Although this nebula is fan-shaped in photographs and has many finer tendrils, in the EP from my location all I was able to resolve was a oval patch of light. Still, this is an interesting nebula and, when using the OIII filter is one that offers spectacular views as it is nestled in a very rich star field.
The nebula was sketched with the OIII filter in place, and the background stars were sketched without the filter. Approximate time at the EP to sketch this object along with the background stars was just a hair under 45 minutes. Digital rendering created using original pencil sketch as a template in PhotoShop.
Here is how NGC 1491 appeared to me: