by Rich Neuschaefer
This afternoon UPS delivered my new Tele Vue TV-76 APO. It's a very well correct 76mm f/6.3 doublet. It is, in practical terms, an APO. I got the full setup, soft case, tube mounting ring, 2" Everbright diagonal, 1 1/4" adapter, and 20mm TV Plossl. It is beautifully made. Very rugged. A fine travel scope.
In a brief test this afternoon the optics proved very nice. I looked at the specular reflection of the sun off a small round surface. The out of focus image on each side of focus showed a series of even defraction rings. At the precise point of focus there is no noticeable false color, not at 68.5x. I was using a Pentax 7mm SMC-XL eyepiece.
Tonight I took the TV-76 out in the driveway to look at the Moon, Jupiter, Saturn, and M42. It performed very, very well. I look forward to doing a side by side with it and my Takahashi FS-78. Certainly for a compact, travel telescope the TV-76 does a fine job. The "rubble" on the floor of Copernicus was easy to see. The lighting for Hadley's Rill was not the best, but the lower section, below the crater, was easy to see. I couldn't see the part of Hadley's above the crater. The seeing was quite good for a 3" telescope. Maybe if I was using one of my more stable mounts I could have fine tuned the focus to see some of the upper part of Hadley's Rill.
Looking at the bright limb of the Moon I tried to see any false color. With a 5mm Pentax SMC-XL and a 7mm Pentax SMC-XL combined with a 2x TV barlow, I could not detect a color fringe when the limb was in the center of the field of view.
Turning to Jupiter with the 7mm plus 2x barlow I was very pleased with how well I could see the belts. I believe the GRS was just past transiting. This was about 7:30 pm PST, Feb. 21, '02. With the TV-76 on a light weight photo tripod with a Tele Pod head in an area with bad light pollution. And, again with a not steady tripod.
Saturn was beautiful as always. The Cassini division was easy to see. Turning to Orion, with the bright lights and no filter M42 was limited to a relatively small area around the Trapezium. The four stars in the Trapezium were textbook pin points. I'm pretty sure I was seeing the fifth star in the Trapezium. Moving southwest, Rigel stood out bright and cold. It's companion was easy to see as a little pin point of light.
I used Betelgeuse for my star test. The rings on one side of focus were a little easier to see, but on each side of focus they were well defined.
The "forth" star in Sigma Orionis was easy to see.
I was enjoying the view through the TV-76 enough that I thought it would be neat if I had a TV-85. Aperture fever. I think that is a compliment to the TV-76. The TV-76 is a great addition to the TV line up. It is what I always wished the Pronto would be.