How about ISO Settings?

More tips for successfully utilizing different ISO settings

Part 3

After learning about the ISO, let’s talk about some useful tips for using ISO Settings.

Do not use Auto ISO…

-If you shoot steady subjects (such as landscape, macro, or even portraits.) You want to control the Depth of Field and Dynamic Range of the photo.

-In Flash Photography, especially if you use off-camera flashes.

-If you are going for a long exposure, Auto ISO can drive you nuts! When you want to slow down your shutter speed, the Auto ISO will keep increasing the sensitivity to maintain the minimum safe shutter speed. Turn Auto ISO off for long exposures.

-If you want to create a very shallow Depth-Of-Field.

Tips on using higher ISO:

-Try to stay at as low an ISO as possible. For example if you can shoot at ISO 1000, don’t set the ISO to 2000. Remember: the lower the ISO, the sharper and cleaner will be the picture.

-If you have to shoot at a high ISO, try to set the exposure a little higher. You can set the exposure compensation to +0.5 or +0.7, to achieve a brighter photo.

Underexposed image. After adjusting the brightness, you introduce more noise to the image

Here is the above image at 2:1 zoom. The noise are very pronounced

Why I should overexpose images when shooting higher ISO?

This is a good question. When you shoot at a higher ISO, and the image is a little too dark, you need to brighten the photo in post processing (editing in Photoshop or Lightroom as examples). By editing to apply brightness to an image, you introduce more Digital Noise (or grain) to the image. For this reason it’s recommended to slightly overexpose images with a higher ISO. Then you won’t need to brighten the image in post processing; if it is a little too bright for your taste or style, you can tone it down a little, which will help to smooth out the digital noise.

An slightly overexposed image with high ISO settings

For Overexposed image, even after adjustments, the noise is not as pronounced as the underexposed photo

As mentioned above, I don’t recommend using Auto ISO in flash photography, but there some exceptions. I’ve scheduled a Flash photography workshop for October 29 and 31. This two part workshop covers all popular techniques in flash photography with lots of hands-on practice.

I hope you enjoyed this look at the role of ISO in establishing good exposures, its advantages and the importance of using high ISO settings with caution.  It can be a helpful technique for those times when shutter speed and aperture need to remain constant.  Happy experimenting with ISO!

Ted and the Omnilargess Team