What’s The Difference Between E-TTL and i-TTL Flash?

If you’ve shopped for a camera flash, you might have noticed the terms E-TTL or i-TTL thrown around. E-TTL is a Canon system, while i-TTL belongs to Nikon; both are metering systems that allow the flash to adjust automatically.

My name is Caleb, and I have more than four years of experience with photography. That includes taking photos indoors or in low light, using flash. 

In this article, I’ll go over the differences between E-TTL and i-TTL and what that means for you. If you’re interested in finding out the details, keep reading.

What Does TTL Mean?

TTL stands for through the lens. It’s a system that helps your flash judge the distance from the subject and automatically adjusts its settings to compensate. In a way, it works similarly to how the automatic mode of a camera does.

TTL has its origins in the days of film photography, but it has changed over the years due to modern camera advancements. The newer TTL methods fire a pre-flash before the photo is taken, then sets the strength of the actual flash using the pre-flash readings.

This feature makes flash photography much easier for the average person, as the flash is the one to do the work of making adjustments.

TTL flashes are traditionally higher priced because of this ease of use. However, they’re widespread enough that high prices aren’t as much of a concern as in earlier days.

What Is The Difference Between E-TTL and i-TTL?

E-TTL and i-TTL are two different TTL systems that serve the same purpose. E-TTL stands for “evaluative through the lens,” while i-TTL stands for “intelligent through the lens.”

The most significant difference is that they’re from different manufacturers. E-TTL is a system produced by Canon, while Nikon makes i-TTL. E-TTL and i-TTL accomplish the same goal, despite having different names for branding reasons.

You may have also heard of D-TTL. This is another form of TTL that Nikon produced, and it stands for “digital through the lens.” It isn’t used today, as Nikon replaced it with the current and improved i-TTL system.

Canon has also made upgrades over the years. Since the 2004 release of the EOS 1D-X Mark II, the more effective E-TTL II has been integrated as the standard built-in TTL system.

The main benefit of E-TTL II is more natural photos, as the system is better at reading the surroundings and making the proper adjustments without getting confused.

Neither E-TTL nor i-TTL is an objectively superior system. If you’re comparing multiple flashes and considering which one is better, you’ll have to consider other factors in making a decision. 

The distinction between E-TTL and i-TTL, after all, is mainly a result of branding.


Here are a couple of related questions that have to do with using flash on Canon.

What Is A Canon Speedlite?

A Speedlite is the same thing as a regular external flash. Speedlite is simply the marketing name that Canon uses to differentiate its flashes from others. It’s not the same thing as Speedlight, which is Nikon’s brand of flashes.

Can You Use Nikon Flashes On Canon?

Modern Canon and Nikon cameras use a universal shoe that allows them to share flashes. Be warned, though, that you’ll lose some features using a Nikon flash on a Canon camera. This is because of compatibility, as Nikon flashes are designed for Nikon bodies.


In short, E-TTL and i-TTL are simply the TTL systems produced by Canon and Nikon, respectively. Both are capable of doing the job, making your indoor or low light photography task much easier.

Are you a regular user of flash? If so, do you have a personal preference for one system over the other or any notable experiences? Let us know about it in the comments.

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