Lesson 8: Shooting in Manual Mode

1. Decide your priority (background blur vs. freezing motion)
2. Set aperture first, based on that priority
3. Set shutter speed second, factoring in motion and the handheld rule
4. Check your light meter, adjust ISO to correct exposure without disturbing your first two choices
5. Take a test shot, check the histogram (not just the screen — it can mislead in bright light)
6. Adjust and reshoot — Manual is iterative, even for professionals

Before your first Manual session

• Learn which dial changes what. On most bodies one dial sets shutter speed and the other aperture in Manual; find out which, so you can change either without looking.
• Fix ISO at first. Auto ISO in Manual is useful later, but while learning, a fixed ISO shows you how all three settings interact.
• Know your metering mode. Matrix or evaluative metering reads the whole frame, centre-weighted favours the middle, and spot reads a small area — useful when only one part of the frame matters.
• Turn on the histogram display, and on a mirrorless camera, exposure preview, so the viewfinder shows the brightness your settings will actually produce.

Reading the light meter

In Manual the camera still meters — it just doesn't act on the reading. The exposure scale in the viewfinder shows how far your settings are from what the meter considers correct, usually in thirds of a stop. Zero matches the meter, +1 is one stop brighter, −1 one stop darker. One stop is a doubling or halving of light: going from 1/250 to 1/125, from f/5.6 to f/4, or from ISO 400 to 800 each adds one stop.

The meter aims to render whatever it sees as an average mid-tone. That's right for most scenes and wrong for scenes that are mostly bright or mostly dark: snow metered at zero comes out grey, and a black cat metered at zero comes out washed out. In Manual you correct for this by deliberately choosing a reading off zero — above it for a bright snow scene, below it for a dark scene where blacks should stay black.

Checking with the histogram

The histogram is a graph of how many pixels fall at each brightness level, from black on the left to white on the right. It's more reliable than the rear screen, whose brightness depends on its settings and the light around you. A spike pressed against the right edge means highlights clipped to pure white; against the left edge, shadows clipped to pure black. Neither is always wrong — a bright window behind a portrait may be allowed to clip — but it should be a choice you make, not something you discover at home. To practise reading one, run a few past photos through the histogram tool.

A worked example

An outdoor portrait just after sunset, subject two metres away, 50mm lens on a full-frame camera. The priority is a soft background, so aperture comes first: f/2.8. Next, shutter speed. The handheld rule suggests about 1/50 s for a 50mm lens, but people move slightly, so you choose 1/125 s for a margin. Then ISO: at ISO 400 the meter reads −2, so you raise it two stops to ISO 1600 and the meter reads zero. The test shot looks right and the histogram sits in the middle, touching neither edge. Ten minutes later the light has dropped by another stop. Rather than slow the shutter and risk blur, you raise ISO to 3200 and leave the other two settings alone. Every change was made for a reason, in order — which is all Manual really is. If you'd like to check equivalent combinations before you go out, the Exposure Calculator solves for whichever setting you leave blank.

Common mistakes

• Changing all three settings at once and chasing the meter. Fix the two that matter creatively, then let the third — usually ISO — take up the correction.
• Forgetting to re-meter when the light changes. Manual exposure doesn't follow the light: walk from shade into sun and every frame is overexposed until you adjust.
• Trusting the rear screen in bright sun or a dark room. Check the histogram.
• Avoiding high ISO at any cost. A sharp photo with some noise is usually usable; a blurred one at base ISO usually isn't.
• Using Manual where it doesn't help. When the light changes constantly — walking through a city, clouds crossing the sun — Aperture Priority with exposure compensation keeps up faster than you can.

Manual earns its complexity in specific situations: inconsistent lighting, a backlit subject the meter keeps misreading, or a series needing identical exposure across frames. Outside those, Aperture Priority with exposure compensation gets you most of the same control with far less friction.