Penta Prisms

Penta Prisms

Penta prism can deviate an incident beam without inverting or reversing to 90°.The deviation angle of 90° is independent of any rotation of the prism about an axis parallel to the line of intersection of the two reflecting faces. It is commonly used in Plumb Level, Surveying, Alignment, Range finding and Optical Tooling. The reflecting surfaces of this Prism must be coated with a metallic or dielectric coating. The standard Penta Prism reflecting surfaces are coated with aluminum or enhanced aluminum.

Standard Precision Penta Prism

Attribute Specification
Material N-BK7 Grade A optical glass
Dimension Axh (mm) 2.5x2.5 ~ 100.0x100.0
Dimension Tolerance (mm) ±0.2 (General), ±0.05 (High Precision)
900 Deviation Tolerance <1 min. (General), <3 sec. (High Precision)
Flatness @633nm λ/2 (General), λ/4 (High Precision)
Reflection (per face@400700nm)  R>90%
Surface Quality 60/40 (General), 20/10 (High Precision)

Size(mm) 1 Min. Deviation 30 Sec.Deviation 10 Sec.Deviation
A x h Part No. Part No. Part No.
2.5 x 2.5 FPP1101 FPP1201 FPP1301
7x5 FPP1102 FPP1202 FPP1303
7 x 6 FPP1103 FPP1203 FPP1304
10 x 10 FPP1104 FPP1204 FPP1305
15 x 15 FPP1105 FPP1205 FPP1306
20 x 20 FPP1106 FPP1206 FPP1307


High Precision Penta Prism

By adding a wedge for deviation correction in output beam surface, it can be used as Percision Penta Prism. It is often used in Plumb Level, Surveying, Alignment, Rangefinding and Optical Tooling.

Material: ------------------------------------------------------- N-BK7 Grade A optical glass
Dimension Tolerance: -------------------------------------------------------------- ±0.2mm
90° Deviation Tolerance: ---------------------------------------------------------------- <5''
Flatness: -------------------------------------------------------------------------l /4@633nm
Reflectivity: ---------------------------------------------- R>90% per face @400-700nm
Surface Quality: --------------------------------------------------- 60-40 scratch and dig
Coating on input and output sides: ------------------------------------------- Uncoated

1 Min. Deviation
10 Sec.Deviation
A x h
Part No.
Part No.
10 x 10
15 x 15
20 x 20


(1). Besides N-BK7 glass, other optical glass is available for custom-made Penta Prisms.
(2). Penta Prism at bigger size is available.
(3). Typical deviation tolerance is 1 minute, better precision such as 30 sec, 10 sec, 5 sec or 3 sec is available.
(4). Typical reflection is >90% by Al coating, other metal coating such as Ag, Cu, or High Reflection Dielectric Coating is available.
(5). Besides uncoating, Anti-Reflective(AR) coating is available upon request. 

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