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Inon Announces S-220 Strobe
By Ian Bongso-Seldrup, July 20, 2023 @ 09:00 AM (EST)

Inon has announced the release of its new S-220 strobe. The S-220 boasts a guide number (GN) of 22 and a beam angle underwater of 140° (horizontal) × 100° (vertical). The strobe offers S-TTL auto and 12-step manual flash modes.

The S-220 is equipped with a “fly-eye” dome, which expands the light coverage. The strobe features a large wheel dial for better controllability, while the phosphorescent control panel ensures excellent visibility even in low-light conditions. It operates on four AA batteries and features double O-rings to reduce the risk of flooding.

The S-220 is compatible with a variety of bayonet-mount filters: (i) Strobe Dome Filter S [SOFT], which increases the beam angle to 150° (horizontal) x 110° (vertical) while reducing light intensity by –0.5EV; (ii) Strobe Dome Filter [ND], which reduces light intensity by –4EV for macro imaging; (iii) Strobe Dome Filter S [4900K], which changes the 5500K native color temperature to 4900K; and (iv) Strobe Dome Filter S [4600K], which changes it to 4600K.

Available soon from retailers such as Backscatter, the S-220 is priced at $420.

When purchasing underwater photography equipment like the products mentioned in this article, please support DPG by supporting our retail partner—Backscatter.com.


Ultra Wide, High Power, Compact Underwater Strobe

  • Compact body yet delivers GN22
  • Equipped with a fly-eye dome lens enabling super wide underwater beam angle of horizontal 140° × vertical 100°
  • Reliable and proven “S-TTL Auto” and 12-step “Manual Flash”
  • Large wheel dial for dramatically improved operability. A phosphorescent panel for easy readability
  • Double O-rings greatly reduce the risk of flooding
  • Front positioned base contributes more flexible lighting
  • Operates on four AA batteries, readily available and reasonably priced
  • Compatible with various strobe dome filters
  • Supports "Quick Holder" for easy one-touch attachment/detachment

Despite of compact body, the S-220 spreads high-power GN22. The full-scale performance coupled with a wide underwater beam angle provides unparalleled performance as a main strobe in all areas, regardless of whether for wide-angle or macro photography or compact digital camera or SLR camera.

Super Wide Beam of 140° Horizontal x 100° Vertical Underwater Created by Fly-eye Dome Lens

A precisely calculated and uniquely designed fly-eye dome lens for the light-emitting part attains extraordinary underwater beam angles of 140° horizontally × 100° vertically with minimal light distribution variation.

This wide beam angle perfectly fills the "UWL-95S XD" + "Dome Lens Unit III" underwater coverage of horizontal 140° x vertical 100° (at 4:3 aspect ratio), enabling a single S-220 strobe to illuminate the entire image.

Reliable "S-TTL Auto" and 12-step "Manual Flash"

Equipped with reliable and proven INON original high-precision automatic "S-TTL Auto" flash control system and 12 step "Manual Flash" function with -0.5EV. increment.

The S-TTL Auto system can be used not only with camera's built-in flash but also with INON original TTL converter equipped with INON housings, "X-2 R6 Mark II","X-2 R6" and "X-2 R5" for even more precise TTL system. You will never miss a shutter chance.

Large Wheel Dial for Greatly Improved Controllability and Phosphorescent Control Panel Improves Readability

Redesigned large control wheel and switches significantly improve operability. In addition, the rear control panel is white-based highly illuminant phosphorescent material, ensuring easy-to-read usability both during day and night diving.

Double O-rings Significantly Reduce Flooding Risk

The battery box is waterproofed with a double O-ring system, consisting of an oil-bearing yellow O-ring and a black O-ring. This greatly reduces the risk of accidental flooding.

Front Adaper Base for Flexible Lighting

Ball adapters such as the "Z Adapter MV" and "Direct Base Ⅲ" is located forward close to the light-emitting surface, instead of rearward in the previous models not let an optical cable to interfere lighting flexibility.

Operates on 4 Readily Available, Inexpensive AA Batteries

The S-220 strobe is powered by four AA batteries that are widely and reasonably available. Especially rechargeable nickel-metal hydride batteries such as "eneloop" and "eneloop pro" are recommended, as they can be used repeatedly and reliably, and can withstand cold temperatures.

Various Dome Filters

The S-220 strobe is equipped with a bayonet mount to use various dome filters. Packaged dome filters are "Strobe Dome Filter S [SOFT]" which increases strobe beam angle to horizontal 150° x vertical 110° while reducing light intensity by -0.5EV. and "Strobe Dome Filter [ND]" which reduces light intensity by -4EV. specifically for macro imaging.In addition, two optional strobe color filters are available: Strobe Dome Filter S [4900K] and Strobe Dome Filter S [4600K], which warms native strobe color temperature 5500K to either 4900K or 4600K.

“Quick Holder” for Easy, Speedy Handling

Using "Quick Base S" or "Quick Base M6W" with the "Quick Holder Set Z" attached on the strobe adapter mount enables one-touch attachment/detachment of the Quick Holder System. The "Quick Base M6W" is especially recommended as you can remove the LED light when shooting still images.


Model INON S-220
Strobe Control Mode (*1) S-TTL Auto / Manual
Connection Optical D Cable
Guide Number at FULL (*2) 22 [without filter]
19 [with Strobe Dome Filter S [SOFT]]
5.6 [with Strobe Dome Filter S [ND]]
Settable power at Manual mode (*2)

*( ) stands for Control Dial position
22(FULL) 19(-0.5) 16(-1) 13(-1.5) 11(-2) 9.5(-2.5)
8.0(-3)  6.7(-3.5) 5.6(-4) 4.8(-4.5) 4.0(-5) 3.5(-5.5)
(1/2EV.increments, 12 steps)
Beam Angle 140°(horizontal) × 100°(vertical)[without filter]
150°(horizontal) × 110°(vertical)[with Strobe Dome Filter [SOFT]]
Color Temp. Approx. 5500K [without filter]
Approx. 5400K [with Strobe Dome Filter [SOFT]]
Recycle Time at FULL (*3) Approx. 2.1 seconds minimum ["eneloop" batteries]
Approx. 2.0 seconds minimum ["eneloop pro" batteries]
Approx. 2.5 seconds minimum [Alkaline batteries]
Approx. 3.5 seconds minimum [Lithium (1.5V) batteries]
Flash Capacity at FULL (*3) Approx. 380 flashes ["eneloop" batteries]
Approx. 500 flashes ["eneloop pro" batteries]
Approx. 350 flashes [Alkaline batteries]
Approx. 640 flashes [Lithium (1.5V) batteries]
Compatible Batteries AA "eneloop" (BK-3MCC) [recommended] x 4
AA "eneloop pro" (BK-3HCD) [recommended] x 4
AA NiMH (*4) x 4
AA Alkaline (*4) x 4
AA Lithium (1.5V) (*4) x 4
Dimensions Diameter: 80mm / 3.1in. Height: 91mm / 3.5in. Depth: 128mm / 5.0in.
(*Including protruded parts)
Weight[air] 348g/12.3oz [no battery, no filter]
463g/16.3oz [including 4x “eneloop”batteries]
Weight[underwater] Approx. 50g / 1.7oz (with 4x "eneloop" batteries)
Working Temperature 0°C - 30°C / 32°F - 86°F [water temperature]
Storage Temperature 0°C - 30°C / 32°F - 86°F [air temperature]
Depth Rating 100m / 328ft
Body Material / Color Polycarbonate/red
Package Contents Strobe Dome Filter S [SOFT],
Strobe Dome Filter S [ND],
Rubber Cap for Sensor
INON Grease

As of July 2023. Specifications/product design subject to change without prior notice.

Test battery

"eneloop" battery Panasonic "eneloop", BK-3MCC, 1.2V, Min.1,900mAh
"eneloop pro" battery Panasonic "eneloop pro", BK-3HCD, 1.2V, Min.2,500mAh
Alkaline battery Panasonic "EVOLTA NEO", LR6(NJ), 1.5V
Lithium (1.5V) battery Energizer ULTIMATE LITHIUM, L91, 1.5V

(*1) Compatible flash mode varies depending on combined camera system.
Please refer the instruction manual for detail.
(*2) Measurement in air/ISO100 at 1m
(*3) Reference test data by INON. Measured with FULL strobe output at 30-second intervals with Advanced Cancel Circuit switch set to “1” in water of 25°C/77°F giving 10 minutes cooling period every 50 flashes.
(*4) Not all Ni-MH batteries are confirmed compatible. To avoid battery issues like battery leak, use good quality batteries that are capable of continuous discharge at high currents referring to (*3)



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