Yes. Unless you are like at 5000 feet on a desert mountaintop or deep in federal lands in Wyoming or some other godforsaken place, your seeing will vary from moment to moment and you have to let your eyes and brain sort out the shifting images. You seem to have done that. I also have a 70-mm refractor and I live in a big city. So, I can relate to your observations. I tip my hat: congratulations on your observing!realflow100 wrote: ↑Thu Oct 21, 2021 12:59 am ... stable jupiter was a clear disk with 2 easily identifiable bands. and looked very nice. fleeting moments I saw maybe 1 or 2 additional bands.
Saturn had very clear ring separation from the planet. and maybe a faint band just above the rings of the planet too.
and I'm almost certain I saw cassini division for a few brief split-second moments in moments of exceptional atmosphere seeing.
Does this sound like typical results for a 70mm achromat doublet telescope? (non-ED)
I took a suggestion from Ronald Stoyan’s “The Visual Astronomer” webpages (here: http://visualastronomer.com/ -- but not https secure and not updated recently) who says that magnification is never wasted and that you need to let your eyes continue to look while the shifting atmosphere is opening and closing for better and worse seeing.
Sorry, John, but I have to disagree. I have tried to split the double-double many times with my 70-mm and never did it because it takes good sky seeing. I know that others do this with 60mm or smaller, but "seeing" is everything and neighborhoods are local. For me, it takes the 102-mm F=660 mm forJohn Baars wrote: ↑Thu Oct 21, 2021 8:17 amSorry to dissapoint you. To me It doesn't sound fully like a 70mm achromat.realflow100 wrote: ↑Thu Oct 21, 2021 12:59 am (...)
Does this sound like typical results for a 70mm achromat doublet telescope? (non-ED)
I know that in many reviews the double double is put forward as a kind of accuracy test. However, they are not, especially for larger instruments. With 2.3 and 2.4 arcsec separation, they are at most a good test for a 50mm instrument. With a good 70mm instrument they are already separable well below 100X. At 70X or 80X you already get the impressions as you describe above.
Also, you need to consider his eyes versus yours versus mine. A person can function quite well with nominally "poor" vision because we adapt to our environments. I discovered that I needed glasses for distance only when my employer sent me to a strange city for a week and I could not read the street signs in the dark while driving. In my home town, the fuzzy clues were enough, given that I usually knew pretty well where I was anyway.