Lunar Sketching with a Dobsonian

While discussing sketching techniques on the Cloudy Nights sketching forum , I thought it might be helpful to post my response here as well concerning my technique for sketching Rupes Recta recently.

Use of charcoal:

I really like the dynamics of charcoal and also how flat it is. Graphite appears shiny to me while sketching and is harder for me to see some of the finer details on the sketch when I need to add more markings.

Sketching with a Dobsonian mount without tracking:

My Zhumell is three strut dob without a tracking platform. I was very spoiled with the LX200 when it came to lunar observing. My husband mainly uses the LX200 now (or the ED 80 piggybacked on the LX200) for his imaging so I’ve adjusted to the constant pushing and nudging of the dob for those long lunar sessions. I think it takes me longer to constantly nudge the scope than it does for me to actually sketch the target…lol. I’ve gotten pretty good about nudging it with my forehead, side of my face, shoulder, nose, back of my sketching hand…

I find it helpful to use eyepieces with a wider field of view when using the dob. It gives me more time between nudges, although still only have time for a few markings on the sketch pad before I have to nudge it again. I sometimes will use lower magnification for the albedo features and then increase for the finer details within the craters, etc.

If I feel pressed for time, such as clouds coming in or the moon getting close to the treeline, my sketches really suffer. I find it much easier when I know I can allow several hours to relax, study the target, and sketch knowing I have no time constraints. I also have an adjustable chair that I scoot along during the duration of the session.

Sketching sequence for Rupes Recta:

As for the sketching itself, I draw the anchors first; ie, in this sketch I drew a faint marking for the scarp and the “scoop” so that I could add Birt in the proper place as well as its proportion. Then I added the background of lunar surface; next came the finer details of the main features: craters, scarp, allusive ridges around Thebit; and lastly the albedo markings.

Persistence is the key, I think. Almost every lunar sketch, and sometimes solar as well, I come to a point where I think the sketch is getting worse instead of better and it’s tempting for me to want to start over. But then if I keep at it, it falls into place at the end.