Like other lens manufacturers, Sony uses codes in the names of their lenses to identify key features and technologies of the lens.
As a relative newcomer to camera and lens manufacturing, Sony doesn’t have nearly as many codes as some other manufacturers that have been in the game a very long time (eg. Nikon or Canon). But that doesn’t make the codes they do have any less confusing. And it’s likely that they’ll expand the list of codes they draw from in coming years as they develop new technologies and features.
Once you know how to read them, they can be very useful. But they can also be confusing. But if you’ve ever wondered by the meaning of GM or OSS on Sony’s lenses is, here’s a breakdown of the codes they use in naming their lenses.
I’ve grouped them by the type of information they convey.
Sony Lens Codes for Mount Types
Codes in this category help identify which lenses are compatible with which types of Sony cameras.
- E-Mount – Sony’s mirrorless camera mount, used in both APS-C and full-frame cameras (NEX, a, and α series). E-mount lenses are compact and lightweight, designed for mirrorless cameras with a short flange distance.
- A-Mount – Originally developed by Minolta and adopted by Sony for their Alpha DSLR and SLT cameras. A-mount lenses are designed for use with Sony’s traditional DSLR and SLT cameras that use a separate autofocus motor and translucent mirror technology.
Sony Lens Codes for Lens Formats
- FE – Full-frame lenses designed for Sony’s full-frame mirrorless cameras (α7 and α9 series). FE lenses can also be used on APS-C E-mount cameras, but the field of view will be cropped, effectively increasing the focal length by a factor of 1.5x.
- E – Designed for Sony’s APS-C mirrorless cameras (NEX and α6000 series). E lenses provide a smaller image circle, making them more compact and lightweight. When used on a full-frame camera, the camera may automatically switch to an APS-C crop mode to avoid vignetting.
Sony Lens Codes for Autofocus Motors
- SSM – SuperSonic wave Motor, a fast and quiet autofocus motor used in Sony A-mount lenses.
- SAM – Smooth Autofocus Motor, a more affordable autofocus motor used in some A-mount lenses. Generally slower and noisier than SSM.
- DDSSM – Direct Drive SuperSonic wave Motor, an autofocus motor used in some high-end E-mount lenses for fast, precise, and quiet autofocus.
- LM – Linear Motor, a type of autofocus motor used in some E-mount lenses for smooth and quiet autofocus performance, particularly suited for video recording because it produces less noise and vibration.
Sony Lens Codes for Optical Technologies
Some lenses feature notable technology that the designers (and marketers) consider worth highlighting in the name of the lens and may well influence a buyer’s decision (and the price). An important example is newer lenses that feature lens optical stabilization.
- OSS – Optical SteadyShot, Sony’s in-lens image stabilization technology to reduce camera shake and allow for sharper images at slower shutter speeds.
- G – Stands for “Gold”, a designation for Sony’s high-quality lenses with excellent optical performance and build quality.
- GM – G Master, Sony’s highest-grade lenses, designed to provide exceptional optical performance, sharpness, and bokeh.
- ZA – Zeiss Alpha, a series of lenses co-developed with Carl Zeiss, featuring high-quality optics and build quality.
- T – A special lens coating technology developed by Carl Zeiss, used in ZA lenses to reduce flare and ghosting and improve contrast and color accuracy.
- APO – Apochromatic lenses, designed to reduce chromatic aberration and provide improved image quality.
- DT – Digital Technology, a designation used for some A-mount lenses designed specifically for APS-C sensor cameras. This has been phased out–it had a time and place to be meaningful.