Dueling Terminaglers

by Marek Cichanski

Last night (Fri 8/15) there was a good crowd at Montebello. Even though the moon came up fairly early, everyone seemed excited to get in a little DSO work before moonrise, and to look at Mars thereafter.

James Turley had his Vixen 114 refractor, and at one point he put his 31mm type 5 Nagler in for some wide-field views of the southern Milky Way. So, he and I and Michael Swartz were all taking turns looking at pairs of widely separated objects that could now be put in the same field. The Swan and the Pillars, the Lagoon and the Trifid, etc... Michael mentioned that he had the new 41mm Panoptic. Someone suggested an eyepiece shootout. So, we each took turns swapping them in and out. It was quite a thrill to sit there in front of the 2" diagonal and swap these massive, deluxe eyepieces in and out. I remarked that it was the height of luxury - like driving a Rolls Royce naked in mink underpants. (A line I stole from TV.)

The differences seemed subtle, but noticeable. There wasn't as much difference in magnification as I expected, but there was some. And the apparent fields looked similar, although one was clearly larger than the other. It looked as though the true fields were about the same. Each of us thought that one eyepiece had a darker sky background, but we didn't always agree as to which.

Then I handed Michael his 41 Pan back. "Er, no, you've handed me the 31 Nag," he said. "Hmm, let me see, I guess I must be holding the 41 Pan, then," I replied... and looked down to see a 31 Nag in my hand.

Turns out we'd been swapping two Terminaglers back and forth the whole time. And yet, we were convinced that we saw differences between them! Shows you how much of tendency humans have to see things that they believe to be there. Shades of Percival Lowell.

(When we finally tried the 41 Pan, it was also a very nice eyepiece. Not as big of an apparent field, but a heckuva true field. And nice sharp stars nearly all the way to the edge.)

(Oh, and we put the Vixen 114 on the Veil with the Terminagler and an OIII filter. That rocked! We could see the entire Veil complex in one eyepiece field. I'd never seen that before. This was one place where a smaller aperture, short-tube refractor gave a DSO view that you pretty much couldn't get through a big Dob.)