Reflector Mod for PT Apex?

[LedSled]

I've been trying out a new Princeton Tec Apex headlamp for the last few days. I notice that its Lux III uses a plastic optic, giving it a very narrow beam, much tighter than either my Inova T3 or my Arc LSHF-P. The Apex easily out-throws the T3, suggesting that this Apex is different from the one Quickbeam reviewed at http://www.flashlightreviews.com/reviews/pt_apex.htm. Perhaps PT has changed the optic since the review, or it's a joker/non-joker issue.

I'll just note in passing that the total output and tint, as judged by my own "Mark I eyeball," exceed my wildest expectations. Tint is just the tiniest degree bluish compared to an HDS U60XRGT. Perhaps I won the Luxeon lottery.

The problem is the lack of sidespill. In a headlamp, it's like having tunnel vision, so I'm asking:
1) Has anyone found a reflector to replace the plastic optic in the Apex?
2) If the answer is yes, how did it work out?
3) What about the joker/non-joker issue?

Thanks in advance for taking time to reply.

 

[jar3ds]

well... another guy on CPF and I are wondering if the Stenlight Reflector will work https://www.candlepowerforums.com/posts/1560424

JSB has yet to give us info on the specs of the reflector to see wheither it would fit or not...

---

the joker/non-joker i'm not sure on... don't know why yours throws more than dougs...

I don't own a Apex but it would seem that if you have a headlamp similar to Doug's reviewed headlamp.... keeping it stock is going to be the best think you can do...

As long as your optic doesn't throw so much that it makes it too anoying... having the option for great, bright, up and close lighting... while being able to spot distant w/ the lux is a great combo...

i guess I would suggest that if your light is throwing too much to use a mild-diffuser or frost the optic to help spread the beam out for you...

 

[jar3ds]

would you be able to give the diameter and the depth of the stock optic... those two numbers would help in figuring out a reflector replacement...

 

[LedSled]

would you be able to give the diameter and the depth of the stock optic... those two numbers would help in figuring out a reflector replacement...

I'll open it up tomorrow and post the numbers ... way past my bedtime tonight.

BTW: I've already had the Apex open. The front cover/window has a rubber o-ring where it joins the base/heatsink assembly. As received, there was a dangling loop of o-ring outside. It was easy to fix (reseat the o-ring and lube with a little silicone grease), but this type of flaw might explain the dunk problem on Quickbeam's review.

 

[LedSled]

would you be able to give the diameter and the depth of the stock optic... those two numbers would help in figuring out a reflector replacement...

The optic has:
Diameter at the mouth flange: 1.046 in (26.57 mm)
Optical mouth diameter: 0.861 in (21.87 mm)
Overall height: 0.542 in (13.77 mm)
Enclosure lens diameter: 0.858 in (21.79 mm)

I also noticed two locator pins molded on opposite sides of the black plastic frame that holds the high dome (Lambertian) emitter.

i guess I would suggest that if your light is throwing too much to use a mild-diffuser or frost the optic to help spread the beam out for you...

Actually the Apex's throw is superb. The problem is the lack of sidespill, since it won't run the Lux III simultaneously with the 4 small LEDs. I very much like the beam on the HDS U60XRGT. On the Apex, a compatible reflector would be wider and a bit shorter, so I'd expect the hotspot to be smaller and more intense, with the sidespill to be more spread out. For me, that would be perfect.

 

[NoFair]

The optic has:
Diameter at the mouth flange: 1.046 in (26.57 mm)
Optical mouth diameter: 0.861 in (21.87 mm)
Overall height: 0.542 in (13.77 mm)
Enclosure lens diameter: 0.858 in (21.79 mm)

I also noticed two locator pins molded on opposite sides of the black plastic frame that holds the high dome (Lambertian) emitter.

Actually the Apex's throw is superb. The problem is the lack of sidespill, since it won't run the Lux III simultaneously with the 4 small LEDs. I very much like the beam on the HDS U60XRGT. On the Apex, a compatible reflector would be wider and a bit shorter, so I'd expect the hotspot to be smaller and more intense, with the sidespill to be more spread out. For me, that would be perfect.

That is somewhat strange. My Apex doesn't throw as far as my HDS, but has a larger hotspot and good spill.... I am also interested in a drop in reflector for the Apex. It is getting a better emitter and a good reflector would be the icing on the cake

Sverre

 

[cave dave]

The IMS 17 reflector fits with room to spare. All I had to to was trim the tabs a bit and it droped right in. Its press fit in now and seems to be secure but a hard knock might pop it out of place so some glue may help.

The Stenlight mclux reflector should fit no problem. The optic in the stenlight is even smaller than the IMS 17. **EDIT , Stenlight reflector physically fits but is not a good match because the spill angles don't line up. ***

 

[LedSled]

The IMS 17 reflector fits with room to spare. All I had to to was trim the tabs a bit and it droped right in. Its press fit in now and seems to be secure but a hard knock might pop it out of place so some glue may help.

Thanks! I downloaded the IMS dimensional specs. I'm very curious how your beam compares with the original optic.

FYI on the stock light:
The hotspot is very tight, smaller than my HDS and much smaller than my Inova T3. It's much brighter than either light. Also, I'm only getting about 50 minute in-regulation runtimes using 2 year old 2300mAH NiMH AA cells, much less than Sway reported at http://candlepowerforums.com/vb/showthread.php?t=96493 using new 2500mAh Sanyos.

 

[jar3ds]

it seems that the JSB Stenlight reflectors MIGHT work...

however, the dimensions given for the optic is close to the McR-27 (short)

 

[NoFair]

Thanks! I downloaded the IMS dimensional specs. I'm very curious how your beam compares with the original optic.

FYI on the stock light:
The hotspot is very tight, smaller than my HDS and much smaller than my Inova T3. It's much brighter than either light. Also, I'm only getting about 50 minute in-regulation runtimes using 2 year old 2300mAH NiMH AA cells, much less than Sway reported at http://candlepowerforums.com/vb/showthread.php?t=96493 using new 2500mAh Sanyos.

It seems your light is either driving the Luxeon a lot harder than others, it has very hight Vf (time to buy a new emitter) or your batteries are in need of either some conditioning or replacement..

I also get very long runtimes using my 2300 mAh Sanyos. About like the ones posted by Sway.

 

[LedSled]

It seems your light is either driving the Luxeon a lot harder than others, it has very hight Vf (time to buy a new emitter) or your batteries are in need of either some conditioning or replacement..

I also get very long runtimes using my 2300 mAh Sanyos. About like the ones posted by Sway.

Thanks for the input. Most likely it's just my Lenmar (Chinese) batteries showing their age. I'll run some deep-discharge cycles to see if that helps.

I did run a quick Vf check. The Lux III on high starts cold at 3.601v and drops through 3.580v as the emitter warms up ... not bad at all! Vf on low runs about 3.200v. I'm guessing I've got an SX0K or TX0K.

 

[Pi_is_blue]

I run my Apex on Lenmar 2300mAh cells that are a few years old, and while I have not done an official runtime test, I do get 2-3 hours on high as near as I can figure (I recharge the cells before the light dims).

 

[NoFair]

Thanks for the input. Most likely it's just my Lenmar (Chinese) batteries showing their age. I'll run some deep-discharge cycles to see if that helps.

I did run a quick Vf check. The Lux III on high starts cold at 3.601v and drops through 3.580v as the emitter warms up ... not bad at all! Vf on low runs about 3.200v. I'm guessing I've got an SX0K or TX0K.

That sounds about right. Mine had a J bin Vf, now has a TW0H. It is sligthly brighter now, 10% up, and should run cooler and longer.

I'd guess it's the batteries as well.

If one of the Mc reflectors fit well I'll probably get one even though I like the optic.
Would a Q3 reflector fit? Isn't it about the size of an IMS... It is nicely textured and I have a pretty beat up Q3 that might be willing and able

Sverre

 

[LedSled]

That sounds about right. Mine had a J bin Vf, now has a TW0H. It is sligthly brighter now, 10% up, and should run cooler and longer.

I'd guess it's the batteries as well.

If one of the Mc reflectors fit well I'll probably get one even though I like the optic.
Would a Q3 reflector fit? Isn't it about the size of an IMS... It is nicely textured and I have a pretty beat up Q3 that might be willing and able

Sverre

I'm reluctant to desolder one of the emitter terminals to measure drive current, but I did measure the battery voltages and currents. The cells were not freshly charged. With the light off the cells produced 5.21v. With the Lux III on high, the cells produced 4.56v at 820mA. I'm guessing that the emitter is current regulated using a buck switcher. At 95% efficiency, the emitter should see 966mA at 3.60v.

I did look at the short McR 27. It's 0.061" too long, and could probably be cut back fairly easily. However, the aperture is 0.988", while the Apex window is 0.861". That would block about 25% of the output beam. The McR and IMS 20 size reflectors also might be fitted with a bit of trimming. I have no idea how the Q3's reflector is sized.

First, I think I'll give variant of jar3ds's frosting idea a try. A 0.600" to 0.700" disk of Scotch Magic Tape attached to the center of the Apex optic might smooth the rings and improve the spill without spoiling the throw. Frosting over the entire aperture spoiled the beam.

 

[jtice]

I took mine apart the other night...

The 20mm IMS reflector looked to be a good diameter, but its a bit too tall.
Might be worth cutting one down to fit.

I plopped a 17mm IMS in it, which fits, but is a much smaller diameter than the optic.
I actually got a goof bit less Lux out of it though,
yes, it was a smoother beam, with some spill to it,
but I didnt like the drop in lux.
The 5mm leds do a nice job of flood, so I left it stock.
I just wish you could turn on both sets of leds at once.

~John