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-   -   Telecine question (https://www.dvinfo.net/forum/alternative-imaging-methods/33260-telecine-question.html)

Charlie McCarrick October 10th, 2004 10:38 PM

Telecine question
 
I'm planning to shoot my first short on 35mm, and I've recently been reading about uncompressed telecine transfers. The transferred footage goes directly to a hard drive, which is then mailed to the customer who, after copying the footage to their own PC, mails it back.

This sounds great for quality retention. But what bothers me is that there must always be quality losses in telecine. Even frame to frame HD transfers at 1920 x 1080 can't match the res of film. So I've been wondering, what do studio level procos (production companies) do for telecine that retains as much quality as possible? Is there something better than HD? Or am I just worried about nothing? Are the quality losses for film transfers basically unnoticeable, provided that the film is high enough quality to begin with? Thanks.

Rob Lohman October 11th, 2004 02:43 AM

Film is processed alot at HD resolutions these days, especially if
there is less money available. Or so I read and hear at various
places at least. Normal scanning is done at 2K resolution however,
which is a bit more, but not much.

Some stuff is scanned at 4K, but I haven't heard of many movies/
companies using it. The data flow is probably just too great to
handle and too much time to process all that data in regards to
the profit (in quality) this would yield.

I assume you can request a sample of a couple of frames to see
the quality and test your workflow on your end? If so do that,
that's the best way. I doubt resolution is the main ingredient
that determines the picture quality on scanning film.

Charlie McCarrick October 11th, 2004 02:51 AM

Rob, great info. Thanks. I'm sure you're right about there being more to IQ than res in transfers. I've been reading about how much more there is. Have you heard of many companies doing direct to hard drive transfers, or is this pretty new and rare? You think the uncompressed video footage would be noticeably superior to getting something back on DV tape? I would imagine, but I don't really know for sure.

Rob Lohman October 11th, 2004 03:08 AM

I'm not into film scanning/processing myself, so I really don't know
if that is a common trent, but I can imagine it would be (due to
filesizes). I also assume the quality will be much better than DV,
but whether this is worth it depends on a couple of things I'd say:

1. your final output format

2. the programs you have to work with the footage

I assume the format you will be getting is DI or some other
format which consumer software cannot read. So make sure
you can handle the files they will be sending to you which a
test might help to identify. Perhaps they can do a short sample
from one scene for you and give you back the raw uncompressed
format and a DV file so you can:

1. see the final quality

2. see the difference in quality between the DV and the other format

3. see if you can handle the uncompressed format

Charlie McCarrick October 11th, 2004 01:57 PM

One service I've been looking at uses a "quicktime file." MPEG4 possibly? Also, I found another service that uses direct to hard drive transfers. They're probably pretty common among the costlier options. In fact, I don't know why they wouldn't be the standard for major motion pictures.

Before shooting the short, I'm going to shoot a short short for practice, to get an idea of what I want for lighting, color correction, DOF, etc. Maybe I'll use this as my sample to compare and contrast the different formats.

Marco Leavitt October 11th, 2004 07:47 PM

I'm sorry to ask a dumb question, but how many pixels is a 2K file?

Juan M. M. Fiebelkorn October 12th, 2004 02:16 AM

2k is 2048 x something between 1556 and 1536.From 10 bit per channel to 16.

The best quality you can get will be from a scanner, which works a little bit different from a Telecine machine.
If you are going from 35mm --> Digital --> 35mm, a film scanner is the perfect option.
For the rest of the cases a normal Telecine will be ok.
My two cents.

Nick Jushchyshyn October 12th, 2004 01:20 PM

For feature film work, film is generally scanned to 10 bit, log scale, Kodak Cineon file format. This is one file per frame.

A newer format, (OpenEXR) has recently been released by ILM.

Charlie McCarrick October 12th, 2004 10:53 PM

Yeah, 2k scanning is typically 2048 x 1556 res. When people refer to resolution as 1000, 2000, 4000 -- those numbers are just practical estimates for what are really 1024, 2048, 4096, respectively.

Anyway, 2048 x 1556 res for 35mm seems odd, although I know it's right. Shouldn't the vertical res be lower to account for the widescreen ratio? After all, 2048 x 1536 (QXGA on a PC monitor) is a 4:3 ratio, isn't it?

Nick Jushchyshyn October 13th, 2004 09:30 AM

The anamorphic ratio is created by the optics of the lenses and projection equipment. The image on film is actually typically a 4:3 ratio just like a 35mm photo slide (though it's generally rotated 90 degrees from the orientation of a photo slide), so the scan itself is not typically anamorphic and needs to be rendered with non-square pixels to accomodate.

Charlie McCarrick October 13th, 2004 11:16 AM

So when an image on film is projected, the top and bottom of the image is cropped off by the projector? If so, then why must film be specially "formatted to fit your" 4:3 television screen? Instead of cropping off the sides, why not just pull back to 16:9 (or whatever widescreen) ratio, then remove the letterbox to display the missing parts of the image on the film? And if 35mm images are 4:3 on film, then what distinguishes 35mm from 16mm?

Richard Alvarez October 13th, 2004 12:05 PM

Charlie,

Nicks answer was correct, if incomplete.

There are a wide range of wide screen formats. (Pun intended)

One way, is to "squeeze" the image into a 4:3 box, and then un-squeeze it with a lens when projecting.

Another, is to shoot the wide screen format, directly on the 35mm film. There are numerous versions of this as well.

SOme ultra-wide screen formats, shoot the film "sideways" like in your 35mm camera, and then "reduce" the negative to fit the normal orientation of the 35mm film when projected.

Some widescreen formats, leave the image in the 'sideway'' orientation even when projecting.

When a film is projected, it has a "gate" that also "crops" the image to the proper format to fit the screen. Depending on the format it was shot in, this "extra" area on the negative can sometimes have extraneous material ie: the boom, show up in it. I

There is a webpage that does a fairly good job of explaining it all

http://www.widescreenmuseum.com/

Drop by and be overwhelmed by more than you need to know about the differences between

Cinemascope
Cinearama
Vista Vision
PanaVision
Technirama

ANd they don't even get into IMAX


Enjoy

Charlie McCarrick October 15th, 2004 11:57 AM

I never doubted Nick's answer. I just wanted to understand it better. I haven't checked out the site yet, but I will later today. In the mean time, what I really what to understand is how the lens squeezes the shot onto 4:3, and then how a projector unsqueezes it. Does the lens simply condense the horizontal grain? If so, this would cause a distorted image, right (kind of like the intro to "First Blood")? But then this wouldn't really matter, since the projector can undo that distortion.

Richard Alvarez October 15th, 2004 02:20 PM

Yes, an anamorphic lens "squeezes" the wide image onto the 4:3 frame, then an anamorphic projection lens "unsqueezes" it when it is projected. It only works in the horizontal plane, not the vertical one.

Les Dit October 16th, 2004 03:48 AM

Hello.
My company does film scanning at telecine type rates.
www.pixelharvest.com for some instant quotes.
Pin registered , Cineon 10 bits, firewire drives, etc.

I can send you a close up of what my scans look like compared with a Spirit HD telecine of the exact same frame. The HD looks worse than the 2K scans.
Feel free to email me from the website.

-Les


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