ISO techniques

Don’t forgot the importance of using different ISO sensitivity settings

You can adjust the ISO speed on your Canon camera to decide the image sensor’s sensitivity to light. In Av, Tv and Manual modes, you can adjust the

ISO accordingly – a low setting of around ISO100-200 is preferable for less noise and when using narrower apertures and slower shutter speeds, likely when you’re shooting landscapes with a wide lens and using a tripod; while a high setting of ISO1600-3200 may be needed to achieve a fast shutter speed for fast-moving subjects and to avoid camera shake when using a long lens handheld.

Hazy early morning light

“I WASN’T expecting these paddleboarders to appear in my sunrise shot of the River Frome at Wareham in Dorset, so I had to quickly adjust settings to freeze their movement. Increasing my ISO to 400 resulted in a fast enough shutter speed of 1/250 sec, while allowing me to maintain my f/11 aperture for sufficient depth of field using my EF 100-400mm f/4.5-5.6l II at 182mm,” says Guy Edwardes. In this instance, a higher ISO setting has helped him to use a narrower aperture – higher ISO settings aren’t just for obtaining faster shutter speeds!

High ISO for fast subjects

“LITTLE OWLS take off incredibly quickly and without much warning, so a high frame rate and fast shutter speed are crucial to capturing a sharp image. Here I used my Canon EOS R5’s electronic shutter to achieve 20fps, along with a shutter speed of 1/4000 sec at ISO4000. For action images, I always maintain a fast shutter speed, even if that results in a high ISO, because noise is easily dealt with using software such as Topaz Denoise AI,” suggests Guy Edwardes.

Night scenes with the moon

“THE MOON moves surprisingly quickly when viewed through a 300mm telephoto lens, so to capture this partial lunar eclipse over the town of Castiglione d’orcia in Tuscany, I had to use ISO3200 to achieve a fast enough shutter speed of 1/60 sec to freeze that movement,” explains Guy Edwardes. “I also had to shoot a bracketed set of exposures to blend in Adobe Lightroom Merge to HDR to capture detail throughout this highcontrast scene. DXO PURERAW software helped to reduce the noise in the EOS R5 Raw files.”

Soft light equals fewer shadows

“SOFT AND overcast light is a little underrated in wildlife photography, but provides ideal conditions to even out contrast and record vibrant colours in the subject,” says Guy Edwardes. “It also reduces any problems with harsh shadows or bright highlights. This hoopoe returning to its nest was shot on my EOS R5 mirrorless with an EF 600mm f/4l IS II using a high ISO of 4000 for a 1/3200 sec shutter speed at f/4. Lower light levels necessitate higher ISO settings, but excess noise is easily reduced using Topaz Denoise AI software.”

“Lower light levels need higher ISOS, but excess noise is easily reduced”