[Review] BRINYTE ZT40 flashlight - Are ZOOMIES cool again?
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Terrible optic design. It’s just a small convex dome in the centre that reduces range by half. They sent the white for review and I bought the IR 850 and 940nm to sample for my store. The IR is half the range it should be.
This optic only reduces the sharp round edge to the focused beam at the cost of half range.
The white version arrived faulty, it dims down to low randomly.
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Looks like good optical design to me.
Most “zooming” type TIR or ultra flat optics are pretty efficient relative to convex lenses but do not focus very narrow, and the total adjustment range is limited.
This one achieves the full adjustment range, but just how good is the efficiency?
Is it a one piece optic?
The narrow beam is achieved by simply losing the output that would have made the beam wider but equally intense. I would hardly consider that an exemplar of good design.
When fully zoomed for distance, as low as all other zoomies.
The issue with the light is not that it’s a zoomie, but that it uses a disproportionately tiny lens for the large head, more than halving the throw achievable in this form factor.
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I think Zoomies are cool and I’m glad some brands are still offering them. A well-designrd zoomie is extremely handy!
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The ZT40 has a much more narrow head than the Z1 and Cometa and shorter length than the EP12 so maybe the unusual design centres around compactness.
Are you just totally making this stuff up, or have you personally tested the optic alongside other zooming optics?
It’s how a zoomie works, no tests needed. A convex lens, when zoomed in, collects only a narrow cone of light emitted in the frontal direction of the LED; the rest is not collected and therefore lost. You might get minor variations in efficiency due to the diameter to focal length ratio, but all of them will be very lossy when zoomed in. Tell me if any of this is totally made up.
Assuming that the lens collects a 60-degree diameter cone of Lambertian emission, the collection efficiency is 25%.
Unrelated, but I’m very confused by the advertising on the Brinyte website. The ZT40 page shows a picture of the T40 claiming a TIR lens, so I looked up the T40, but the site gives conflicting beamshots that are characteristic of either a convex lens or a reflector, no TIR to be found. They gotta stop the misleading advertising.
This is a new light with some kind of unconventional optic in it, possibly.
Testing is required, unless you are ok with speaking straight out of your butt, presenting your theories as validated facts, when they are not.
I can say that I have tested all of Ledil’s zooming lenses, all of Gaggione’s UFO and one piece zooming lenses, various fresnel lenses including 20mm diameter ones, and various convex lenses. All of these lenses have some sort of compromise about them. This doesn’t make them terrible, it makes them more or less suited to a particular design goal.
Gaggione UFO:
A common convex lens, with blackout shrouds:
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I greatly respect your commitment to testing these lenses and, more generally, your careful approach. I’m sure that you are much more knowledgeable than I regarding the lenses you’ve tested.
In the case of the ZT40, there are already two video reviews out, with plenty of demonstrations and beamshots, both of which are consistent with the optic being a simple convex lens, and not consistent with any other type of optic I know of. The page may advertise some fancy TIR, which would be blatantly false. Unlike TIRs (which can have intricate internal and surface designs), convex lenses have very little design variation among them other than size and material: those used in flashlights are essentially just scaled versions of each other.