OK, so after a fair bit of waiting, and posting on this thread, I have finally received my H600Fc MK4 and wanted to provide my initial impressions after 3 days with the light.
I will skim through the usual and spend more time reporting the quirks.
Construction:
Construction is fantastic, as with all my other Zebralights, and it continues to make every other light I have owned or handled feel cheap.
Battery compartment:
The Battery compartment is quite slim to the point where I cannot insert certain batteries.
My green protected NCR18650B fit no problem, and so do my unprotected NCR18650GA (red ones from Zebralight).
My
Sanyo/Panasonic NCR18650GA Protected 3500mAh batteries purchased from MTN Electronics DO NOT FIT. I was a little disappointed by this, but its no deal breaker by any means.
Tint:
The tint, which I consider one of the most important aspects of any light passes with flying colors on this model. The colour temp is warm, as expected. The tint feels clean and free of Green hues. A little orangy/yellow, but just a touch. Quite close to a Nichia 219C 4000K but a minor touch more yellow. The spot/spill is very even with no color variations or colour temp variations. Can't say for sure if this is attributed to the LED, as the frosted optic might be doing all the work blending inconsistencies in the beam.
Beam:
This is my first F model from Zebralight. I think it makes a fantastic all around headlamp, but my preference would have still been a traditional reflector with spot/spill. Unfortunately, Zebralight doesn't make one with 90+ CRI. Since high CRI and warm/neutral colour temps are prerequisites for any light, I was willing to take this compromise. Between 2-10 meters away, the beam is beautiful, with super smooth transition from spot to spill. No tunnel vision. My H53c is able to shine quite a bit further at the same lumen output, which is one of the reasons why I like spot/spill better. Although they aren't more efficient, you tend to use them at lower outputs.
Output:
The output of this light is VERY impressive, especially at the H1 (1500+ lumens) setting. This setting is really just a temporary turbo and of little use to me, as the light overheats VERY quickly as others have mentioned already. Regardless of how long it lasts, seeing things with 1500 lumens at 4000K and 90 CRI is just amazing!! I just don't understand anybody who continues to buy 70 CRI lights, be it a thrower or flooder, but that's just me. I always favour quality over quantity, and in my metaphor, would rather eat a small cup of delicious Ben and Jerry's icecream instead of a large tub of knock off house brand cheap ice cream. This Headlamp delivers both quality of light, and heaps of quantity of lumens. Really can't complain.
Moonlight:
Still very good moonlight, but not as dim as my H53C.
PID:
The PID of this headlamp matches reports from all other users. Under the ceilingbounce app, you can clearly see the oscillations as the light increases and decreases in output to try and chase the optimal temperature. My SC600w MK3 HI is seamless in comparison, drawing a really smooth line with very minor "steps".
App aside, in H1(1500+) and H2(900+ lumens), the oscillations are VISIBLE to my eyes, but not in any detrimental way.
I am not of fan of these visible oscillations, and feel like Zebralight cut some corners and released the MK4 lights too soon. As it was the first time I pre-ordered something, I expected the same standards as my MK2 and MK3 lights, so this caught me a little by surprise.
The reality is, that in a scenario where the PID needs to kick in, the light will have to step down anyways, so whether it does this in a pretty or non noticeable fashion is not a deal breaker. When I will be using the light, I already know what the ambient temp is, or speed of my activity, and will set the light to a realistic output that I know it can sustain. IE, if its cold and I am skiing, will put it at 900 lumens. If its warm outside, will stick to 300-500 lumens max. If I need to see as far as possible or make my friends say wow, I'll put it at 1500 lumens for a minute or two.
When running on H1 or H2 for several minutes, I noticed that when I touched the head, the PID would adjust quickly and increase in output. The PID works, but the calibration to achieve a more linear transition is a fail.
Summary:
The light is def a keeper. The H1 and H2 modes and poorly implemented PID were disappointing, but reality is that in any extended use (in most situations), even a MK3 light will eventually step down to the 300-500 lumen setting at the same rate. This is where the H600fc MK4 shines best
Beautiful tint, hopefully better runtimes at medium output settings compared to MK3 lights.
PROS:
-Amazing Zebralight build quality
-Amazing even Tint
-Amazing Output
-Great Color Rendering, at par with my H53c
-Programmable (my setup: G5, G6 with H1 set at 900 lm, G7 with H1 set at 500 lm)
-Moonlight mode
CONS:
-very poorly implemented PID compared to MK3 generation lights
-Tight battery compartment won't accept all 18650 batteries
-Unrealistic H1 setting compared to MK3 lights. *would have preferred lower output with better PID if it was an option.
-Moonlight not as dim as some other models.
