Photography Shows Around DC...

Another presumably semi-boring historical show at the NGA that opens the 30th:  http://www.nga.gov/exhibitions/serialinfo.shtm

http://www.gfineartdc.com/ has a good show through Oct. 20 by Patrick McDonough that is not strictly photo, but is very well done.

Margaret Heiner in Georgetown http://heinercontemporary.com/ has a Satomi Shirai photo show through Oct. 27 that is contemporary - I have yet to see.

National Portrait Gallery http://www.npg.si.edu/exhibit/exhasian.html has a photo show also including Satomi Shirai that is, as well, presumably worth seeing.

Hemphill has Bill Christenberry through Oct. 27, more of a small retrospective looking at his art rather than just photo -- though there are of course photos, also a hologram, old rusty signs, a table of objects, a sculpture, and plenty of works on paper.

Adamson http://www.adamsongallery.org/ has Karen Knorr through Oct. 27.  This may be interesting to you from a techinique perspective... not that exciting subject wise.  Their Press Release explains: http://www.adamsongallery.org/press-release/