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ISO (Sensitivity) Adjustment contd.

ISO noise JPEG vs. RAW

As expected shooting in either JPEG or RAW makes virtually no difference to the amount of noise visible in an image. The samples below were shot as RAW + JPEG.

Settings: Parameters: Standard / Color matrix: 1 (sRGB)

ISO 1600, JPEG
ISO 1600, RAW (resaved as JPEG for the link above)
ISO 1600, RAW +1.0 EV (resaved as JPEG for the link above)

Center line

When rumours of the EOS-1D first surfaced there was a lot of talk about the use of two sensors mounted side by side. It's my belief that this rumour could have grown out of something closer to the truth. That the EOS-1D has one sensor but two readout buffers, one on the left side of the CCD and one on the right side. This would explain its ability to transfer such large amounts of data so quickly (as would be required at 8 frames per second). [Note: all of this is theory, nothing confirmed by Canon]

Examining several high ISO 'pushed' images it became apparent that there is a slight difference between the left and right side of the image (which wouldn't be visible without pushing an image). This can be clearly seen in the extremely pushed (about 4 stops) image below (the small red markers indicate the exact center of the image).

ISO bracketing

One feature unique to the EOS-1D is the ability to 'ISO bracket', with an ISO sensitivity selected and the ISO button combination (AF+Meter) 'held' you can use the quick command dial (rear of camera) to select ISO bracketing of between -3 and +3 EV in 0.3 EV steps. With drive mode switched to continuous the camera will automatically take three (or more, custom function) frames at the selected ISO +/- the selected bracket level, shutter speed and aperture remain locked. Although the ISO sensitivity is changed that is not reflected in the EXIF header (a little confusing).

ISO 640 ISO 640 -1 stop ISO 640 +1 stop

White balance

The EOS-1D provides a wide range of white balance options. On top of all of the normally selectable pre-programmed white balance settings (incandescent, fluorescent, shade, sunny etc.) there is also a Kelvin temperature selectable white balance (2800 - 10000 K in 100 K steps), manual preset white balance and three 'personal white balance' presets which can be programmed via the TWAIN software.

Settings: ISO 200-400 / Parameters: Standard / Color matrix: 1 (sRGB)

Daylight: Auto Daylight: Cloudy (Shade / Sunny) Daylight: Manual
Incandescent: Auto Incandescent: Incandescent Incandescent: Manual
Fluorescent: Auto Fluorescent: Fluorescent Fluorescent: Manual

As you can see automatic white balance works best under natural light. Despite the additional white balance sensor the EOS-1D only managed an average performance for automatic white balance under artificial lights. I found that the pre-programmed white balance settings weren't close enough to my own lighting and there was no way to 'fine tune' these (as you can on the Nikon D1 series). That said manual preset works well and the ability to manually select a Kelvin temperature (especially in such fine steps) is very useful if you often work under the same studio lighting.

Kelvin temperature white balance

Below is a fairly extreme example of selecting Kelvin temperature white balance, these were shot in the light from a window and so the ideal white balance is somewhere between 5800 K and 6200 K.

Settings: ISO 200 / Parameters: Standard / Color matrix: 1 (sRGB)

4000 K 6000 K 8000 K

White balance bracketing

Another useful feature of the EOS-1D is the ability to bracket white balance. This is enabled by holding the white balance and DISPLAY buttons and turning the quick command dial. You can select up to three levels of white balance adjustment plus and minus the selected white balance. Each level of adjustment equates to 5 mired (as would be produced by a colour conversion filter).

Settings: ISO 200 / Parameters: Standard / Color matrix: 1 (sRGB)

Normal Minus Plus
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