Yep, it's a lightbulb. As a part of my renewed commitment to my work, I am participating in a weekly sketch over on Wetcanvas. The great thing about this site is that it provides reference photos without any issues of copyright. The photo gallery over there is wonderful! I have spent many nights browsing the photographs, from people, animals to landscapes and machinery. However, the downside of drawing or painting from a reference photo is that you can be limited by the quality of the photo and its composition. The one thing I never thought about was that you are also limited by your printer. I printed a photo of the lightbulb and went on my merry way to begin the sketch. The shadow kept bothering me since it was cropped so harshly. Once I finished, I went back to the site to post my progress and lo and behold the original photo was different! My printer cropped the shadow more than the original. I know, it's a little irritation that can be easily remedied by adding more to the right of the sketch. Since I used vine charcoal, it's easily corrected.