Dosun R5 - first impressions & beamshots...

(moved from General Flashlight Discussion)

*** UPDATE ***
Quicky beamshot added below!
A few quick snapshots too!

Finally received my Dosun R5 from Fenix Store...

Some first impressions:
- much smaller than i expected
- much heavier than i expected
- very VERY nice finish and build - one of the nicest lights i've seen
- the mode selector ring rotates smoothly enough to be used by thumb (singlehandedly)
- mine doesn't bind, but it did feel a bit raspy the first few turns
- comfy to cigar-grip thanks to the widened tailcap
- o-ring well lubed - perhaps too well, b/c it leaked a bit when i tightened the tail
- very warm tint on mine, slightly greenish
- brightness on max seems similar (by eye) to Fenix P3D Q5 on High (120 lumens)
- as expected, stays cold (it's around 30°C ambient over here) even when kept on maximum brightness for a longer period of time
- no whine or hiss of any kind on any setting, but the PWM flicker is visible on lowest setting (in broad daylight - it will probably be less noticable in the dark)
- the levels are pretty weirdly set - there's a huge "gap" between the lowest output level and the next one, then it's pretty linear and then there's a very small difference between the next to brightest and brightest levels
- there's a weird "bug" - when turning the light on, it switches on in the lowest brightness level, then immediately switches to the selected brightness - makes morseing practically impossible except in lowest brightness
- i like the clicky a lot - takes relatively small amount of force for momentary and a lot to click it in
- no manual, package text proofing is rubbish
- the footnote under the runtime graphs states: "Test condition for Ni-Mh 2700 batteries"... oh really?
- there's a cut-out morse code table printed on the inner cardboard

Edit - some second impressions:
- modes aren't that superfluous or useless, actually...
- one SOS is continuous (...---... ...---... ...---...) while the other works once a minute (i.e. ...---... then nothing for the rest of the minute)
- one beacon is a strobe (flash... flash... flash...) while the other's a 50% duty cycle blinking (on...off...on...off...)
- tactical strobe is nuts - i've made the error of flashing myself with it (i can't help it, i always end up doing that) and kept hitting the furniture for the next few minutes

Edit2 - beam comments:
- general comment - i like it
- nice, regular, circular hotspot
- very soft transition to spill with no rings
- there's a light ring at the very end
- tint changes a bit throughout - from yellow to reddish to yellow then reddish again
- my emitter seems to be a bit off-centre - can't really see it through the optics, but one side of the beam hotspot is a bit brighter than the other

Edit3 - would've, could've, should've:
- it would've been nice if the mode icons were painted with GITD paint
- focus would be a VERY welcome addition
- the grooves in the tail cap aren't enough to keep it from rolling - a flat would've helped
- the holster could've been a bit less tight
- and, of course, the max. output could've been a bit higher, esp. considering it's a 2x123 light

Some photos and beamshots to follow (in a few days). If anyone's interested, that is...

Re: Dosun R5 - first impressions...

Yes please photos!
Pricey light, but looks like a functional U2-ish light - a stepped down U2B (1/4 of the lumens) =)

How does one select the strobes, are they at the extremities of the selector ring?

Btw, the weirdness of the output level spacing, is due to our eyes' perception of brightness being logarithmic in relation to lumen number increase.

Re: Dosun R5 - first impressions...

The ring functions go like this:
-> Brightness 1 -> B2 -> B3 -> B4 -> B5 -> Tac. strobe -> Battery level for rechargables -> Battery level for primaries -> Beacon 1 -> Beacon 2 -> SOS1 -> SOS2 -> and back to Brightness 1.

I.e. it wraps around, so it's real easy to get where you want no matter what direction you turn it.

Re: output levels - the thing is, it's neither fully linear nor fully logarithmic, but a weird mix of the two. There's a big jump between level 1 and 2, then a small one between 2 and 3, then a big one between 3 and 4, then a small one between 4 and 5. Or something like that

Re: Dosun R5 - first impressions...

Cool, thanks for what must have been a big headache to type that out =) Pretty neat. There used to be a Bushnell light that had Low -> Med -> Hi -> Sos -> Slow strobe -> Strobe, but it only went in one direction, which I thought was lame.

Yeah, thanks for the correction - I saw the lumens output they have on 4-7s' website; odd! I wonder if it is because they are relying on some serial/parallel combo of resistor circuits within the ring-selector...that happened to come out with gaps that are 'roughly' spaced out...

Re: Dosun R5 - first impressions...

A few quick'n'dirty beamshots @ approx. 1m...
P3D Q5 set to High on the left, Dosun R5 set to max on the right.







... yes, it really IS that warm
And it IS a collimator.

Re: Dosun R5 - first impressions...

Cool...doesn't seem bad at all! The other reports on the Dosuns said they were really weak on output, some said ~50lumen apparent, one said 17lumen! But this looks ok, comparing favorably against the P3D Q5...

Re: Dosun R5 - impressions, beamshots, pics...

I was too lazy to break out my main gear bag (containing a Canon 1Ds MkII and other goodies) so here's a few lamish detail snapshots taken with my measly EDC Canon G9...

Some more quick'n'dirty photos...

Tint comparison (clockwise, from top left - Streamlight Twin-Task incan, Dosun R5, P3D Q5):




Size comparison (next to a P3D):




In the holster it came with:

Re: Dosun R5 - first impressions...

orcinus said:

The ring ...I.e. it wraps around, so it's real easy to get where you want no matter what direction you turn it.

Click to expand...

the ring on my R6 is will not wrap around. can't remember if it did on DAY 1 before it started binding badly. upon recovery of relatively smooth operation (no longer thumb only, but easy, relatively smooth thumb and forefinger operation), it definitely doesn't wrap now. again, can't recall if it wrapped b/f the binding started.

despite my "crabs" about the ring and brightness of my particular unit (which was later concurred with by another Poster with his Dosun light), i really do like the R6. have to look into a possible emitter upgrade though.

regarding the brightness of my particular R6 (referring here to another Poster's comments), here is some of what i said in another Thread dealing with the R1:

"since, my testing of the more powerful R6 (which arrived fine the same day with no problems as a separate order) demonstrated to my eyes that my particular R6 doesn't appear to be as bright as some of the finer lights that i own that rate their lumen output lower than the R6 (e.g., Ra Twisty-100-TW on its default 17lm MED o.p. level, is brighter than the R6 on its 48lm o.p. level, and both the Twisty and Muyshondt Nautilus on their highest o.p. modes, 100lm and 107lm respectively, blow away the R6 on it's highest o.p. level which is a Mfr. claimed 120lm - the difference in brightness is so very easily noticeable; they are not even close."

yet elsewhere, i also added a question, wondering if Dosun inflates their light o.p. lumen values, or if some of the other Mfr's UNDERESTIMATE theirs. perhaps a little of both, and this accounts for some of the discrepancy b/t light output of at least some particular Dosun lights when compared side-by-side with other lights. perhaps Dosun doesn't QA the emitters they receive to make sure that they are up to snuff??? don't know. but some, myself included, have received lights that don't appear even close to the claims the Mfr. makes regarding their Lumen o.p.

great beamsots. ya' gotta' love the warm tint though. to put this in better perspective, i like pure white and slightly cooler beams. yet, i really like the tint of my R6. i also really like my H1 headlamp (in a short time one of my favorite headlamps). so, please, don't consider me an "anti-Dosunite".


lastly [for this Post, at least], regarding the spacing of the light levels. i get the impression that the light levels are really intended to be more like just a three level LOW-MED-HIGH, *BUT* with an added bonus, i.e. TWO really close levels for FINE TUNING of the light level for greater burntime. what i mean is that the user can STEP DOWN to a VERY SLIGHTLY LOWER level that will probably in nearly all cases suffice to adequately accomplish the task at hand and get the added benefit of greater burntime. if this is what Dosun intended by this interesting spacing of their levels, i think that it is very clever - if i said "pure genius" might be a bit of an overstatement in this regard, but it would get the point across.

we all know that stepping down slightly in light level often suffices just as well, but gives the added bonus of often a significantly greater increase in burntime. i'm glad two have these two additional cleverly spaced light levels.

Re: Dosun R5 - first impressions...

half-watt said:

the ring on my R6 is will not wrap around. can't remember if it did on DAY 1 before it started binding badly. upon recovery of relatively smooth operation (no longer thumb only, but easy, relatively smooth thumb and forefinger operation), it definitely doesn't wrap now.

Click to expand...

You mean you can't turn it freely the whole 360 degrees? Maybe you should return it for a replacement?

half-watt said:

despite my "crabs" about the ring and brightness of my particular unit (which was later concurred with by another Poster with his Dosun light), i really do like the R6. have to look into a possible emitter upgrade though.

Click to expand...

I was thinking about how hard it would be to disassemble and mod it, but the head looks a bit scary with all the optics and the mode ring and everything... If you decide to do it, make a lot of photos, please

half-watt said:

Perhaps Dosun doesn't QA the emitters they receive to make sure that they are up to snuff??? don't know. but some, myself included, have received lights that don't appear even close to the claims the Mfr. makes regarding their Lumen o.p.

Click to expand...

Seems to me like Dosun has some unresolved QA issues all over. There are probably significant differences in the emitters, as i expected mine to have abysmal output after the comments on R1, R2 and R6, but it actually holds up pretty well. It definitely could've been a bit brighter, but it's not bad at all.

Oh, and one more thing... I'm wondering ig people may be overreacting a bit because of the tint. Colder whites are traditionally percieved as brighter than warmer whites, even when they are the exact same brightness...

half-watt said:

Great beamsots. ya' gotta' love the warm tint though. to put this in better perspective, i like pure white and slightly cooler beams. yet, i really like the tint of my R6.

Click to expand...

Yeah, i feel the same. The color reproduction seems much better and less outlandish than the traditionally cold cree's. Especially on greens and reds. At least to my eyes, that is.

Oh, and that's some great reasoning on the output levels. Makes a lot of sense (though mcmc's series/parallel explanation sounds rather probable too)

Very very nice. Is the lens glass (plastic?) and you said it was about 120 lumens. Does the Fenix store or the manufacturer specify lumen levels for each level and run time?

I probably will buy one, its very nice.

I wouldn't go so far as to claim it's 120 lumens, but it's very close to P3D on High, which is advertised as 120 lumens. If one claim is off, so is the other

The factory specified lumen levels and run times are as follows (according to Fenix-Store's blurb):

• 120 lumens : 3.5 hours
• 96 lumens : 4.5 hours
• 48 lumens : 9 hours
• 36 lumens : 12 hours
• 12 lumens : 37 hours

Oh, and the lens is glass. Looks multi-coated to me (it has a slightly purplish/reddish sheen).

I've measured the PWM frequency... (yay for RCM tachometers)
125 Hz. Pretty low, so no wonder it's noticable on the lowest duty cycle.

The tac. strobe is 16-17 Hz (my meter doesn't have enough resolution to determine which).

Comparison beamshot with a LiteFlux LF5XT w/ Energizer Lithium (R5 - left, LF5XT - right):

:wow: nice warm tint,just like my modded Novatac with U2SVOH emitter.

Yeah, the tint really got me by surprise...
That, the tight yet soft beam and the general build and design really redeem the somewhat underwhelming output. At least in my book.

orcinus said:

Yeah, the tint really got me by surprise...
That, the tight yet soft beam and the general build and design really redeem the somewhat underwhelming output. At least in my book.

Click to expand...

swap the driver :devil:

The head doesn't look very mod-friendly... What with the selector ring, collimator etc. And i'd bet it's glued and i'm not quite sure about dunking it in a pot of hot water

Maybe one day, when i really REALLY get fed up with it (won't be that soon) or get REALLY bored

A few additional observations after using it for a while...

- i STILL can't get over how warm the tint is... it's not a "warm white", it's almost yellow
- throw's pretty nice - saves the day considering the relatively unexciting output
- i have an even higher opinion about the build quality after using it for a while
- the selector ring sounds and feels as good as the first day
- the forward clickie hasn't loosened and is still Just Right (TM) - not too tight, not too loose

Upon closer inspection, i've found a few interesting details:

- the outside contact ring connecting the tail cap to the non-anodized edge of the body isn't just a flat ring, but has three little leaf springs to improve contact
- the PCB inside the tail cap has "Ver 1.1" inscribed in it
- the complete inside of the flashlight is anodized as well and nice as the outside!
- the walls of the casing are absurdly thick - 5 mm in the head (!), 3 mm in the battery tube (strengthened with three extrusions on the inside that run the length of the flashlight)
- in addition to the "+" nipple, the head PCB has two JTAG-like contacts - for debugging or reflashing?
- the head PCB is screwed to whatever's above it (another PCB or the pill?) with two screws


Edit: Looking at my beamshots above, i could SWEAR it's even more yellow now than a few weeks ago. What the *bleep* is going on? I'll try to make a new beamshot tomorrow and see how it compares.

i think Dosun uses Cree 5AQ2 emitter.
I have mine received from DX ( sku12501) and yes it is a lovely warm almost identical to an incan bulb.