I’m looking for a relatively inexpensive (under 100:money_mouth_face: flood flashlight for video mapping of cave systems.
I need it to be able to constantly output >1000 lumens for at least 1 hour without overheating (and optionally to have 2000lm “boost” mode)
Also it needs to be fairly compact to be held with one hand (and coupled with a GoPro)
A very welcome bonus would be high CRI LED
I tried using my Lumintop D1 2000 lm flashlight (which has actual max output of 1000lm).
In terms of light output, colour and pattern it was OK for my needs with a diffuser,
However it overheats too fast and steps down to ~400lm. Also its battery life is too short.
Please let me know If you know specific models (Preferably available on Amazon or Ali-Express)
A Convoy M3C will put out 1600 lumens for its entire battery.
The 4000 lumen will step down but the 1600 lumen does not (use stepped mode so you know how many lumens you are using).
The M3-C can be had with several different emitters. The XHP 70.2 or 70.3 Hi will be the most efficient. If you wanted to get that high CRI then the GT FC-40 emitter is also available. I’m not sure what the sustained output would be with the FC40 though. It might still be around 1000 lumens on the second highest setting but I have not seen measurements for that.
Do you need high CRI or is 70 CRI OK?
Acebeam E70-AL will provide around 1hr45min at 1200 lumens with XHP70.2 and is much smaller than the M3-C. Olight Seeker Pro 3 has similar sustained brightness.
Convoy M3-C is 1440lm with XHP70.2 and 1000-1100lm with high CRI GT-FC40.
Actually doing some research for this made me quite surprised that there is actually not many flashlight that can do high CRI at 1000 lumens. For example convoy M3C can do high lumens but it is actually quite big with 26650 body, and the led is CRI70 led.
The Fireflies E12r maybe another good option. It is 21700 body so it is actually much more smaller than the M3C. It can do about 800 lumens for 165 min according to 1lumen review, but that is with very inefficienct 219b led. If you pick the Samsung LH351d led, it should be able to do 1000 lumens for the same time, which makes me realized how surprisingly good the new fireflies flashlights are.
The main problem you have is the thermal capability of a small flashlight. If you use something like the Acebeam X50, it is much more expensive but you can do 5000 lumens for 70min, or 2100 lumens for 3 and a half hours. Actually I checked the Nocitgon DT18 and it is surprisingly weak for long duration runtime for a 3-cell flashlight which shows the limits of linear flashlight drivers.
I don’t really need it to be pocketable - just not too heavy (preferably under 200g).
So I guess M3C should do since it appears to be the cheapest option here, and has CRI. A few questions:
Can the optics be removed (or at least lined with a white paper) so the flashlight will become truly “flood”?
Can I use a regular green panasonic 5A 18650 with it? (will it be enough to sustain 1000lm?)
It has a quite small body - can it really sustain 1000lm without stepping down?
The O-Light is too expensive. And I couldn’t find a vendor with international shipping for Acebeam E70-AL (Which is also not too cheap). Also it doesn’t accept 18650?
The M3C should fit your purpose but if you want high CRI you need to choose FC40 option which will be a lot less bright than XHP70. For more flood choose the XHP70.2 and not the HI version. it will also be brighter.
You should not use the green panasonic 5A 18650. Convoy says it needs a battery that can do at least 11A. Since you are picking the M3C, you should use a bigger battery. The 26650 KeepPower is good with 5500mah capacity.
You should be able to remove the bezel and remove the optic for a big flood, but it looks like Convoy also sells a diffuser cap you can put on top of the flashlight to convert it into a diffuse flood.
I think the M3C would be great for this, too, as long as the body diameter isn’t too fat for you to comfortably grip it with the camera. It is a little weighty and a bit bulky for regular pockets but it’s a great light with the ability to sustain good brightness for quite awhile. You can run an 18650 in it but you won’t get the run time or as much of a sustained current with those…definitely would get a 26650 (or you could buy it with the 26800 cell for some exceptional run time…adds a little length to the light (included adapter) but also feels great and balanced in the hand…the increase in capacity is fantastic). I would really recommend the 26800. You could bring some good 18650 along in waterproof containers as emergency spares.
I would buy the optional stainless steel bezel for the light, too. If you drop it, it’s heavy enough to ding/bend the aluminum bezel…the steel will prevent that and also go a long way toward preventing the glass lens from cracking. (Might be wise to pick up a spare lens, too…). One great thing about Convoy is that if you ever need parts, they are cheap and easy to order them, so if a drop or water ingress takes out the driver (or any other part), you can get a new one with no hassle and minimal wait time.
Even though it’s not the slimmest or shortest light, it should tuck into any pack pretty easily. You can unscrew the tail cap 1/4 or 1/2 turn and it will mechanically lock out the light even if there is pressure against the cap in a crammed pack. Some lights aren’t quite as reliable there and may still come on if the tail cap is pressed (or you have to unscrew them a lot further).
One thing you should know about this light, however, which could be important to you, is that it is designed with a spring on the tail end, but only a solid brass post on the head end. Because of this single spring, sometimes when you set the light down or bump it, the light may cut off when it is in lower modes. It comes right back on when you press the button, but it can be irritating. The spring isn’t quite strong enough to support the weight of the heavy batteries, so with a bump it might lose contact with the brass post for a moment. In higher modes, if this happens the light might flicker once but it won’t cut off. One small flaw in an otherwise excellent light, but something you should be aware of. Also, the side button is easy to find in the dark but it is not an illuminated button.
For a diffuser, if you happen to have some dead household led bulbs with covers something like these, you can pry them off carefully and there is a thin lip on the bottom…just a little trimming and it is a great fit on the M3C bezel and a fantastic full flood smooth diffuser. The plastic one Convoy sells is ok. You might also look around for clear textured vinyl window film that could be applied to the lens (DC Fix is one brand here but there are all kinds out there that would serve the purpose).
I believe that some kind of LED-bar or-LED matrix will be more suitable for this application. It will enable better heat dissipation and also tint mixing.
If you have some DIY modification abilities, you can glue a heat sink to Sofrin D25L to enable it run longer on 1000Lm before it gets too hot. It is only 1000Lm but it costs 20$ so you can buy 2 for 2000Lm
I don’t like The M3C stock diffuser or Led bulb housing because they will scatter the light backwards, into my eyes. I only want forward looking beam (~120 degrees, same as the camera). I guess I’ll just remove the optics or add that vinyl film.
I might stick to high current 18650 - since is that what I use in my 2 headlamps (and I always carry spare batteries, its a safety issue in caving).
How about sofirn SP36? It has 3 x 18650s and also a high CRI LED.
Nice!