Pencil sketch of NGC 7640, using a 10-inch reflector at 183x. 

Image compliments of  Dr. James Dire from Hawaii:

Observers Challenge Report:  OCTOBER 2014 OBSERVERS CHALLENGE – NGC-7640-2

Visual description:  10-inch reflector at 183x from my moderately polluted backyard, this galaxy is faint with an overall low surface brightness.  It is elongated NNW-SSE, with a subtle brightening in the central region, and is situated inside a triangle of three fairly faint stars.  roger