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adjacency effects at duplication??


Filip Plesha

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Hi

 

I've noticed something really weird while watching some old trailers on DVD

 

There seem to be some kind of strange edge effects in some old trailers, which seem to be printed in IB process, but perhaps it's not related to the printing stage.

 

Take a look at this:

http://img185.imageshack.us/img185/2640/59380581nn8.jpg

 

 

both of these trailers seem to be telecined from old prints.

And both have these edge effects, which are too strange for video edge enhancement.

First , because, they don't seem to be symetrical which is kind of strange,

and that are rarely white, but always seem to have some kind of color cast.

Furthermore, they seem to be everywhere.

I've actually played all my pre 70's DVD's and looked for trailers, and

the worse the print was (older and more generations from the original), the more the

edge effects seem to be present.

 

 

But that's not all, I've found them also in a movie transfer too, so it can't be a print effect.

 

Here is a couple of frames from the movie Horror of Dracula:

 

http://img170.imageshack.us/img170/8163/38171725nq1.jpg

 

first frame shows how the whole movie looks like, no trace of over-the-top EE,

but then when the character drives a spike through the vampires heart, the

movie switches to a dupe, obviously, the contrast jumps, the image appears lower in res

and the grain is worse, and the color starts jumping all over the place (in dark areas

there are local shifts in color balance) and again there are the edge effects.

Just like in those old trailers.

The movie switches back to a normal negative (or positive), and it's gone.

 

Also, I've watched a couple of old movies where there were dupes for

each transition, and it seems every time there is a transition, the image jumps to

a dupe element, and besides the color shifts, again there are halos around edges

 

 

Now, I know that film naturally produces edge effects due to

developer diffusion, causing mackie lines in the part of MTF space where

the curve is above 100% (usually up to 10-15 cycles per mm )

But this seems a bit too much.

 

And I'm pretty sure they didn't use unsharp masking for making duplicates

which would probably be too complicated to do in an optical printer.

 

And, it's too ever-present and consistent with various producers and transfer houses

to be simple EE, because I seem to spot it everywhere, and it seems

to be stronger to one side of the frame than the other. Which is something that isn't consistent with digital EE.

 

So is it something inherent to old dupe stock? Or some kind of process tweak

like high-acutance developers or something.

 

Any ideas?

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