EP shoot-out

asimov (John) · #1 20-08-2005, 04:28 AM

Hi all.

I want to compare my 20mm TV plossl BARLOWED......with a ED-2 9.5mm. Close to being the same magnification, but would the TV "suffer" slightly from light transmission because of the barlow? Would this be a fair comparison test do you think?

ausastronomer (John Bambury) · #2 20-08-2005, 09:07 AM

Depends entirely on the quality of the barlow you use. In a poor quality barlow the image will be degraded with a loss in contrast, sharpness and light transmission. With a good barlow you wont see any difference. FWIW if you use a top grade barlow the TV plossl will outperform the ED-2 in terms of lunar/planetary performance IMO. I have never compared them side by side but used them both independantly.

CS-John B

asimov (John) · #3 21-08-2005, 02:36 AM

The barlow for the test is the meade series 4000 APO 2X.
I've actually already conducted this "test" about a week ago.