I am married to a Turk, we go 'home' each year, if not twice or thrice.
I am going to Turkey for 10 days at the end of August.
It's going to be very hot. Forget walking about extensively in the daytime.
The light is also going to be very strong; too much so for any decent outside photography bar the golden hours.
I'll arrive in Istanbul on Wednesday evening, work Thursdsay and Friday, have the some time off on Saturday and Sunday. Travel to Izmir on Sunday afternoon, work there on Monday. Maybe have the morning off and travel to Ankara on Tuesday afternoon. Work in Ankara Wednesday, Thursday and Friday. Fly back on Saturday morning.
Turkey is a huge country. My advice is to stay local and make the most of what you've got.
I'd spend the weekend in Istanbul:
You could shoot Sultan Ahmet (sp?) in the early morning whist the light is good.
Once it's too hot visit the Bascilla, Grand Bazaar and Spice Bazaar - photography is allowed inside, but be subtle in the Bazaars and watch your gear. Forget a tripod.
The Sultans Palace and Harem is worth a visit, but frankly not very photogenic, although the view over the Bosphorus from the tea garden is good.
Near to Sunset take a Bosphorous tour from the boats at the harbour by the Spice Market. They'll take you out of the Golden Horn where you'll the original Ottoman suburbs and wooden houses, Ataturk's House, and plenty more.
Sunday consider an early trip up the Galata Tower for some good views.
The old trams running up and down the main drag into Taksim are photogenic as well.
A ferry ride up the Golden Horn is also nice - get off the ferry at the last stop and take the cable car to Pierre Lotti which is a tea garden on top of a huge cemetery overlooking Istabul.
I have not been to Izmir or Ankara. Have you got any tips about those places?
Ah Izmir, my wife's home town.
Izmir is close to Efes (Ephesus), but it's going to be very hot. If your schedule allows then try and stay in the town nearby (I forget the name) and get there early in the morning before the heat and crowds arrive.
The Izmir Bazaar is very nice - similar to Istanbul although a lot quieter and thankfully smaller. The tea house round the corner from the mosque inside the bazaar does the best Turkish Coffee you'll ever try!
The old Greek district of Izmir is very traditional and worth a look. Decent bars and fish restaurants in the side streets as well.
A ferry boat trip around Izmir harbour is also nice, espically at sunset. Take the ferry from Alsancak. Be wary of taking photo's in the city harbour itself - there are several military installations: signs will warn you not to take photos.
If Ankara is interesting I could fly back on Sunday instead.
The majority of Turk's I know don't rate Ankara at all. Having spent one day there (en-route to Cappadocia from Istanbul by car - 2 hard days of driving) I wouldn't rush to return. ymmv.
If you get a taste of the country then flights from the UK to Turkey are pretty reasonable - check out easyjet/BA to Istanbul, or Cyprus Turkish Airlines to Antalya or Izmir.
Cappadocia is a trip in itself, best saved for the cooler spring time, out of season.
I've got to reiterate - it's going to be very, very hot.
Maybe it'd be better to put the photography in at second place and just take it easy.
İyi yolculuklar!
Mark