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Can I do anything with this cutoff ?

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  • Can I do anything with this cutoff ?

    Hello everyone , last month I bought a 2019 Toyota Land Cruiser and here are a couple of pics of the stock headlight low beam projector cutoff . I've been a long time Range Rover driver and I absolutely liked the color shift produced from their headlights . However this time I switched to the Land Cruiser and I immediately noticed the lack of said color shift . I already bought a set of clear lenses and some tools from TRS to switch the lenses out but before I do so I wanted to ask if it's worth it specially since it's my first kinda serious mod .
    I'm not looking for higher wattage or brighter output or sharper cutoff or wider beam or none of those extreme , sometimes illegal results . Just looking to get that nice wide color band back if possible . The headlights are otherwise totally adequate . I didn't remove the headlights yet so I'm sorry I don't know the technical details of the headlight's optics other than the lens is 2.5 inch diameter , the bulbs are LED all over and the high beam has its own separate projector .
    If you hate colorful headlights and think I'm just a fool trying to project rainbows everywhere then please spare me the critical comments . I want this to be informative for everyone , I don't think it's a crime to like the chromatic aberration effect . Let me know if you think the lens swap will accomplish this or if I need a completely different setup and projectors and possibly even complete headlight assemblies ?

  • #2
    As you may know, the colorband at the edge of the cutoff depends on the position of that edge relative to the projector optics. One thing worth noting is that if the cutoff shield in that projector is rigid, e.g. cast metal or very thick sheet metal, then it might be challenging to bend the edge of the shield such that it curves just right to catch those precise positions to create the colorband.

    For example, if you look at aftermarket projectors with relatively thin sheet metal used to create the edge of the shield, one with a flat sheet will not be able to achieve a wide colorband. Even if you move the shield slightly forward or backwards, the most you can achieve is a strong colorband at the center.

    On the other hand, some aftermarket projectors with thin sheet metal are deliberately curved. For this type, you can start by adjusting (forward - backwards) for the center colorband, and then adjusting the "wings" of the curved shield so that they too stay in the colorband-maximum location.

    So, the first order of business is to determine the construction of the shield in that OE projector.
    Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

    3-way quad wiring; foreground limiter; squirrel finder;


    • #3
      Thank you Satrya . So it looks like for what I want , it's a matter of the cutoff shield configuration and not the lens itself . Like you said I guess I have to take those headlights apart if I'm to make any progress . Learn something new everyday ...


      • #4
        If the projector is not a biXenon, then at least the complication of a moving shield isn't there. Since you indicated that the high beam is separate, the low beam projector isn't likely to have the high beam function as well (via moving shield). This makes it simpler.

        Here's an example of the shield of a low-beam-only projector:

        The panel on the bottom side is the low beam shield, with that indentation at the center having some "step" like shape that becomes the cutoff elbow of the projector's shadow cast on a wall ahead.

        The panel on the top side is the foreground limiter. It may or may not be present in a projector.

        Going back to the low beam shield portion, some people graft a curved shield from thin sheet metal like this sketch:

        As it may be necessary to move the up-down position of the shield due to the introduction of the curved shield, it may also be necessary to slot the mounting holes (also marked green) to make up for the new shield height.

        This is tricky work, and relies on the assumption that once you bend the curved (add-on) shield, it stays precisely in that position. I've never personally attempted this.

        At the center (of the bulb-bowl-lens alignment axis pointing straight to the road ahead), the amount of adjustment should be no more than a few millimeters. Other unintended consequences with the beam pattern might happen otherwise.
        Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

        3-way quad wiring; foreground limiter; squirrel finder;


        • #5
          I suggest reading a couple of good papers written evaluating chromatic aberrations and how they are RESOLVED to better understand how this optical side effect occurs.

          This SAE Technical Paper HERE.
          These papers HERE and HERE.

          In a nutshell, as satrya already eluded, the cutoff shield shape and position plays a role in the color separation along the cutoff but its not the only factor. The optical characteristics (and material) of the lens can affect the color.

          Since the OEM projector system was designed to minimize this color aberration effect you would have to reverse the effects which will take some trial & error.

          But there are a few problems...

          1) The Koito LED projectors found in the 19 Land Cruiser aren't really *tweakable*. The headlamp contains the BILED module along with a Mono LED projector. The shields for both are different as well as the lenses.

          The BILED has a curved plastic molded shield. Unlike a typical HID or halogen projector where they have a metal flat or curved shield that can be somewhat easily manipulated the Koito LED shield is not.

          The Mono LED projector has the shield molded into the reflector (all plastic). Actually the lens holder, reflector and shield are all 1-piece.

          This photo here isn't the exact LED projector from the Land Cruiser (different heatsink design) but I'm just providing an example of what the reflector/shield assembly looks like, which is virtually the same for ALL Koito Mono LED projectors. The shield is really just a protruding long nib. Hard to see in the photo (circled in red).

          2)The next problem, and its the most important, is that even if you found a way to create the blue colorband you would be compromising the lighting performance of the projectors. Mostly because you don't know what your doing. Lens spacing is often discussed for the BILEDs but I can assure you by moving the lens from its optimized position you WILL alter its performance negatively. Even if you don't recognize any adverse changes with the naked eye.


          • #6
            evo77 : that indeed looks much more hopeless to tweak than the simple single low beam projector I thought the OP's vehicle low beam might have.

            freestyler I wasn't sure if "LED all over" included the low beams. But if the low beams are indeed LED projectors, then we're entering a different territory here.
            Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

            3-way quad wiring; foreground limiter; squirrel finder;


            • #7
              Thank you evo77 and satrya . Honestly it's the first time I see chromatic aberration being referred to as a defect in those technical papers . But yes the low beam on my truck is LED indeed . I attached an image , the lit projector is the low beam and the other is the high beam . Right underneath them is the LED strip for the DRLs and on the side of course are the signal flashers .You can even slightly see the " golf ball " texture pattern on the low beam lens . The information you pulled about my headlights was greatly appreciated . I realized quite a few things . First is that it isn't worth it given how much I would be negatively impacting with my headlights and safety . Second is that even if it was worth it , I don't think I have the skill needed to modify all of that . I was way off thinking that I could . Thank you for helping a member avoid a disaster , had I taken those headlights out without first asking about it here !


              • #8
                You could still exchange the high beam projector for a bi-led projector. It would give you the benefits of a better low beam and probably a sharper cutoff too. two projectors per side would look good as well. thats the road I would take for a modern land cruiser.
                Subaru Outback retrofit:
                License plate lights with dual brightness:


                • #9
                  freestyler : For what it's worth, I think the days of (low beam) headlight retrofit is rapidly disappearing, as newer systems employ more complex features like AFS / active bending light, adaptive high beam from an LED matrix, etc.

                  Retrofitting something that came with sealed beam halogen lights, freeform reflector lights, or even some early HID lights, may make sense if done correctly. But the newer headlights will likely to be adversely impacted one way or another with a retrofit. I don't think I would want to retrofit laser high beams (like in some newer BMW models). In addition, newer vehicles seem to have almost everything connected to each other via a more expansive control unit beyond just the engine control module.
                  Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

                  3-way quad wiring; foreground limiter; squirrel finder;


                  • #10
                    Oh that’s right laser headlights , I totally forgot about those . I’m reading up about those now and it’s quite interesting not to mention complex .

                    On a side note I think I choose the new Acura MDX as the vehicle with the nicest color shift . It has those multiple small rectangular projectors in each headlight . Jewel lights I think they call them . I call them bug eyes but the other day an MDX was riding behind me and the color shift was so nice I had to tell my wife in the passenger seat . Needless to say she couldn’t care less but luckily she does allow me to waste money on my useless projects lol
                    Last edited by freestyler; March 21st, 2020, 10:25 PM.


                    • #11
                      Most of the color in the MDX (and many other vehicles with projectors) doesn't really come from the cutoff border but rather just below it. There is a specific test point in the regulations that is angled towards the front of the vehicle in the opposing lane at 50 meters which is believed to control bounce back glare during wet road conditions. The shading that occurs in the beam creates the same color aberration. And when the vehicles pitch changes this blue colored patch gets flashed into opposing eyes.

                      17 Mini Cooper and 19 Mini Cooper TOP
                      17 Acura MDX BOTTOM



                      • #12
                        evo77 where did you find those images if I may ask ? Looks like you have access to quite a lot of good information .


                        • #13
                          Many LED projector especially low beam dedicated one has cut off shield that also function as sub reflector that contribute to beam composition. If you see cut off shield equivalent component shiny reflective, any modification will greatly negatively affect output.

                          Also, lens material tend to be polycarbonate which has much higher refractive index of 1.586 compare to typical glass lens of 1.47-1.53 ish (some glass has higher, but it gets rare and expensive to make)

                          Matching diameter and adjust to its back focus distance still dose not give compatible beam output result.

                          When design projector, selection of lens and light source is the start point.

                          Higher refractive index lens have greater chromatic aberration.

                          Modifying LED projector is very much different from halogen or HID projectors.

                          OEM LED projectors are mostly made to satisfy basic lighting performance with minimum weight and power consumption.

                          So there will be much more powerful aftermarket LED projectors to retrofit. But also should aware, almost non of aftermarket LED projector does not comply with regulation beam quality. Some has terrible beam quality.


                          • #14
                            upashi Thank you for this detailed answer . It seems like my only hope is to buy an entire headlight housing and hope that the color shift is to my liking . I found a set online but I have no clue how well made they are or if , more importantly , the beam output is legal and not glaring or blinding to other drivers . I keep looking at the 19 Mini Cooper bean cutoff above and it looks great honestly .


                            • #15
                              Without an independent & objective test, it would be difficult to decide if that is a good option from the light output pov. And at that price point, it might be risky.
                              Jul 2012 ROTM (3-way quad headlight) ; Sep 2015 ROTM (custom muli-lens 7" fogs)

                              3-way quad wiring; foreground limiter; squirrel finder;