Why no adjustable beam lights?

For $10 on Amazon I bought a 3XAAA light with a head that slides forward and backward. Slide forward for a tightly focused spot, slide back for a wide flood beam. The beam is basically all center spot with no spill, but that spot is adjustable from narrow to very wide.

It seems to me to be a very nice feature for a light used for both close and distant illumination.

So my question is why don't the manufacturers of higher end lights include a feature like this on some of their lights?

Thanks!

From what I understand is you lose lumens, I really appreciate that feature as well. My guess is there is also a loss of ruggedness too.

Excluding the cheap DX zoom-to-flood lights LED Lenser is pretty much the only company that does it.

I think it's because they have a patent on the feature.

It isn't primarily a loss of lumens - if the optic is well designed and manufactured, the loss can be minimal. As far as I know, the main reason is waterproofing. When you adjust the zoom, you change the volume of air inside the light, and nature abhors a (even partial) vacuum. So when that happens, water can get sucked into a light very quickly. No zoom light has an IPX8 rating, that I am aware of. It also is more complicated, expensive, and does increase the chances of failure in a light. Obviously the fewer moving parts it has, the better for reliability.

My recommendation, if you really like the feature (I like it myself) is to get an LED Lenser. They may not be popular on this forum, but I have had only good experiences with my T7. Just don't try to submerge it, and be careful about using the zoom if there is water on the light that could be sucked in.

As Imon mentioned the main reason is LED Lensor having patent on the function of focusing a LED with zooming lens.

A quick search: https://www.google.com/search?q=led+lensor+patent&sitesearch=www.candlepowerforums.com

Ummm... Maglites are adjustable, and they're just about the most common flashlight out there. You sacrifice a nice beam profile, and waterproofing (but Maglites are still pretty good at water resistance). But if you want an adjustable light, Maglites have the trade-off pretty good IMO.

USA made LensLight offers several different models all with focusing aspherical lenses. They are somewhat expensive and are available in various metals and finishes. Their website claims that six strategically placed O-rings make them water resistant and weatherproof.

I assumed it was because the reflectors were optimized to maximize OTF lumens, and perfect the beam profile. I also figured that the only way to effectively change the beam profile from spot to flood was to change the shape of the reflector which is not possible at this time that I know of. I have seen the cheap DX zoom lights and they have terrible tint when you start focusing the beam. I am interested in knowing how wrong this perception is though.

I think the loss of lumens argument is legitimate. a reflector catches a wider angle of emitted light, some of which is outside the circle of an adjustable lens-based light. The effect worsens when the lens is adjusted further from the emitter. On some lights I see a noticeable lessening of ceiling-bounce light when zoomed to a tight spot, which I assume is caused by this loss. Or I could be confused, in which case I'm sure someone will spank me.

MBI has a zoom head too...there are others, you might just need to look around a bit more. DX alone has several, etc.

In addition to the above factors, the focus of a light is hard to optimize for flood AND throw, as they have different ways of being optimized. It ends up not throwing as well as if it were made to throw, and not flooding as well as if it were made to flood. The artifacts can be an issue as well, because most obtain the flood function by simply defocusing the throw function.

They can be useful when you think of them as the moral equivalent of carrying a multi-tool that has a philips head and a flat blade screw driver on it, instead of carrying a philips head and flat bladed screw driver.

The multi-tool will not drive the screw as well as a dedicated screw driver, but is a compromise way of at least being ABLE to drive the screw.

Etsu said:

Ummm... Maglites are adjustable, and they're just about the most common flashlight out there. You sacrifice a nice beam profile, and waterproofing (but Maglites are still pretty good at water resistance). But if you want an adjustable light, Maglites have the trade-off pretty good IMO.

Click to expand...

Maglites are focusable, that is different from an adjustable beam.
Lenslight is probably the best adjustable beam light.

Etsu said:

Ummm... Maglites are adjustable, and they're just about the most common flashlight out there. You sacrifice a nice beam profile, and waterproofing (but Maglites are still pretty good at water resistance). But if you want an adjustable light, Maglites have the trade-off pretty good IMO.

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Emphasis added because it's a significant understatement. Like all parabolic reflectors, the maglite' reflector has a single focal point that best collimates the light into a spot and all other positions are less than optimal. Within a slight range (likely defined by the size of the light source), there is tolerable adjustability that shapes the hotspot, but you're simply playing with the error induced by a non- point source. Too far forward and you get a ghostly ring with only spill light in the center. Too far back and you get a donut that's likely wasting lumens behind the reflector.

The "zoom" systems out there maintain an extremely uniform beam profile by comparison using lenses to maintain collimation. Such systems can distribute the light into a tight intense spot or a wide diffuse flood with minimal loss of lumens ... at the expense of complexity with its attendant expense and ruggedness problems.

ShineOnYouCrazyDiamond said:

As Imon mentioned the main reason is LED Lensor having patent on the function of focusing a LED with zooming lens.

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If this is in fact the reason, that's crazy. Why isn't a projector which can zoom its beam, violating this? So then what if I make a pocket projector that only displays a white screen?

How the hell can you patent basic optical theory and function? Patents in general may have a place (probably not) but the effect here is stifling and unacceptable, if the case.

YDrvSlo said:

For $10 on Amazon I bought a 3XAAA light with a head that slides forward and backward. Slide forward for a tightly focused spot, slide back for a wide flood beam. The beam is basically all center spot with no spill, but that spot is adjustable from narrow to very wide.

It seems to me to be a very nice feature for a light used for both close and distant illumination.

So my question is why don't the manufacturers of higher end lights include a feature like this on some of their lights?

Thanks!

Click to expand...

I think high end lights tend to be more optimized for specific uses while the mid to low end lights are more utilitarian in usage. I have 2 black and decker clamp lights that focus and are useful but for a decent long throwing beam they are less than optimal reflectors tend to be better than optics when the distance increases I think. Focusing optics add to the bulk of a light and also it has to be made more rugged to protect the focusing apparatus.

Imon said:

Excluding the cheap DX zoom-to-flood lights LED Lenser is pretty much the only company that does it.

I think it's because they have a patent on the feature.

Click to expand...

AFAIK, LED Lenser's patent only covers their Advanced Focus System (AFS) design. Suprabeam in Denmark makes adjustable focus flashlights that are similar to LED Lensers but appear to use a slightly different reflector/lens combination.

Beckler said:

If this is in fact the reason, that's crazy. Why isn't a projector which can zoom its beam, violating this? So then what if I make a pocket projector that only displays a white screen?

How the hell can you patent basic optical theory and function? Patents in general may have a place (probably not) but the effect here is stifling and unacceptable, if the case.

Click to expand...

The typical standards for a patent are "useful", "novel", "not obvious to one skilled in the art", and "no prior art exists".

Not knowing the particulars for the LED Lensor patent, I can only speculate that it fulfills the various standards as currently interpreted by the patent office and differs sufficiently from contemporary optical systems as to be patent-able.

The #1 reason is patent infringement. No company wants to produce a light and set themselves up to be sued. Led lenser has a very different mechanism for zoom which probably keeps them pretty safe from Maglite. That or mag's patent ran out.

Used both and concluded that in fact it is not very useful anymore. The TK35 for example has a bright central spot that reaches far away while enough flood to light the surroundings. Adjust the beam power and you get the same effect as a zoomed lens with less mechanical complication and no waterproof issue.

BoarHunter said:

Used both and concluded that in fact it is not very useful anymore. The TK35 for example has a bright central spot that reaches far away while enough flood to light the surroundings. Adjust the beam power and you get the same effect as a zoomed lens with less mechanical complication and no waterproof issue.

Click to expand...

No its not the same.

First, sometimes I'm interested in illuminating something quite small far away. The flood to throw gives two advantages in that situation:
-no light reflecting from your surroundings and blinding you.
-less attention is bring to you, and you distract other people much less

Now the other way around, you want to ilumminate wide, close area. The flood to throw gives you nice uniform light without hotspot. Almost like a mule (but less wide)
-It's better to work on something because the hotspot doesn't blind you.

Imho this is future of the lights. It would be probably little bigger but would replace two lights. Its possible to make waterproof, focusable optics, just look at some professional lenses for DSLR's. I would give a lot for quality, 3 or 4 x 18650, uniform (the head and body could have the same diameter) light with zoom to throw and infinite levels (or decent amount of discreet levels selectable with a ring)

Because they're hard to waterproof. Durability is also compromised unless they find a way to make it work magnetically.