Welcome to BigScreenBiz.com

What is the difference between actual 70mm film (such as a 70mm blockbuster film a theatre may book?) and IMAX (documentary type).

Does one roll vertically and one horizontally? Etc? I always thought 70mm was IMAX, and that was it.

---

"Would you like fries with that?"

70mm film is used in 70mm feature presentations and large format film presentations.

70mm can be used vertically with 5 perforations per frame for feature presentations like Lawrence of Arabia and the original Start Wars.



For large format presentations 70mm film can be projected vertically using an 8/70 projector. In this case the frame is 8 perforations tall instead of 5 perforations tall.

IMAX uses 70mm film running horizontally and uses 15 perforations per frame. This makes the image area much larger than standard and the picture can be that much larger and clearer.

IMAX uses a patented system of rolling loops and compress air to handle the film instead of sprockets and intermittent.

Here is a comparison of film sizes.



Read an artical on how IMAX works at: http://www.howstuffworks.com/imax.htm

[This message has been edited by Large (edited November 28, 2002).]

Its pretty neat to watch an IMAX projector working. The soundtrack is on a separate player and not on the film its self. Computers keep the track in sync with the film.
The soundtrack also has a redundancy back up in case one system fails.

GTE, I noticed that at our local IMAX, as they have "The Gallery", where you can view how everything works, behind the room. The back wall is all galss, for this purpose.

Is the soundtrack on a 70mm print?
How many titles are usually available for 70mm first-run product?
How much more is it for a 70mm print in your building?

Is it worth it, to make your image clearer or sharper?

---

"Would you like fries with that?"

There are two types of 70mm soundtracks. The first one was 6-track magnetic stripes on the film. This was read by a penthouse reader. Now they just put on a DTS timecode and hook up a DTS player. It's much cheaper.

In IMAX there is either a 6-track mag sountrack on a 35mm dubber or a separate Digital Disc based system that is synced to the film.
There are no 70mm first-run print available. They used to make them for large venues in large cities. Since the introduction of Digtal Sound, the studios have stopped supporting 70mm releases. There are still a few specialty print made each year.

IMAX releases like Apollo 13, Attack of the Clones, The Lion King & Treasure Planet may revive interest in Large Format presentations.
A 35mm print's replacement cost is $2K-$3K depending on length. A 70mm print's replacement cost used to be $20K-$40K. But the theatres pay Film-Rental so the cost for the theatres isn't much more. Shipping costs a lot more though.
Yes! It is so worth it.

Bigger is Better!

Thanks Large!

---

"Would you like fries with that?"

Hey Andrew e-mail me you address and I'll send you a piece (about 10 inches) of IMAX film that is collecting dust on my desk.(if you want it)
GTE

Some links:
http://www.cinergetics.com/formats.htm
http://www.imax.com
http://www.iwerks.com/NotShocked/products/p-giant.html
http://www.megasystem.com/projection%20systems/projection%20systems%20frameset.html
http://www.in70mm.com/
http://www.widescreenmuseum.com/widescreen/wingto1.htm
http://www.bigmoviezone.com/whatis/
http://www.imaxnorth.co.uk/home2.asp
http://www.howstuffworks.com/imax1.htm

---

John P. Pytlak, Senior Technical Specialist
Worldwide Technical Services
Entertainment Imaging
Research Labs, Building 69, Room 7525A
Eastman Kodak Company
Rochester, NY 14650-1922
Telephone: 585-477-5325 Cell: 585-781-4036 Fax: 585-722-7243
E-Mail: This e-mail address is being protected from spambots. You need JavaScript enabled to view it
Website: http://www.kodak.com/go/motion

Thanks Mr. Pytlak! I've got some reading to do!

GTE, That e-mails should be going out now!

---

"Would you like fries with that?"

Here is a article on the cinesphere Imax http://www.hometheaterhifi.com/volume_8_3/feature-article-cinesphere-7-2001.html