[Konvas] Bolex reflex lens? (off-topic)

[Rick Garbutt]

> 
> I'm not in a hurry, since the shoot is this summer, but I'm looking for
> an inexpensive c-mount through-the-lens-viewing lens (like the old
> non-reflex Bolex cameras sometimes had), for my one high-speed 16mm
> camera rig. Preferably a zoom in good condition (and hopefully fairly
> fast). Like the old Bolexes, this high speed camera is non-reflex.
> 


Why, O why is it would-be directors/producers/any number of other folks who
should know better just WILL not wrap their heads around the concept that

"special effects shots, including special effects shots that you don't think
'should' be special effects shots, 'cheap' and 'high quality' never, EVER go
in the same sentence."

                                                  ?

I had one idiot patiently explain to me, years ago, that the shot "was only
going to be a few seconds long," as if that should somehow cut the cost to
what he could dig up by redeeming a case of empty beer bottles.

For what you're describing, it makes little difference if the shot is 3
seconds or 4 minutes long:  it's the equipment, setup, and knowledge of how
to do this that's expensive/valuable.

You may find some of these dog-leg reflex lenses relatively cheaply, but you
must remember the optical designs are typically 40+ years old, and if you're
looking to intercut this with something that was otherwise shot with Cooke
S-primes, you're in for a probable disappointment.

At least one or two tests are in order, and you've certainly got the time.
So try a mockup of the shot at 64fps on your Bolex, double-frame print it,
and I suspect you'll be in the ballpark.  A boxing glove whack to the chin
takes on the order of 3 seconds, including the lead-in and spittle-flying
parts of the action.  Therefore, if you slow it down by a factor of 5
(equivalent 120fps) you'll have a 15-second shot to pick the juicy bit from,
and that oughta be pretty close.  And you can use your reflex Bolex with
regular C-mount lenses.

Plan B (always, ALWAYS good to have Plan B):  An Arriflex 16S or SB or ST,
equipped with a wild motor, is easily rugged enough to endure OCCASIONAL
bursts to 100 or maybe 120 fps.  Just connect the beasatie to 24VDC.  As the
tach is good to 50fps, you'll be kind of winging it, but that's what tests
are for.  NOW you've got a non-prism reflex, with the single registration
pin, AND around 100fps that you can easily double-print to 200fps.  I've
done this to film neck whiplash for an insurance claim, and the court loved
it.  So.  Respect your poor little camera, and don't do a lot of this.

Pretty good Plan B, I'd say.  And I didn't invent it.

Hope that gives some food for productive thought.

Best to all from -20ºC and about a half-foot of new damn snow,

Rick Garbutt, soc