Telescope Reviews: What do Veteran Observers view?

I have seen literally hundreds (if not thousands) of objects that are "at the limit". Often, they are companion objects to my targets (satellite galaxies or other memebers of a group), or simply very low surface brightness, thus hard to see.
One could argue I'm looking at objects that are really beyond the aperture of the scope I'm using, but I see it as an observing challenge.
I often get full write-ups of details on these ultra-faint objects.
How?
Even objects so faint they appear as "breath on the eyepiece" can have some details noted:
--shape
--orientation on the sky
--superimposed/nearby stars noted
--brighter centers?
--accompanying objects?
--held what % of the time with averted vision?
--relative brightness to nearby objects?
--size in the field?
If you make those notes about the objects at the limit, you will be able to go back later and determine the difficulty of the observation and may be able to contribute to a conversation about the visibility of the object in a certain size of scope when asked by someone doing a project.
One thing is for certain--you will never know if a certain object is visible in your scope unless you look. I can't tell you how many hundreds of objects supposedly beyond the sizes of scopes I've used I've been able to see, while other objects supposedly visible were not found. You won't observe at the limits very long before you realize the positions and descriptions of a lot of objects are not accurate (at least the ones often found in books). Fortunately, we are in a golden era of amateur astronomy, and great reference books exist (like the Night Sky Observer's Guide of Kepple and Sanner, or Star Clusters by Archinal & Hynes, or Steinicke and Jakiel's Galaxies and How to Observe Them).

Why look for objects at the limit? One very obvious reason: to teach yourself how to see things at the limit of vision. This pays off in spades when looking at brighter objects because many more details will be seen and noted. Spending so many years with a small scope looking at faint galaxies means that when I look at a bright object these days my notes may run to a full page of writing about the object. Sometimes I just give up and appreciate it for what it is, and take no notes at all.
A recent view of M17 through an O-III filter on a very dark night showed the Swan shape was merely a bright knot in a nebula over a degree wide. So many waves and tendrils of gas were visible that I had to move the scope several eyepiece fields before I was sure I wasn't still looking at nebula. Much of that nebula was about as bright as the very faintest galaxies that only pop in and out. I credit all those years of looking at faint fuzzies for the ability to see the stuff in the first place.
[Note: long time exposures show M16 nd M17 are bright parts in the same nebula, so some aperture will probably see this]

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Don Pensack
12.5" Truss Dob, 5" Maksutov
Sustaining Lifetime IDA member, TeleVue junkie