I know the family asked for the camera at the occassion of Maria´s birthday, but were rejected.
From the Ipatiev guard duty book, 1/14 June 1918:
There was the Romanovs’ usual walk. Tatyana and Maria asked for photo equipment to finish making photographic plates, but, of course, the commandant refused. The guard commander reported that somebody had stolen his Nagant revolver on record at the House of Special Purpose and it was not found. The guard of Post No. 6 stopped two gymnasia pupils, the Telezhnikov brothers who were taking photographs of the House of Special Purpose. After a search and interrogation they were sent to the Extraordinary Investigation Commission.(Maria's birthday was 14/27 June, so this was actually two weeks prior. There is no entry in the duty book for Maria's birthday.)
But their is so many pictures up for debated wether they are the last picture or not. I would say that the Rus picture could well be one of the real last pictures but we can't for shore tell what picture was the last because their is a lot of picture that never made it outside Russia.
There are a number of photos that have been mid-identified as the "last" picture of various members of the imperial family, but Holly is right about the final photos of OTAA. They were a pair of snapshots taken by Stanley Gibbes on board the Rus en route to Ekaterinburg.
More photos from the Tobolsk period may eventually surface, but no images of the Romanovs in Ekaterinburg are known to exist. As others have said, no camera equipment was permitted inside the Ipatiev house, and neither the guards' duty book nor the imperial couple's diaries mention the Bolsheviks photographing their prisoners. Because of the whitewashed windows and double palisade no passersby could snap photos of the imprisoned Romanovs either.
I haven't heard anything of a Rus issue.
The "Rus issue" refers to controversy raised by Fate of the Romanovs regarding OTAA's treatment during their voyage to Ekaterinburg. You can read about it on other threads if you search "Rus." Discussions on that topic tend to get quite heated, however, that's no reason to avoid discussing Gibbes's snapshots.