Jump to content


Photo

Can Vision 200T be pulled to approximate Vision 50D?


  • Please log in to reply
11 replies to this topic

#1 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 16 April 2007 - 12:28 AM

If I start with 200T and add an 85 filter, my effective ASA is 125, if I overexpose 2/3's of a stop, my ASA is around 80. If I just go ahead and rate the 200T at 50ASA and then pull one stop during processing, might I be able to approximate the grain structure of either 100 ASA or Vision 50D?
  • 0

#2 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19769 posts
  • Cinematographer
  • Los Angeles

Posted 16 April 2007 - 01:27 AM

Sort of but not quite.

You see, the largest grains in the stock basically determine the speed, so 200T has larger grains than 50D and the largest grains are the first to always get exposed because they are the most efficient at collecting light.

Overexposing causes the smaller grains between the bigger grains to also get exposed, filling in the gaps more tightly, so the effect is really a tighter grain structure, not a smaller grain structure - but the overall effect is the perception of less grain. But the biggest grains are always there.

Whether you overexpose and pull-process or just overexpose and process normally doesn't make as big a difference -- it's the overexposure that is tightening the grain structure. The pull-processing is just reducing density closer to normal, which may help reduce noise problems from transferring a dense negative. But pull-processing also softens colors and lowers contrast, which can give the impression of softening the image.
  • 0

#3 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 16 April 2007 - 06:28 AM

Thanks for the explanation David. From the rank cintel operator's point of view, which can they manipulate for less grain easier, the overexposed but unpulled Vision 200T, or the overexposed pull processed Vision 200T negative?
  • 0

#4 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19769 posts
  • Cinematographer
  • Los Angeles

Posted 16 April 2007 - 10:54 AM

Thanks for the explanation David. From the rank cintel operator's point of view, which can they manipulate for less grain easier, the overexposed but unpulled Vision 200T, or the overexposed pull processed Vision 200T negative?


On a Rank, you may be safer with the overexposed/pulled footage if they tend to have noise problems in brighter highlights, rather than transferring very dense footage. But it depends on the amount of overexposure. 2/3's of a stop isn't so dramatic so it's probably not worth spending the money on pull-processing.
  • 0

#5 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 16 April 2007 - 12:20 PM

On a Rank, you may be safer with the overexposed/pulled footage if they tend to have noise problems in brighter highlights, rather than transferring very dense footage. But it depends on the amount of overexposure. 2/3's of a stop isn't so dramatic so it's probably not worth spending the money on pull-processing.


If I rate 200T with an 85 filter (125 ASA) at 50 ASA, I would be overexposing by approximately 1.3 - 1.5 f-stops.

So given two choices, overexposure by 1.5 stops with regular processing, or 1/2 stop overexposure because I'm pulling one f-stop in processing, which would the rank cintel colorist prefer if the goal is to reduce grain?

And what if I just go two full stops (30 ASA) and then pull one f-stop, might that be the best of all worlds for outdoors shooting if the goal is reduced grain?
  • 0

#6 Matt Frank

Matt Frank
  • Basic Members
  • PipPip
  • 78 posts
  • Cinematographer
  • Pasadena, Ca

Posted 16 April 2007 - 01:53 PM

If I rate 200T with an 85 filter (125 ASA) at 50 ASA, I would be overexposing by approximately 1.3 - 1.5 f-stops.

So given two choices, overexposure by 1.5 stops with regular processing, or 1/2 stop overexposure because I'm pulling one f-stop in processing, which would the rank cintel colorist prefer if the goal is to reduce grain?

And what if I just go two full stops (30 ASA) and then pull one f-stop, might that be the best of all worlds for outdoors shooting if the goal is reduced grain?



Out of curiosity why not just shoot 50D?
  • 0

#7 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 16 April 2007 - 02:51 PM

Out of curiosity why not just shoot 50D?


It's not offered in Super-8.
  • 0

#8 David Mullen ASC

David Mullen ASC
  • Sustaining Members
  • 19769 posts
  • Cinematographer
  • Los Angeles

Posted 16 April 2007 - 10:21 PM

If I rate 200T with an 85 filter (125 ASA) at 50 ASA, I would be overexposing by approximately 1.3 - 1.5 f-stops.

So given two choices, overexposure by 1.5 stops with regular processing, or 1/2 stop overexposure because I'm pulling one f-stop in processing, which would the rank cintel colorist prefer if the goal is to reduce grain?

And what if I just go two full stops (30 ASA) and then pull one f-stop, might that be the best of all worlds for outdoors shooting if the goal is reduced grain?


You need to shoot some tests and find out -- I haven't done anything that extensive.

Personally, I don't believe in free lunches, that you can get something for nothing, so I think there are limits to how far you can reduce the inherent grain designed into the original.

Two stops overexposed (whether or not you pull-process) and you're putting a lot of highlight detail in the shoulder of the characteristic curve, which is flatter. You may end up with muddier highlights with less sharpness. In 35mm, that may be fine (Roger Deakins did something similar for the desert scenes in "Courage Under Fire" -- something like an overexpose 2-stops, pull-one) but I worry about Super-8 where sharpness is important.

I would do three tests:

normal exposure / normal process
one-stop over / one-stop pull
2/3-stop over / process normal

And see which gives you the best results in the telecine.
  • 0

#9 Fran Kuhn

Fran Kuhn
  • Sustaining Members
  • 352 posts
  • Other

Posted 17 April 2007 - 02:13 AM

It's not offered in Super-8.



They have it at Pro 8mm (cut from Kodak 5201).

Fran
  • 0

#10 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 17 April 2007 - 05:54 PM

They have it at Pro 8mm (cut from Kodak 5201).

Fran


Like I said, it isn't offered in Super-8.
  • 0

#11 Fran Kuhn

Fran Kuhn
  • Sustaining Members
  • 352 posts
  • Other

Posted 17 April 2007 - 06:06 PM

Like I said, it isn't offered in Super-8.


Hi Alessandro,

I know all the stories, but I have to say the folks over at Pro8 have actually been really nice lately. Good people on the customer service counter again. Maybe you could give them a try and see if you like the 50D and other Vision 2 stocks. Then there's always Spectra and Velvia (also 50D).

BTW (sorry, a little off-topic) How's that magazine article on low-cost Super 16 cameras coming along? :)

Fran
  • 0

#12 Alessandro Machi

Alessandro Machi
  • Sustaining Members
  • 3318 posts
  • Other
  • California

Posted 18 April 2007 - 12:41 AM

Hi Alessandro,

I know all the stories, but I have to say the folks over at Pro8 have actually been really nice lately. Good people on the customer service counter again. Maybe you could give them a try and see if you like the 50D and other Vision 2 stocks. Then there's always Spectra and Velvia (also 50D).

BTW (sorry, a little off-topic) How's that magazine article on low-cost Super 16 cameras coming along? :)

Fran


Not enough positive energy being generated to warrant one, we reap what we sow.
  • 0


Media Blackout - Custom Cables and AKS

CineLab

Ritter Battery

CineTape

Paralinx LLC

The Slider

rebotnix Technologies

Opal

Technodolly

Rig Wheels Passport

Visual Products

Glidecam

Gamma Ray Digital Inc

Willys Widgets

Abel Cine

Tai Audio

Aerial Filmworks

Broadcast Solutions Inc

Metropolis Post

Wooden Camera

FJS International, LLC

Abel Cine

Paralinx LLC

Willys Widgets

CineLab

Rig Wheels Passport

Technodolly

Metropolis Post

Broadcast Solutions Inc

rebotnix Technologies

Visual Products

Glidecam

Media Blackout - Custom Cables and AKS

Ritter Battery

Wooden Camera

Aerial Filmworks

CineTape

Opal

Tai Audio

Gamma Ray Digital Inc

FJS International, LLC

The Slider