ISO Sensitivity / Noise levels

Standard Test

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" (gain) on the CCD's signal amplifiers. Nothing is without its price however and doing so also typically increases visible noise (random speckles visible all over the image).

We are now using a more reliable, repeatable and neutral method for evaluating noise. Shots are taken in daylight lighting in our studio. Noise is measured as the standard deviation of the medium gray patch on a Gretag MacBeth ColorChecker chart. The image is normalized before measurement of noise to remove the possibility of figures being affected by images with low contrast. Note that noise numbers shown on the graphs below can not be compared to those in older reviews.

In the comparisons below we used aperture priority mode and selected an aperture which would produce a shutter speed as near as possible the selected sensitivity value (ie. ISO 200, 1/200 sec).

Test notes:

• Shots taken at approximately 21°C (~70°F)
• Lighting was simulated daylight measured as 10.1 EV (at ISO 100)

Olympus E-1 vs. Canon EOS-10D (ISO 100 - 3200)

• Olympus E-1: Olympus 50 mm F2.0 lens, Aperture Priority (F4), Manual WB,
  Default Parameters, JPEG SHQ
• Canon EOS-10D: Canon 50 mm F1.4 lens, Aperture Priority (F4), Manual WB,
  Default Parameters, 50 mm F1.4, JPEG Large / Fine

	Olympus E-1 ISO 100, 1/100 sec, F4	Canon EOS-10D ISO 100, 1/100 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 200, 1/200 sec, F4	Canon EOS-10D ISO 200, 1/200 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 400, 1/400 sec, F4	Canon EOS-10D ISO 400, 1/400 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 800, 1/800 sec, F4	Canon EOS-10D ISO 800, 1/800 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 1600, 1/1600 sec, F4	Canon EOS-10D ISO 1600, 1/1600 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 3200, 1/3200 sec, F4	Canon EOS-10D ISO 3200, 1/3200 sec, F4
Partial crop
Red Green Blue channels

Olympus E-1 vs. Fujifilm S2 Pro (6mp) (ISO 100 - 1600)

• Olympus E-1: Olympus 50 mm F2.0 lens, Aperture Priority (F4), Manual WB,
  Default Parameters, JPEG SHQ
• Fujifiilm S2 Pro: Nikkor 50 mm F1.4 lens, Aperture Priority (F4),
  Manual WB, Default Parameters, JPEG 6mp / Fine

	Olympus E-1 ISO 100, 1/100 sec, F4	Fujifilm S2 Pro (6mp) ISO 100, 1/90 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 200, 1/200 sec, F4	Fujifilm S2 Pro (6mp) ISO 200, 1/180 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 400, 1/400 sec, F4	Fujifilm S2 Pro (6mp) ISO 400, 1/350 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 800, 1/800 sec, F4	Fujifilm S2 Pro (6mp) ISO 800, 1/750 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 1600, 1/1600 sec, F4	Fujifilm S2 Pro (6mp) ISO 1600, 1/1500 sec, F4
Partial crop
Red Green Blue channels

Olympus E-1 vs. Nikon D2H (ISO 200 - 6400)

• Olympus E-1: Olympus 50 mm F2.0 lens, Aperture Priority (F4), Manual WB,
  Default Parameters, JPEG SHQ
• Nikon D2H: Nikkor 50 mm F1.4 lens, Aperture Priority (F4), Manual WB,
  Default Parameters, JPEG Large / Fine

	Olympus E-1 ISO 200, 1/200 sec, F4	Nikon D2H ISO 200, 1/200 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 400, 1/400 sec, F4	Nikon D2H ISO 400, 1/400 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 800, 1/800 sec, F4	Nikon D2H ISO 800, 1/800 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 1600, 1/1600 sec, F4	Nikon D2H ISO 1600, 1/1600 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 ISO 3200, 1/3200 sec, F4	Nikon D2H ISO 3200, 1/3200 sec, F4
Partial crop
Red Green Blue channels
	Olympus E-1 n/a	Nikon D2H ISO 6400, 1/6400 sec, F4
Partial crop
Red Green Blue channels

Up to ISO 800 noise levels from the E-1, EOS-10D and D2H are relatively similar. Of these three cameras the EOS-10D has the cleanest images at ISO 100 and 200 followed by the D2H and then the E-1. At ISO 1600 the E-1's noise levels leap notably (and visibly) higher than the EOS-10D and D2H which both maintain similar levels. Also noteworthy is the increase in brightness of the EOS-10D image at ISO 800, 1600 and 3200. Throughout the ISO range Fujifilm's impressive S2 Pro plots a shallow noise curve none of the other cameras can match.

The luminance noise graph below contains data from the E-1 with the noise filter disabled and enabled (NF), you will note that although the filter reduces noise slightly it doesn't have a significant effect (and does impact hugely on image write times).

Luminance noise graph (ISO 100 - 3200)

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity (normalized) on the vertical axis. The label E-1 (NF) indicates the Olympus E-1 with Noise Filter enabled.

Luminance noise graph (ISO 100 - 800)

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of luminosity (normalized) on the vertical axis. The label E-1 (NF) indicates the Olympus E-1 with Noise Filter enabled. Note that the scale on this graph has been zoomed to provide a closer look at this specific range of sensitivities.

RGB noise graph

Indicated ISO sensitivity is on the horizontal axis of this graph, standard deviation of each of the red, green and blue channels (normalized) are on the vertical axis. Note that the noise levels for the Olympus E-1 red & blue channels at ISO 1600 and all channels at ISO 3200 are greater than the maximum value shown on this graph.