Sometimes a single photograph can be a key to a lot of little-known facts.
The picture was taken in 1916 by one of the members of Matson Photo Service (American Colony, Jerusalem) at Huj airfield, Palestine, 9 miles from Gaza. Before the United States entered the war, American photographers were quite friendly with Ottoman and German forces. I believe this set of pictures (included in the World War I in Palestine and the Sinai album, Library of Congress) was commissioned on the occasion of Gen. Kress von Kressenstein visit to Huj. On this page we see the General with Colonel Gott, and also with assorted German and Turkish officers.
Who was famous Herr Felmy? A short article about Ross "Haji" Smith, the best Allies' aviator in the Midlle East, tells us: "The most capable German pilot in Palestine was Gerhard Felmy, a particular courageous and capable pilot... " A brief research brings more: Felmy was born in 1891 in Berlin (so he was 25 years old when the picture was taken), started his Army service in 1910 with an Infantry regiment, retired on August 2, 1914 (an interesting date, isn't it?), spent nearly five months in the Niederneundorf Flying School and formally returned to active service on March 1, 1915 as a volunteer. Actually he was enlisted in the 51st Field Flying Battalion earlier, on January 27. In September 1916 he was transferred to Palestine and joined the Fleger-Abteilung 300 commonly known as "Jasta Felmy". The commander was his older brother Helmuth Felmy (later a Luftwaffe General, imprisoned after the Second World War as a war criminal for crimes committed in occupied Greece).
There is an interesting discussion @ theaerodrome.com about the proper designation of Felmy's unit, listed also as 55/1 (F) and probably 2 (F). It was finally demobilized in March 1919 after a rather busy service.
Was it really busy? People use to think about WWI in the Middle East as of something archaic, Turkish Lancers against Imperial Camel Corps with Col. Lawrence in the background (or in the foreground, for more fun). But a look at the war reports unfolds a different story: air war, not so active as in the Western Front but real.
I'm not sure about the name of the pilot who shot Dittmar. Theaerodrome.com. mentions Steele but Australia's Norman Steele was shot earlier, in April 1917. Probably someone will be able to clear the subject.
Regarding the famous Herr Felmy: he was forced to return to Germany suffering from malaria in August 1917. General Kress von Kressenstein wrote that "with Felmy's departure, our luck departed too. After his leaving we were no longer masters of the air". Between January and April 1918 Felmy briefly returned to Palestine, this time to command FA300. His post-WWI career is quite disappointing. Finally demobilized in 1920s with the rank of Hauptmann (Captain), he joined German police and slowly but surely ascended from Lieutenant to General. He received his General-Major (Police) badges short before the Reich's fall, on January 30, 1945. The legend says he, like many other German pilots, sported a swastika on his Albatros' fuselage: