On 10 February 2014 I made a sketch of lunar crater Gassendi. At the time I was just starting out in lunar observing and this was my first sketch of a major lunar crater. It goes without saying that I found the task quite challenging. Yesterday, and almost two years down the road, I had the opportunity to make a new sketch of Gassendi.
At both occasions Gassendi was sketched under similar (but not identical) lighting conditions and with good seeing (4/5). This means that the differences between the two sketches are due not to atmospheric conditions or the sun angle, but rather to my experience as a lunar observer.
After many years of deep sky observing I know from experience that the hours spent at the telescope slowly increases your ability to see faint details and to observe low contrast object. But when I started out doing lunar observations I would never have guessed, that the hours spent gazing at comparably bright and contrasty lunar features, would have a similar effect. Obviously they did. My sketching techniques has improved somewhat (still a long way to go), the precision in the depiction is better, but most notably I am happy to see that my attention to detail have increased.
I will try to return to Gassendi in the years to come. Hopefully the next sketch will show some further improvements.