G'day Ray,
I just sent a link to your image to Prof. Ron Buta (University of Alabama), as I feel that the faint outer spiral structure of NGC 5101 is particularly well shown in your image.
Buta essentially "wrote the book" on ring and bar structures in disk galaxies, extending the original Sandage-Hubble and de Vaucouleurs-Sandage-Hubble galaxy classification systems so that they include notations that express more detail about the bar and ring structures that are found within spiral and S0 galaxies.
In the case of NGC 5101, there are at least two ring structures, that which immediately surrounds the bar, and the ring (or broken ring) structure that is formed by the overlap of the outermost spiral arm (or arms).
For comparison purposes I attach a deep UKS image that was made by David Malin:
The following NIR image (J+H+K bands) from the 2MASS survey hints that this galaxy might contain a third ring, a small tight ring immediately surrounding the centre:
Cheers,
Robert
Notes added in edit:
I further note that IIS member Martin Pugh has also recently imaged this field.
As another comparison, here is the B-band ("blue") image from the online version of the De Vaucouleurs Atlas of Galaxies:
The blue knots in the faint outer arms are emphasized, on account of the bandpass of this image.
The outer arm structure is reminiscent of a weak density wave, perhaps caused by the inner bright oval section of this galaxy (the bar plus the bar-encircling ring) acting, itself, as a bar.
(for info on this sort of thing, one can 'google' on the phrase "resonance rings" in the context of galaxy morphology)