Cinematographic Instrumentation in Cineradiology

A special 35mm motion-picture camera now being used routinely for cardiac angiography has a nonstandard format permitting the phosphor image of the intensifier to be recorded as a 25-mm circle. The increase in picture size has improved definition, particularly with high-speed films (Cineflure) with which coarse grain structure has detracted from quality. The shutter has a 180° open phase when used with triggered x-ray emission, a design which better records movement because the x-ray exposure may now be twice as long as previously. No increase in movement blur has been detected in individual frames by increasing pulse widths to 10 ms at a rate of 50 frames (56. 25 in.)/s. The film is advanced six sprocket holes at a time instead of the standard four; therefore it was necessary to design and build a prism-type editor for diagnosis. This apparatus projects a 9-in. picture onto the screen. An optical step-printer head has been designed for the reduction of the nonstandard 35mm pictures onto standard 16mm film. Some detail is necessarily lost in this reduction process, but since the 16mm printing stock has a very high resolving power, this detail loss is difficult to detect. Reduction printing onto 16mm film has also meant that the gradation of the original negative can be controlled and if necessary varied to suit the particular subject being reproduced.

Print ISSN

0361-4573

Published

1967-11

Content type

Original Research

DOI

10.5594/J13665