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Digital and Photochemical Pull process


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#1 Glenn Hanns

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Posted 12 September 2005 - 02:46 AM

HI,
I have to present an argument to a director Im working for and I just wanted to know if there is a difference between doing a 35 mm photochemical pull in processing pos print and doing a scan off the neg. and pull digitally ( say 1 stop for eg.) . Ive done a DI pull on S16 but not a photochemical one. Do they have a different look to each other? Does colour react differently in each?
What other thoughts about the process do you have?
Cheers Glenn
:)

Edited by glenn@uow.edu.au, 12 September 2005 - 02:50 AM.

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#2 David Mullen ASC

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Posted 12 September 2005 - 11:14 AM

There's no such thing as a digital pull-process. You can certainly bring down an overexposed negative in digital color-correction.

If the real question is: is there any point in overexposing / pull-processing the negative if the film will go through a digital color-correction, versus just color-correcting the image for that look... well, it's debatable. Sort of depends on why you are pull-processing. You can certainly flatten the contrast and soften the colors digitally without resorting to pull-processing. You can get less grain by switching to a slower stock (rather than overexposing a faster stock) or by using digital grain reduction processes.

There may be some minor advantage to overexposing / pull-processing neg for something meant for scanning, although it may be better to simply either use a low-con negative stock (if you want a flatter image with more shadow detail) or a slower-speed stock (if reducing grain is one of the reasons for the pull-process.)
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#3 L K Keerthi Basu

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Posted 12 September 2005 - 11:32 AM

What I found in this is the Sharpness of the Image becomes soft when you scan and record back to film comparatively . It is better do that in Photochemical.

L.K.Keerthibasu
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#4 Glenn Hanns

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Posted 12 September 2005 - 06:07 PM

There's no such thing as a digital pull-process.  You can certainly bring down an overexposed negative in digital color-correction.

<{POST_SNAPBACK}>


Yes I did mean a digital exposure correction vs a chemical one (pull process).

I was thinking in terms of richer blacks,reduced grain and a thicker neg. I know that these are the benefits of doing a pull photochemically but I wondered if this would also help in a digital pathway as well.
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#5 John Pytlak RIP

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Posted 12 September 2005 - 09:40 PM

Yes I did mean a digital exposure correction vs a chemical one (pull process).

I was thinking in terms of richer blacks,reduced grain and a thicker neg. I know that these are the benefits of doing a pull photochemically but I wondered if this would also help in a digital pathway as well.

<{POST_SNAPBACK}>


A "pull process" (reduced developer time) will generally lower contrast and speed, and soften grain. It will NOT result in a "thicker" (denser) negative or richer blacks.

For richer blacks, reduced grain, and a "thicker" negative, simply give a bit of overexposure and process normally.
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#6 David Mullen ASC

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Posted 12 September 2005 - 10:49 PM

Actually pull-processing DECREASES density (or actually, prevents it from building up to a normal level), hence why you overexpose to compensate. So a one-stop overexposure combined with a one-stop pull-process would result in a negative of normal density.
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#7 dbledwn11

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Posted 13 October 2005 - 02:28 PM

Actually pull-processing DECREASES density (or actually, prevents it from building up to a normal level), hence why you overexpose to compensate. So a one-stop overexposure combined with a one-stop pull-process would result in a negative of normal density.


i can't quite work out why pull processing is measured in stops when, according to John Pytlak, its a matter of reduced development time. can anyone explain/clarify this for me?

and also - John Pytlak states: "For richer blacks, reduced grain, and a "thicker" negative, simply give a bit of overexposure and process normally".

surely if you overexpose and process normally the negative will just appear... well... overexposed?

davids point out that one stop overexposure combined with one stop pull gives a normal density - but of course with all the benefits that one was hoping to gain from the process in the first place.

Both of these sources are obviously very reliable and undoubtedly know what they are talking about, but can anyone else see why i think there is a discrepancy and explain it for me. in fact there probably is no discrepancy - i've just mis-understood.
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#8 Max Jacoby

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Posted 13 October 2005 - 03:29 PM

There is no discrepancy indeed.

After exposing and processing the film you still need to print it (or telecine), which is what John is refering to. There, just like in the previous steps, you can make adjustmens as well. If you overexpose your neg and process it normally, you will have an overexposed negative. Then when you print it, you can correct for this overexposure by printing down (making it darker), so that your endresult will be correctly exposed image.

By rating the filmstock differently from the manufacturers rating (either overexposing or underexposing it) and correcting for this in the printing, one can achieve different looks. A lot of Dops tend to overexpose their stocks by a third to a full stop, especially if they are shooting Super35, to get tighter grain and good blacks.

On the other hand there is Harris Savides who underexposes his stocks sometimes between 2 and 3 stops (as he did for 'The Yards), to get a more mellow look. For that film he shot anamorphic, which due to its greater negative area allows for more underexposure latitude than say Super 35.
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#9 Stuart Brereton

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Posted 13 October 2005 - 03:39 PM

A lot of Dops tend to overexpose their stocks by a third to a full stop, especially if they are shooting Super35

For that film he shot anamorphic, which due to its greater negative area allows for more underexposure latitude than say Super 35.


I think you mean Super16 rather than Super35 here, Max
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#10 Max Jacoby

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Posted 13 October 2005 - 03:44 PM

No, since anamorphic has 1.7 times the negative size of Super 35, the grain is proportionally smaller (for the same projection size). If you print up an underexposed shot, the grain won't be so apparent with anamorphic. of course the same is also true for Super 16, since the negative area is even smaller.
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#11 Stuart Brereton

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Posted 13 October 2005 - 04:00 PM

sorry, didn't realise you were talking about a 2.35 extraction only rather than the full aperture
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#12 dbledwn11

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Posted 13 October 2005 - 05:02 PM

There is no discrepancy indeed.

After exposing and processing the film you still need to print it (or telecine), which is what John is refering to. There, just like in the previous steps, you can make adjustmens as well. If you overexpose your neg and process it normally, you will have an overexposed negative. Then when you print it, you can correct for this overexposure by printing down (making it darker), so that your endresult will be correctly exposed image.

By rating the filmstock differently from the manufacturers rating (either overexposing or underexposing it) and correcting for this in the printing, one can achieve different looks. A lot of Dops tend to overexpose their stocks by a third to a full stop, especially if they are shooting Super35, to get tighter grain and good blacks.

On the other hand there is Harris Savides who underexposes his stocks sometimes between 2 and 3 stops (as he did for 'The Yards), to get a more mellow look. For that film he shot anamorphic, which due to its greater negative area allows for more underexposure latitude than say Super 35.


ok i see. when choosing to pull process there are two decisions to be made:
1) development time of negative at processing stage and
2) stop adjustment at printing stage (i assume this is where it will become a positive print)

i think i'll be using this process for a 16mm film i'll be shooting so there'll be more questions coming soon, but here's another i can think of for now:-)

is there necessarily a difference between rating the stock at a different asa and using the "new" stop reading as opposed to leaving the rating the same and just making your own stop adjustments??? hope that makes sense.

also on a side note. where did you start making your own films and camera assisting - UK or Luxembourg? its just i'm from the UK myself and was curious about the way in which you've combined an obvious commitement to making your own films as well as working in camera depts on other projects. this is a route I am particularly keen to follow. any info very much appreciated. Will M.

p.s. thank you for all the other info.
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