dan kessler

read about it here

http://www.film-tech.com/ubb/f14/t000220.html

so is this the total abandonment of 15/70 by Imax?

Indeed, those articles speak to filmaking (as in storytelling), not film manufacturing, which is what I thought we were discussing.

I think Pav Deep was alluding to both.

Main point being, with such demand remaining

in the world for film, it's like Mark Twain

once said -- Reports of his death are greatly

exaggerated.

Well, this took me about 2 minutes to find:

http://en.wikipedia.org/wiki/Film_industry

India is largest producer of films in the world.[1][2] In 2009, India produced a total of 2961 films on celluloid, that include a staggering figure of 1288 feature films

More recent stats found here:

http://cbfcindia.gov.in/html/uniquepage.aspx?unique_page_id=30

That's assuming that there's not something else

going on in the camera itself. You said the

previous owner had it serviced... you sure

everything's okay?

First thought is overloading due to binding, misalignment,

or underpowered motor.

I'm getting real suspicious about this motor.

Well, there's the Unilux strobe system, which is routinely used

at high frame rates for nice, crispy slo-mo splashes, crashes, etc.

Very common in TV commercials. Of course, the flash rate is fully

synched with the camera shutter, so the lighting appears continuous.

For a party strobe effect, you don't want that perfect sync, obviously,

but then again, a random flash rate is going to be hit-and-miss with

the shutter timing.

Surely it will work, just don't know if you can be too picky about

controlling it. Sounds like something you really should test beforehand.

Exposure? What about using a light meter designed for flash?

These financial articles never seem to mention

Kodak's motion picture operation, which,

according to some here, has always been

profitable. Like everyone, I wonder where

those pieces of the company will end up

if there is a bankruptcy.

This news will spread quickly, I'm sure

http://news.yahoo.com/kodak-hires-law-firm-jones-day-restructuring-advice-183948864.html

Who knows more about it?

There are cameras that allow for a lens offset to accommodate either format.

My question is this: In practical terms, if you have a camera set up for full ap,

is it ever really necessary to change it?

If the lens covers full ap (and which of them don't?), then I can't see why

a mechanical shift would be necessary. Mask for the format you want, then pan

over a smidge either way to compose for that format.

Even in 4-perf anamorphic, is it a problem?

Granted, one could conceivably have a centration mismatch between camera and

projector anamorphs, but it's so small... does anyone see the difference on-screen?

Okay, I was already typing this up, so I'll go ahead post it:

To put it in simplest terms, in motion picture cameras, the shutter

generally takes the form of a rotating disc with a wedge cut out of it,

like a pie with a missing slice. The open wedge is the part that allows

light to reach the film.

The term "shutter angle" refers to the angular sweep of the open wedge.

So, a 180 degree shutter angle would be half of the total disc.

A 90 degree shutter angle would be one-quarter of the total disc, and so on.

Some cameras have a fixed shutter angle, while others have variable shutter angles.

Shutter angle is one of the factors that determines shutter speed.

The other factor is the speed at which the shutter rotates.

At 24 frames per second, the shutter makes one complete revolution every

24th of a second. If our shutter angle is 180 degrees, then for exactly

one-half of that time the shutter will expose the film, that is, the

shutter speed will be 1/48th of a second.

Here's the formula:

Exposure time (or shutter speed) = (Shutter angle/360) X (1/frames per second)

Wide shutter angles naturally provide longer exposure times, while narrow

shutter angles have shorter exposure times.

Besides controlling the amount of light, the shutter angle will also affect

the amount of blur a moving subject records on the film. Wide angles allow

more blur; narrow angles allow less blur.

Google 'view camera' at wikipedia, then

google 'scheimpflug principle' at wikipedia

I also like the idea of modifying the adapter,

but, Alex, it's your baby.

Okay, so not your garden variety pin hole lens.

Got it. Doesn't change a thing regarding your

original question. Grab that PL Ultra Prime and

your calipers and you've got your numbers.

Want a little extra room? Subtract a couple of

thousandths from the OD and wing thickness. Done.

Oh yes, and I'm sure you'll watch out for shutter

clearance on those short focal lengths, too.

Okay, Alex, a pin hole lens. That's more like

a lens port cover than a lens mount. Why all

the stress?

No joke, you could make this out of cardboard

and Elmer's glue and the light rays wouldn't

know the difference.

I programmed and ran CNC's for several years,

and, at the other end, I've breadboarded

optical assemblies on my kitchen table

with a straight edge, a razor blade,

toilet rolls and scotch-tape.

Sure, I know all the warnings about dial calipers

not being accurate, but everybody and their

brother uses them with no problems. Most jobs

just don't call for jo block accuracy, and this

is one of them.

Your CNC guys will grab a piece of scrap aluminum

bar stock and knock this out on their lunch break.

When faced with the very same question a long time ago,

I paid a visit to a camera shop, asked to look at one

of their PL mount lenses, then asked if they minded me

taking measurements (they didn't), and, since I just

happened to have my dial calipers with me, that's what I did.

Now, I'm guessing that the tolerances on an Ultra Prime

are EXTREMELY TIGHT.

So, if you called those Ultra Prime measurements your

upper limit, then held the downside as close as you could

(dead on would be good), I'd say you were close enough.

Fitting it to the lens is probably the more critical part.

Never done it myself, but surely you'd need a collimator

with an accurate standard for the flange focal length.

Then again, maybe an honest-to-goodness optical guy will be

appalled enough at my reply to come in and tell us both

how to do it.

“Because a standard 35mm frame covers 4 perforations or pitches,

whereas a 16mm frame only has 1 perforation or pitch.”

Sorry i cant undersatnd this answer sir ?? can u explain it clearly ?

Bcos,in 16 mm there is 1r & 2r Film stocks . in 2r 16mm film the answer u gave is not applicable ??? do u mean 1r by saying "16MM Frame only has 1 perf"

Dats why i cant undersatnd.

 

“Deepak, you're firing off questions left and right.”

 

Sir, i also know there are stuff available in net. But i prefer it hearing from ppl in simple term thats why i relay on u ppl :)and, i get best answers here from genius technicians :)

Okay. You're correct in pointing out that 16mm can have one or two rows of perforations, but that doesn't

change what I said. 35mm always has two rows of perforations, one on either side of the frame.

I was referring to the height of the frames as measured in perforation distance or pitch. So, once again, a standard 35mm frame is four pitches high, i.e., 4 x .1866 = .7464 A 16mm frame is one pitch in height, i.e., .2994

As to the specific reason WHY these are the dimensions, one must do some reading, because it involves the long history

of motion picture film. In the case of 35mm film, its dimensions and pitch can be traced all the way back to

Thomas Edison and George Eastman. They established it very early and it has endured to the present time.

Many variations have come and gone over the years. Again, Kodak is one good place to start your research, since

they have played a central role in the history of film.

You've correctly hinted that digital fx can be used to do it.

There's almost nothing you can't do digitally, given enough

time and money, because it can still be labor intensive.

There are lots of ways to do it during production, too.

1) Remove the glass entirely, if possible

2) Choose a position that angles the reflection off-axis

3) Flag off the camera

4) Use dulling spray

Everybody join in!

I'm just curious as to how projector lenses (non-anamorphic ones) work in comparison to the lenses placed on a camera. Since I have only dealt with the latter, I actually realized that I don't understand how the former works.

 

For example, since the projector lens is usually very far away from the screen compared to its distance from the film it's projecting, the focal length of the lens must be measured in meters, right? So how is it able to focus so closely and yet project a focused image so far away?

 

There's really no difference in principle between camera lenses and projector lenses.

You know that the film is located a just short distance away from the lens in a camera,

and that is where the lens focuses an image. The subject is on the other side of the lens,

only much further away.

The same geometric arrangement exists for a projector lens. The only difference is the

direction in which the light rays are traveling.

The relationship between object, image, and focal length for a simple positive lens

is expressed as:

1/d1 + 1/d2 = 1/f

where d1 is the distance from the subject to the lens

d2 is the distance from the lens to the image

f is the lens focal length

Take a look at some simple ray diagrams and play with the formula.

Very interesting stuff for anyone who's serious about their photography.

Because a standard 35mm frame covers 4 perforations or pitches,

whereas a 16mm frame only has 1 perforation or pitch.

Deepak, you're firing off questions left and right.

There's a lot of reference material out there that you can

directly access for answers. Kodak is one good site, but there are

many others. Try that google thingy. I use it all the time.

16mm long pitch = .300 (print)

16mm short pitch = .2994 (camera neg)

Well, your first calculation will be 2.4/1.78 = 1.348

This is your anamorphic squeeze ratio.

After that, things get a little trickier.

When I google 'anamorphic prisms,' all sorts of

diagrams appear, but no simple formulae.

Looks like you'll have to do some digging.

Here is a link you might want to check out:

www.zuggsoft.com/theater/prism.htm

There you will learn about some of the drawbacks of

anamorphic prisms.

Choice (a) will definitely distort the image.

Pretty much agree with Ian's troubleshooting sequence,

and the fact that your motor fired up when wiggled

suggests a connection problem rather than bad electronics.

I would look for something loose, broken, brittle, cracked, etc.

in the power wiring to the motor, maybe even inside the motor

itself.

Hey, it wasn't my intention to discourage you. More than one CG artist began their career

at precisely the point you're at now. If you're motivated, start learning it.

For this project, do what Adrian suggested. Build the best-looking prop weapon you can.

Do some screen tests with it to refine the look.

Then rotoscope in the death ray. This will still involve the challenge of animation,

but it will be far less daunting than modeling, animating, tracking, lighting and

compositing the entire rig.

Again, you can experiment with the ray; blur, color, pulsation, lighting bolt fx, whatever.

Comping it in will be relatively easy.

This approach has been used countless times in countless movies, so it can definitely

give you good results.

Unless you're independently wealthy, know now that making movies will constantly challenge your

resourcefulness, your skills, your knowledge.