Flash photography tip: Flash brightness is indicated by its power

Thursday 12 February 2026, 16:08 by Elja Trum | 1,793 views | 1 comment

This article was translated from Dutch with the help of AI. Read the original.

When you use flash, you do so at a certain brightness. This is indicated by the flash power as a fraction. Full brightness, or maximum power, is shown on your flash as 1/1.

If you turn down the flash power, you might go to 1/2, for example. You are then only using half the power.

Halving the light also means 1 stop on your camera. So, if you take a photo at f/8 and need full power for a good exposure, you can expect the same correct exposure when you photograph at f/5.6 while your flash is set to 1/2.

Just as you can set your camera to 1/3 stops by default, you can usually do this on most flashes too. You can usually set flashes from 1/1 to 1/64. Sometimes even to 1/256.

With each step, 1/1, 1/2, 1/4, 1/8, 1/16, 1/32, 1/64 and 1/128, you halve the light output of your flash. It is useful to have a flash whose power you can turn down considerably.

Share: WhatsApp Facebook

About the author

Elja Trum is the founder of Photofacts and online photography course website Photofacts Academy. He has been writing about photography since 2006. Elja is also the author of (Dutch) books on composition, black-and-white photography, flash photography and portrait photography.

Be careful when removing power lines and dust spots in Luminar NEO
by Nando Harmsen
10 Tips for Beginner Photographers
by Elja Trum
Flash photography tip: Save your batteries
by Elja Trum
Flash power has nothing to do with how hard your light is
by Elja Trum
Flash photography tip: Make your flash more powerful by moving it closer
by Elja Trum
Flash photography tip: Make sure you have enough flash power
by Elja Trum

Show every article in Flash photography

home

1 comment

jozef Dumon wrote on Wednesday 18 February 2026 at 08:26 | reply
Thank you for this basic explanation of how to set the flash manually. I was missing that. I’ll definitely read through your flash bible
Translated from Dutch.

Have your say

Please note: Articles older than a week can only be commented on by signed-in visitors.
Would you still like to comment? sign in or create a free account.

Become a better photographer every week

A practical photography tip in your inbox every week.
39,178 photography enthusiasts already receive the tips! More about the weekly mail. Or keep up to date via Facebook. Sign-up secured with Google reCaptcha.

Elja Trum

Photofacts; everything to do with photography!

Would you like to take better photos and keep up with what is happening in photography? Photofacts publishes articles that teach you something about photography — from a product announcement to a practical shooting tip or a look at a website. Photofacts covers photography every day and is a hobby project of Elja Trum's that got out of hand. The articles are written by a team of volunteer authors. If you would enjoy writing one or more articles for Photofacts, do get in touch.More about Photofacts

Photofacts is made possible in part by