/Interlaced vs Progressive Scan

Interlaced vs Progressive Scan

Camera Technologyintermediate3mo ago

How interlaced CCD readout works, which Mavica models use it, and the visual artifacts it produces compared to progressive-scan sensors.

sensor interlaced progressive ccd artifacts

What is interlaced readout?

An interlaced CCD reads image data in two separate passes — first the odd-numbered rows, then the even-numbered rows. The camera's processor then weaves (interlaces) these two "fields" together to form a complete frame. This technique originated in analogue television (NTSC/PAL) and carried over into early digital cameras.

Progressive scan

Progressive-scan CCDs read every row in a single pass, top to bottom. This produces a cleaner image with no inter-field timing difference, but requires faster readout electronics.

Why Mavica used interlaced sensors

In 1997–1998, progressive-scan CCDs were significantly more expensive. Sony used interlaced sensors in the budget VGA-class models to keep costs down while delivering 640 × 480 output.

Which Mavica models are interlaced?

Model	Year	Resolution	Interlaced?
FD5	1997	640 × 480	Yes
FD7	1997	640 × 480	Yes
FD51	1998	640 × 480	Yes
FD71	1998	640 × 480	No
FD73	1999	640 × 480	No
FD75	2001	640 × 480	No

All models from the FD81 onward — and the entire CD series — use progressive-scan CCDs.

Visual artifacts of interlaced readout

Combing

When a subject moves between the two field captures, the odd and even rows show slightly different positions. This creates a horizontal "comb teeth" effect along the edges of moving objects. On a 640 × 480 Mavica image the effect is subtle but visible at 100% zoom.

Reduced vertical sharpness

Because the two fields are captured at slightly different times, fine horizontal detail can appear softer than on a progressive-scan sensor of equivalent resolution. Static scenes are less affected.

Moiré patterns

Interlaced readout can amplify moiré on subjects with fine horizontal striping — fabrics, blinds, and fences are common triggers.

Creative use

Some lo-fi photographers deliberately shoot fast-moving subjects on the FD5 or FD7 to exploit the combing artifact, creating a ghostly motion-blur effect that is unique to interlaced CCD cameras and impossible to replicate authentically in software.

Practical advice

For the sharpest results on an interlaced Mavica, keep the camera and subject as still as possible.
Interlaced artifacts are most visible in prints or crops; at web resolution (social media) they are rarely noticeable.
If you own both an FD7 (interlaced) and an FD71 (progressive), compare the same scene to see the difference firsthand.