Askar F3.9 full-frame focal reducer
The new Askar FRA400 F3.9 full-frame reducer reduces the effective focal length of the telescope by a factor of 0.7x. The original f/5.6 apo becomes an f/3.9 apo. Its exposure time is significantly shorter, it is reduced to about 50%. The field of view becomes considerably larger.
The FRA400Red was developed for use with the FRA400 and FRA500 flatfield refractors and offers good correction with these telescopes, even when full-frame size sensors are used. The working distance from the M48x0.75 thread to the camera sensor is 55 mm. The camera adapter is equipped with a 2" filter thread.
Scope of Delivery:
Products specifications
| Recommended distance from focal plane to connecting thread | 55 mm |
| Focal length reduction | 0.7 x |
