I was shooting some photos of birds on our bird feeder when I realized I wanted a little more depth-of-field than wide open at ƒ/4.8, so I closed down the camera to ƒ/8. ƒ/8 made it possible to keep the bird in focus.

In Aperture Mode, the camera would typically drop the Shutter Speed to low to freeze the birds and look in focus. See, the bird feeder hangs and would swing a little as the birds land.

Now, if I chose Shutter Speed Mode and picked 1/1000, the camera would open up the aperture, which isn’t what I wanted.

In film days, you would typically not get this photo because I would generally have put ASA 100 [ISO 100] since the photo was in sunlight. So you would be stuck with whatever ISO you had put in the camera, but today with digital, this can change frame to frame.

AUTO ISO

The thing I love the best about digital is the Auto ISO. In this situation, I put the camera in Manual Mode and pick the ƒ/8 and 1/1000, and the camera’s Auto ISO will now select the ISO that gives me a well-exposed photo.

Fuji X-E2, XF 55-200mm, ISO 3200, ƒ/8, 1/1000

The Fuji X-E2 Auto ISO

When you choose the Auto ISO on the camera, the camera automatically selects a sensitivity between the default and maximum values. Sensitivity is only raised above the default value if the shutter speed required for optimal exposure is slower than the value selected for MIN. SHUTTER SPEED.

Suppose the value selected for DEFAULT SENSITIVITY is higher than that chosen for MAX. Then, SENSITIVITY and DEFAULT SENSITIVITY will be set by you to the value selected for MAX. SENSITIVITY.

The camera may select shutter speeds slower than MIN. SHUTTER SPEED if underexposing the pictures at the chosen value for MAX. SENSITIVITY.

I have set my AUTO ISO range of 200 to 6400. The one thing I do go to change regularly is the minimum shutter speed. I have it set for 1/500 sometimes for quick-moving subjects and then maybe change it to 1/60 for more fixed issues.

Let the ISO climb higher if you need to control the Aperture and Shutter Speed to get the photo. With today’s sensors, the higher ISO isn’t as noisy as in years past. I think you will agree that the cropping of the images above is acceptable noise for shooting at ƒ/8 and 1/1000.