Last night I was looking for M80 from my backyard, and had several things going against me. 1) I am in a light-polluted area, and can only see 3 stars in Ursa Minor. 2) The moon was bright in the South. 3) The seeing was not particularly good ... brighter stars were not resolving to a sharp point but remained slightly fuzzy at moderately high power.
FIRST, I hunted M80 in my brand new (to me) 80mm APO with manual EQ mount. (Am still learning this scope.)
This took me maybe 10 minutes or less from consulting the star chart, to hopping in the finder scope to the right location, looking in the EP in that area ... repeat about 3 times. Found it at 102x as a small smudge.
Then, I wanted to see M80 in my 8" Dob. Long story short - I NEVER FOUND IT.
Here are the main issues I see with my Dob, when looking for a "small faint smudge" that needs 100+ power to find in my light-polluted skies.
- I have come to believe that the red-dot finder kinda sucks. It does not allow seeing more stars than my un-aided eyes. So for example, I could not see Omicron Sco (mag 4.6) with my eyes or the red-dot finder. I was left trying to "hop" starting from the visible Al Niyat to Omicron to M80, using the EP to validate the hops and directions. Also, the red "dot" itself is a large slightly out of focus "sort-of dot" ... it definitely does not help find things like my APO's 6x30 finder scope with cross-hairs.
- Trying to "nudge" the XT8 Plus with finesse and accuracy, in the right direction, across a distance of more than a couple FOV's, feels kinda like an exercise in futility. The slow motion controls on an EQ mount are far better for this. In order for the Dob to be stable at high power, and not move accidentally too far in the altitude aspect, I need to at least somewhat tighten the tension knobs. But then smooth movement becomes difficult to manage.
Note I do not want to get a Go-To scope to solve the issue of finding things. I want to learn the skies. Is a manual Dob simply not the right scope, for a goal of observing all 110 Messier objects, from a light-polluted area?