Solarforce host/SST 50 - what lense?

I'm just waiting on my Nailbender drop in and read somewhere a while back that the lens supplied with the Solarforce torch doesn't allow as much light to be transmitted as others do.
I've been on DX and KD but don't know what I need - can anyone help out please?

I think what you are looking for is the UCL lens that allows as much as 10% more light OTF.

I use the G2 version sold at lighthound.com for all my 6P and Solarforce bezels.
http://www.lighthound.com/UCL-for-SureFire-G2_p_2254.html

I ordered mine from Flashlightlens.com (http://www.flashlightlens.com/str/index.php?app=ccp0&ns=prodshow&ref=ucl_lens) - get the 28.6mm version. CS at that site is AMAZING - I messaged asking if I could also get a $2.50 bezel remover, and got a personal response from the owner within hours stating that he put it in the order for free, and shipped it personally. That was Friday the 25th. Monday afternoon I opened my mailbox to find the package. I've never had that fast of shipping from ANY site using USPS. And the total was a few dollars cheaper then Lighthound.

What sort of lumens do you expect from the sst-50 drop in?.
Ive read over 500+ but doubt that.
My question is do you think this drop in would be worth the extra dollars for an L2M? or would it be almost imposible to tell the diffrence with just a single 123 driving it.
I know if i shine it at a wall the donut hole will stand out but in real use what gives the best bang for the buck?.
Thanks.

nutzz said:

What sort of lumens do you expect from the sst-50 drop in?.
Ive read over 500+ but doubt that.

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It seems no one has tested a top-binned, properly installed drop in with clear lens, proper heatsinking, a good cell etc. etc., so all we have is theoretical for now. Here's what I conjured up using infallible mathematics. Skeptical though I am, Cree rates their numbers at +-7%, and Seoul +-10%. So variables like heat aside, my results are likely at least within ballpark range.

Flux binning specs:


Assuming I'm getting a W57S GJ bin, I can expect a minimum of 500 emitter lummens at 1.75A



Source: PhatLight SST-50 Rev. 2 Data Sheet

Based on this chart, 2.5A would give us roughly 135% rated output. Therefore, emitter lummens for a SST-50-W57S-F21-WJ-G4 bulb would be a minimum of 675. Assuming a 25% loss of efficency due to optics, we end up with a minimum of 506 OTF lummens - a spec that should be reasonably accurate, as all but the reflector waste come from factory specs, and reflector waste seems to be generally accepted at 25% for high-quality, 30%-35% for low quality. If we assume that our LED falls at the higher end of the binning spectrum (as Nailbender stated he tried to provide upon request), ideally we would see (600 * 1.35) * .75 = 608 lummens. In other words, the amperage boost over spec should result in rated emitter lummens closely approximating OTF lummens after reflector loss.

In short: A SST-50 should give anywhere from 221 (worst case WE bin) to 608 (best case GJ bin) OTF lummens when driven at 2.5A.

Now, if we tried to feed it 5A, ignoring the obvious overheating problems, we would get a 235% increase, giving us a best-case (600 * 2.35) * .75 = 1058 OTF lummens.

Again, all of this is forgetting about heat and the loss of lummens that result as well as overstatments in the data sheets. But all of it makes me somewhat optimistic that we'd see at least 500 instant OTF from a good WJ bin.

That being said, we could easily get <200 from another LED of the same color bin but inferior flux. So I think binning matters much more then the type of LED - we're talking about a 2.8x variation in brightness from the exact same LED.

You need to measure the diameter of your lens. It is usually 28mm, however I saw one report that the Solarforce L2M's from DX are larger, over 29mm.
For the 28 mm lens, people were using the 26.8mm x 1.85mm UCL v2 from Flashlightlens. It fits a bit loose but workable.

This one from KD fits but not sure how effective the coatings are.
http://www.kaidomain.com/ProductDetails.aspx?ProductId=1766

Take a look at http://candlepowerforums.com/vb/showthread.php?t=228492&page=8, from post 195.

I have a P60 drop-in made by Nailbender and it was tested in my Solarforce direct drive with a single IMR 18650 cell next MrGman will test it with a 3 mode 2.5A driver to see how performance is affected..

Check his IS Sphere thread for the results which will be eye opening and hopefully early next year .

Which UCL lens from flashlightlens.com would fit a L2p? I don't have the host yet so i can't measure the original lens myself. Thanks!

My L2P lense is just the same as the other Solarforce lenses meaning 1.8 mm thick and 27.7 mm in diameter. I have earlier bought a lense from Flashlightlens with these dimensions. They seem to be out of stock now.

They dont even list that diameter in the Application & Spec Chart , maybe they discontinued that size :mecry:

28.6 is too large, 26.8 is a hair small but it still fits fine in the rubber seal.

This, 28mm x 2mm, seems to be good lens for L2P. It has greenish coating.

If I remember correct my L2P had exactly the same size lens as the one I linked to.

Edit: I can't find the original lens of my L2P, only L2M SS. Anyway, 28mm x 2mm was a perfect fit for both.

The 28.6 was slightly too large, I don't know if the 28.0 would work. But shipping from KD takes 3 weeks+ (I'm still waiting on an aspheric that I ordered 1 month+), whereas I ordered a lens from FSL Wednesday evening and got it Friday afternoon

Shipping isn't the problem. Getting them to process the dang order is.

I just recently got a shipping notification for the order I placed 3 weeks ago. :F

ackbar said:

Shipping isn't the problem. Getting them to process the dang order is.

I just recently got a shipping notification for the order I placed 3 weeks ago. :F

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Your right. Just realized that I haven't gotten a shipping notification for an order I placed 4.5 weeks ago :ironic:

I sent an email to solarforce asking about the size of the L2p lens and got this answer:

"The diameter and thickness of the L2P lense are 27.8 and 2mm respectively."

Now I only have to convince flashlightlens.com to start cutting the UCL lens in that size

Yea, the 26.8/1.89 is slightly smaller then stock, but it still fits fine. The exact size would be nicer, though.

joshconsulting said:

28.6 is too large, 26.8 is a hair small but it still fits fine in the rubber seal.

Click to expand...

i'm thinking of ordering that size from flashlightlens. how are you enjoying yours?

joshconsulting said:

The 28.6 was slightly too large, I don't know if the 28.0 would work. But shipping from KD takes 3 weeks+ (I'm still waiting on an aspheric that I ordered 1 month+), whereas I ordered a lens from FSL Wednesday evening and got it Friday afternoon

Click to expand...

how are you enjoying your aspheric lens? i got this one sku.5297 from dx and the diode is clearly showing. is it suppose to be like that? the throw is great and all but is there anyway to get rid of the diode from showing.

I use the 26.8mm x 1.85mm UCL V2 lens from flashlightlens in my Solarforce L2 and L2P lights.

It is a bit smaller that the original lens, but since the Solarforce L2* lights have that rather original inward sloping o-ring, they fit in nicely.

BTW, that is the same UCL lens that MrGMan uses in his IS Sphere tests when using Solarforce hosts.