Overview

The Sofirn IF24 is a multifunction flashlight with a focused main white LED at the front, and diffuse high-CRI LEDs and RGB colored LEDs on the side. It is powered by an included 18650 battery and has a USB-C port for internal charging. The IF24 can be used as a standard flashlight with a balanced beam and enough intensity to spot large objects 227m away, as a magnetic work light, a beacon or warning light, and a colored accent light for photography. A side switch combined with a rotary mode selector make it easy to access a variety of functions.

Maximum output of the main LED is advertised as 2000 lumens, but tests at about 1400. The side LEDs exceeds their advertised maximum of 550 lumens, testing at 960. Colored LED output ranges from 20 to 40 depending on color, and cannot be adjusted. Output in all modes decreases as the battery drains. Both main and side LEDs are adequate for general use, but the low output of the colored side light makes it better suited to use as a beacon or marker light than an accent for photography. Some might want to use the colored light set to red to preserve dark adaptation, but that has the opposite problem: it's too bright, and the white side light on ultra-low is likely to work better. The color rendering of the main LED is bad, but the side LEDs are good despite some green tint.

The IF24 is a bit of a mixed bag, having many appealing features, but some rough edges in the execution. For those who find its features appealing, I suggest considering the new IF24 Pro, which has more efficient electronics, regulated output, changes to the user interface, and more throw. If it's unavailable, the IF24 is conditionally recommended.

Highlights

• Flashlight, work light, and colored light in one package
• Flood light has high CRI
• Works well with both unprotected and protected 18650 batteries
• Rotary control makes managing many functions in a small package easy
• Side LED max output exceeds claim

Lowlights

• Cool white, low CRI main LED
• All modes have unregulated output
• Main LED performance falls short of claims
• A single button press from max mode might be a lower mode, or might be off
• Magnet is not very strong
• Efficiency is poor
• No glass lens over plastic TIR optic

Specifications

Spec	-
Battery	1x18650
LED	Luminus SST-40, white CSP LEDs, RGB CSP LEDs
Color temperature (main)	7254K
Color rendering index (main)	66.8
Max output (main)	1379 lm
Max throw (main)	227 m
Max sustainable output (main)	n/a
Max output at 50% battery (main)	1080 lm
Best efficiency (main)	95 lm/W @ 133 lm
Candela per lumen (main)	9.2 (balanced)
Color temperature (side)	5536K
Color rendering index (side)	92.6
Max output (side)	960 lm
Max throw (side)	36 m
Max sustainable output (side)	n/a
Max output at 50% battery (side)	767 lm
Best efficiency (side)	118 lm/W @ 405 lm
Candela per lumen (side)	0.31 (extremely floody)
Length	126mm
Head diameter	27.5mm
Weight	101g
Weight with battery	145g
Charging	USB-C
Low Voltage Protection (LVP)	Yes, 2.9V
Lockout	Electronic (rotary switch) and mechanical (tailcap)
Approximate price	$40
Provided by	Sofirn
Rating	★★★☆☆ (conditionally recommended)

Details and technical analysis

Versions

There is only one version of the IF24. A newer model called the IF24 Pro was recently introduced; it has regulated brightness, user interface changes, and more throw on the main LED.

Accessories

The IF24 comes with a battery, USB A-to-C cable, user manual, and pocket clip.

Modes and user interface

User Interface

The main function is selected by rotating a ring surrounding the side switch, which has four positions: lock, main, side, and color. Within each group, the brightness level, color, or blinking mode is selected with the side switch as follows.

1C means click (press and immediately release the button); 1H means press and hold for about half a second. 2C means click twice; 2H means press and release the button, then press and hold.

State	Action	Result
Off	1C	On (last-used mode)
Off	1H	Ultra-low
On (except turbo/blinky)	1C	Off
On	1H	Adjust brightness/color
On/off	2C	Turbo/blinky modes
Turbo/blinky	1C	Last-used mode (which can include off)
Turbo/blinky	2C	Next turbo/blinky mode

For the main and side lights, the turbo/blinky group always starts in turbo and includes the following functions:

• Turbo
• Strobe (alternating between two frequencies)
• SOS
• Slow beacon

For the colored lights, the blinky group always starts with a medium beacon in the current color, and the following blinky modes exist:

• Medium beacon
• Police strobe
• RGB rainbow
• RGB waterfall
• RGB droplets
• RGB slow fade

My main complaint about this UI is that a single click from the turbo/blinky group might return to a lower mode, or might turn the light off. Both are technically a return to what the light was doing before activating turbo, but it requires the user to remember, or be surprised by the behavior.

Modes

Main light

Mode	Estimated lumens	Estimated throw (FL1 meters)
Ultra-Low	1	6
Low	12	20
Med	133	68
High	660	156
Turbo	1379	227

Side light

Mode	Estimated lumens	Estimated throw (FL1 meters)
Low	32	6
Med	155	14
High	405	23
Turbo	960	36

Output, runtime, and efficiency

Testing was performed using a Sony VTC6 battery with a tested capacity of ~2600 mAh.

Main light

Mode	Estimated lumens	Time to 80%	Time to 50%	Time to 10%	Efficiency (lm/W)	Current (mA)
Standby	0			16.5 years	0	0.018
Ultra-Low	1			16.1 days	36	6.73
Low	12			3.4 days	92	31.8
Med	133			7.7 hours	95	340
High	660	38 minutes	78 minutes	2.5 hours	83	1392
Turbo	1379	1.7 minutes	2.0 minutes	2.1 hours	92	None

Side light

Mode	Estimated lumens	Time to 80%	Time to 50%	Time to 10%	Efficiency (lm/W)	Current (mA)
Ultra-Low	1			16.1 days	36	6.73
Low	32			1.5 days	105	74.6
Med	155	3.4 hours	7.0 hours	9.9 hours	106	326
High	405	92 minutes	3.0 hours	4.1 hours	118	760
Turbo	960	3.1 minutes	43 minutes	2.5 hours	99	1900

The colored LEDs draw about 145mA with output ranging from just over 20 lumens to 40. These are very rough output estimates, as I do not trust the calibration for non-white LEDs.

Beamshots

Main

Turbo, high, Zebralight SC64c LE for comparison

Tint vs BLF 348 and Zebralight SC64c LE

Side

Turbo, high, Zebralight SC64c LE for comparison

Tint vs BLF 348 and Zebralight SC64c LE

Color

Light quality

Readings are taken from the center spot diffused with DC Fix diffusion film using an X-rite i1Pro spectrophotometer.

Main light

Mode	Color Temperature	Tint Duv	CRI	CRI R9 (deep red)	CRI R12 (deep blue)
Ultra-Low	5668K	0.0141 (2x extremely green)	68	-56.9	34.8
Low	6580K	0.0038 (moderately green)	67	-41.3	40.8
Med	7254K	-0.0011 (slightly rosy)	66.8	-30.8	42.2
High	7218K	-0.001 (slightly rosy)	67.5	-29.3	42.6
Turbo	6867K	0.0008 (neutral)	68	-32.4	42.8

Side Light

Mode	Color Temperature	Tint Duv	CRI	CRI R9 (deep red)	CRI R12 (deep blue)
Ultra-Low	6064K	0.0029 (moderately green)	92.2	86.5	73.8
Low	6064K	0.0029 (moderately green)	92.2	86.5	72.9
Med	5536K	0.0049 (very green)	92.6	59.9	76.2
High	5636K	0.0044 (very green)	93.1	62.8	75.5
Turbo	5505K	0.0049 (very green)	92.6	60.3	75.3

Batteries and charging

The IF24 uses one 18650 battery, and Sofirn's usual 3000 mAh button top is included. There are springs on both ends of the battery tube, and all 18650s I tested other than extremely long cells with USB charging ports are compatible. The light stays on constantly when vigorously shaken, even with unprotected flat-top cells.

There's a USB charging port on the body of the light, which can charge all compatible batteries. Both A-to-C and C-to-C cables work with every power supply I tested. Charging takes about 2.5 hours from empty.

Construction

While the IF24's construction is high-quality and rugged overall, I do have to fault it for not including a glass lens over its plastic TIR optic. This will lead to scratches.

Size and ergonomics

It wouldn't be fair to compare the size of the IF24 to single-function flashlights. It is larger than the average 1x18650 light, approaching the size of some lights using the larger 21700 battery. It's larger than my preferences for carry in a pants pocket, but adds significant functionality for that size.

It can be attached to surfaces using a magnet in the tailcap, which is held in by the spring and can be removed. I would prefer a stronger magnet.

Modification potential

The bezel is easily unscrewed allowing removal of the optic. Underneath is the LED and MCPCB, which appear easy enough for anyone with basic soldering skills to replace.