21st August 2003
While prepping a Arri 435 Advanced yesterday, we wanted to know what the exposure times were for the Added Feature slow frame rates. They weren't what a bunch of us initially thought ... although it was pretty obvious after we did the calculations, and stop watch timed the actual (long) shutter movement.
0.1 FPS is an exposure time of 5 seconds...then obviously 0.5 FPS is 1 second and of course 1.0 FPS is 0.5 seconds. The in between times from 1.0 to 0.5 FPS are covered by 0.5 seconds...while the FPS from 0.5 FPS to 0.1 FPS are covered by four seconds...log scale? 0.25 FPS has an exposure time of 2 seconds.
>Further...regarding the previous
message on 435 Advanced Exposure >Times
So the 435 Advanced can "go as slow as" 1 frame every 10 seconds...with exposure times varying from 5 seconds per frame to 1/3rd second per frame with an 11 degree shutter
Other steps are 1 frame every 5, 3.3, 2.5, 2, 1.7, 1.2 and 1.1 seconds. A regular 435 goes down to 1 FPS ...
Not sure how protected the film is with a 5 second exposure...protected only by the mirror/shutter. With sun down the barrel it could be iffy.
If you were to expose a very long, multi-second exposure with
a very narrow shutter (eleven degrees over five seconds) would
you risk strange positioning artefacts with fast-moving items?
Okay, this is a theoretical possibility even with more everyday
rates and angles, but you could end up with a combination
of rate, angle and speed which would render an object as an
angled streak across the frame.
Mako Koiwai wrote:
> Not sure how protected the film is with a 5 second exposure ... protected
I thought you could add an internal capping shutter to the 435...
Of course...but the idea is that the 435 Advance'd allows
one to do some real time lapse...without having the Intravelometer
door and gate. Note, you cannot buy a "regular"
435 anymore...apparently...all 435's are now the Advance model.
We did a 3.5 hour take on Sunday at 1 frame every 10 seconds...doing an exposure compensation with the shutter via the RCU...and it came out beautifully.
Makofoto, Cameraman, Glendale, CA