Quiz

You change the aperture from f/4 to f/5.6. How much light gets through now?

f/4 to f/5.6 is one full stop, and one stop halves the light. A bigger f-number means a smaller opening.

Which aperture is the larger physical opening?

The f-number is focal length ÷ opening diameter, so a smaller number means a bigger opening.

On most cameras, how many clicks of the aperture dial make one full stop?

Cameras usually click in thirds of a stop, so three clicks make one stop.

A car is blurry at f/8, 1/125 s, ISO 100. You change to 1/500 s. Which aperture keeps the same brightness at ISO 100?

1/125 to 1/500 s is two stops faster, so the sensor gets one quarter as much light. Opening f/8 to f/4 adds those two stops back.

A 50 mm lens is set to f/2. How wide is the opening?

Opening diameter = focal length ÷ f-number: 50 ÷ 2 = 25 mm.

Why is the full stop after f/2 marked f/2.8 and not f/3?

Halving the area needs the diameter divided by √2, so each full stop multiplies the f-number by about 1.414: 2 × 1.414 ≈ 2.8.

What does raising the ISO by one stop do?

ISO doesn't change the light reaching the sensor. It brightens the recorded signal, which is why noise tends to show more at high ISO.

You double ISO from 200 to 400 but leave aperture and shutter unchanged. What changes?

Doubling ISO brightens the result by one stop. Aperture and shutter still determine how much light is captured.

A running child is blurry indoors at ISO 100. Which change can help freeze the movement?

A faster shutter reduces subject motion blur. A higher ISO can restore brightness after the shorter exposure.

You change ISO 100 at 1/30 s to ISO 800 at 1/250 s. Brightness is similar. Why may noise show more?

The shutter change is about three stops faster. Less captured light makes noise more visible, even if ISO restores the brightness.

When is Auto ISO especially useful?

Auto ISO can adapt brightness while you keep the shutter and aperture suited to the subject.

On a LUMIX S5IIX, which pair does Panasonic list as the V-Log base sensitivities?

The S5IIX has different dual-native pairs by profile: Normal 100/640, V-Log 640/4,000, and HLG 400/2,500.

You switch a dual-base camera to its higher base but keep aperture and shutter fixed. What stays the same?

The lens opening and exposure time still determine captured light. The new base changes how the camera reads and handles that signal.

What does a second or third base ISO give a camera?

A camera may switch to another optimized signal path. It can reduce electronic noise, but the light captured still depends on the scene, aperture and shutter.

You spot-meter a black cloth that fills the metered area and shoot at the meter's 0. How does it look?

The meter aims to make what it reads a middle tone, whatever its real colour. Subtract about 1 to 2 stops to keep black black.

Bright sun, ISO 200, no meter. What does Sunny 16 suggest?

Sunny 16: f/16 with the shutter at 1 over the ISO, so 1/200 s at ISO 200.

Overcast, shadows barely there, ISO 100 at 1/125 s. Which aperture does the Sunny 16 table give?

Overcast is two stops down from bright sun: f/16 → f/11 → f/8.

You spot-meter a white wedding dress in a dark room and follow the meter exactly. How does the dress look?

Spot metering makes whatever it reads middle grey. Add about +1 to +2 stops to keep a white dress white.

A friend stands in front of a bright window. Matrix gives a dark face. Which mode reads just the face?

Spot reads only a small circle, so the bright window has little say. The window will turn white, which is often fine.

A singer under a spotlight on a black stage. Which mode keeps the bright costume from turning white?

Highlight-weighted exposes for the brightest areas. The dark stage goes darker, which usually looks right.

What sets the height of each bar in a histogram?

Each pixel adds one to the bin for its brightness. The bars are then scaled so the tallest fits, so heights show proportions.

A bright red flower looks fine on the brightness histogram. Why check the RGB histogram too?

Brightness = 0.2126 R + 0.7152 G + 0.0722 B, so a clipped red channel can hide in the middle of the brightness histogram.

Where does middle grey (18% light) land on a 0–255 sRGB histogram?

The sRGB curve encodes 18% light as about 118. One stop below white is 188, not 128.

You're in M with a fixed ISO and switch from matrix to spot. What changes in the photo?

In full manual you set the exposure. The metering mode only changes the camera's suggestion.

The histogram has a tall spike against the right wall. What does that tell you?

Right is white. A spike against the right wall means pixels pushed to pure white. Decide whether those areas matter.

You're shooting cyclists and want to choose the shutter speed yourself. Which mode?

Shutter priority (S on Nikon, Sony and Fujifilm; Tv on Canon and Pentax) lets you set the shutter and the camera sets the aperture.

In A / Av at the meter's 0, you open the aperture from f/4 to f/2. What does the camera do?

f/4 to f/2 is two stops more light, so the camera speeds the shutter up by two stops to keep the meter at 0.

In full manual, with aperture, shutter and ISO all fixed, you set exposure compensation to +1. What changes in the photo?

Compensation shifts what the camera aims for. With everything set by hand the camera isn't choosing anything, so the photo doesn't change.

Is there a perfect histogram shape?

A snowy field should sit to the right and a night street to the left. What matters is whether important areas are clipped.

A scene spans 12 stops. How much brighter is its brightest part than its darkest?

Each stop doubles the light: 2¹² = 4,096.

What does making the exposure darker do to the camera's dynamic range?

Exposure moves the window along the scene. Darker keeps more highlights and gives up shadow detail; the width stays the same.

Nikon quotes 13+ stops for the Z 6III in N-Log; Photons to Photos measures about 10.4 at ISO 100 for RAW photos. Why the difference?

Nikon's N-Log video figure and Photons to Photos' RAW photographic figure use different modes and noise criteria. Compare values measured the same way.

In an ideal still scene, you merge shots at −2, 0 and +2 stops. How much extra range could they cover?

The darkest shot reaches 2 stops further into the highlights and the brightest 2 stops further into the shadows.

A 200 mm lens on a full-frame camera, no stabilisation. What's the handheld starting speed?

1 ÷ focal length: 1/200 s (1/250 on some dials). Treat it as a starting point and check the photo.

A 50 mm lens on an APS-C camera (1.5× crop). What's the handheld starting speed?

It frames like 75 mm, so 1/75 s, which is 1/80 s on the dial.

Your starting speed is 1/80 s and the lens has 3 stops of stabilisation. How slow could you try?

Each stop doubles the time: 1/80 → 1/40 → 1/20 → 1/10 s. Start faster and check a few frames.

You shoot a flying bird at 1/15 s with 5 stops of stabilisation. What happens?

Stabilisation steadies the camera, not the subject. Moving subjects need a fast shutter whatever the stabilisation.

Children running around a park. Where should the shutter speed start?

The chapter's starting point for running children and pets is 1/500 to 1/1000 s. Check the photo and go faster if needed.

How many stops does an ND8 filter cut?

ND8 means 8× longer, and 2 × 2 × 2 = 8, so 3 stops.

A sunny waterfall meters f/16 at 1/125 s. You want 1/2 s at the same aperture and ISO. Which filter?

Count the stops: 1/125, 1/60, 1/30, 1/15, 1/8, 1/4, 1/2. That's 6 stops, and 2⁶ = 64.

When should you meter and focus if you're using a 10-stop ND?

Through 10 stops of dark glass, most cameras can barely see. Meter and focus first, then add the filter and adjust the shutter.