Jump to content


Photo

Wratten 85 confussion


  • Please log in to reply
8 replies to this topic

#1 Andy_Alderslade

Andy_Alderslade
  • Basic Members
  • PipPipPipPip
  • 1055 posts
  • Cinematographer
  • London, UK

Posted 22 February 2006 - 07:22 PM

I've suddenly become confussed about 85 filters. I woke up in a swet from a wratten nightmare.

All 16mm tungsten colour negative film cans say filter No. 85 for daylight use, and Super 8 Negative films say use No. 85 as well.

Now Super 8 Ectachrome 64T intructions say use No. 85b filter, and I know most super 8 cameras have an internal 85a filter.

In stills photophraphy filters like Cokin, Kood, etc they only refer to 85a and 85b and 85c.

So is the regular 85 filter that goes out in most pro 16mm kits one of the specifics mentioned or another variant.
  • 0

#2 David Mullen ASC

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

Posted 22 February 2006 - 07:32 PM

I've suddenly become confussed about 85 filters. I woke up in a swet from a wratten nightmare.

All 16mm tungsten colour negative film cans say filter No. 85 for daylight use, and Super 8 Negative films say use No. 85 as well.

Now Super 8 Ectachrome 64T intructions say use No. 85b filter, and I know most super 8 cameras have an internal 85a filter.

In stills photophraphy filters like Cokin, Kood, etc they only refer to 85a and 85b and 85c.

So is the regular 85 filter that goes out in most pro 16mm kits one of the specifics mentioned or another variant.


This has been argued here before -- unfortunately there is some confusion among filter makers as to whether the 85 and 85A are the same filter or not, further confused by the fact that the MOST commonly used filter is the 85B, which is often called an 85 too.

Technically, the 85B converts 5500K (daylight) to 3200K (tungsten). It is used for almost all tungsten-balanced stocks (modern color negative, modern E6 color reversal tungsten, etc.) for shooting in daylight.

A few older films are "Type A", balanced for 3400K tungsten photoflood illumination, not standard 3200K tungsten. They need to use the 85 filter (5500K to 3400K), which is why Super-8 cameras all have 85 filters in them, not 85B filters. Some manufacturers say that the 85A filter is the same as the 85, the "A" standing for Type A filters. Some others make an 85A filter that is slightly different than an 85.

Trouble is that we often call the 85B filter an "85" for short, like when ordering combo filters (85ND's). In fact, it's so common to call the 85B an "85" on a film set, I cause more confusion than accuracy when I ask for the 85B filter from some camera assistants.

Luckily color negative has such latitude that it really doesn't matter if you use the 85 or 85B because it's within a simple correction range. With color reversal shot for direct projection, you have to use the correct filter since there are no further color adjustment stages. So when using the new 64T stock, you probably should use an external 85B filter rather than the camera's internal 85 filter, unless you are prepared to correct a little coolness out of the image in post.
  • 0

#3 Andy_Alderslade

Andy_Alderslade
  • Basic Members
  • PipPipPipPip
  • 1055 posts
  • Cinematographer
  • London, UK

Posted 22 February 2006 - 07:39 PM

Thanks for the clear, and quick as lightening reply David.

Presumably there is little use of 85a filters on proffesional shoots then?
  • 0

#4 David Mullen ASC

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

Posted 22 February 2006 - 07:43 PM

Someone might use an 85 instead of an 85B because they want a faintly cooler bias to the image, I don't know. It's hard to actually find filters labelled "85A" though -- most are 85 or 85B.
  • 0

#5 santo

santo
  • Guests

Posted 22 February 2006 - 07:46 PM

If you're shooting 64t reversal in super 8, a simple and readily available solution is to pick up a Skylight filter for the lens and use it in combination with the camera's 85 "A' filter when shooting outdoors. Knocks it down right about 200 degrees. Mostly, it gets rid of the extra touch of blue cast you get otherwise. Improves your images a lot. Of course you can pick up the right filter, the 85b, but it might prove hard to find depending on lens filter size.

The unfortunate A film designation comes from an old attempt to amateurize motion picture stocks and make them easy to understand. "A" being, naturally, the film stock you'd use most often indoors. It is the old standard to which Kodachrome 40 was balanced for.
  • 0

#6 John Pytlak RIP

John Pytlak RIP

    (deceased)

  • Sustaining Members
  • 3499 posts
  • Industry Rep
  • Rochester, NY 14650-1922

Posted 22 February 2006 - 08:19 PM

Filtration:

http://www.kodak.com....4.9.6.26&lc=en

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

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

http://www.kodak.com...iltration.shtml
  • 0

#7 Andy_Alderslade

Andy_Alderslade
  • Basic Members
  • PipPipPipPip
  • 1055 posts
  • Cinematographer
  • London, UK

Posted 23 February 2006 - 08:11 AM

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

Hmmm' curiously to confuse matters the table in the above link appears to have two 85 filters, one for conversion to 3800 and one to 3400.

The one thing i've never doubted on shoots is that the 85 filter (as in 85b) requires an increase of 2/3s of a stop (and thats in the table above). However in a stituation when you are using non-standard filters, like having to use stills photography filters is the neccessary increase likely to change.

For example when I went to use a Kood (similar to a Cokin) 85b filter on the front of a Beaulieu Super 8 with the E64 t film, the internal light meter indicated the filter was taking 1 stop of light. I took the filter of and checked it with the spot on my Sekonic Light meter, and it was taking the reading down by a whole stop. Is the non-standard filter reacting differently and requires a whole stop adjustment or should one still use 2/3 rule?
  • 0

#8 David Mullen ASC

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

Posted 23 February 2006 - 10:36 AM

The truth is that most 85B filters lose more than 2/3's of a stop but less than 1 stop. But since meters are usually set in 1/3-stop increments, it's hard to compensate more precisely than that, plus anything under 1/3 of a stop in color negative is insignificant.
  • 0

#9 Andy_Alderslade

Andy_Alderslade
  • Basic Members
  • PipPipPipPip
  • 1055 posts
  • Cinematographer
  • London, UK

Posted 23 February 2006 - 11:04 AM

The truth is that most 85B filters lose more than 2/3's of a stop but less than 1 stop. But since meters are usually set in 1/3-stop increments, it's hard to compensate more precisely than that, plus anything under 1/3 of a stop in color negative is insignificant.


Brilliant, that makes sense.

Cheers, thats much appreciated David, its cleared up my confusion.

Many thanks,
Andy
  • 0


Broadcast Solutions Inc

Ritter Battery

Opal

Rig Wheels Passport

Abel Cine

Visual Products

The Slider

Media Blackout - Custom Cables and AKS

Aerial Filmworks

Wooden Camera

FJS International, LLC

Tai Audio

Glidecam

Technodolly

CineLab

rebotnix Technologies

Gamma Ray Digital Inc

CineTape

Metropolis Post

Paralinx LLC

Willys Widgets

Ritter Battery

Wooden Camera

The Slider

Willys Widgets

Aerial Filmworks

Broadcast Solutions Inc

Tai Audio

rebotnix Technologies

CineTape

Visual Products

Media Blackout - Custom Cables and AKS

Glidecam

FJS International, LLC

Technodolly

Opal

CineLab

Metropolis Post

Abel Cine

Gamma Ray Digital Inc

Rig Wheels Passport

Paralinx LLC