Yajiamei (or any other cheap optics) VS Ledil/Carclo

YuvalS · 2018-10-22T16:56:19.000Z

I am searching for optic (TIR tight spot) for a flashlight I am building.
I used to buy Ledil lenses but one BLF member recommend Yajiamei optics, and I also saw some very cheap lenses in Bangood/AliExpress etc.

Has anyone tested these lenses and can recommend Yajiamei (or any other cheap optics) since it cost like 1/30 of the Ledil I am using.

Thanks.

Jerommel · 2018-10-22T20:33:46.000Z

Well, most of their stuff is good.
Some of it is mediocre or crappy…
Shipping is quite high too, but not when you order several optics.

You should check out the Jarmay store too.

What size thrower TIR are you looking for?

YuvalS · 2018-10-22T21:30:16.000Z

Jerommel:

Well, most of their stuff is good

Comparable to Carclo or just better than unbranded lenses?

Jerommel:

What size thrower TIR are you looking for?

As short as possible - around 10 mm, diameter is less important 10-30 mm.

Jerommel · 2018-10-22T22:06:00.000Z

I don’t know, i never did any comparative testing.
Seems production methods and materials are similar.
To me it’s all trial and error.
I have ordered many cheap optics in various sizes, so i have some choice in stock.
Some optics work best with certain LEDs and / or purposes.

You can try the 22.5mm TIR from Yajiamei, get the smooth surface ones. They’re 10mm high, and you can use regular 3535 centring gasket, but that will add 0.5mm

Jerommel · 2018-10-22T22:09:05.000Z

BTW, FWIW, they have the TIRs they use in the Skilhunt angle lights.

Bob_McBob · 2018-10-22T23:02:29.000Z

Jerommel:

To me it’s all trial and error.

Very much this. Many times clear optics look awful unless they are focused exactly right. Sometimes a 10 degree optic looks great and a 15 degree optic has tons of distortion. An emitter with a larger die will be fine, and one with a smaller die will make an ugly square beam. It’s so variable you can’t really say something will be a good choice unless someone has already tried the exact configuration, so there is a lot of trial and error involved. Much less so for the floodier optics though.

YuvalS · 2018-10-23T07:33:07.000Z

Bob_McBob:

Jerommel:

To me it’s all trial and error.

Very much this. Many times clear optics look awful unless they are focused exactly right. Sometimes a 10 degree optic looks great and a 15 degree optic has tons of distortion. An emitter with a larger die will be fine, and one with a smaller die will make an ugly square beam. It’s so variable you can’t really say something will be a good choice unless someone has already tried the exact configuration, so there is a lot of trial and error involved. Much less so for the floodier optics though.

Maybe it is because Ledil/Crclo lenses are made for specific LED model while Yajiamei are generic 5050 or 3535

aswang · 2018-10-24T08:10:48.000Z

Hi YuvalS. Maybe you can tell us what type of emmitter you’re using and which size and type of optic you intend to use. Maybe somebody here can give their experiences.

If throw is desired large smo reflectors give the best result with weight considered but the spot+spill don’t combine nicely with floody lights if you want to use them together.

Personally I’ve tried a few 17mm and 20mm Yajiamei clear and beaded optics for different emitters on some of my lights and here are some of my very rough throw calculations done with a phone light sensor all measured at highest output.

https://docs.google.com/spreadsheets/d/1FCGZF4txRcA9mzm-hNfcjOxXeBKhe299OXRtunJGuwM/edit?usp=drives DK

Basically for maximum throw, low angle clear optics paired with throwy leds (no dome or smaller die size e.g xpl-hi) gives the best result but these oftentimes produce undesirable beams with rings and other artifacts especially the 5° clear. Personally I sometimes use my H03 with xpl-hi under 20° 17mm clear Yajiamei if I need a throwy headlamp (With a decent 200+ meter throw). It has some faint artifacts on the edges but only visible on white walls close range and I don’t notice them otherwise. And also combines ok with my floody light.

But most of the time I use nichia 219c under 20° beaded optics as my complementary headlamp. I measured only 140m of throw but the tint, cri and beam are much nicer and most of the time in caves its all I need.

I have an emisar D1 in my pocket or in my tackle bag when I need more than this.

I also have a few high cri samsungs and sst-20s as well as a few other optics coming I’ll test later on.

YuvalS · 2018-10-24T12:58:28.000Z

aswang:

Hi YuvalS. Maybe you can tell us what type of emitter you’re using and which size and type of optic you intend to use. Maybe somebody here can give their experiences.

I am still on the research stage so I don’t yet decided which (or how many) LEDs I am going to use.

I want 2 different beams: one throwy and one floody and I thik it is better to use the same type of LED for both of them

The floody is less problematic since I only need max output of 500 lm and can use wide angle lens that are easy to find or even bare LED.

My problem is with the spot beam. I need max output of 800-1000 lm and tight spot lens but also want to keep it compact = mcpcb + optic < 15 mm high and less than 1 cm is even better.

The only combination I found under the above constraints is triple mcpcb with 3*Nichia 219c and Carclo 10507 lens.

The mcpcb is 1.75 mm and the lens is 6 mm so in less then 8 mm height, I can get 1000+ lm and 90+ CRI using this congratulation but FWMH is 26 and I would be happy to find tighter spot.

aswang · 2018-10-24T14:50:54.000Z

Under 10mm I’m only familiar with carclo triples and quad optics.
219cs under Carclo 10507 are nice but are still a bit floody and not throw so much especially at 800 - 1000 lumens. They even might render your flood light redundant. Multi-emitters in my opinion are a lot better for floody lights.

Under 15mm I think you can fit Yajiamei 20mm or 17mm diameter optics or maybe those carclos for single emitters. Yajiameis are 12.8mm in height so plus 1.75mm mcpcb still under 15mm.

If you prefer to use only one type of high cri emitter with nice tint for both flood and spot you might want to look at the newer Samsung LH351D or CRI95 Luminus SST-20s also. 219cs are nice but I find it difficult or inefficient to make throwy beams out of them. High CRI samsungs and sst20s have positive reviews here at blf and they should work better than nichias if you plan to use Direct Drive FET drivers. You can push more lumens with the samsungs and the sst20s should have more throw because of their smaller dies.

So if it was me with your requirements I guess I would use

For flood:
quad or triple under floody carclos. Even at max 500 lumens they would be much more efficient than single emitters but I would probably push them a little bit higher. I also like floody optics better than bare emmitters because in my opinion with bare emmitters there’s a lot of wasted lumens at areas outside your vision and the optics direct them in front of you. Quads and triples also tend to produce flower shaped beams when bare.

For spot:
Same single led under 20° or less Yajiamei Beaded or Clear optics or equivalent Carclos.

With LH351D you can push more lumens and flood light with SST 20s you could theoretically get more throw with lesser output.

Of course this is all based on reviews and test of people that I know have the same preference for LED tint and CRI as me. I have nichia 219cs, 219bs and e21as that I’ve played with and they’re very nice. My orders for the LH351Ds and SST20s have yet to arrive (sometimes takes forever here in the Philippines).