ISO Sensitivity / Noise levels

ISO equivalence on a digital camera is the ability to increase the sensitivity of the sensor to enable faster shutter speeds and/or better performance in low light. The way this works in a digital camera is by "turning up the volume" on the CCD's signal amplifiers. Nothing is without its price however and doing so also amplifies any noise that may be present and often affects color saturation.

The EOS-1Ds provides a wide range of selectable sensitivities between ISO 100 and 1250 in 0.3 EV steps. Additionally you can also enable (via a custom function) the 'L' sensitivity (equiv. to ISO 50) although this setting does have lower dynamic range.

Our noise comparison test involves shooting a GretagMacBeth ColorChecker at a selection of ISO sensitivities and then measuring luminance and RGB noise at a 'mid' grey patch (patch 22).

Canon EOS-1Ds vs. Canon EOS-D60

Camera settings / test notes

• Canon EOS-1Ds: Parameters: Standard, Large/Fine JPEG (4064 x 2704), Manual WB
• Canon EOS-D60: Parameters: Standard, Large/Fine JPEG (3072 x 2048), Manual WB
• Measurements taken at approximately 21°C (~70°F)
• Lighting was daylight

	ISO 50 (L)
	Canon EOS-1Ds 1/2 sec, F7.1	Canon EOS-D60 n/a
Original crop
Red channel
Green channel
Blue channel
	ISO 100
	Canon EOS-1Ds 1/4 sec, F7.1	Canon EOS-D60 1/4 sec, F7.1
Original crop
Red channel
Green channel
Blue channel
	ISO 200
	Canon EOS-1Ds 1/8 sec, F7.1	Canon EOS-D60 1/8 sec, F7.1
Original crop
Red channel
Green channel
Blue channel
	ISO 400
	Canon EOS-1Ds 1/15 sec, F7.1	Canon EOS-D60 1/15 sec, F7.1
Original crop
Red channel
Green channel
Blue channel
	ISO 800
	Canon EOS-1Ds 1/30 sec, F7.1	Canon EOS-D60 1/30 sec, F7.1
Original crop
Red channel
Green channel
Blue channel
	ISO 1000
	Canon EOS-1Ds 1/40 sec, F7.1	Canon EOS-D60 1/40 sec, F7.1
Original crop
Red channel
Green channel
Blue channel
	ISO 1250
	Canon EOS-1Ds 1/50 sec, F7.1	Canon EOS-D60 n/a
Original crop
Red channel
Green channel
Blue channel

As was noted when we posted the first few EOS-1Ds samples noise levels are very low, not quite as low as the EOS-D60 at the lower sensitivities but very respectable all the same. The EOS-1Ds keeps a fairly constant noise to sensitivity ratio as you can see from the graph below and performs better than the EOS-D60 at higher sensitivities (from ISO 800 upwards).

It's important to remember that the 1Ds produces larger images than the D60, this means that at the same print size noise will be less visible for a 1Ds image than a D60.

Luminance noise graph

ISO sensitivity is on the horizontal axis of this graph, standard deviation (average) is on the vertical axis.

RGB noise graph

ISO sensitivity is on the vertical axis of this graph, standard deviation (average) is on the horizontal axis.