Sensor	Width (mm)	Height (mm)	Area (mm²)	Crop Factor
Medium Format (44x33)	43.8	32.9	1441.0	0.79x
Full Frame	36	24	864.0	1.00x
APS-C (1.5x)	23.5	15.6	366.6	1.53x
Micro Four Thirds	17.3	13	224.9	2.00x
Smartphone Flagship (1/1.3")	9.8	7.3	71.5	3.54x

What is this?

Camera sensors come in many different physical sizes, from the large medium-format chips used in studio cameras down to the tiny sensors in smartphones. A larger sensor captures more light, produces less noise, and makes it easier to blur backgrounds. Sensor size is one of the biggest factors separating camera categories.

How it works

Sensor size affects photography in several interconnected ways. A larger sensor has a bigger area to collect photons, improving signal-to-noise ratio and dynamic range. The "crop factor" describes how a sensor compares to the 35mm full-frame standard: an APS-C sensor with a 1.5x crop factor gives the same field of view with a 35mm lens as a full-frame camera would with a 52.5mm lens. This crop factor also multiplies the effective depth of field — a smaller sensor appears to give more depth of field at the same framing because you need a wider (shorter) lens to match the field of view. Pixel density (pixel pitch) is another key metric: packing more megapixels onto a smaller sensor shrinks each photosite, reducing per-pixel light gathering. A 24MP full-frame sensor has ~6µm pixels while a 24MP APS-C sensor has ~4µm pixels, which is why the full-frame sensor typically performs better at high ISO.

Key factors

Physical Dimensions — Width and height in millimeters determine the total light-gathering area and the field of view for a given lens.

Crop Factor — The ratio of the full-frame diagonal to the sensor diagonal. Multiplied by focal length, it gives the "equivalent" focal length.

Pixel Density — How tightly pixels are packed. Smaller pixel pitch means more detail but less light per pixel, affecting noise performance.

Sensor Area — Total area in mm². A medium format sensor has roughly 1.7x the area of full frame, and about 13x the area of a smartphone sensor.

Pro Tip

Use the overlay mode to see exactly how much bigger one sensor is than another — the area difference is often more dramatic than the numbers suggest.

Pro Tip

Switch to pixel density mode and enter your camera resolution to compare pixel pitch. If your camera has very high pixel density, you may hit diffraction limits at wider apertures than expected.

Pro Tip

When comparing cameras, sensor area matters more than megapixel count for noise performance. A 20MP full-frame sensor will typically outperform a 40MP APS-C sensor at high ISO.

⚡Challengebeginner

You want to see how a smartphone sensor compares to full frame. Which two sensors should you enable in the comparison?

Hint: Look for "Full Frame" and the smartphone option.

Sensor Size Comparison