Olympus D-450z

ISO and shutter speed

The Olympus D- series models, the D400z, D450z, D460z, and D490z are all very simple to use, and produce great photos. Since they lack a manual shutter speed or aperture adjustment, some have wondered if they can use the manual ISO settings to force the camera to use a higher shutter speed, or a larger/smaller aperture.

The easiest way to find out was to run some tests, taking identical photos with different ISO settings, then read the EXIF information from the file to see how it affected shutter speed or aperture. A bonus to this was I could directly compare the image quality, since it is known that using a higher ISO (similar to a higher film speed) causes more "noise" in digital photos. Click for samples.

In the photos linked below, you can compare the images using different settings, and see the effect of manually setting the ISO, under different lighting situations. Click the links to see the test images.

Under full sunlight, you can see that with the ISO set higher, the camera used a shutter speed of over 1/1000 second...maybe useful for sports or action shots. There is some loss of image quality, so you would have to decide if it's worth it in any given situation. Click for samples.

In a moderately-lit room (without flash), you can see how manually setting a higher ISO gives a more useful shutter speed of 1/44 second, instead of the 1/19 that would have been used if the camera was set to "auto". Colors and shadow detail are slightly better in the photos with lower ISO settings. Click for samples.

With low room light (no flash), none of the shutter speeds were very useful for handheld shots, but note that automatic mode still chose the middle ISO, even though it used a shutter speed of 1/2 second...nearly impossible to get a clear, hand-held shot. These were on a tripod, but still apparently got some motion blur from me pressing the shutter button. Click for samples.

Conclusion

These tests show that it is very easy to force the camera to use a higher shutter speed by using the ISO settings in the Olympus D450z. For fast-action shots, even outdoors in sunlight, this might be something to consider. Forcing it to use a larger or smaller aperture, however, is not so easy.

I assume the D400z, D460z, and D490z would behave in a similar fashion, but you may want to try your own tests on these cameras. The ISO settings are different on the different models. The D450z gives a choice of 160, 320, and 640, where the D490z, for example, gives 100, 200, and 400.