Description
The Topcon standard prism (‘General Topcon prism’, Prism-2 / プリズム2型) is a survey prism made by Topcon (part number 51803 (PRISM 2)).
Its absolute prism constant is 0.0 mm, which is +34.4 mm on the Leica scale.
Specifications
| Model: | Prism-2 |
| Manufacturer: | Topcon |
| MPN: | 51803 (PRISM 2) |
| Status: | Current |
| Absolute constant: | +0.00 mm |
| Leica constant: | +34.40 mm |
| Constant source: | Manufacturer documentation |
| Maximum range: | 5,000 m (GT-1500: 1.3-5,000 m; GT-700: 1.3-4,500 m (no haze, visibility ~40 km, overcast, no scintillation); GT-1200/600 JP spec: 1.3-5,000 m (6,000 m in good weather)) |
| ATR / tracking range: | 1,000 m |
| Mount: | Topcon Prism-2 holder / tilting holder |
| Last verified: | 21/10/2026 |
Sources
Topcon standard prism ('General Topcon prism', Prism-2 / プリズム2型) FAQ
Below is a list of frequently asked questions about Topcon standard prism ('General Topcon prism', Prism-2 / プリズム2型).
What is the prism constant for the Topcon standard prism ('General Topcon prism', Prism-2 / プリズム2型)?
The absolute prism constant for the Topcon standard prism ('General Topcon prism', Prism-2 / プリズム2型) is 0.0mm. The Leica constant is 34.4mm.
Can I use the Topcon standard prism ('General Topcon prism', Prism-2 / プリズム2型) with a Leica instrument?
Yes, just set the prism constant to 34.4mm.
