I'd like to share some beamshots / whitewall-shots of modified Sofirn C8F lights. These were equipped with Samsung LH351D / LH351B emitters bought from Andrey ("AEDe"). Once again, Большое спасибо for these wonderful LEDs, Andrey! :BEER: All pictures were shot on iPhone 6S with manual settings. If you have any suggestions how to improve the beam quality comparison between those beamshots, I'd be glad to hear about it. My photography skills are very limited so far.
As far as the rendition is concerned, yes - the pics reflect quite well what I saw with my own eyes. I agree that the LH351D 5000K 70CRI appears quite similar to the XP-L2 “fried egg” beam (yellow corona, blueish rim in the outer spill) but once you reach a distance of let’s say at least 3 meters you won’t recognize it anymore. From a farther distance both 5000K 70CRI and 90CRI looked the same on a white wall. It might has something to do with the SMO reflector in combination with the LH351D but I can’t tell for sure. I guess Djozz once tested the LH351D in a Convoy C8 with SMO and reported something similar.
Personally, I prefer the 4000K 90CRI most or - even better - a quad of 2x 4000K 70CRI / 2x 5000K 70CRI would be just perfect to gain a 4.500K beam profile with best efficiency (e.g. in an Emisar D4S or a P60 quad pill). Unfortunately, the 90CRI has less output than the 70CRI.
If you’re a fan of incandescent light, the LH351B 2.200K 80CRI is just fine. You get about 1,900 lumens on turbo with three of these emitters in the C8F 21700. Another benefit of the LH351B is its small die size, resulting in a more concentrated spot (= better throw).
I prefer the 4000K range myself, but the 3500K SST-20's are looking ok to me so far, and I've been using an EDC, SWM C20C, with triple XPL HI 2700K's with a nice incandescent feel that I like in this light. Few years back I recall comparing indoor looks at first a 3C/3D, then 4D, then 5D, and it just got better and better, but if I went to a 7A/7B level, it was too much, and my preferences are still there.
Thomas, unless you are doing “something” else in these cases, I am pretty sure you may be overdriving to some extent the LH351B emitters in such host. Don't you think?
Oh! Well, I see the 21700-C8F's output isn't as impressive (versus 18650-C8F).
FWIW, the C8F-21700 FET-driver is somehow limited or at least not as powerful as other FET drivers. It's quite hard to override a certain "threshold" of about 10A with this driver. Even with a Samsung 30T/40T you will not get that much above it. In terms of the LH351B it appears it can easily sustain a current of 3 - 3.5A, even though it's supposed to be driven to Imax = 1.5A i.a.w. the datasheet. Using the Sofirn brand battery (which appears to be a Lishen LR2170SA cell) the current for all three emitters is probably 9A or less.
Olight mods! So I put a LH351D 4000K 90CRI in my S1R Baton II, and LH351D 5000K 90 CRI in my S2R Baton 2. These perform really well with the stock optics! I will actually EDC some of my Olights now…
Has anyone tried a single LH351D in direct drive? I’m planning running a sliced dome 5000K on a Bistro FET+6+1 TA driver. The Vf is not that low so I hope it will be OK to blast a few FET turbo runs now and then.