5 Killer ISO Tips

By Steven Reid

One of my favourite things about aviation photography, is just how much it pushes your camera skills and your equipment. I thought I would share some of the geeky things I have picked up pushing various cameras to the max over the last few years, and where better to start than with some ISO tips.

There is no such thing as ISO...

Although ISO stands for International Standards Organisation there is no specific standard for Digital Sensor Sensitivity. Most manufacturers try to align the sensor sensitivity to what you would have expected from a similar rated film. Some manufacturers use this grey area to over claim their sensitivity levels .

A great video on this can be found here: https://youtu.be/3OwxdCrfc6w

First Base

It is worth looking up what the Base ISO is for the sensor in your camera, at this ISO your camera will record the highest dynamic range or the most data. Also note the Base ISO is not the ‘Lowest’ ISO your camera can record at.

Second / Third Base

Some modern cameras have Two Base ISOs and some even have three. These are not always well documented. When the ISO starts to climb there will be a point where the internal circuitry of the camera will switch to use a separate circuit better tuned to handle higher sensitivities. With a dual ISO camera it is worth learning where the switch is happening, as you may be able to record more data by shooting at the second Base ISO level rather than a lower ISO level , IF you are going to bring the Shadows up by a stop in post.

Invariance

Some sensors are deemed ISO invariant, which basically means the ISO or exposure is set by software after exposure. If your sensor is ISO invariant you can actually under expose by a significant amount, as increasing the exposure in post is a very similar process.

Some more Information here: ISO Invariance Explained (photographylife.com)

ISO Hacks

Some cameras have settings and shooting modes which can expand the dynamic ranges being captured. To note , I am not referring to the HDR modes and exposure bracketing , but instead to modes like Canon’s Highlight Tone Priority. These settings will force you to use a higher ISO , but will retain more details in the Highlights.

Here is a good article on it : Does Highlight Tone Priority Have Any Effect When Shooting Raw? | Fstoppers and yes It does affect RAW files.