The EXR Sensor .. SN mode
SN mode is the last “special mode” that you find in the EXR menu. You will note that I haven’t mentioned the EXR Auto mode. This is for good reason, as auto modes tend to be highly variable in their output, and this is true of EXR cameras as well. Many folks report that EXR Auto does a great job and just as many others consider it rubbish. My advice, use it at your peril.
So what exactly is SN mode?
SN stands for signal to noise ratio. Its main purpose it to provide an enhanced method of low noise and high sensitivity shooting in lowlight condition. Think dawn, dusk twilight, that sort of environment where the light is very fickle and changes quickly.
And how does it work? In essence it turns the sensor into a 8Mp sensor. It does this by combing the pixels of the sensor into larger pairs. Larger pixels equal less noise and a much greater sensitivity to light. That is of course only part of the equation. The information from the combined pixels is then processed through the EXR CPU. The processing decides what the aperture is, what the ISO and shutter speeds are as well as noise reduction to give the most detailed and uniform image from the sensor’s input. Once this has been processed it only remains for the user to press the shutter button.
As you move the camera about and refocus the camera constantly updates the data ensuring optimal shooting conditions for the subject at hand. For most work, if I am in SN mode I tend to like to have a bit more control on this process, and of course you can. I tend to set the camera to Auto ISO 400 and vary the EV as necessary. There are times when I may manually select an ISO that’s permanently set rather using the auto mode and this can be done up to ISO 1600. Anything above ISO1600 is likely to have a good deal of noise as will ISO 1600 if there isn’t sufficient light, so good noise reduction software will be a great help in this situation. Does it really work? Yes within reason. There still needs to be an amount of available light to get the best from the camera. As with all things you will need to do some trial and error shooting to see where the optimal settings lie for your use, suffice to say that for a lot of lowlight conditions SN mode is a handy option.
Some time ago Fuji put up a EXR demonstration site, using the Super CCD used in the F200EXR , this isn’t the same as the BSI CMOS sensor now being used in the newer cameras ( F200EXR is only 12Mp), whereas current EXR sensors are 16Mp for the F & HS series cameras.
Below is an image taken from the Fuji website. Click the image to go directly to the EXR site.