There are some absolute prohibitions. You cannot take photos on a military base, for example. Take care as there are military aircraft at Luxor airport, so heed the ‘photography prohibited’ signs.
In Luxor itself there has been no problem taking pictures outside, in a non-military environment. This used to include the outside of the Valleys of the Kings and Queens, where the major tombs are situated, but a new ban on all video and still cameras prevents any camera being taken into the Valley of the Kings. They have to be left outside the Valley, so you may as well leave them in the taxi or the tour bus.
At the other sites (Queens, Nobles, Workers) there is nowhere to leave the cameras outside and you can take them in to the area, but see below about taking photos in the tombs.
Nefertari’s tomb (when it was open) and Tutankhamun’s tomb have been photo-barred for some while.
It used to be possible to take photos in the other tombs if you bought an extra camera ticket for about LE10. However, photography is no longer allowed in the tombs, even if you are prepared to pay extra. For a while after the rule was introduced it was quite easy to get round it by chatting up the guard and giving him something. The rules are being more firmly applied now and if you are found taking photos your camera will be confiscated.
In our recent experience there are no naughty guards and neither a friendly chat nor a bribe will enable photography inside any of the tombs, with or without a flash.
At the Valley of the Kings you have to leave your cameras etc at a kiosk by the entrance to the site. At the Valley of the Queens you leave the camera at the entrance to the tomb itself, although they will allow small cameras, camera phones etc to be taken in as long as they stay in your pocket or bag.
As with the tombs, photography was once permitted in the museums. Now it is not. Cameras have to be left in a foyer and collected on departure. If you make a trip to Cairo, you will find the same restriction in the Cairo museum, so you will not be able to photograph Tutankhamun’s mask.
Taking photographs of people is not as sensitive as it is in some other parts of the world. For obvious reasons it is courteous to ask first, if possible. Usually pointing to the camera and making a thumbs up sign is understood if the subject does not speak English. Children and older people with character-full faces usually appreciate a tip. Keep small value notes handy.
It is not always possible to ask. From a cruise boat, for example, it is not possible to communicate with someone on the river banks. We have never had a problem taking photos from a boat of anything or anyone on a bank or on the Nile. In fact, many people, especially younger people tend to perform for the camera even though they are out of reach of a tip.