SEACAM Flash Systems

There are two ways of controlling flash  - either by manual setting of appropriate power settings on the flash - or by TTL (Through The Lens) automated control where the camera interfaces with the flash unit and automatically shuts off the flash unit when its programming computes that an appropriate amount of illumination has been received by the digital sensor.

SEACAM  currently offer three flash systems:

Seaflash housings to take Nikon and Canon flash units - these are Automatic systems only, utilising the manufacturer's current TTL system flash units. They have a powerful inbuilt illuminator and are supplied with a charger unit for this. Currently it is only possible to use ONE flash unit per camera housing in TTL mode as hard connecting two is not supported by the flashes. A second flash can be used via its slave function.

SEACAM  Seaflash units designed for manual flash photography only. These Seaflash 100 units utilise electronics built by Subtronic of Germany, are small, easy to carry and offer a variety of power settings and an inbuilt white led spotting light.

SEACAM now produce their own flash unit - the SEACAM 250TTL (see below for full specifications).

This is a highly specified flash unit available for either Nikon or Canon. It automatically detects the camera (film or digital) to which it is fitted and operates utilising TTL accordingly. It also offers an extensive range of features including a multi-power manual system, an inbuilt illuminator, variable colour temperature, and much more. It is built to SEACAM's high standards, is very versatile and can be firmware updated (for a charge from SEACAM) as camera models change.

We use a 250TTL unit ourselves with a Canon 1DS and currently (7/07) have been using it in lower than ideal visibility with both macro and wide-angle set ups. We have found that exposure on TTL to be very consistent with a bias towards the right of the histogram and only occasional very slight highlight clipping (but nothing that cannot be pulled back in the Raw converter). Light quality is very good and the ability to shift colour temperature is interesting even when shooting macro in cold water. Battery capacity is excellent with power level down to 70% after 2.5 hours underwater and over 200 images shot - at small apertures. The pilot light is also surprisingly powerful and for macro work the PA (where the pilot light switches on when the camera shutter is depressed halfway) to be incredibly useful. On the warmer colour temperature setting, this is the first flash unit we have ever had which produces well exposed images of red seaweeds which are notorious for their ability to absorb flash light!

Seacam Seaflash 250 - Specifications:

The 250TTL is a fully digital flash unit offering fast microprocessor control compatible with Nikon digital i-TTL, Canon digital e-TTL (also Nikon and Canon 'film' TTL). It is updatable to next ttl generation operation via firmare updates (available in future from SEACAM for a charge).

Underwater guide number (GN) is 20 - ISO 100 / 1m at full power (250Ws) with a coverage angle of 120° via a precision reflector and corrected dome glass. 190 flashes at full power with a recycle time 0.3~5 sec. Adjustable color temperature 4300°K or 5200°K, using two selectable flash tubes. Manual 7 stop power level selection. Built in power LED spotting light with 3 manual power settings offering a continuous burn time of up to 6h. Built in high sensitivity slave sensor usable with all manual settings with or without the spotting light. Offers a true SOS signal (a low power flash is emitted every few seconds) for approx. 3h

Synchro socket is either Nikonos V or S6. Charging socket.

Digital multi function display, fully illuminated with automatic dimming which includes a display of the power delivered after each exposure . Battery status indicator and fully automatic battery charger with auto shut off and an audible alarm for preserving battery life. Charger - a lightweight power supply operating from 110-240V and complete with a 12V adapter - is automatic, fully controlled by voltage, temp. and time - charging time is approx.100 min. Utilises a high quality Sanyo internal battery pack (easy to replace but during service only)

Precision machined SEACAM silver housing, sea-water resistant aluminium, with macro focusing and protection ring. Neutrally buoyant.

Dimension L x Ø: 250 x 110 (120) mm. Weight 2100 g. Depth rating ~ 80m.

Flash Accessories

As well as offering their own flash unit, SEACAM also produce a variety of ancillary equipment. There is an extensive range of articulated arms designed to position flashes securely underwater - adapters are available to allow the use of other types of flash unit with these arms too (including Ikelite, Sea & Sea and Nikonos). Heavy duty cables are available with Nikonos V type, Ikelite type or the very robust and versatile S6 type connectors.  These are available in coiled or longer straight cable types. SEACAM also produce coloured filters  for use with their flash units and reducing masks  to allow tight control of lighting. Lastly, there are neoprene covers to offer protection against abrasion, weights to neutralise buoyancy and quick release handles.

These images have all been taken using a single Seaflash 250TTL with manual ambient light exposure and the flash set to TTL. Camera was a Canon 1DS, various lenses.