Photography Tip–Don’t Forget to Check Your ISO

Info media photography : ISO speeds are probably the easiest concept to understand in photography. The basic thing you have to remember is that the higher the ISO speed, more sensitive the sensor is to light, making images in low-light possible. Sure there’s more to it than that—the aperture, primarily, which is the size of the opening in your lens when your shutter is released. If you want a sharp photo in low light, you’ll want to keep the aperture wide, but be warned that it’s likely to make the rest of the image (away from the focus point) soft.

A bad photography day would be one where you were running around taking shots without changing your ISO speed from the night before. I’ve had a lot of those days, taking pictures at 1600 ISO in bright sunlight, only to find that when I look at them at 100 percent resolution, they’re useless for stock/microstock.





Noise and texturing at high ISO

To prevent those bad days, the first thing I do now is to check my ISO speed before I start the day’s shooting. Here’s a guide as to what ISO speed I use, which is dependent on weather/light conditions:

1. Bright sunny day sun shining directly on subjects/objects—100 ISO
2. Cloudy summer day—200 ISO
3. Shade—200-400 ISO, depending on light intensity
4. Cloudy winter day—400 ISO
5. Bright light indoors—200 ISO
6. Normal light indoors—400-800 ISO
7. Dim light indoors—800—3200 ISO

All of these values are also dependent on the manufacturer/model camera you have. For example, I’ve found that the Canon Rebel (older models, APS sensor) produce better images at high ISO speeds than the 5D (full size sensor).

In shot tests, the Nikon dSLR models usually outperform the Canon dSLR models at high ISO speeds. Photographybay.com tested the Canon 5D Mark II and Nikon D700, and found that the later model constantly outperforms the former at ISO speeds from 1600–25,600.

The biggest enemy of high ISO speeds is noise. Although some cameras are getting close to eliminating it when you use a high ISO speed, they aren’t quite there yet.

Texturing and chroma artifacts can also be a problem at high ISO speeds. Texturing is when your image begins to have texture, something you definitely want to avoid. There’s noting worse than a complexion on a portrait looking like rough wallpaper. Chroma artifacts, also called chromatic aberration, are when you get a bright color outlining a subject or object in your photograph.