5D Mark iv. Aperature Priority - Auto ISO not compensating high enough

[svodde]

To get this out of the way, I shoot landscape & Astrophotography as a hobby.  I can pull off flash photography in a staged setting with a cooperative subject, but when it comes to 'live action' shots in lower light, I'm out of my depth.  So, I hope this is a simple 'n008b' question.

Here is what I'm (ineffectively) trying to do... I'm shooting indoors at night with moving subjects (live action shots). I'm running a Canon 5d Mark iv, 24-70 f2.4, & a speed light on top.  The subjects (people) are moving, I'm moving, and the lighting is changing.  I want to control depth of field, so I'm in Av.  Because people move, I have the shutter speed range restricted to 1/15 at its slowest.  Flash is set to TTL.  ISO set to Auto.  The camera keeps selecting a low ISO (400) and the shutter speed is blinking because its / I'm about to underexpose it. 

What am I doing wrong / what don't I know?

[deebatman316 · Accepted solution]

All Canon DSLRs behave this way. You'll need to manually set your ISO higher. The EOS R series will bump the ISO up as high as ISO 1600 or 3200. What brand speedlite are you using Canon or 3rd Party.

[deebatman316 · Accepted solution]

All Canon DSLRs behave this way. You'll need to manually set your ISO higher. The EOS R series will bump the ISO up as high as ISO 1600 or 3200. What brand speedlite are you using Canon or 3rd Party.

[svodde]

Thank for the insight deebatman316, very helpful.

The speedlights are 3rd party (Godox TT658II or TT350).  Based on what Im reading, the ISO 'deciding' on 400 is something in the programing and I'm either bumping up the ISO manually, or staging off camera flash; both sorta defeat the goal of having ready to grab and go rig for toddler life.

As for the R series, I'm one of those stuck in there ways idiots who wants to look through the lens and (mostly) make my own decisions and mistakes.  I was working off of 60D's until Canon announced they were going to abandon the full frame 5D; hence the learning curve.

[deebatman316]

A lot of those features in mirrorless can be turned off if you prefer not to use them. The AF in mirrorless cameras are much faster even with adapted EF lenses. Canon has pretty much withdrawn from the DSLR market. No further DSLR or lens development is happening. 

[stevet1]

svodde,

See if your camera has a menu setting for "ISO Speed Settings" and "Max for Auto ISO"

On my camera, it is in the red camera menu settings, Tab# 2. You may have inadvertently set a low number for your Auto. ISO.

Steve Thomas

[deebatman316 · Accepted solution]

With flash and EOS DSLRs even with the Auto ISO range maxed out. The camera ALWAYS sets ISO 400. There isn’t a way around this other than manually setting the ISO higher. Such as using ISO 1600 for example. Or switching to the EOS R series it’s been this way for DSLRs for years. 

[stevet1]

Demetrius,

Thanks. I wasn't aware of this.

Steve Thomas