RUSH REVIEW - 4Sevens Mini Mk II (1020 lumens)

[UnknownVT]

Yes, in my hot sweaty hands is the brand new 4 Sevens Mini Mk II with 1020 lumens from a single 4Sevens custom high-discharge rate RCR123A.
Review sample courtesy of 4Sevens.com.

1020 lumens from a tiny single CR123 light of about 2.17 in long -
that's roughly the equivalent of a 75 watt incandescent household light bulb -
but with the light concentrated in a flashlight beam....
(just for comparison a typical US halogen car headlight on high beam is about 1200 lumens)

Packaging -

Back -

Size -

left to right - AA battery, original 4Sevens Mini (in titanium), Mini Mk II, 4Sevens Quark Pro QP2L-X

left to right - IMR16340, CR123A, Mini Mk II, Quark QP2L-X head on Quark 123 body, AA battery

Heads -

left to right - Mini Mk II, QP2L-X

The lens of the Mini Mk II is not plain/flat as in most other flashlights -
but it is dished with a frosted center dome -

According to 4Sevens Specs on the Mini Mk II -
this is a TIR Optic lens
(see Wikipedia explanation of Total Internal Reflection,
and this pdf of types of TIR lenses suitable for LEDs)

Flex Charger in kit, and the 4Sevens custom high-discharge rate RCR123A -

The Flex Charger's contacts have very strong magnets to hold on to the battery terminals.

At first I was very concerned as those contacts are not marked in any way as to which was positive or negative,
and high discharge RCR123 are not to be taken lightly...

I immediately read the manual -

The contacts are not specific to either the positive or negative terminals; just make sure that one contact is attached to each of the two battery terminals.

I would also caution since it is so easy to have the charger contacts stuck to each other -
always make sure they are attached correctly to the battery terminals before inserting the USB connector to a charger/supply

Manual -

$64K question - how bright?
I only have one flashlight that's even in this league - the 4Sevens Quark Pro QP2L-X with burst mode of 780 lumens
despite that, hopefully I can still do some interesting comparisons -

The closest apples-to apples using the QP2L-X head on a Quark 123 body and IMR 16340

vs. QP2L-X using 2x CR123A (standard configuration)

I wondered if the Mini Mk II would be as bright using an IMR 16340 reputed to be capable of high discharge -
since I don't have two Mini Mk IIs to compare, I compared it with QP2L-X in standard configuration with 2x CR123A

interesting huh?

May be pocket rocket is finally appropriate?

EDIT to ADD -

Measurements by reppans

...
For the record, my lightbox is calibrated to what I believe to be US ANSI and ties up closely with my HDS 325 (@0.02 and 325) and ti-force's review of a couple Quarks (btw, ti-force is the only CPF reviewer that claims very accurate lumens using laboratory tested calibration lights). This scale is lower than that used by Selfbuilt, and most Chinese domicile companies - for example, the best I can get off my 1st gen ZL SC52 is ~230/440 lms from an Eneloop/14500 (all the other modes are similarly off as well).

My measurements on a fully charged OEM cell are as follows, runtime calculated assuming 550mah batt spec is correct:

- Max 1000-1050 lms, 3A current draw, 11 mins calc assuming continuous
- Medium 280 lms, 0.514A, 66 mins
- Low 17 lms, 35ma, 16 hours
- Moonlight 0.25 lms, 4ma, 138 hours

My sample holds max (very flat) for 30 seconds, and then ramps down over the next 10 sec. to ~325 lms and then regulates flat again - I don't know where the 15sec comes in, except to say it could be 47s "under promise/over deliver" thing, and also perhaps to technically qualify for the 30sec ANSI FL1 rule. The light seems to hold a flat 1k+ over 4V, and I'm even getting a flat 800+ at 3.6something V. The head gets warm, but nothing uncomfortable against your upper lip.
...

EDIT to ADD 2 -

reppans made some measurements of the supplied 4Sevens RCR123A battery (link to his post)

 

[kreisl]

how's the tint?

if the tint is not the same as on the New Preon (also XP-L CW), then i'm definitely interested!

i love CW tints otherwise, see for example K18 in the video link.

 

[UnknownVT]

how's the tint?

if the tint is not the same as on the New Preon (also XP-L CW), then i'm definitely interested!

i love CW tints otherwise, see for example K18 in the video link.

I think it looks pretty OK... but then I am kind of "dazzled" by this light (literally).

My side-by-side comparison beamshots are done with fixed Daylight White balance and have been pretty representative for showing tint -
unfortunately I do not have a new Preon to compare to be certain -
however the only thing I can say is that a 1AAA Preon might be marginally under-driven(?)
whereas this Mini Mk II using a High discharge RCR123 is more likely to be slightly over driven - so to show less green tint(?)

By my eyes - as kind of confirmation there is definitely some green in Moonlight - less so in Low,
Medium and High kind of white/white - and I would not say any green, if anything, there might be a blue outer edge.

Just figured how I can show the tint pretty accurately.

I have a setup for photographing objects - the lights used are 65K (100watt equivalent) GE CFL bulbs (the closest I could get to CIE Standard Illuminant D65 - Wikipedia link)

I use my camera set to manual white balance for that setup, on a sheet of white paper (so it is as close to D65 white balance as my modest home equipment can get)

Using Medium on the Mini Mk II (more likely to reveal green than High)
with my camera set to manual white balance for the set up
Left is with lights On (to compare the tint to my set up lights), and right - lights Off.

Hope that helps somewhat.

 

[parnass]

Thanks for the review, Vincent.

The Mini Mk II's beam pattern looks more oval than circular in your photos. Was the flashlight being held at an angle with respect to the target?

 

[UnknownVT]

Thanks for the review, Vincent.

The Mini Mk II's beam pattern looks more oval than circular in your photos. Was the flashlight being held at an angle with respect to the target?

Ha-ha! well observed!

Yes, to get a clear shot of as much of the beam as possible, the flashlights do have to be tilted upwards and to the left or right respectively.

Just pointed the light at the ceiling and the beam does look pretty round, and not oval at all.

However you don't need to just take my word for it - I just took beamshots with the light on medium pointed more centrally -

The beam is really just one big hot spot but with 4 pointed "side-spill" -
looking kind of like a feint square with a circular bright hot spot.

 

[Chauncey Gardiner]

Thanks for the review, Vincent.

+1 for dazzled by the new Mini Mark II.

~ Chance

 

[matrixshaman]

Thanks Vincent! and like Chauncey says dazzled by this new Mini and can't wait to add it to my collection of 4seven's Minis. Dreaming of one in shiny Titanium too

 

[xiaoxixi]

wow~~~
the way of charging is really nice and creative !

 

[Chauncey Gardiner]

Thanks Vincent! and like Chauncey says dazzled by this new Mini and can't wait to add it to my collection of 4seven's Minis. Dreaming of one in shiny Titanium too

Be still my heart; otherwise, you're gunna kill us!

~ Chance

 

[lampeDépêche]

Vincent, this is a terrific review, and thank you so much for doing all of that work!

Especially for follow-up pictures in response to questions--that is really going beyond the call of duty.

A titanium model? Maybe David will do it, but here's why I doubt it: heat management.

This little beast is possible only because of exquisitely controlled heat management. And that requires a body that can pull heat away from the emitter quickly, before it cooks itself. Titanium is an *extremely* bad conductor of heat.

But I really have no idea--maybe the aluminum shell here is so minimal that it does not contribute much to the heat management in any case. So a Titanium version could have a slug of better-conducting metal near the emitter (AL or copper or brass) and have a Ti shell, and not be much worse off than the Al version is.

We shall see!

 

[UnknownVT]

... for follow-up pictures in response to questions...

Thank you so much lampeDépêche for your kind words.

This is exactly why I do review on the forums,
and is all part of the process for me -
since I only have a single sample, and
cannot possibly hope to cover all the aspects people are interested in -

I try to convey some initial impressions based my own experience first -
then open and expect - questions, corrections and additional knowledge/comments -
to get a more comprehensive view of the flashlight.

For example, I did not realize the poorer heat conductivity of titanium -
thanks to you - now we kind of know better.

I also gain more knowledge about the flashlight by reading other threads on it -
like getting those measurements by reppans (that I linked to in the OP)

Then the spec'd 15 secs of High before ramping down -
seemed to have been different for different people -
as you suggested in your post over in that other thread
might be a temperature controlled ramp down -
if so, this is a much cleverer light than I initially gave it credit for.

Thanks

 

[UnknownVT]

Kind of a dOh! moment for me -
I've been wondering what kind of lens is used for the Mini Mk II -
then I looked on the 4Sevens webpage of the Specs for the Mini Mk II - and there it was...
TIR optic lens - (Total Internal Reflection)
I've now updated the OP with relevant links.

...
The lens of the Mini Mk II is not plain/flat as in most other flashlights -
but it is dished with a frosted center dome -

According to 4Sevens Specs on the Mini Mk II -
this is a TIR Optic lens
(see Wikipedia explanation of Total Internal Reflection,
and this pdf of types of TIR lenses suitable for LEDs)

 

[UnknownVT]

I know some have been clamoring for this - in my email today -
some real eye-popping candy ...

 

[fyrstormer]

Question about the limited-edition lights: Is the cutout around the tail of the light shaped specifically for the pocket clip, such that if the clip is removed there's an uneven surface exposed underneath?

 

[TKC]

Thank you for the great review.

 

[hahoo]

good review, but ive got an old thrunite about that size that ive been running for years, that puts out over 300 lumens otf....
thats about what this does after the quick stepdown?
think i paid like 20 bucks for it