Sky-Watcher Explorer 130 vs 130p

1 Comment13 December 2017  |  Admin

People often ask which is the best 5” Newtonian?  The Sky-Watcher Explorer 130 or the more expensive Sky-Watcher Explorer 130p

Both have the same 130mm (5") aperture and are supplied the same EQ2 mount but the 130 has a longer (f7) tube length which enables the use of a spherical mirror. Spherical mirrors are relatively easy (cheaper) to manufacture to a high standard. 

The Explorer 130p has a shorter (f5) tube length, which results in a shorter cone of light with steeper sides. Short light cones require a more sophisticated (expensive!) parabolic mirror. 

For visual astronomy the 130 (or 130M with tracking motor) with it's longer tube is arguably the best choice. The views are very nice and the longer tube length makes it easier to achieve the higher magnifications often used when observing the lunar surface, planets and binary stars.  It is also cheaper! 

For astrophotography the 130p is better because its shorter tube results in shorter exposure times and it's slimmer spider-vanes (they hold the secondary mirror) increase contrast and reduce diffraction spikes. The 130p's smaller size also makes it less likely to act like a sail in a breeze and a little easier to store. 

However, neither model is suitable for use with a DSLR camera because their focusers haven't enough inward focus travel for a DSLR to achieve focus. Attaching the DSLR  to a suitable barlow lens will overcome this but field of view is reduced so it is a compromise. Instead, consider the 130P-DS which will achieve focus and has a larger more sturdy focuser. 

HTH smiley

Neil Allen
28 March 2018  |  14:06

Great post. I went for the 130 which I was very pleased with. I often wondered if I made a mistake not getting the 130P for the parabolic mirror. As I only use for visual observing, not astrophotography, I think I made the right choice :)