Last Spring the GSLAA had an artists' swap meet at our normal monthly meeting time.
One of the other photographers had this super long lens, 650 mm collapsed and extending to 1300 mm, f/8 to f/16 fixed aperture. When I saw that it was a T-Mount and adaptable, we made a deal.

From the start I was hoping to try it out on the moon when I had the opportunity.
Yesterday was a cool clear evening, the moon better than 96% full with a predicted moon rise time of about 6:00 PM. So I mounted the lens to a Pentax 6.1 megapixel body, plugged in a remote cable release, and dusted off that big old metal tripod.

Before sundown I did a few test shots from the driveway, distant treetops and looking toward the end of the street, kind of hand held supported by the tripod. The view with the speed limit sign is about 1/6 mile away. The test was encouraging.

Shortly after 8:00 PM with a night sky the moon cleared the treetops and I was ready.
Camera body was set to aperture priority mode, lens fully extended and f/16.
First of the moon images below is untweaked and shows the full frame visible. Other shots are cropped a little to cut out some of the dark sky and center the moon.
I did some bracketing, progressively compensating the exposure by -0.5 step, then -1.0, -1.5, and finally -2.0. The moon is actually always in full daylight, and quite bright, and the compensations helped in bringing out some details in its geography.
With each image below, I show first untweaked from the camera, then after "Auto Enhance" with ACDSee software. ASA was set at 800 at time of exposure. No sharpening software tools were used.

I think this lens is promising.

Please click on thumbnails to see enlarged.
All images are ©2019 E.J.Kowalski.
Thanks! Ed