Moon, 5½ day

First image using an Explore Scientific x2 2" focal extender in the optical chain. The sharpness falls off slightly towards the top of the image (i.e. bottom of the sensor), perhaps more evident on the individual subs. I'm wondering if this is a result of a slight droop in the optical chain, given the overall length of the chain behind the draw tube of the 'scope, which includes a 100mm spacer, and that the ES focal extender weights about ½kilo!

About 40 RAW images converted and tweaked in Capture 1 prior stacking in AS!2, and final sharpening and re-sizing in Picture Window Pro. Equipment: Altair Wave 102mm f7 SuperED APO, Fuji X-T1, Nexstar 6/8SE alt-az mount. 12th April 2016.