dan kessler

We're analog beings and light is an analog system, so is film.

 

Digital cameras take photon's of light and converts them to one's and zero's. However, there are guidelines about how many one's and zero's you can fit into a given stream of data.

 

Can't cite the specific source just now, but I'm certain that I read that the sensors in digital cameras are in fact analog devices. It's the outboard circuitry that digitizes the signal. Pretty interesting, eh Tyler?

Can't the seller tell us?

Art directors are not threatened by the digital revolution.
Virtually every cg feature you see employs one or more art directors.
They play a very significant role in the look and design of the
entire film. They usually come from a strong fine arts background and
have very impressive portfolios.

All you need to know is the distance from the camera to the green screen. Just calculate based on your field of view.

However, you don't necessarily have to fill the whole frame with green. If you just want to extract a matte for your foreground subject, the screen only needs to be big enough to put a green border around that subject. Everything else can be garbarge-matted out.

So with regard to your motion blur question, the answer is no, the amount of motion blur will not be the same when shooting at different frame rates with a film camera.

As you increase the frame rate, the exposure time decreases, so the amount of motion blur also decreases.

Ray tracing is probably the oldest and most fundamental cg 3d rendering
method that exists. To be slightly more specific, rays are computed
for each pixel in an image. There are other rendering schemes, some much
faster, but ray tracing is good for photorealism and accurate shadows and reflections.

We tend to talk about lens properties such as focal length and image plane in absolute terms. We visualize a cone of light from a lens coming into focus at an exact point. Ideally, the film or sensor is positioned at that point, rendering the sharpest possible image. However, there is a margin of error, a deviation from that exact point, that our eyes will allow, yet still perceive as sharp. The light cone can overshoot or undershoot the plane of exact focus, producing circles, rather than points. The maximum allowable circle size that we still perceive as sharp is called the circle of confusion.

It is this concept that gives us depth of field, or a range of perceived sharpness, rather than just a single plane.

For 35mm motion picture film, I think the maximum allowable circle size is approximately .001 inch.

A magnifying glass IS a lens. They are usually double convex in shape.

The hand-held type usually don't magnify more than around two times, so the

focal length is probably around five inches.

Infinity focus will be roughly one focal length away from the lens. The closer you get to a

subject, the further you must move the lens away from the film plane or viewing screen to hold sharp focus.

You can fashion a crude barrel out of cardboard and make it slip snugly into another cardboard sleeve

to make a focusing mount.

A simple lens of this type will suffer from a variety of aberrations, which will result in a soft, imperfect image.

If you want to improve its performance, you will have to make a cardboard stop with an opening much smaller

than its full diameter. Do some research on simple optics and you will understand the principles better.

As David knows, Kubrick's modified f0.7 lens for 'Barry Lyndon' racked through two complete revolutions in order to get enough accuracy for pulling focus.

Lens mechanics are what we make them.

Helicoids consist of multistart threads with long leads, giving them

a lot of linear translation for a little rotation. A normal thread

is typically a single start with a much shorter lead. It will rotate

multiple times to achieve the same linear travel.

Hate to say it, but there are no major effects studios left in Hollywood.
You better include instructions on how to get work in foreign countries.

If you read the ebay item description, it plainly says it's for a Bolex 8mm camera.

If I'm not mistaken, no major studio even has a camera department any more. It's all contracted out.

Just need to confirm the exact angular position of the locating pin on a PL mount.

Is it precisely 45 degrees clockwise from the top when facing the lens port?

I'm no electrician but 42v seems like a LOT of power to be running through that camera. I have the Arriflex S/B with a 12v torque motor for the 400ft. mags but there is no connector or any port for one.

 

Just some general info - AC synchronous motors in this application typically run on 110 volts, so 42 volts

isn't a lot, really. Their main advantage is that they lock to the drive frequency and maintain constant speed. However, they don't have a lot of torque. You have to make sure the motor is big enough for the load.

DC motors generate more torque, even though they run on less voltage.

Okay, there's another option I didn't consider before, because

I've never used one myself. That would be a borescope.

Just saw some demo stuff online that looked rather cool.

They are routinely used to inspect gun barrels.

You say the original Bond opening was shot with
a pinhole. Are you sure? I'm inclined to think
it was a graphic element comped over the

live action. In any case, you will probably
get the best results using CG.

No lens I know of can give you the extreme
depth of field at the magnifications you would
need for such small props. Plus, lighting the
interior would be tough, to say the least.

If you're going to go the practical route,

you should consider a much larger prop.

I wouldn't bother, though. CG can do it all.

Perhaps it is needless to mention the classic example of this

effect as employed by Conrad Hall in 'In Cold Blood.'

Here's a link describing how he did it, but no doubt you

can find the info elsewhere.

http://www.theasc.com/magazine/may03/cover/page2.html

(a few paragraphs down)

It depends on what you're shooting. Zooms are good for documentary
or news gathering, where it's handy to have a range of focal lengths
available without stopping to change lenses.

As already mentioned, zooms tend be bigger and heavier than primes.

The longer and faster you want the lens to be, the bigger it gets.
If you don't need a long lens that often, why be burdened with hardware
that mostly accommodates the long end?

For motion picture storytelling, the majority of the shots are at the
shorter end of the focal range. Also, the zoom capability is only
occasionally (if ever) needed in this application.

Don't forget the studio tours. Paramount, Universal, Sony, Culver, Warner Bros.

For a number of years, the name Alan Smithee was used by directors, writers, actors and others

to dissociate themselves from projects on which they had worked, but wished they hadn't.

Sometimes things could get complicated. Check out the wikipedia article. Maybe you should

consult an entertainment lawyer.

Try the folks at www.film-tech.com They're all about projection.

Well obviously you can't just directly use stills film; the take time would be severely limited if nothing else :rolleyes:

But assuming the blank stock is still being made, could that be cut to standard MP lengths and punched with MP type perfs?

And as far as Remjet goes, could the anti-halation problem be attacked with low-reflectivity pressure plates?

 

But anyway, Polaroid film lives on after it was abandoned by Polaroid; I don't see why something similar can't be done for movie film.

I would think it possible to get the right perfs, if the demand was there. And yes, pressure plates can be modified.

Take a look inside any 35mm still camera -- the pressure plates are black.

Along that same line, no anti-halation backing also means that
cameras with polished chrome pressure pads can cause, well, halation.

Also, pretty sure the perfs in 35mm still film are Kodak Standard, rather
than Bell & Howell, which is the standard for 35mm motion picture neg.
Shape and height of the perfs do not match. This is only a problem,

of course, for cameras with registration pins, but the best ones have them.

In the ebay description it says Model Mk 1 prototype.

As for the mirror, you're probably right about it being electronically synched.

 

 

Years ago I did some DIY contact printing. I bi-packed the B&W neg/print stock through a pic sync (motorized syncronizer). I used my small maglight with a custom cardboard shroud on the end, a thin slit for the light. A couple of wedge tests to set the basic exposure level (can't remember if I used slit size or ND gel or both) and I was good. Sounds ridiculous but it gave me a good usable WP.

Not ridiculous at all. This is the basic concept of a Bell and Howell Model C printer. The sprocket diameter is even correct for lining up short pitch negative with long pitch positive stock. I've often wondered about a DIY project along these lines, and the fact that you did it proves its merit! Would like to hear more about it.