Air Ministry Night Simulation Epidiascope Attachment

In a lifetime of collecting RAF memorabilia we have never seen one of these before. Whilst at school in the 1960's I remember the Epidiascope being used to project images, text from books and photographs onto a white screen ; 50 years ago this all seemed very 'high tec' to myself and my classmates! The example we have here is rather special. It is nicely Air Ministry (A.M.) marked and carries reference nos 14A/3039 with '14A' being the RAF parlance for all camera equipment. It is also embossed 'NIGHT SIMULATION ATTACHMENT FOR EPIDIASCOPES USE WITH WHITE SCREEN AT 18 FT'. The instrument was clearly designed to be mounted over the epidiascopes lens and by altering the central slide filter made up of clear, opaque and dark glass different conditions could be simulated. The filter is marked 'Slide Out' for full moon, 'Slide In' for half moon and 'Flap Down' to simulate starlight -we assume when no moon. A pointer is attached to the filter top and this in turn can be read off on the top of the instrument depending on climatic conditions and height. So using the filter it was possible to project target photographs taken in daylight and simulate how the same view would look at night having factored in weather conditions, the state of the moon, general visibility and aircraft height. What makes this example potentially even more interesting is a typed label has been attached inside reading 'Nuremberg Raid March 30/31st 1944.' The RAF Bomber Command raid on Nuremberg on 30-31 March 1944 resulted in the highest number of aircrew losses for any single operation in World War 2. Out of 779 bombers sent to attack 105 did not return. 534 airmen made the final sacrifice and a further 157 were captured. We have no way of proving if this instrument was used at the Nuremburg briefing but if it was it makes it an item of significant historical appeal. The dark filter shows some age wear but everything is in place with the body being made from black painted brass. It would certainly make a unique addition to a Bomber Command collection or a perfect display item if you happened to own a 1940's Ross military Epidiascope! Measures 7" across (18 cm)