[Review] D-C-Fix Window Film

Joshk · 2019-09-24T19:54:08.000Z

I bought D-C-Fix 346-0211 Self-Adhesive Privacy Glass Window Film, Milky from Amazon to diffuse some light and I thought I would post meter readings for how it modifies light.

Brightness = –4.24%
CCT = –62
Duv = +0.0001
Saturation = –1%

I’m quite happy with those numbers considering how well it diffuses light.

I stood outside in my sunny backyard with a piece of D-C-Fix over the meter’s sensor and the sensor aimed at the sun. I took a reading and saved it. Then without moving the meter I ripped it off and took another reading right away and saved it. I repeated the test 3 times to make sure it was consistent. The 3rd time was with a different piece of D-C-Fix just to mix it up a bit.

The reason I didn’t use an LED flashlight is because battery drain, emitter temp, and meter position after messing with the setup will all introduce errors. By using the sun and ripping the diffuser film off fast and taking another reading I was able to get perfectly repeatable results.

DavidEF · 2019-09-24T21:19:11.000Z

Well, if you want somebody to tell you how you did the test wrong, you first have to tell us how you even did the test.

If this is legit, then D-C Fix is proven to be as good as we all thought it was.

EDIT: I’m a bit surprised that it changes the CCT, though.

Joshk · 2019-09-24T23:17:04.000Z

I was surprised too, I guess it affects long and short wavelengths slightly differently, tipping the balance ever so slightly to warmer.

I stood outside in my sunny backyard with a piece of D-C-Fix over the meter’s sensor and the sensor aimed at the sun. I took a reading and saved it. Then without moving the meter I ripped it off and took another reading right away and saved it. I repeated the test 3 times to make sure it was consistent. The 3rd time was with a different piece of D-C-Fix just to mix it up a bit.

Lightbringer · 2019-09-25T00:14:14.000Z

DavidEF:

EDIT: I’m a bit surprised that it changes the CCT, though.

Nah. Even “clear” glass, when you look at panes edge-on, will look that nice bluish-green color. This plastic is probably just a tad on the yellow/red side.

Lightbringer · 2019-09-25T00:23:54.000Z

And yeah, “milky” is the good stuff. I got “snow” by mistake trying to cover up a peek-a-boo window, thinking it to be uniform, but it was quite patterned instead. Little flicks of light around the periphery, nothing too terrible, but I wouldn’t want it on a flashlight.

There was a third one I got, but forgot its designation. “Frost”? Don’t recall. It’s “grainier” and diffuses less, great for smoothing out a dark hole or cross in a hotspot and blurring the transition from hotspot to spill, but “milky” is what gives a great even blanket of light without spreading it around so much like a mule would.

Oh yeh. All my LuxPro lights with G3s would have hideous beams, a hideous urine-yellow corona around a decent hotspot but cold-white spill. Even sans reflector but just shined at a wall you could see the hideous angular color-shift. Yuck, yuck, yuck.

My 2×D light has the grainy stuff and now has a quite-nice beam, still a decent hotspot for some semblance of throw, and my 2×AA and 4×AAA lights have “milky” and are perfectly perfectly floody.

Joshk · 2019-09-25T00:32:13.000Z

Ah, yea, plastics do tend toward the yellow/red naturally, don’t they? Good call.

DavidEF · 2019-09-25T00:35:18.000Z

Joshk:

Ah, yea, plastics do tend toward the yellow/red naturally, don’t they? Good call.

I didn’t know that was the case. I thought they could be made “neutral” tint. Learn something new every day! :student:

Evgeniy · 2020-04-19T04:49:32.000Z

“Brightness = –4.24%
CCT = –62
Duv = +0.0001”

thanks.
Only 4% ? It’s good.