Hi All -
Spent several nights up -way- too late observing from a dark sky location with my Meade DS-90 (90mm achromat) and my newer LX200 (8"). On Friday, I actually was up late enough to catch Saturn. Seeing seemed great as I was able to view Saturn very clearly with the DS-90 at 250X (cassini VERY clear, shadows on rings, cloud belts clear, etc.) - it was razor-sharp. Since I have never before used the 8" to view planets, I trained the LX200 at Saturn. At the same magnification, Saturn did not appear nearly as sharp. I could barely make out the Cassini division, and the image lacked the sharpness provided in the refractor (saturn has always been this sharp in the 90mm.) I checked collimation, and it appeared to be fine at this magnification.
Shouldn't Saturn appear clearer in the 8"? Is the 8" more succeptable to seeing? The one variable is that I was using different EP's on the two scopes: on the DS-90 I was using a 4.5mm Vixen Lanthanum (great planetary EP!), and on the LX200 I was using a Meade (series 3000) 16mm EP and a 2x barlow. The 16mm and 2x combination normally provides a sharp view on the DS-90, but it also is half the magnification with that scope (1000mm FL.)
Is this just the difference in EP's, or is the refractor just a sharper image by design, even though it has less aperture?
-Jake
Spent several nights up -way- too late observing from a dark sky location with my Meade DS-90 (90mm achromat) and my newer LX200 (8"). On Friday, I actually was up late enough to catch Saturn. Seeing seemed great as I was able to view Saturn very clearly with the DS-90 at 250X (cassini VERY clear, shadows on rings, cloud belts clear, etc.) - it was razor-sharp. Since I have never before used the 8" to view planets, I trained the LX200 at Saturn. At the same magnification, Saturn did not appear nearly as sharp. I could barely make out the Cassini division, and the image lacked the sharpness provided in the refractor (saturn has always been this sharp in the 90mm.) I checked collimation, and it appeared to be fine at this magnification.
Shouldn't Saturn appear clearer in the 8"? Is the 8" more succeptable to seeing? The one variable is that I was using different EP's on the two scopes: on the DS-90 I was using a 4.5mm Vixen Lanthanum (great planetary EP!), and on the LX200 I was using a Meade (series 3000) 16mm EP and a 2x barlow. The 16mm and 2x combination normally provides a sharp view on the DS-90, but it also is half the magnification with that scope (1000mm FL.)
Is this just the difference in EP's, or is the refractor just a sharper image by design, even though it has less aperture?
-Jake