I know…many of you are saying “What the heck is he talking about?”
What exactly is Manual Mode with Auto ISO?
As many of you know, Manual Mode allows you to set aperture, shutter speed and ISO. Setting ISO to ‘Auto’ allows the ISO to adjust to light conditions for a given aperture and shutter speed combination. So it’s kind of like an auto mode except you control depth of field (aperture) and shutter speed.
So when would you use Manual Mode with Auto ISO?
I recently had the great privilege of being part of a tour of the Willamette Falls Heritage site in my home town of Oregon City. The site contains a now closed paper mill on the Willamette River just down stream of Willamette Falls (the second largest waterfall in America). The plan for the site is to restore the site and develop it into green space, retail space, and for the first time in 150 years…public access to Willamette Falls.
The challenges I faced:
- The tour was only 2 hours long and there were 14 other people present, so I could not afford to mess around with camera settings and hold up the tour.
- I shoot RAW so Auto mode would not work.
- The light conditions were all over the map – from unlit darkness inside buildings to daylight conditions outside.
- I was shooting handheld (with a 24-105 stabilized lens).
My first thought was to use Shutter Priority Mode to insure I had a fast enough shutter speed to get sharp images. But then aperture would be all over the map and I’d have to adjust ISO to keep depth of field in check. Remember, I had little time to think and just wanted to shoot.
A while back I read about using Manual Mode with Auto ISO and BAM…there’s my solution. So I set the camera to Manual Mode, shutter speed to 1/60, aperture to f/8, and ISO was to Auto. I figured ISO would be all over the map but my Canon 1DX handles noise very well, so I wasn’t too worried about noise at higher ISOs.
This method worked like a charm. If I wanted shallower death of field, all I had to do was bump aperture down and not worry about other exposure settings. Of course all other metering concerns were still there, but that’s always part of the game and I’m used to that.
I was surprised that the highest ISO chosen by the camera in all the shots I took was 6400 and that was in a very dark area with some light streaming in from a distant doorway. Most shots were in the 100-640 ISO range which all resulted in noise free images.
Are there any drawbacks to using Manual Mode with Auto ISO?
- Exposure compensation is not available in Manual Mode. But this wasn’t a big issue. None of my images were too far under or over exposed.
- If your camera does not handle high ISOs very well, you may want to compensate for this by adjusting aperture or shutter speed accordingly to get the ISO down to an acceptable level in low light.
Would I use Manual Mode with Auto ISO again?
Absolutely. But only when I want to concentrate on shooting and not have to think too much about camera settings.