35mm vs 70mm
Yavaz
I'm not a film major but it is obvious in terms of RESOLUTION. If you
film on a smaller format (i.e. 35mm) and blow it up to 70mm, you still
only have a 35mm resolution. You may have a larger "film" but the grain
of the origianl 35mm negative is only going to be as sharp at the
original negative. THat is a physical fact!
For instance, take a computer graphic that was scanned in at 100 dpi
(dots per inc). Put it a program like photoshop and change the
resolution to 300dpi and look closely. The actuall resolution of the
picture has not changed even though the "new" copy is technically at a
higher resolution.
Dukjin Im
Yavaz wrote:
Actually, that's sort of true, but not quite.
Film is an analog medium, not a digital one.
The "resolution" of the 35 mm negative and the 35 mm print is the same, but
the transfer process is optical, and the maximum resolution film can hold is
determined largely by grain size (the grains are sort of like pixels, but
they are randomly shaped, and not all the same size. Also the grains on the
negative do not line up exactly with those on the print).
Going from 35 mm print to 70 mm print results in less graininess in the
final projected image, even though you start with a 35 mm negative. This is
a non-trivial difference. The bigger print preserves more information than
the smaller print (if you make a big enough print, you will be able to
preserve the color and shape of each individual grains that was in the
original negative)..
Taking an extreme example: Let's say we want to make slides: If you make an
8"x10" inch slide from a 35 mm negative, and then a tiny 35 mm slide from
the same negative...
When you then project both using appropriate lenses onto a wall to produce
the two equal sized images (let's say 50 feet across), the image from the 35
mm slide will have more visible grain and be less sharp.
The image from the 8"x10" slide will have almost no visible grain from the
slide medium itself (any graininess you see will only be what was on the
original negative).
That is why 70 mm prints look a little better than 35 mm prints (in theory.
other factors that can effect the image quality include the differences in
optics used to expose the negative onto the print, resolution of the print
film vs. the negative (generally the same), etc.). Hope that was helpful.
-Duk
Here2Fore
Also, the transfer process from "master" to "print" always results in some
loss of resolution. If the process is from 35mm (the "master" size) to
70mm, the effect on the screen is less noticable (since it is only enlarged
about 50% the amount).
Would be nice of they actually projected the "master", but Cameron is not
THAT crazy (nor is he nuts enough to actually FILM in 70mm).
Dukjin Im wrote in message <34ECD224...@greystoneapts.com>...
dgri...@theriver.com
Yes, exactly. Remember the 110 film? It made cute, small negatives, and
the standard prints looked OK. But when you blow up a 110 neg. or slide
to an 11x14 or poster-sized print, whoa, look out. It looks like
doo-doo..[I'm trying to clean up the language in here]...
35mm blows up fine..slides, etc and onto the movie screen..but 70mm is
even better.
DavidN1327
"If you film on a smaller format (i.e. 35mm) and blow it up to 70mm, you still
But the image degradation that results from a projector lens enlarging a
70mm-film image isn't as significant as that from enlarging a 35mm-film image.
Light-loss is also less with a 70mm-film image than with a 35mm-film image.
Finally, focus is superior with a 70mm-film image than a 35mm-film image.
Admittedly, the print-to-print image resolution is insignificant, but the claim
that there is any resolution degradation from striking a 70mm print from a 35mm
original negative is no more true than from striking a 35mm print from the same
negative.
Michael Stegen
>On Thu, 19 Feb 1998 15:18:28 -0700, Yavaz wrote:
>
>>I'm not a film major but it is obvious in terms of RESOLUTION. If you
>>film on a smaller format (i.e. 35mm) and blow it up to 70mm, you still
>>only have a 35mm resolution. You may have a larger "film" but the grain
>>of the origianl 35mm negative is only going to be as sharp at the
>>original negative. THat is a physical fact!
You forget that Cameron films in Super-35. In this format the space
where normally the optical audio tracks would be, is now also used for
the picture.
Afterwards this Super 35 film is used to produce the 'normal' 35mm
anamorphic prints as used by most theathers.
For a detailed explanation of the different format's:
http://www.cs.tut.fi/~leopold/Ld/FilmToVideo/
I have watched both 35mm and 70mm versions of Titanic, and i can only
say that the 70mm has much more detail and no anamorphic distorsion.
Michael
Wide Gauge
>If you
>>>film on a smaller format (i.e. 35mm) and blow it up to 70mm, you still
>>>only have a 35mm resolution.
It doesn't work that way. If you blow up a super 35 (Titanic's camera format)
negative directly to a 65mm interpositive, you have the advantage of being able
to use precision optical equipment with the film immersed in a liquid gate.
Once the movie is on 65mm, one can mass produce 70mm release prints with
negligible generation loss. 70mm projection is also superior to 35mm
projection. The 70mm prints of Titanic can be, and are, better than the 35mm
anamorphic prints.
>Cameron films in Super-35. In this format the space
>where normally the optical audio tracks would be, is now also used for
>the picture.
Because of this, standard 35mm anamorphic prints of Titanic are optical
reductions horizontally and enlargements vertically. Add to that the use of
anamorphic lenses in optical printing and the sorry state of most 35mm
exhibition in the US, and it's easy to understand how the 70mm prints can look
so much better than the 35mm.
Scott Marshall
Wide Gauge Film and Video Monthly
http://members.aol.com/widegauge/