Last Updated 99/07/23 1200PST
Subject: Re: Using Filters with B&W Reversal Super 8 film From: [email protected] (Super8mm) Date: 1999/03/04 Newsgroups: alt.movies.cinematography.super8 ---> Your Source for Super 8mm & Regular 8mm Film Services <--- MARTIN W. BAUMGARTEN Plattsburgh, New York 12901-1827 U.S.A. Tel: (518) 561-6312 E-Mail: [email protected] Website: http://members.aol.com/Super8mm/Super8mm.html * Business hours Mon-Fri 9am - 5pm e.s.t. Closed for all USA holidays. --> Visit KODAK's New Super 8 dedicated site! http://www.kodak.com/US/en/motion/super8/ March 4, 1999 Hi John, You posted: >I have read Martin Baumgarten's discourse on the subject (Super 8 >Metadirectory) but I have a question. ---> I suppose I'm lucky to have seen this posting of yours. I apologize for any confusion, as I haven't seen the listing to which you refer to. However....I'll try to clear this up a bit for you here. >On the back of a packet of Tri-X it states that the meter should be set >to 200/24 when using Tri-X in Daylight with Filter. The article mentions >that the filter is removed by the cartridge so does that mean that the >film is being exposed at 160/23? ---> There is an error in the package printing that has proliferated for years now. Some years back....Kodak Motion Picture Dept. information release stated that Super 8mm Tri-X 7278 is ASA 250. This was either incorrect and/or the film was changed when the emulsion was reformulated quite some years back. Anyhow....even if the film were ASA 250, if you used the builtin filter (if you were even able to!), the rating wouldn't be ASA 200, it would be ASA 160! Okay....let's jump to the facts. ---> Kodak TRI-X 7278 B&W Reversal film is rated for Daylight use at ASA 200 WITHOUT filter. The cartridge DOES NOT have the filter notch......thus, the cartridge will REMOVE the filter out of position in the optical path on 95% of all Super 8mm cameras. There is no way to override this...since the film chamber button leaves the manual filter position setting knob inactive. IF you want to be able to use the builtin #85A Daylight filter, and it would be nice to do so for various reasons, you will have to break off a tiny section of the cartridge wall with a pair of needlenose pliers. This won't harm the cartridge as that spot is intended to have various notches in it for different functions. ---> Tri-X film is a high-speed film, so you have to be careful in Daylight. I recommend using a contrast filter (Yellow, Orange, Green or Red in whichever strength you require for the desired effect) coupled with a 4x or 6x Neutral Density filter. Then you can cut the light down enough to rate it at ASA(E.I.)25 or something similar....making using the film in bright daylight much easier. Even a polarizing filter will generally cut the light down about 1.5 Stops....which would help immensely. All Black & White film should be used with at least a medium yellow filter when shot in Daylight to compensate for the film's inherently high sensitivity to blue...which normally caused loss of cloud and sky detail....often rendering them white or washed out.....or just gray..due to the autoexposure compensating, but still not providing you with the detail. This way, the image density will look 'normal' with correct contrast ranges. To make things easy....just break off the cartridge wall and use the builtin filter...which works nicely. Why Kodak did this for Plus-X 7276 and not Tri-X is beyond me! >I don't understand where the 130ASA comes into it that is mentioned in >his article. >Am I making any sense? ---> Well, I honestly can't remember what I wrote. But I must've been referring to the rating of Tri-X when using the filter. The builtin (or addon if you use that) Wratten #85A Daylight conversion filter which was originally intended to convert Super 8mm color films for daylight use (since All Kodak Super 8mm color films are actually Tungsten balanced), will cut the light down by approximately 63%. For example, Kodachrome 40 Type A is ASA 40 Tungsten, but drops down to ASA 25 for Daylight use when using the filter. This is roughly 63% less incoming light due to the filter being in position. The change is roughly 2/3rds of a Stop of exposure....which if you just average that at 66%, then you get 132....and I most likely just averaged that to 130. Technically speaking, if the filter's transmission factor is where it should be, and the film's exposure response curve from manufacturing is where it should be...and the film is within it's use date range, and all things being equal......the correct rating is ASA 126....not to confuse you here....but to explain it all out....so there's not any more confusion here (but I'm sure there will be by somebody!). ---> About the box printing: Kodak used to include film date sheets with all their films. They stopped doing this for all their still films (professional grade films notwithstanding), and also for their Super 8mm movie films. On the Tri-X 7278 date sheet....the exact same block as printed on the boxes now....states ASA 200 in Daylight (no filter). My own tests over many years of using this filmstock....and having discussed this with various powers-that-be at Kodak........the box is in error....and no one seems to have done anything about it...and I kind've doubt we'll see it change anytime soon......knowing full well Kodak's massive bureaucratic engine! :o) ---> I'm on a roll here...what else can I add? Don't be afraid to shoot with Tri-X in bright light...just use the proper filters for contrast control and/or also Neutral Density or Polarizing filters to cut the light down so you can manage your exposure controls adequately. It's wonderful filmstock....crisp grain, nice rich deep blacks, and clean highlights. It is very different than its Plus-X 7276 counterpart......and if you're doing a B&W film project and want to maintain the same 'look' and 'feel' throughout the project....use the same filmstock. Then even your lowlight shots that are Push processed, your non-Push processed existing light shots, and your bright daylight shots....will all match together nicely. Just my two cents here. ---> On Tri-X, with its ASA 200 rating, if you were to use the builtin filter or screwed a #85 onto your lens, the effective ASA would be ASA 126 (if you figure 63% of the ASA 200 rating). I probably just rounded it off to 130 in what I wrote....perhaps 125 would've been better. Anyhow...it's small potatoes here since the difference is too tiny to worry about. Happy filmmaking! Martin W. Baumgarten
Subject: Re: Tri-X From: [email protected] (Super8mm) Date: 1999/03/04 Newsgroups: alt.movies.cinematography.super8 ---> Your Source for Super 8mm & Regular 8mm Film Services <--- MARTIN W. BAUMGARTEN Plattsburgh, New York 12901-1827 U.S.A. Tel: (518) 561-6312 E-Mail: [email protected] Website: http://members.aol.com/Super8mm/Super8mm.html * Business hours Mon-Fri 9am - 5pm e.s.t. Closed for all USA holidays. --> Visit KODAK's New Super 8 dedicated site! http://www.kodak.com/US/en/motion/super8/ July 20, 1999 Hi Folks, Yes, PLUS-X 7276 Super 8mm B&W Reversal film is finer grained, and offers a nice smooth fine tonal gradation. However, TRI-X 7278 B&W Reversal film, even though the grain is coarser, has really nice deep rich blacks, crisp tones, and clean brilliant highlights. It can easily be used in bright daylight also, by using a .6 Neutal Density filter which will drop it from it's ASA 200 rating to ASA 50. The TRI-X Super 8mm cartridge will automatically remove the builtin #85 daylight conversion filters on the majority of Super 8 cameras, however...you can defeat this by breaking off a notch on that part of the cartridge using some small pliers. That way you can take advantage of the orangish #85 filter which will bring out splendid cloud and sky details, and great for filming along waterways, as well as knocking down the effective filmspeed to ASA 32 (most automatic exposure Super 8mm cameras will rate the film at ASA 25, WHEN you have notched the cartridge and are using the .6x Neutral density filter on the camera...but this is well within the film's latitude range. Perhaps the nicest advantage to filming in TRI-X in daylight, is that the entire film project can be filmed with the same filmstock...for both brightly lit scenes and dimly lit scenes. That way the film will have basically the same contrast, texture, grain, tonality throughout the entire film. TRI-X is ASA 200 Daylight without the Filter...since remember...it doesn't have the filter notch in the cartridge (unless you put it there!), and the an effective Tungsten rating of ASA 160 (ALL B&W filmstocks lose filmspeed in the absence of blue and UV light, which explains the higher daylight filmspeed rating). The film can easily be pushed 1 to 2 Stops if an even higher filmspeed is required (thus ASA 400 or ASA 800), and even as high as 3-Stops (ASA 1600) IF necessary...but with severe increase in film contrast and grain. However...since most film pushing is due to exposures made in low artificial lighting and not daytime...the actual effective filmspeeds via Push processing would be: 1-Stop(ASA 320), 2-Stops (ASA 640) & 3-Stops (ASA1280). Another great advantage to filming with TRI-X in daytime is that you can use all those wonderful B&W filters for maximum effects.....without losing much of your filming power due to a lower effective filmspeed. Combining them with other lesser strength Neutral Density filters, and you can maintain total control over how you want to film, and how much or how little depth-of-field you want in your film in any given shot. Hope this helps. Best wishes, Martin W. Baumgarten