Product Code: 1607150

Interfit S1 Twin Head Kit

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The Interfit S1 is an affordable 500Ws, AC/DC powered monolight with high speed sync and TTL for Canon and Nikon cameras. The head is powered by a high-capacity 4500mAh Li-Ion battery which provides up to 350 full power flashes in Manual and TTL modes and over 400 full power flashes in high speed sync (HSS) mode. Firmware updates now available here

Interfit S1 Firmware update!

Key Features: Interfit S1 Twin Head Kit

New firmware update available - Unlock the pull power of the S1!
Interfit engineers are pleased to announce their latest firmware update that bundles together enhanced Canon 5D Mk IV compatibility and two additional stops to the bottom of the power range, read more here:

Power Supply:
Each Interfit S1 comes standard with both battery- and AC-power sources. The interchangeable 4500mAh Li-Ion battery provides up to 350 full power flashes in Manual and TTL modes and over 400 full power flashes in High Speed Sync mode. This wire-free power source gives photographers the freedom and mobility to venture out from the studio and rapidly set up and reposition lights on location. For traditional studio work, the S1 also ships with an AC power pack, an industry first for an advanced TTL/HSS battery-powered monolight. This multi-voltage adaptor can be used anywhere in the world (100-240v) and lets photographers continue to shoot while their battery is charging.

Shooting Modes:
The S1 has three different shooting modes, each to serve a different purpose and shooting style. Interfit's new S1 Remote for Canon or Nikon enables photographers to take advantage of their camera's TTL system just like they would with a speedlight. This automated light output uses the S1's entire 9-stop power range (500Ws - 1.9Ws), is automatically calculated in 1/10th stop increments, and allows for +/- 3 stops of exposure compensation, manually adjustable within 1/3rd of a stop. Having an automated flash exposure allows the photographer to quickly and easily achieve their vision. This automatic mode is ideal for environments with constantly changing ambient light, and shoots that require you to quickly change your setups or location.
For those that prefer to have complete control over their light and have time for fine-tuned adjustments, the S1 can be used in the traditional manual mode. Manual shooting mode also utilizes the entire 9-stop power range, controllable in 1/10th stop increments. While in manual mode, users gain access to the S1's High Speed Sync mode, reaching shutter speeds up to 1/8000th of a second. High Speed Sync mode utilizes the top 4 stops in the power range (500Ws - 62.5Ws) and is manually adjustable in 1/3rd stop increments.

Utilising IGBT technology, the S1 is able to offer short flash durations while maintaining color accuracy throughout the power range. Flash duration ranges from 1/1,000 at full power, down to 1/9,000 at minimum power. By shortening the flash durations, we were also able to improve color accuracy, giving the S1 a consistent 5700k (+/-100k) color temperature throughout the entire power range.

S1 TTL Remote:
The S1's TTL remotes give the users direct control over any S1 light in any shooting mode from the camera position. This camera-mounted transmitter is available for both Canon and Nikon camera's and supports E-TTL ll and i-TTL protocol, respectively. Having three individual groups gives users the freedom to control lights individually to create dynamic lighting ratios with a working range of up to 100m (300').

Interfit S1a - AC-powered flash:
The S1a has all of the same features as the S1 sans battery. This unit is designed primarily for use in studio or for photographers who have already invested in external power packs with sine wave inverters. Slightly smaller than the S1, the S1a works seamlessly with its battery-powered counterpart at a 40% lower price point.

Additional Features:
We made durability our priority for our portable flash units, so we built the S1 and the S1a within a strong and lightweight aluminum body rather than plastic. We also include a frosted glass diffuser dome to protect the flash tube. Both the S1 and S1a feature the widely-used Bowens S-Type modifier mount, giving users hundreds of high quality and affordable modifier options to choose from including Interfit's line of softboxes, reflectors, grids, beauty dishes and more. A mini-USB cable is included with every light, allowing for firmware updates when new cameras are released.

S1 Specifications:

  • Maximum Watt/Seconds: 500Ws
  • Guide Number 100ISO, 1/125sec., 3m (10'): 48.7m (160')
  • Flash Power Range: 9 stops
  • Flash Variability: 1/10th stop increments
  • Recycle Time: 3 sec. (AC & DC)
  • Flash Duration: 1/1,000 - 1/9,000 (max-min power)
  • Colour Temperature: 5700k +/- 100k
  • Modeling Lamp: 10w LED (off, 50%, 100%)
  • Wireless Control: Interfit TTL-C/N 2.4GHz Remote / Sync Port, IR/Optical
  • Shooting Modes: Manual, TTL (Canon/Nikon), HSS
  • Maximum Sync Speed: 1/250 sec. In normal sync mode / 1/8000 sec. in High Speed Sync mode
  • Operating Voltage: 100-240 VAC
  • DC Battery Type: 4500mAh Li-Ion
  • Battery Life: 350 full power flashes
  • Battery Charge Time: 3 Hours
  • Fan Cooled: Yes
  • Auto Dump: Yes
  • Temperature Regulation: Yes
  • Dimensions (Length x Diameter) Inc. glass dome and handle: 34 x 13cm (13.4 x 5.1")
  • Weight Inc. battery (S1 only): 2.85kg (6.3lb)

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Product Specification

Auto Dump Yes
Colour Temperature [k] 5700k +/-100k
Flash Duration 1/500s (Max Power) 1/9000s (Min Power)
Flash Power Range 9 Stops 1.9Ws to 500Ws
Guide Number 48.0
Included Accessories 2 x S1 units / 2 x mains charges / 2 x Li-Ion Batteries / 2 x battery chargers / 2 x 7” reflectors / 2 x upgrade cables / 2 x sync cables / 1 x Dedicated S1 Backpack.
Modelling Lamp 10w LED
Power Source 100-240v AC or 4500mAh battery
Power [Ws|Joules] 500
Recycling Time 3 sec
Size [cm] 34 x 23 x 13
Manufacturers Link Interfit
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Your flexible credit options available

Interest Bearing

with a choice of repayment plans over 12, 24 or 36 months 13.9% APR (representative)

Buy now pay later

36 month loan with a six month deferral period, 18.9% APR (representative)

Interest Bearing Finance

This option comprises term loan with a choice of repayment plans over:

  • 12 months
  • 24 months
  • 36 months

The balance of the finance agreement is payable directly to Novuna Consumer Finance in equal monthly instalments by monthly direct debit. The direct debit payments will commence at the end of the first month following receipt of your goods. The interest rate charged is 13.9% APR. Late payment and early repayment penalties apply; full details of these will be provided in the loan agreement pack.

For customers based in the Channel Island, please call us to apply for finance

  12 Months 24 Months  36 Months 
Cash price  £1,299.00  £1,299.00  £1,299.00
Deposit £0.00 £0.00 £0.00
Loan Amount £1,299.00 £1,299.00 £1,299.00
Monthly Instalment 11 x £116.07 23 x £61.81 35 x £43.82
Final Instalment £116.07 £61.81 £43.82
Total Amount Repayable £1,392.84 £1,483.44 £1,577.52
Representative 13.9% APR 13.9% APR 13.9% APR

Buy now pay later

The Buy Now Pay Later option comprises a 36 month loan following a six month deferral period.

During the six-month deferral period, it is possible to pay off the loan, either by way of a lump sum or in smaller amounts. If the loan is partially repaid within six months, the remaining interest will be adjusted to reflect the new balance. If the loan is fully repaid within the six-month deferral period, then no interest is payable, however, a £29 early settlement fee is payable in respect of repayments within these six months.

Following the six-month deferral period, Novuna Personal Finance will initiate a monthly direct debit payment for the remaining duration of the loan. Interest will be charged at a rate of 18.9% APR on outstanding balances (backdated to the first date of the loan). Novuna Personal Finance will send a reminder letter approximately one month before the six-month deferral period is due to elapse.

For customers based in the Channel Island, please call us to apply for finance

  Balance settled in full within the six month deferral period Balance NOT settled in full within the six month deferral period
Cash price £300 £300
Deposit £0 £0
Loan Amount £300 £300
Settlement fee £29 £0
Settlement payment £329 -
Monthly Instalment - 36 x £11.57
Total Amount Repayable £329 £416.52
Representative 18.9% APR 18.9% APR

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Product Code: 1607150-wex Manufacturers Part Number: INTS12K1