I have a Convoy M3c high cri, and need a ~160 degrees diffuser for it (for recording video with a gopro in caves) which wastes as little light as possible. How should I make one? Or is there a cheap option I can buy?
The stock diffuser is too wide, and throws a lot of light backwards. I measured with a phone roughly 220lux at 1 meter (when flashlight runs on sustainable 40% mode) and I think I could get at least twice as much
Could try some DC-Fix on the lens, not sure it would get you 160 degrees though.
The light looks like it has a light orange peel reflector, maybe Convoy sell a more rough reflector? The old way to make a reflector rough used to be to use hair spray… never tried it so can’t comment on the results.
Alternatively, you might have to look into 3D printing a better diffuser as an option.
I have D-C-Fix on my M3-C and it works a treat at diffusing the beam, but still with a hotspot.
On the cheap, plastic covers/diffusers from ordinary household led light bulbs are a great fit on the bezel with usually minimal size adjustment on the inner rim. Could line the inside or outside of the cover with aluminum tape or something else to black out a portion. Perhaps cutting a disc from thin translucent plastic sheet would be enough diffusion although it wouldn’t get you 160°…still might soften everything enough to be effective. The smooth side of milk milk jugs, craft pp sheets, etc. There are sheets inside of some led monitors and TVs that might be suitable if you have junkers to part out (although some of the sheets are a bit thick). I’ve found the light bulb covers to be very pleasant and useful but I don’t care about the 280°-ish emission because that works great for how I tend to use it.
@michael11:
Check out this thread by Boaz to get some nice diffuser film on the cheap.
https://budgetlightforum.com/t/-/35838
I think he ships to Israel, but if not, he can definitely recommend the right diffuser film for you.
I followed your advice and used a light bulb diffuser.
It is way more effective - I get 2-3 times higher lux in the middle and same at peripheria.
However there is still (a very diffused) hotspot. I’ll Try adding some tape to the bulb. Also I cant figure out how to increase the inner diameter to insert the flashlight (I need ~3mm more) It is very hard plastic that I can’t cut without breaking. Does it response to heat?
I’ll ask him (he got an Israeli name by the way so I’ll guess he will ship).
Probably hard to melt it nicely but I’ll bet it would work. I don’t have an extra on hand or I’d test that for you. Options that you may have or can get cheaply: sandpaper, sanding drum (drill press or dremel sized…carefully), metal cutting burrs (carbide, large or small shank is fine), hand metal deburring tool (the kind with the dogleg bits…works a treat, just go around and around), fine cut files, and worst case, a very sharp utility knife, which works ok. The diffusers vary a lot by brand. The ones I’ve been pulling only need about a 1mm increase (0.5mm trimed).
Just melted it using soldering iron and it fits perfectly.
I don’t care for aesthetics too much
Great! Hopefully it does what you need nicely.
The DC Fix film is also well worth buying, by the way. I don’t use it a lot but it’s been great on a few lights for softening the spot or minimizing rings or tint shift…sometimes the only fix for lights where you access the head to adjust or swap parts.