# Lens numbering # Lens numbering

This is archived post, see new version on new [platform](https://www.kurokesu.com/blog/lens-numbering).

[lenses on Kurokesu web page](https://www.kurokesu.com/Lenses/) has unified numbering. After few years of testing different naming conventions, this one seems to be finally working fine. Main purpose was to make it clear what kind of lens it is from a glance and have distinct SKU. It may not reflect full information though as overpopulating with extra information would make it even more difficult to read.
**L****001****FZA****-****2.8Z12****-****CS****-****VIS**
LensIDFeatures Zoom range Lens mount Filter
**M** - Motorized lens **Z** - Zoom **F** - Focus **A** - Aperture **D** - Day/Night **NN** - Fixed **NNZMM** - Zoom **N** - No lens mount **C** - C-mount **CS** - CS-mount **M12** - M12-Mount (S-Mount) **M16** - M16 lens mount **M8** - M8-mount **D14** - D14-mount **VIS** - Band Pass 380-650nm (IRCUT) **NF** - No filter **NIR1** - Long pass 850nm filter
- **L** – Fixed starting letter - **ID** - unique lens identification number, in some cases few lenses with similar specs can have same description code but identification nr will be unique. Even if lens SKU is abbreviated only to L{nr} it will make full sense and that lens still will be fully identified. - **Features** – this non-positional section describes key lens features. If lens has no adjustments, this section can be omitted. - **M** – motorized lens, if this letter is omitted it means lens is hand adjusted. - **Z** – Zoom adjustment is present - **F** – Focus adjustment is present - **A** – Aperture (also known as Iris) - **D** – Day/Night filter - **Mount** – indicates lens mount format - **CS** – CS-mount. Thread is Imperial 1″ 32TPI. Flange focal distance is 12.526mm - **C** – C-mount. The same as CS-mount just flange focal distance is 5mm longer, which is 17.526mm. Usually used with bigger sensors. Frame size can be up to 1″ - **M12** – M12-mount also known as S-mount. It has metric thread M12\*0.5, despite small size frame size can reach 1″ and has no flange distance. Back focal distance can be in a range of 1..12mm - **M16** – M16-mount - **M8** – M8-mount - **D14** – D14-mount. Has smooth bore and secured with side lock screws - **Filter** - **VIS** - Band Pass 380-650nm, OD=2. Also known as IRCUT filter. - **NF** - No filter. - **NIR1** - Long pass 850nm filter.

If no filter specified for CS or C-mount lenses, assume **NF** lens option.

If no filter specified for M12-mount lenses, assume **VIS** lens option.

#### Examples
**Lens SKU** **Explanation**
L010-3.2-M12M12 lens, focal distance 3.2mm, IRCUT filter
L010-ZFA-2.8Z12-CSCS zoom lens, focal distance 2.8-12mm, no filter
L010-MZFAD-5Z50-D14 Motorized 5-50mm D14 lens with zoom, focus, aperture and day/night selection mode
L010-3.2-M12-NFM12 lens, focal distance 3.2mm, no filter