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#1 Ivan Lebedev

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Posted 03 March 2009 - 05:38 PM

Hi, does anybody know what is the main reason to make flash in positive and difference (in effect) between this one and the same thing in negative. Lubezki in his article about Children of a man has said that 5229 stock is like a flashed positive... is it about desaturated colors and low contrast (especially poor blacks) or smth. else??
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#2 David Mullen ASC

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Posted 03 March 2009 - 05:50 PM

Hi, does anybody know what is the main reason to make flash in positive and difference (in effect) between this one and the same thing in negative. Lubezki in his article about Children of a man has said that 5229 stock is like a flashed positive... is it about desaturated colors and low contrast (especially poor blacks) or smth. else??


Actually 5229 is more like a mildly flashed negative, i.e. lifted blacks.

Flashing negative or positive both lowers contrast, but when done to the negative, the contrast is lowered by lifting the blacks and shadows, when done to a positive, you grey-down the whites and darken the bright highlights. If you ever fog a piece of printing paper in a darkroom, you know what I mean -- it gets darker.
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#3 Steve Zimmerman

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Posted 03 March 2009 - 06:00 PM

Flashing ... ... when done to a positive, you grey-down the whites and darken the bright highlights.


I'm not sure, but it looks like A Clockwork Orange uses a flashed positive for some of the blown-out highlights from whited-out windows (i.e. when Alex, lying in bed, first meets the female psychiatrist), and the bare lightbulbs in some of the shots. It looked like the contrast changed when it cuts to the reverse angle so maybe it was only certain shots and not an entire scene that was positive flashed? I had not noticed this before watching ACO on High Def cable. I always wanted to ask about this, Thanks. :)

Edited by Steve Zimmerman, 03 March 2009 - 06:05 PM.

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#4 David Mullen ASC

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Posted 03 March 2009 - 06:13 PM

I'm not sure, but it looks like A Clockwork Orange uses a flashed positive for some of the blown-out highlights from whited-out windows (i.e. when Alex, lying in bed, first meets the female psychiatrist), and the bare lightbulbs in some of the shots. It looked like the contrast changed when it cuts to the reverse angle so maybe it was only certain shots and not an entire scene that was positive flashed? I had not noticed this before watching ACO on High Def cable. I always wanted to ask about this, Thanks. :)


LIKE I SAID WHEN YOU FLASH A POSITIVE LIKE AN I.P. OR PRINT, YOU DARKEN THE WHITES AND HIGHLIGHTS.

Flashing a positive does not cause highlights to blow-out more. Think about it: when printing a negative to a print stock or I.P., more exposure causes more density on the print, i.e. it gets darker. The thin areas on the negative corresponding to the darkest parts of the scene will cause the most amount of light to pass through to the print stock, causing more density to form there. So flashing a print stock, rather than adding a white veil to the image as when done to the negative, causes a blackening of the whites, a dark veil or greying down.

Similarly, if you put diffusion somehow in front of the negative when printing or transferring (like in a telecine), the positive image created will have foggy blacks instead of foggy whites as when diffusion is put on a camera lens.

In terms of shooting, when pointing a camera lens into a bright window or lights, there can be contrast loss due to flaring and veiling in the lens.
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#5 Ivan Lebedev

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Posted 04 March 2009 - 12:36 PM

So, it's right that Mr. Lubezki is not enough correct in this situation, isn't it ??? ;)
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#6 David Mullen ASC

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Posted 04 March 2009 - 01:21 PM

So, it's right that Mr. Lubezki is not enough correct in this situation, isn't it ??? ;)


Here's the actual quote for AC Mag, Dec. 2006:

With (Kodak Vision2 500T) 5218, when you don't light faces, they look a bit harsh. I wanted the midtones to be softer in the faces, and 5229 allows you to achieve that. It's very similar to flashing the positive."

He's talking about the midtones, not the shadows. Flashing a positive works from the top down, it affects the highlights first, the shadows last. Flashing a positive often smooths out skintones by taking the harshness out of their highlights. So he's correct in that aspect, though I don't particularly think of 5229 in that way. It does have smoother skintones but it also has more grain in the midtones.

But in terms of black levels, 5229 is more like a slightly flashed negative -- it has lighter blacks, unless you expose it well and print it down. Then the blacks are fine. Or you can increase the blacks in the D.I. or by using a silver process in the prints -- Lubezki has done both.

I'm just trying to explain to everyone how flashing a positive works -- by darkening the whites and highlights, it lowers contrast. But this can lead to "muddy" whites that aren't really white, just like flashing a negative can lead to milky blacks that are not really black.

But 5229 is a low-con negative stock, not a flashed positive stock.
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#7 Ivan Lebedev

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Posted 04 March 2009 - 01:56 PM

It's such a clear explanation, thanks a lot David !!!!
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#8 K Borowski

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Posted 04 March 2009 - 01:57 PM

He's talking about the midtones, not the shadows.


Forget it Jake, it's Chinatown.


On a more serious note, I still get Polaroids I shoot with the dark slide in mixed up as extreme *over*-exposure and this is, Christ, after 20 years of shooting film.

So it is easy to get mixed up. I had an instructor, a PhD, in a filmmaking class mix it up, so it is easy to invert whites and blacks in one's head.
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#9 David Mullen ASC

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Posted 04 March 2009 - 02:07 PM

So it is easy to get mixed up. I had an instructor, a PhD, in a filmmaking class mix it up, so it is easy to invert whites and blacks in one's head.


Just the other day, I got mixed up when talking about the RED, saying it was less sensitive to red and more to blue, which is why it behaved less well under 3200K lighting. Graeme Nattress corrected me and said that the opposite was true -- the RED is less sensitive to blue, hence why it likes 5500K lighting which has an excess of blue. It's also why the blue layer has to be faster and grainier in tungsten balanced stocks.
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#10 K Borowski

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Posted 04 March 2009 - 03:07 PM

Just the other day, I got mixed up when talking about the RED, saying it was less sensitive to red and more to blue, which is why it behaved less well under 3200K lighting. Graeme Nattress corrected me and said that the opposite was true -- the RED is less sensitive to blue, hence why it likes 5500K lighting which has an excess of blue. It's also why the blue layer has to be faster and grainier in tungsten balanced stocks.


You know David, I am surprised that we find ourselves in agreement on a particular issue. Is this a first (for 2009 at least?) ;)

It's funny, I was talking to my parents on the phone the other day (because of my youngest sister's impending wedding), and they said that they really enjoyed the imagery in "Astronaut Farmer". I told them "Oh, I talk to the guy that photographed that movie, on the net all the time. And they stared laughing! I started laughing too. . . B)

Edited by Karl Borowski, 04 March 2009 - 03:07 PM.

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#11 Erik Turestedt

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Posted 23 March 2009 - 01:09 PM

I first heard about flashing the negative some months ago,

But I never understod what it really means?

What's the actual process?

Any film where it's obvious that this process was made?

I think I heard that Minority report, or was it Private Ryan was both Bleached and flashed?
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#12 David Mullen ASC

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Posted 23 March 2009 - 02:02 PM

Flashing involves exposing the film to an overall wash of weak light, to evenly fog it. When done to the negative, it causes the blacks to be lifted, become milkier, and it lowers contrast and softens colors. Often a negative flash is done in combination with a silver retention print process that would normally add a lot of contrast to the print, to counteract the contrast increase and loss of shadow detail. In this case, the silver retention is being used more to reduce color saturation than to increase contrast.
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#13 Brian Pritchard

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Posted 24 March 2009 - 03:22 AM

Flashing involves exposing the film to an overall wash of weak light, to evenly fog it. When done to the negative, it causes the blacks to be lifted, become milkier, and it lowers contrast and softens colors. Often a negative flash is done in combination with a silver retention print process that would normally add a lot of contrast to the print, to counteract the contrast increase and loss of shadow detail. In this case, the silver retention is being used more to reduce color saturation than to increase contrast.


Flashing can also be used for other purposes. For example you can reproduce a tinted film by flashing the colour positive stock to the required colour. You print a black and white negative so as to get a neutral colour, then with that setting you print the picture and you flash the stock to say blue light to get a yellow tint.

Flashing can also be used to get very bright colours when making slide titles on colour reversal. You pre-flash the stock to the rquired colour and then expose white letters on a black background to get white letters on a coloured background. It is difficult to get white letters on a saturated coloured background by photographing white letters on a coloured background.

The most important thing about flashing is to get an even exposure.

Brian
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#14 Dominic Case

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Posted 24 March 2009 - 05:20 PM

What's the actual process?

Several options:-
  • Raw negative stock is run through a contact printer in the lab before it is exposed.
  • Exposed camera negative is run through a contact printer in the lab before it is processed, with an extremely low exposure.
  • Raw negative stock is run through a camera, exposing it (several stops under) to a uniformly lit, out of focus grey card, prior to actual image exposure.
  • Same as above, but after the primary exposure.
  • Varicon or similar techniques, in which a uniform low level of light is exposed onto the negative simultaneoulsy with the main image exposure by means of a half-silvered mirror or prism beam-combiner.
The advantage of flashing before exposure (i.e.preflashing) is that if anything goes wrong you only have to reshoot a greycard. If the preflashing is done at the lab, they will usually remove a couple of feet and process it before returning the stock to the production, just to be sure. However, any unused stock at the end of the shoot is no longer "raw stock".

The advantage of postflashing is that only the exact amount of stock is flashed. Howver, if you get it wrong, you ruin the already-exposed image.

There is no visible difference in the results if you pre-or post-flash.
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#15 David Mullen ASC

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Posted 24 March 2009 - 05:44 PM

There is no visible difference in the results if you pre-or post-flash.


Funny thing is that if you are using a Panaflasher, depending on if the unit is on the top or rear mag port of a Panaflex, with the film mag on the other port, you will either be pre-flashing or post-flashing the image.
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#16 John Sprung

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Posted 24 March 2009 - 05:49 PM

[*]Raw negative stock is run through a camera, exposing it (several stops under) to a uniformly lit, out of focus grey card, prior to actual image exposure.
[*]Same as above, but after the primary exposure.


In either case, using a 35mm camera, you have to make a sharpie "X" mark thru the aperture outlining a frame you can line up on for the second pass. Otherwise, you have only one chance in four of getting the frame lines the same for both runs.



-- J.S.
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#17 Daniel Porto

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Posted 24 March 2009 - 09:04 PM

...you have to make a sharpie "X" mark thru the aperture ...


Use a pencil to reduce the chance of gate flare
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#18 K Borowski

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Posted 25 March 2009 - 04:59 AM

There is no visible difference in the results if you pre-or post-flash.


I would say that there is a subtle difference. It'll only be noticeable when you have a higher degree of flashing, but the pre-flash can obscure detail more than the post-flash, as it "eats up" the actual amount of imaging material.

Difference is very subtle, but it is there.

I am not going to comment on whether this affects highlights or shadows more, lest I invert the two in my head, and someone comes on here and corrects me for it.

I was shooting some test shots on some direct-positive instant print material, and I was under-developing by mistake and the exposure was off to boot, and I was trying to correct the results on the fly, and I just couldn't deal with, in my head, what I needed to do, working with a material that works the opposite way as the neg. film I'm used to using.
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