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Author Topic: Shooting your own test films? John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 02-19-2009 04:41 PM                     Out of curiosity, has anyone experimented with shooting your own test film? In particular, for lp/mm resolution targets? Mostly for fun. After all, still pin-registered Vistavision cameras are widely available . (Mostly this came up when I was thinking about resolution targets and noticed how little RP40 we have left...). In particular, since our RP40 has the straight-line targets: and it might be nice to have some with wedges: I guess RP40 was revised in 2003? Does it have wedges now? While this idea is kinda half-baked and probably not all reasonable for cutting apertures, it seems like it might work OK for resolution tests (or other special neat-oh tests). One thing I'm not sure about would be to how to line up two 4-perf images within an 8-perf frame. Maybe it would be easiest to expose half the frame, rewind the film, offset it by 4 perfs, and shoot it again. --jhawk  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-19-2009 08:34 PM                     John, The yield is where test films kill you. The time frame between when you shoot it and measure it, then adjust and do it again...etc. You also have to contend with the film stock...cameras are pin registered, as you know but film projectors reference the edge of the film. As such, any skew caused during the perforation process will affect both stability and position. Kodak will tell you everything is within tolerence even though the image is moving all about and not caused by the projector. For steadiness, I've used Schneider's test film as it has been notably steadier. Right now, there are two sources of "RP-40"...there is SMPTE, which sources from Clyde McKinney and there is NTAV (the same people that make some of your leaders). The NTAV target is nearly identical to the SMPTE target (whereas they both are based on the RP40 document that specifies the pattern. NTAVE does have 100 lp/mm towards the center of the image. NTAV Target They also now make (again) Tone, Pink Noise and Buzz Track...they don't have the Dolby Digital track on them but are otherwise superior to Dolby's test films in that they are much more consistant from batch to batch. I've tried to get some labs to make 16mm test films (that process 16mm, Super-16 and have the cameras to shoot it)...they all seem scared to do it due to the low yield...which is often beyond their control. Steve  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 02-19-2009 09:13 PM                     Yup, I was mostly joking about pin registration, but the point was that my "Vistavision" camera is no better than what the real RP40 gets produced on. (Of course it's probably got much crummier registration, not all pins are equal). As long as I'm not going for position, just resolution targets, I figure I'm pretty safe. Obviously for cutting plates, that's a whole different story. It doesn't look like NT-PT has wedges either. RP216 has wedges, not that I have a 3-perf projector (or a 3-perf camera). I know NT was formerly the source lab for Dolby films. Do you know what changed in the '03 rev of RP40? --jhawk  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-19-2009 10:35 PM                     Whereas I sit on the SMPTE committee that governs RP40 and I had a heavy hand in its current target...I can say the target has not changed in quite some time. I'm almost positive that it did not change in 2003. We have to review all documents at least every 5-years to ensure they remain valid. Sometimes, all they need to get is a "reaffirm" vote to put the new date stamp on them. Often a word or phrase is changed to satisfy someone's concerns. Sometimes the SMPTE or ANSI will make policy changes and the documents need some form of clarical revision to conform in how the document itself is formated. The 35-PA target though does not change all that easy. Once that target changes...one is back to square one, in a sense to impliment the new changes and verify it measures (under a microscope) properly. Typically, one test of the camera is to shoot the target, then shoot the target in reverse and then shoot the target forward again. Upon processing, it should not be multiple images...if there are, the camera has registration problems. 35PA does indeed have something like the curved resolution lines...the rosettes in the middle of each resolution pattern. At their outter parimeter, they are about 8 lines/mm and then converge...The rosettes theoretically have infinate resolution towards the middle...however, they are naturally limited in the source target by that which made them and on the film by the film grain itself. Steve  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 02-20-2009 02:12 PM                     Unrelated, but when did they add that section with the black background to the line pairs?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-20-2009 05:03 PM                     It is more like...when did we remove it. It isn't in the current target. The current target came out in 1995, I think. I don't recall why they were not included in the current target. In the older target, they were the "corners" to the targets on either side of the diamond. They were not in the 16 or 70mm targets either. However, if you are interested in black resolution fields as well as "white"...then check out Schneider's test film. I don't recall ever reading anything different between the two styles..however Schneider's predominately black target DOES soak up a lot more heat and will show such effects more than 35PA. No matter how you cut it, you are measuring an equal number of black and white lines. Steve  |  IP: Logged John Hawkinson Film God Posts: 2273 From: Cambridge, MA, USA Registered: Feb 2002 posted 02-20-2009 05:14 PM                     For comparison, here are some targets. This is the RP40 I have. It's fairly old, probably 1980s: This is NTAV's target, from their web site: This is Schneider's CLT, from the PDF on their web site: This is the RP91 (1997) target, for 70mm: This is the RP216 (2002 draft) target, for 3-perf 35mm: I've only used the SMPTE RP40. It does look like the NTAV and the CLT don't have anything quite as convenient of RP40's checkerboard for actually making fine measurements. I guess it's hard to tell from NTAV's target, maybe what looks like moire is really a fine checkerboard. While we're here, is there a good way to quantify chromatic aberration? I mean, you can see it, but what's the right way to decide how bad it is? --jhawk  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-20-2009 06:28 PM                     NTAV's targe has the same checkerboard pattern as SMPTE's. The purpose is the same...to try and have approximately 50% transmission. The NTAV target has everything the SMPTE target has plus a couple of extra goodies. It is also very well made. As for chromatic abberation....I don't know of anything where one would quantify it other than one could state what percentage of an image or what the offset is. Kinda like convergence. Steve  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 02-20-2009 10:08 PM                     Another small difference; all the 70PA I worked with didn't have the black background for the text, "70-PA" "RP-91" but for me, there was next-to-no 70mm features requiring test film after 1990 or so.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-20-2009 10:19 PM                     RP-91 changed its target slightly in the late 80s/early 90s...Note too your RP91 also likely didn't have the 1.85 lines either. These were added since many features were 70mm 1.85. While using the hard matte's might be acceptable on some screens (flat ones) on curved screens, they call attention to themselves. At the Uptown, we had separate plates for 70mm 1.85 and 70mm full frame. A tradition that I have carried over to the AFI/Silver, even though they have a flat screen. It makes for a very uniform show without the image jumping about on reel changes (platter or changeover). Steve  |  IP: Logged John Walsh Film God Posts: 2490 From: Connecticut, USA, Earth, Milky Way Registered: Oct 1999 posted 02-21-2009 09:56 AM                     I didn't notice the 1.85 lines above; it wasn't on 70PA when I set up, 'Cocoon' and would have been handy, but that was the only 70mm/1.85 I ever did. I always wished 70PA had general inch scales like the 35PA, rather then just markings for cropping and standard ratios. I also liked the 'old' 35PA; (JHawk's top photo) because the inch lines were longer and easier to follow to the number text. Also the numbers were larger and easier to read. They should have kept the 0.839 markings because some theaters still project that (I know it's not right, but it would be good for demonstration reasons.) In the early 1980's I was buying a lot of test films from SMPTE. I really wanted to try out the magenta 35PA, but couldn't justify the cost as they would only sell it in 200ft lengths. There was a woman (who's name I can't remember right now) that ran that department. She called me and said they cut a roll wrong, and had 50ft of magenta 35PA left and would give it to me for free. To show how projection-nerdy I was, I drove down at got it that day.  |  IP: Logged Richard Fowler Film God Posts: 2392 From: Ft. Lauderdale, FL, USA Registered: Jun 2001 posted 02-21-2009 11:22 AM                     Anne Seminara....she has been there forever in the Test Film Department  |  IP: Logged Brian Guckian Jedi Master Film Handler Posts: 594 From: Dublin, Ireland Registered: Apr 2003 posted 02-21-2009 04:38 PM                     quote: John Walsh I always wished 70PA had general inch scales like the 35PA, rather then just markings for cropping and standard ratios. There's probably a case for revising RP-91 given the recent increased popularity of 70mm and also the appearance of variant aspect ratios such as DTS-70, where the picture information (in the case of 2.39:1 blow-ups) has been extended into the area formerly occupied by the inner magnetic stripes. Also, what are the possibilities of manufacturing the 35-PA test film with standard KS-1870 perforations as well as BH-1866? This would improve the product. Steve Guttag brought this up before and it would be interesting to know what the issues in doing that are. It would be great if all test films were seen as an investment by a cinema and were considered in the same way as a piece of equipment, especially since films like 35-PA are meant to be run as a roll, not as a loop! A new lens costs hundreds of dollars, pounds, euros etc. so why not a precision test film?  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 02-21-2009 05:53 PM                     The theory that the space covered by the inside tracks are reclaimable is a false one. First, it still does not get you back to 2.39 but more importantly, it would require modifying virtually EVERY gate and trap in existance...something that isn't likely to happen at this juncture in 70mm's life. There would likely need to be a severe resurgance of 70mm before that target gets any attention. Remember, if the SMPTE redesigns a standard or RP it has ramifications to several entities. For instance, when we unified the width of the 35mm projection images at .825"...that meant that Panavision and Arri had to regrind all of their viewfinders to reflect the actual projectable frame size...not a cheap proposition. Clearly with test film...one has to create the new target and go through the process of verifying that you are making the target properly. Also, any film on the shelf becomes instantly obsolete. It is tough enough to get folks to make target film already. Anyone remember a few years ago when 35PA became almost non-existent? How about the 16mm test films...the RPs are on the books but, to the best of my knowledge, nobody is making them. 16PA and 16RT are sorely needed for those of us that work in 16mm still. As are the sound test films. It would be really nice if a 16mm optical Pink Noise existed. The problem arises that it isn't enough to just make the film...it has to be measured to ensure it is accurate...it really lowers the yeild (profitability). If an entity were to make 16PA...how much do you think they would sell in a year? You don't want to make too much because you run the risk of the film shrinking (much less of an issue with poly than in the acetate days). I've trying to get folks to make it for years now. I'd like offical Super-16 test film too. Speaking of which...Super-35. B,L &S had some custom target made that worked with the formats that use film center rather than the offset for the optical soundtrack. I bet you it cost a pretty penney to get it made. Steve  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 02-21-2009 05:57 PM                        I have super-35 focus loops and an anamorphic focus loop from a couple of productions. My understanding is that any production that shoots on super-35 (and maybe any format) shoots a focus loop with the edges of the frame marked. Presumably they do this to ensure that the camera viewfinder markings line up with the projection aperture dimensions and also so that the optical house that does the anamorphic squeeze knows how to properly set up their equipment. A version 35PA/RP40 that included the silent frame would be most appreciated as well, especially since there are several different standards for it. Is there a reason why this isn't included? Does anyone make 16mm buzz-track? And are the NT audio-visual pink noise loops now preferred over the current Dolby ones (on color stock)?  |  IP: Logged

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