Re: How were photographs taken from within a nuclear expsosion?

The best source of information about the filming of nuclear tests that I 
was able to find is the film "The Atomic Filmmakers: Behind the Scenes". 
This film was produced by Peter Kuran, who is also responsible 
for "Trinity and Beyond". If you're really interested in the details, I 
would recommend you get this film; it costs about $20. Here are some 
things I learned from it:

Most of the shots were taken from quite a distance away; if you have the 
DVD version of "Trinity and Beyond" there is one clip which shows the 
actual sound delay between the wisual explosion and the arrival of the 
sound; it's about 30 seconds, which corresponds to about 6 miles (sound 
travels at a speed of about 5 seconds per mile). According to the "Atomic 
Filmmakers", the closest they ever got to a shot was about 4 miles, 
although for smaller shots they were able to get even a little closer than 
that. They also had cameras in metal containers that were closer; some 
were as close as a mile. For the thermonuclear tests in the Pacific, the 
photographers were farther away, more like 20 miles. Planes would fly as 
close as 4 miles at the instant of detonation but would then fly away as 
fast as possible to minimize the shock.

There is a type of camera called a GSAP (for Gun Sight Aiming Point) 
camera; these were installed in the wings of WWII planes and shot film 
whenever firing took place. These were the cameras that were mounted close 
(that is, as close as a mile) to the shots, and which took the films of 
the destruction of buildings and so forth. They were designed to be 
robust; they were sometimes knocked off their supports but would continue 
filming anyway. There was even a film developed which was resistant to 
gamma rays!

The amount of film shot during the tests is truly astounding; each shot 
was filmed by many dozens of cameras of many different types. There were 
cameras at ground level, in towers (up to 300 feet tall), and in planes. 
Presumably what we see are the best results.

Hope this helps; for more information, see the film!