Emisar D4S review

LMAO Literally what I was thinking when I read what Hank said and continued to read on lol…. Had been debating on getting an XP-L HD variation but now the SST-20 has been thrown in the mix.

Anyone give any details about how the beam of the SST-20 will be?

Someone already measured CRI sst-20 5000k?

Here ya go…https://www.illumn.com/miscellaneous/no-ox-id-a-special-electrical-grade-conductive-grease-2oz.html

The Good stuff :+1:

Thank You.

:wink: :+1:

Vinh claims 42kcd for xpl hi 5000k on the D4s, whereas intl outdoor claims 45kcd. That’s not .76

Vinh says 42kcd for the XP-L HI V2 3A, which is not as bright as the V3 1A. 45kcd is what the cool white gives.

However I the differece between leds is not 25%, so this doesn’t account for 0.76.

Measuring photometric intensity is easier than total lumens but a reliable detector is still necessary and that’s not easy to find. See the recent efforts by djozz.

So, we need someone who has calibrated the luxmeter with Maukka’s calibrated lights to check this issue.

With the vaporizer crowd and power tool manufacturers flocking to the 21700 format, I do find myself wishing that a 21700 battery tube were available since that formfactor may yet see some improvements on its already-impressive power/density characteristics.

I had a similar issue and thought it was a driver or firmware or mechanical issue. Turned out to be a simple mechanical issued alright - the tube:head connection wasn’t as snug as it could be. Tightened it up and the issue disappeared.

Interesting. Looking again now, he also no longer lists 170 kcd for the stock D1S. I wonder if he updated his meter, or otherwise changed measurements to improve accuracy. That would be welcome news. :slight_smile:

OTOH, the D4vn still lists 40 kcd, but on mine I measured 28.6 kcd.

Here it is (left) next to a D4-219C 80 CRI model (right), underexposed to show the size of the hotspots better:

It’s certainly the throwiest D4 I’ve seen, but I measured mine as only 41% throwier than an XP-L HI model, not 98% throwier as claimed.

I think his lux readings are weird. Some seem to measure high, some low. For instance, he measured the stock GT at under 1m cd, while others measured it around 1.1-1.2m cd.

On the other hand, he measures the ROT66 with LH351Ds at over 20kcd, while my Zebralight SC600 MK3 HI, measured at 18kcd, definitely has a more intense hotspot in comparison.

All that aside, his measurements of the White Flat 2mm are probably reasonably accurate, and such a high performing emitter would be pretty great to have stock in the D4S.

Recently I collected all measurements that I could find for a number of lights:

In some cases there are Vinh’s numbers.
In 1 case the number is indeed an outlier, in others its not.
GT Mini: Vn 170 kcd, others average 128.5 kcd
Cat V6: Vn 175 kcd, others average 178 kcd
T27: Vn 335 kcd, 1 other 340 kcd

Do you think it would be sensible to mix SST-20 3000K 95CRI and SST-20 4000K 95CRI on the D4S to gain a beam profile with 3.500K color temperature? Would this even work as the 3000K version is probably subject to become warmer and less efficient in conjunction with the 4000K SST-20 at full brightness level? (...thinkin' about Vf, thermal specs, maximum current, etc.).

Whew to my eyes that is one green beam; doesn’t matter if it throws a mile, no ty.

On a good note I ordered a 3000k SST20. Super excited :smiley: about that. I.already have 2 D4S, a Nichia and XPL-HI 5000k. I hope the SST20 is as nice as djozz found with his testing! Should be amazing in this quad! Thanks again Hank!

@Lux Perpetual, since the VF usually changes significantly when going with different emitters or higher CRI emitters, going with 2x 3000K and 2x 4000K SST-20s will be about perfect in terms of tint mixing compatibility.

@Lux Perpetual,
Keep in mind that two one other thing will happen when mixing tints:
+Tint will fall lower on the BBL line, so less green, more purple

In general mixing just tends to average out the CRI. So no fear in getting worse CRI if both sources are high CRI to begin with.

Thanks for correcting me Maukka, must have misread a previous post.

Of course there are exceptions. Such as combining a red, green and blue will naturally result in a much higher CRI than any of them separately. But mixing is usually done with emitters having similar characteristics in the SPD (i.e. they have their peaks and valleys at the same wavelengths, just in different amounts).

I was about ready to order my D4S with 5000K XP-L Hi, and now this appears.

Is it correct that the SST 20 provides about the same performance, without the $15 upcharge?

Assuming I’m fine with the slight increase in throw, are there any downsides? Heat? Beam pattern?

Yes, I think that should work.

I also suggested a while back that Hank should consider offering LH351D sometimes, and should offer a 2x4000K plus 2x5000K option to get a tint-mixed 4500K. This should provide a CCT closer to what is most popular, and should also help make the tint a little less green.