Speedlite Transmitter ST-E2 – an infrared marvel for wireless flash
The Canon Speedlite Transmitter ST-E2 is an infrared flash controller that allows for simple control of wireless flash set-ups for up to 15 metres (indoors) and 10 metres (outdoors).
Who is it for?
If you’ve got one or more Speedlites that can be used as wireless slave units, the ST-E2 is for you. It provides a lightweight unit that controls the remote units by acting as a master flash unit.
Key features
- E-TTL II flash control
- Ratio control over two groups of flashguns
- High Speed Sync control
- Up to 10m range outside
Key benefits
When you don’t want to carry a dedicated master flash but you need wireless control of your flashguns, the ST-E2 is the answer. It attaches to the hotshoe of the camera and emits a controlling infrared signal to control remote flashguns.
It is not just for use in controlling flashguns though. In some locations flash is not allowed, but if the light levels are low, it can be hard to focus. If you can’t use a flashgun, then the ST-E2 provides the focusing beam grid to make autofocus faster and more accurate.
Key technologies
- Ratio control between flash heads
The ST-E2 can be used to control the ratio between two flash groups – group A and B. The unit provides from 1:8 to 8:1 control in half stop increments.
- High-speed sync
The ST-E2 allows for remote high-speed sync so flashguns can be synced at speeds higher than the maximum sync speed of the camera – up to 1/8000sec This can be used to obtain a faster shutter speed and therefore darken the ambient light captured in the image.
Speedlite Transmitter ST-E2 specifications
| Compatible Cameras | Type A EOS cameras (E-TTL, autoflash); Type B EOS cameras (Manual flash) |
| Sync Speed | High-Speed Sync (FP flash): Enabled with high-speed sync mode |
| Flash Exposure Confirmation |
1. Before flash fires during FE lock Adequate flash exposure indicated by the flash exposure level icon lit in the viewfinder. Insufficient flash exposure indicated by the flash exposure level icon blinking in the viewfinder.
2. After flash fires ST-E2’s flash confirmation lamp lights in green for 3 sec. |
| AF Assist beam | Effective Range: Approx. 0.6 to 10m |
| Transmission system | Infrared pulse |
| Transmission range | Indoors approx. 12-15m, outdoors 8-10m |
| Flash ratio control | For A:B ratio: 1:8 to 8:1 in half-step increments |
| Flash coverage | Transmission Coverage: +/-40 degrees horizontal and +/-30 degrees vertical |
| Slave operation confirmation | With test transmission button. Slave A fires followed by slave B at 1/64 output. |
| Slave Unit SE Mode Cancellation | Cancels when the test transmission button or FE lock button is pressed to turn on the slave unit. |
| Power source | 1x 2CR5 lithium battery |
| Battery life | Approx. 1500 transmissions at room temperature |
| SE Mode | While the power switch is set to I or HOLD, the transmission turns off automatically after approx. 90seconds of non-use |
| Dimensions | 62 x 51 x 80 mm |
| Weight | 100g excluding battery |
