DIY version of the sola 2100 FS video light?

[raftingtigger]

Raftingtigger,

Did you think the holographic diffuser worked better or the white paint? I can't tell just looking at the photos (maybe cause I'm inexperienced and don't really know what to look for).

I'm still waiting for my supplies to arrive so haven't started my DIY mod yet. Hopefully everything will come this week.

heehee62, not a fair test. The draw (900 mA or 350 lumen) with the painted reflector is less than the draw (1100 mA or 450 lumen) from the one I put the holographic filter in. Look at the brightness of the patio, it is pretty obvious which is brighter. The one where the wall in background shows is both lights together (900 lumen). These are all clips from a single take on a GoPro.

The holographic filter works great, but I wonder at the light loss. The painted reflector is super easy to do. Let me do a few more tests. I'll repaint one reflector with silver paint, and use another with no reflector and just a spacer. I dislike taking apart stuff that is properly sealed so am going to leave the holographic filter in place in the Singfire. If somehow another piece or two of diffuser ends up in 3Ddivers drysuit this weekend (hint, hint 3D) I'll do some more tests.

I did order a second Singfire SingFire SF-749B CREE XM-L U2 800lm 8-Mode Ultra Bright Diving LED Flashlight (1x26650/18650/3xAAA) - Free Shipping - DealExtreme as I like the easy magnetic switch, construction, and it uses the bigger 26650 battery. Wish it were single mode, and with the magnetic switch there is very little DIY I want to do on the driver board. Someone with more electronic and soldering skills than I have could remove a few limiting resistors and drop a mode or two and boost the light to close to 900 lumens rather than the 450 I'm getting now. Now that would be a sweet little <$20 light!

 

[3D diver]

For identical light source there are two factors I'd call your attention to:

1) The transmission efficiency of a simple white plastic diffuser is about 50%. I would assume a painted reflector is comparable. The manufacturers quoted efficiency for the holographic diffuser is 90%.

2) With a simple white diffuser the light is spread almost 180 degrees. The holographic diffuser is rated at 60 degrees, but the actual spread is different because of the reflector. The narrower spread will yield a higher apparent intensity.

This may be splitting hairs, though, because the camera's autoexposure feature will compensate, so it's hard to say how much light is enough.

If you visit this weekend, raftingtigger, maybe we can waste a little water and do some bathtub beam comparisons.

 

[heehee62]

3D diver, I thought painting the reflector meant painting what's behind the light, so not the same as a "white diffuser"?

I'm just curious cause I realize I get myself into too many projects and if someone else is already trying it, might as well save me some effort.

Also, I'm hoping I can convince about 5 of us (2 lights a piece) to do this and I don't think I can get free film samples for all (nor am I sure I would not want to pay for using that much of their samples). They seemed to sell the diffuser film only in bulk size at like $200 a pop. At that price, I think white paint is looking prettier if it's only slightly less effective. It didn't look like there was room to move the LEDs closure to the front with the light I got (though I still haven't received it yet so not sure) - so I might have to try that idea out next time.

Thanks for sharing your results with us raftingtigger. Looking forward to reading your findings.

 

[dfx]

For identical light source there are two factors I'd call your attention to:

1) The transmission efficiency of a simple white plastic diffuser is about 50%. I would assume a painted reflector is comparable.

I'm not so sure that this is correct. If I had to imagine a surface which reflects all visible light uniformly into all directions, I'd come up with something matte white. I can't think of anything that would work better.

 

[3D diver]

Well...the paint is a thin film. Some light is reflected at the air/paint interface, some passes through the paint and is reflected at the next interface. This latter path presumably has some loss. 50%? I don't know. The paint is likely much thinner than most diffuser sheets so the efficiency may be better.

Your experience, and Raftingtigger's, has shown modifying the reflector with paint or tissue paper does work nicely as a diffuser, no question about that.

---------- Post added March 26th, 2014 at 04:26 PM ----------

Also, I'm hoping I can convince about 5 of us (2 lights a piece) to do this and I don't think I can get free film samples for all (nor am I sure I would not want to pay for using that much of their samples). They seemed to sell the diffuser film only in bulk size at like $200 a pop.

Are you talking with the same company I got my holographic diffuser from? When I got mine the quoted price was about $25 a sheet, plus another $25 for shipping (they way over packed it). I think I had to talk with someone to get that price, though. It may not have been posted on their website...it's been a while.

Edit: just revisited their site---their 4-sheet packs aren't very practical as they mix diffusion angles (and are pricey). Give them a call and you can likely put together a better deal for just a single angle.

 

[fjpatrum]

$50 battery source??? I get my 26650 batteries for $18/pair for actual 4000 mAH each. DIY still needs power from somewhere. Unless it is a custom battery or a new type of battery it shouldn't make a difference in the cost. An 18650 will work in place of a 26650 with a simple plastic sleeve.

Some light tests
View attachment 180457View attachment 180458View attachment 180459
The first is the DX Singfire ($19 with nice alum body and magnetic switch) with holographic diffuser. The second is the $12 yellow DX light with a white painted reflector. The last is both together. Both lights have the same listed light output. The middle one is a Cree XML-T6 at 940 mA on a 18650, the left is the Singfire with a Cree XML-U2 at 1200 mA on a 26650, and the last is both. Both batteries were fully charged to 4.2 V. To get 900 lumens you have to drive the Cree at close to 3000 mA.

If 3D and I ever get together I would like to do the same test with his Impact. I think the impact might be a little brighter, as I cannot tell by eyeball the difference between the Singfire and the DRIS 1000 lumen long body with no diffuser installed.

The impact seems to be more like a mini can light, so the power source has a separate housing from the light head, which may or may not be convenient depending upon personal preferences. My DIY lights actually use the same battery as my camera so it works out really well for me.

 

[raftingtigger]

Did a quick and dirty test between the painted reflector and no reflector with the emitter near the front. Area illuminated was about the same, but the white painted reflector was perceptibly brighter. I have 2 lights and had them side by side.

---------- Post added March 26th, 2014 at 05:34 PM ----------

The impact seems to be more like a mini can light, so the power source has a separate housing from the light head, which may or may not be convenient depending upon personal preferences. My DIY lights actually use the same battery as my camera so it works out really well for me.

Not according to what I see. The confusion is that they sell extra bodies for $49.95. The whole light with either the spot OR the video is $129.99. Here is the link. Stubby Impact Dive Light

 

[fjpatrum]

Did a quick and dirty test between the painted reflector and no reflector with the emitter near the front. Area illuminated was about the same, but the white painted reflector was perceptibly brighter. I have 2 lights and had them side by side.

---------- Post added March 26th, 2014 at 05:34 PM ----------



Not according to what I see. The confusion is that they sell extra bodies for $49.95. The whole light with either the spot OR the video is $129.99. Here is the link. Stubby Impact Dive Light

Yes, you can buy the whole body & light head for $129.99 but the heads themselves are $79. This is why I assumed they were separate from the power source, which may have been a bad assumption.

 

[sharkbite]

Let me do a few more tests. I'll repaint one reflector with silver paint, and use another with no reflector and just a spacer.

coming in late to the piece , i know ...but....

you could just rough up the surface of the reflector with sandpaper - same effect as silver paint!

I like the idea of the holographic diffuser as you can actually reverse the mod and have your original light back!

I am considering the "white paint" mod though, and was wondering if anyone has some underwater footage with this in use...?
(i am curious about the angle of the light and whether it causes vignetting)

P.S. was also considering adding one of these if it fits...

http://www.dx.com/p/jr-47mm-fgb-1w-reflector-white-190289#.UztnN6LeNWg

cheers

 

[raftingtigger]

I am considering the "white paint" mod though, and was wondering if anyone has some underwater footage with this in use...?
(i am curious about the angle of the light and whether it causes vignetting)

No vignetting. All my videos are done using these lights.

link to a video is https://www.facebook.com/photo.php?v=546268078792458&set=vb.100002278115814&type=3&theater

The light doesn't help for distance shots, but works quite well for the close ups.