William Optics Apochromatic refractor AP 51/250 RedCat 51 OTA The iPolar® finder ensures accurate

The iPolar® finder ensures accurate alignment of the system with Polaris

mountain ranges

gear wheel for easy installation onto the tracking shaft

The most straight forward way for polar alignment is just to find the true north point and match its position with the rotation center of your R

star diagonal mirror and eyepiece

William Optics Apochromatic refractor AP 51/250 RedCat 51 OTA The iPolar® finder ensures accurateFeatures The William travel apochromat RedCat 51 K. RC51lx Gen. 1. 5 is perfectly suited for astrophotography and nature photography on photo tripods or travel mounts. Aperture 51 mm focal length 250 mm focal ratio f 4. 9 Petzval design with chromatic aberration free FPL53 objective (4 elements in 3 groups) Very well corrected image field of 44 mm diameter even suitable for full frame cameras Camera connection via male M48 thread (suitable adapters