SD700X 7X Optical Zoom Lens Module for Compact Digital Cameras

Adding real optical zoom to a compact digital camera means fitting the lens, zoom mechanism and autofocus system into a very limited space. At the same time, the lens still needs to provide useful focal coverage, reliable positioning and consistent image quality. The SD700X 7X Optical Zoom Lens Module was developed for this type of camera project. It combines a 4.74–31.14mm focal range, retractable optical structure, autofocus and a dual-motor drive system in a compact lens assembly.

7X Optical Zoom from 4.74mm to 31.14mm

The SD700X provides a physical focal range of 4.74mm to 31.14mm, equivalent to approximately 25–175mm on a 35mm camera. At the wide-angle end, the lens provides an 84° diagonal field of view, giving compact cameras useful coverage for landscapes, architecture, group photos and everyday shooting. At the telephoto end, the focal length reaches 31.14mm with a 14.2° field of view, allowing users to bring distant subjects closer and capture more detailed shots. The 25–175mm equivalent range covers many common shooting situations without relying only on digital zoom, making it well suited to compact cameras intended for travel and everyday photography.

Dual-Motor Zoom and Autofocus System

The SD700X uses separate motors for zoom and autofocus. The zoom mechanism is driven by a DC motor operating at 4.0V. According to the current specification, the lens can move from wide angle to telephoto in as little as 1.43 seconds. An internal optical positioning sensor monitors pulse counts during zoom movement, allowing the lens to control and repeat its zoom position more accurately. Autofocus is driven by a 2-phase stepping motor with a single-step precision of 5μm. Micro-step control is used to keep focusing movement smooth, with specified AF operating noise of no more than 55dB and zoom operating noise of no more than 60dB.

Autofocus from Close-Up to Telephoto

At the wide-angle end, the minimum focusing distance is approximately 5cm, making the lens useful for small objects, product details, documents and close-up photography. At the telephoto end, the minimum focusing distance is approximately 100cm. The autofocus system combines coarse and fine adjustment to locate the focus position, while backlash compensation is used to reduce focus errors during repeated movement.

8-Group, 9-Element Optical Design

The SD700X uses an 8-group, 9-element optical structure. Sixteen optical surfaces feature multi-layer AR coating to help reduce flare and ghosting while improving light transmission and contrast. The maximum aperture is F3.07 at the wide-angle end and F5.95 at the telephoto end. The lens is designed for 1/2.33-inch CMOS sensors and supports approximately 12-megapixel optical resolution. An IR Cut filter is also included to reduce infrared interference and improve color reproduction.

Key Optical Specifications

Parameter	Wide Angle	Telephoto
Focal Length	4.74mm	31.14mm
Diagonal Field of View	84°	14.2°
Maximum Aperture	F3.07	F5.95
Center Resolution	1400 TVL	1300 TVL
Peripheral Resolution	800 TVL	800 TVL
TV Distortion	-4.46%	0.80%
Relative Illumination	48.8%	93.2%
Minimum Focus Distance	5cm	100cm

Compact Retractable Structure

The SD700X is built around a retractable mechanical structure suitable for compact camera bodies.

Parameter	Specification
Optical Zoom	7X
Physical Focal Length	4.74mm–31.14mm
35mm Equivalent	Approx. 25–175mm
Outer Diameter	Φ44.2mm
Width	51.4mm
Thickness	24.5mm
Weight	<40g, excluding IR filter and CMOS sensor

The lens assembly uses an M1.7 precision focusing screw and a reinforced mechanical structure designed to maintain stable transmission and withstand vibration and impact during normal operation.

Tested for Repeated Zoom and Focus Operation

For a retractable optical zoom lens, mechanical durability is just as important as optical performance. The SD700X has been tested for 36,000 zoom cycles and 36,000 autofocus cycles. The lens has also been evaluated under high and low temperatures, temperature cycling, thermal shock, vibration, impact and drop-test conditions.

Test	Condition
High-Temperature Operation	+45°C / 60% RH / 6 hours
Low-Temperature Operation	-5°C / 6 hours
High-Temperature Storage	+70°C / 30% RH / 24 hours
Low-Temperature Storage	-30°C / 24 hours
High Temperature & Humidity	+50°C / 95% RH / 24 hours
Temperature Cycling	-20°C to +60°C / 8 cycles
Thermal Shock	-20°C to +60°C / 7 cycles
Zoom Durability	36,000 cycles
Focus Durability	36,000 cycles
Random Vibration	X/Y/Z axes / 2.09Grms / 30 min each
Impact Test	150G half-sine wave / each side

The module also complies with RoHS requirements according to the current product specification.

Designed for Compact Camera Projects

The SD700X is intended for camera manufacturers, brands and imaging solution providers that need a real optical zoom system for a compact camera platform. Typical applications include:

• Compact digital cameras: 7X retractable optical zoom for everyday consumer cameras.
• Travel cameras: 25–175mm equivalent coverage for wide-angle and telephoto shooting.
• Pocket cameras: Optical zoom capability in a relatively compact lens structure.
• Content creation cameras: Autofocus and flexible focal coverage for photo and video use.
• Customized camera projects: Suitable for integration into new digital camera platforms.

Inspection and Packaging

Each SD700X lens module is individually protected with vacuum anti-static packaging, cushioning material and reinforced outer packaging to reduce the risk of lens scratches, dust contamination and transportation damage. Before shipment, the modules are inspected for optical resolution, motor drive operation and positioning sensor performance.