Sofirn C8G

Curious about this myself as I want to give this light a driver swap, more specifically the C8F driver which has a perpendicular pcb soldered on the main PCB, thus taking some space in the vertical plane as well. So far I haven't found anything online about the internals, only exterior pics, that's all. I imagine the driver for this light would be either single PCB, or a sandwich of two, to save space in the vertical plane due to the single, thus deeper reflector I'd imagine.

It’s a 21mm driver, Kaidomain and Mountain both offer 20 or 22mm drivers. I think all those drivers are clicky based and would need some tweaking for an E-switch. Lone Oceans has a 20mm driver, its clicky based. He has released the firmware (arduino based) so maybe someone can write some new code for it.

There doesn’t appear to be anything too fancy going on with the mcu, its probably as large as it is just to get enough memory. A switch, some indicator lights, three volts out for enable and the pwm signal to the boost converter. Possibly a voltage monitoring input. The rest of the pins appear unused to me. Unfortunately the tricky part of swapping out the MCU is the millivolt feedback from the sense resistors seems to go back to an op amp which then turns into a voltage output feeding into the mcu.

The mcu is contiuously modulating the pwm output. It appears the driver will run away if you just give it a pwm signal with no feedback loop. I don’t know of any BLF firmware that does a feedback loop. I can’t figure out what the boost converter is. With my limited knowledge, no data sheet and no programming skills its looking like a dead end for me. I might pull the mcu board off at some point and feed it a pwm signal with my power supply current limit set safe just to see what happens. Probably wait till Sofirn starts selling replacement drivers first. Or put a 4000k led in it and leave it be.

It’s a good light as it is, just a little clunky on the user interface. If it wasn’t for Tom and Toykeeper spoiling us we would probably love it.

- we've been hit with no many negatives as of late, nice to hear some good words

Same as the Convoy L6. I don’t find this an issue

Then just unscrew the tail cap a half turn to switch off and on. No need to use the rear switch. Maybe you should only get side clickys moving forward.

Too many complaints from a budget friendly light.

Moonlight access on a dedicated thrower? Why is this a huge issue, I’d only ever use this light for hunting. Use something else if you’re needing moonlight. like an EDC.

Well it's more of a commodity, a convenient feature tohhave on a light, thrower or not. Of course it wouldn't be of too much use outdoors but let's say you want the moonlight at night when you're in bed - just point the light to the ceiling and you get some ambient just like you would with a flooder. Myself, I find 1LM or even sub Lumen pointed at the ceiling plenty light to brighten up my small room at night. Even the stand-by LED's from the various equipment, monitor, router, mouse, etc. are a noticeable amount of light in pitch dark and I can see where to pick up the flashlight. My GT Mini or even micro, with the lowest moonlight lvl. set up it's perfectly enough for such purpose. If anything, while indoors there's always much reflection from everywhere compared to outdoors, so, no reason not to have a nice feature if it's a possibility ;)

Some thoughts after receiving my C8G this Friday.. Well, mostly nags and some rantings actually.. :|

- Driver seems to be the same layout as the C8F - main PCB with a perpendicular secondary / daughter PCB - just a bit shorter than the one on the C8F tho and a bit more off-center as well to accommodate the small inductor for the boost circuit that sits on the main PCB - a C8F driver would almost fit if not just barely in this host, as the compartment hosting the driver, under the emitter's shelf it's a bit shallower due to the deeper single emitter reflector in the C8G. The C8G overall it's around 2mm longer than the C8F just because of this deeper reflector.

- There's no Stand-By function on the side switch as on the C8F, which I knew it would to be a letdown, but not as much as it actually was when I got the flashlight and practically tried to use it.. Very dissappointing :( Likely that is because of the boost diver circuit doesn't have a stand-by function itself.. ?

- The Ramping itself seems to be linear current, thus the start of the ramp seems to ramp up the perceived brightness very fast from moon to a relatively high brightness, then, for the longest remaining part of the ramping after the initial part, the brightness only seems to slower and slower gain in intensity for a long period.. :| which is another bigger letdown in practice then in expectation (also didn't even expected or knew this beforehand to begin with.. ) This linear current ramp really beats the purpose of having a practical ramping UI in the first place.. because, well.. it's not that practical in real usage scenarios.. :|

- The Moon mode - 10LM - Waaaay too much (even if it's a thrower.. ) - 1LM, even if at least from the cumbersome accessible Moon mode straight from Off (holding the side switch & power On from the tail clicky) that, btw, leads me to the next point/nag..

- The Moon mode access it's cumbersome and non practical at best: One method is a buton combo and only from the from Off state, the other mode has you first accessing the Turbo mode and from there going down to Moon mode - which beats the purpose of the Moon mode in the first place.

Ok, so there is at least one plus side of this driver compared to the C8F a reference though with this flashlight, so it's not all bad :)

- Just noticed on this light, compared to the C8F, that from Turbo or Strobe modes, a long press it's not considered a alternate way of standing-by the light (hence, this light doesn't feature such a function to begin with anyways.. ) but actually, more convenient, more intuitive, long press from Turbo mode would start ramping down (just like with Narsil) and from the Strobe mode, it would cycle through the disco/flashy modes (Strobe [of variable frequency] > Beacon [~2s interval] > SOS [a fast one just as I like it] > cycle back to Strobe > etc. > .. ) On the C8F, oddly and quite disappointingly for me personally, long press from Turbo/Strobe modes would put the light in Stand-By.. :| I guess it's an "alternate" way, a "shortcut" to straight away put the light in stand-by without clicking twice from those special modes. Makes sense, but I'd rather have the C8G's like behavior, seems like the most convenient, intuitive for me. Even the Narsil way still has a "flaw" as far as my preference goes, as accessing the Turbo would always first stand-by the light, so single click from Turbo will be stand-by.. :| then clicking again would power on the light back on in the previews level of brightness.

Btw, some pics of the 2 relevant IC's on the C8G's driver:

1st pic - the MC

2nd pic - the Boost IC (and the inductor as well)

On the plus side… the switch appears to be on its own board, making a driver replacement much easier if one is so inclined to do so. Are you able to measure the driver diameter?

I know you could always ignore the tailswitch or use it for lockout purposes, but I’d welcome a no-switch tailcap offering.

I'll measure the driver diameter when I'm getting back home, but until then I'd recall it was a 21mm or 21.5..? Just the same as the C8F if you have the measurements for that one.

And about the tail switch, the Lumintop GT Mini would fit the bill quite nicely if you don't have it already, although slightly bigger head diameter and I'd argue a more cumbersome access to the various blinky modes. Other than that, a bit nicer design I'd say and only 18650 fuel compatible.

FUN…
I use the twist the rear cap to isolate ALL my torches. even the copper and Stainless ones.
Get into the habit. Just one flat is usually enuff.

Thank you.

- 21mm

Thanks, 80T.

And good point about the GT Mini. Definitely a contender as long as someone isn’t hung up on 21700 capability.

Yesterday I got the C8G in my mailbox (was sent to me for review).

First impressions are good.
The only thing I didn’t like is the wanky ramping: The transition from low brightness to high is quite fast for my liking.

The review should be ready by the end of the next week, but if anyone is interested, today I can capture some comparison beamshots between the C8G, C8T and GT Mini (will add C8A to the mix, provided that I have it included in my flashlight box :slight_smile: )

The previous topic was deleted, glad to see the talking here. :smiley:

I got mine a week or so ago.
Pretty good light for the price i guess. I’ve come to terms with the tail switch, it seems to be a good quality one. Also the side switch is very satisfying to click, so no problems there. I’m not too fond of the beam pattern and color though. You can clearly see some yellow tints and you get a bit of a weird spill ring. One other “problem” is that the battery indicator light lights up every time you press the side switch. But some people would probably like that for easy visibility and so on.

As far as modes go, i prefer ramping. It starts on moonlight, which gives me plenty light for small things. If i need turbo, its a double click away, single click back to moonlight. and tbh i rarely use turbo other than to impress non flashlight-guys .

It is a decent thrower for its size, 300m for sure. 500 might be a bit of a stretch, depending how dark it it.

The C8T gives 1193 lumens and the C8G gives 1470 lumens measured at 30 seconds. These measurements were taken with a calibrated lumen tube.

I tried bypassing the springs but this made no difference.

The C8G will not out throw the XPL HI at that output. I’d much rather stick with XPL HI for a thrower when it comes to the pricing between the two

Since the new C8F 21700 released Sofirn has been overrating their lights quite badly

Myself I've swapped the C8G's reflector with the one on my C8+ (XP-L HI) Now the beam pattern it's better on the C8G with the C8+ reflector and on the C8+ it got.. worse. Quite a nice light for what it is now, but still, the driver it's killing it.. The ramping curve it's as bad as it can be and I can't get over the lack of the stand-by functionality on the side switch like with the C8F. Now, the C8F, that's a great light as is, as it came out of the box. The C8G on the other hand.. not so much. Sofirn really has to update the driver on this one and put in the standard C8 reflector, something's wrong with the current one.

Here's a few comparison beamshots at 220m (White house)

Sofirn C8G - Sofirn C8T


Lumintop GT Mini - Sofirn C8A


The C8G is of course the brightest of all.
The GT-Mini has a tighter hotspot and thus more throw, though the C8G might even be a bit more throwier than the C8T and delivers a wider spot :)

Most of the reason the C8G looks brighter is from the cool white tint being trapped in the atmosphere on the way down range. It’s only 270 lumens more, not much