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#1 Simon Walsh

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Posted 15 May 2006 - 08:48 PM

Ok, so I just finished shooting a short and have a few rolls left over that I want to use to shoot another one!

I'm shooting on 16mm using Kodak colour negative stocks.

1 roll is a Daylight balanced 250D 400ft roll. I want to convert this to Tungsten balanced using an 80A filter or similar. My question is what will be the loss in stock speed and change in T stops once the filter is used?

The can says that with an 80A filter it will go from 250 speed to 64?? Please don't let this be true, i'd find it impossible to expose to such a low speed.

Simon
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#2 Dan Goulder

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Posted 15 May 2006 - 10:43 PM

The can says that with an 80A filter it will go from 250 speed to 64?? Please don't let this be true, i'd find it impossible to expose to such a low speed.

Yes, my son, the can has spoken.
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#3 John Pytlak RIP

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Posted 15 May 2006 - 10:51 PM

Ok, so I just finished shooting a short and have a few rolls left over that I want to use to shoot another one!

I'm shooting on 16mm using Kodak colour negative stocks.

1 roll is a Daylight balanced 250D 400ft roll. I want to convert this to Tungsten balanced using an 80A filter or similar. My question is what will be the loss in stock speed and change in T stops once the filter is used?

The can says that with an 80A filter it will go from 250 speed to 64?? Please don't let this be true, i'd find it impossible to expose to such a low speed.

Simon


And if you don't believe the can, here is a table that also says the filter factor for an 80A is two stops:

http://www.kodak.com...onversion.shtml

Tungsten light has relatively little blue light compared to daylight. So the blue filter needed to match a 5500K source absorbs quite a bit of red and green light.

Why not save the film for another daylight or HMI shoot?
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#4 David Mullen ASC

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Posted 16 May 2006 - 12:56 AM

The correction filter for daylight film for tungsten-balance (80A) loses 2-stops, while the correction for tungsten film for daylight-balance (85B) loses only 2/3's of a stop, hence why most people avoid using daylight-balance stock for a tungsten-lit scene requiring the use of the 80A filter. It's also the reason why the majority of motion picture color negative stocks have traditionally been tungsten-balanced. In the still market, it's the other way due to the use of daylight-balanced flashes.
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#5 Adam Frisch FSF

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Posted 16 May 2006 - 02:51 AM

It really isn't very hard to light to 64T, unless you're on a night exterior.
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#6 Chris Pritzlaff

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Posted 16 May 2006 - 03:10 AM

While we are on the topic of conversions, What about the 85 filter - I used it on a shoot a few months ago on 7218. While I was able to manipulate quite a bit in color correction, the end result did not match with the 250D stock that we had run out of. The colors were not as saturated and beyond that it felt different (sorry its hard to explain) Is there any technical differenc in the quality that would explain the difference when shooting tungsten film with an 85 filter?
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#7 Dan Goulder

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Posted 16 May 2006 - 03:56 AM

I would not recommend cutting between 250D and 500T w/85 filter within the same scene. You're still getting two different looks. The grain level is close with the latest stocks, but you'll notice a definite shift in flesh tones.
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#8 Chris Pritzlaff

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Posted 16 May 2006 - 04:10 AM

I would not recommend cutting between 250D and 500T w/85 filter within the same scene. You're still getting two different looks. The grain level is close with the latest stocks, but you'll notice a definite shift in flesh tones.



Yup - i noticed - i didn't have a choice - we ran out of the 250D stock. Even the colorist who worked really hard could not get the two to match. I noticed most of the differenc in the highlights now that I am looking at it. They seemed to be blocked up a bit more (not blown out, but less of a difference in tonal range) am I using the right terms here? Also the skin tone is definately warmer, but adjusting the color temp in post cause the backgrounds to shift to much towards blue again.
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#9 David Mullen ASC

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Posted 16 May 2006 - 08:59 AM

Was this the older '46 daylight stock? The new '05 250D stock should intercut well with '18 with an 85B filter. The only difference really, other than speed/grain, is that the daylight stock has a slower-speed blue layer, so blues might be less grainy compared to color-corrected tungsten stock of the same series. But the older '46 Vision 250D is more saturated than the Vision-2 500T stock, so it's not going to match as well.

Not that I recommend mixing two different stocks in the same scene though.
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#10 Chris Pritzlaff

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Posted 16 May 2006 - 03:43 PM

Was this the older '46 daylight stock? The new '05 250D stock should intercut well with '18 with an 85B filter. The only difference really, other than speed/grain, is that the daylight stock has a slower-speed blue layer, so blues might be less grainy compared to color-corrected tungsten stock of the same series. But the older '46 Vision 250D is more saturated than the Vision-2 500T stock, so it's not going to match as well.

Not that I recommend mixing two different stocks in the same scene though.


I didn't want to mix the stocks for the same scene either. We unfortunately ran out of our 7205 film stock and 7218 was all that I had on hand to shot the remaining 3 shots. But even with the 85 filter in, it really did not match as well as I had hoped.

Edited by Chris Pritzlaff, 16 May 2006 - 03:44 PM.

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