluminum you cut off the LED initially is just thick enough to take up that slack. It’s great when you get to reuse something you otherwise would throw out.
Hole for Camera Mount
I got so carried away getting this LED in the holder I forgot to drill my 1/4 hole so I can mount it to the tripod mount of my camera. You should have space for it near the red wire, just be sure to keep your drill bit from cutting the wire. Here is a shot of the screw location and that extra bit of aluminum plate I stuck between the heat sink and plastic wall.
When you are done drilling holes this is what your light can look like.
Here is what it would look like with a thumbscrew.
Mount to your tripod
With a 1 inch set screw and a coupling nut you can make your own thumb screw with tapped hole allowing you to mount the light to your camera and tripod at the same time.
Mount to your Pro Camera or SLR Cold Shoe Mount
You can also get an accessory cold shoe piece and screw that onto the light as well so you can mount it on top of your SLR or professional or prosumer grade camcorders.
More Heat Considerations
As an extra measure of caution I later decided to drill a few holes in the bottom and top of the battery holder near the heat sink. This will allow some cool air to flow under the holder and exhaust hot air through the top. I used a small 1/16″ drill bit.
This LED outputs a cool white light. You might notice it, but most digital cameras today will automatically adjust their white balance so the light in your photo or video wont seem so blue.
But if you did want to change the color output of the LED you can use a filter gel. Notice how the LED lens is hidden behind the wall outer surface? This gives you the freedom to simply tape a very small piece of filter gel or color correcting gel right over the hole.
Here is a photo of a Rosco #205 1/2 CT Orange filter that makes the light appear warm.
You can buy sheets of this gel at a photography supply store for only about $6 and you only need a tiny sliver of it.
You can also use a white frost gel if you think the light output and cast shadows are too harsh. For this I recommend the Lowel ip-72 Frost Gel .
Note that any filter placed in front of the light will slightly reduce its output strength. But at 700mA and 160 lumens its bright enough even with filters.
The battery life is of course dependent on the capacity of the batteries you choose to use and the current setting you have selected.
In my project I used 900 mAh AAA NiMh rechargeable batteries and expect these results**
Low – 350mA – about 2.5 hours.
High – 700mA – about 1.3 hours
**Use NiMh batteries. They will output a steady current for most of its life. Alkaline batteries will soon fade and not last.
Mount this to your bike handle bars or your helmet and you have yourself a very inexpensive yet powerful bike light. Did you know that commercially available bike lights sell for about $180 to $200 for the same brightness? That is about $1 per lumen! Make your own for a fraction.
Here is a list of the parts I used and where I buy them. Keep in mind that they are from different sources so your total cost will increase when you consider shipping costs. Also note that I bought a complete heat sink and cooling fan package when I only needed half of one heat sink. And a large sheet of color correcting gel when I only needed a small sliver. So if you don’t want to bother with all that extra stuff you can feel free to contact me and I can sell you whatever heat sinks or pieces of filter gels I have remaining. **In the near future I will put together a kit with only the stuff you need for this light. I think I found an LED and heat sink that requires no cutting. Please leave comments below if interested.
4x AAA battery holder
Luxeon Endor Rebel
RAM/VGA Heat Sink pack of 8pcs
CompUSA or Zalman
3 position switch
Resistors: I used two 2.5 ohm 1/4 watt resistors. But you need to choose the appropriate resistor based on your requirements. Either way resistors should only cost a few cents each.
Create a warm output with Rosco #205 1/2 CT Orange Filter -
Available at BHphotovideo part #RO205S $5.99
Soften the white output with Lowel iP-72 Frost Gel -
Available at BHphotovideo part # LOIP72 $5.50
For me this project cost about $23 in parts- not including shipping or the color correcting filters. Shipping from two locations would add at least $12.
So I put together a kit so you can gather all the parts conveniently from one place.
The NightVlogger 160 parts kit is now available for sale!
The LED and Heatsink are pre-cut to easily fit into the battery holder. No cutting or fussing required! (aside from cutting the battery holder). This kit also includes filter gels and a coupling nut and set screw to make a thumbscrew that allows you to mount to a tripod.