Personal note, unrelated to movie processing:

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IMPORTANT NOTICES

IMPORTANT NOTICE for Ektachrome users.

Eastman Kodak is discontinuing all of its VNF-1/RVNP Ektachrome films in all formats, first 7239 and 7240 in the summer (including the Super 8 Ektachrome), then 7250 and 7251 by the end of 2004.. It is introducing Kodak Ektachrome 7285 in 16mm, a 100 asa Daylight balanced film, that uses the very common E-6 process. It has already been available in 35mm as 5285. No plans as of yet have been announced to introduce it in Super 8. Although this new color reversal emulsion is very modern, raw stock expense is greater than with the older VNF-1/RVNP emulsions. For more information check Kodak's website.

IMPORTANT NOTICE for those developing KODAK BLACK AND WHITE REVERSAL FILMS (all formats)

As of October 1st, 2003 Eastman Kodak has introduced two new black and white reversal films that are to replace the older Plus-X 7276 and Tri-X 7278 films. They are to be called Plus-X 7265 and Tri-X 7266. Kodak reformulated these films to accomodate a new black and white reversal process that uses a new environmentally safe bleach and a higher energy developer. The new R-10 bleach does not use the metallic compounds that the older R-9 used, therefore making it more environmentally friendly and less costly to dispose of. The new developer/bleach combination allows Plus-X film to be exposed at 100 ASA.

In addition, the new Plus-X features increased sensitivity (100 ASA in daylight) at what Kodak terms a slight grain penalty, while the new Tri-X features finer grain for its 200 ASA (daylight) speed and lower contrast than its older brother, 7278.

Kodak claims full cross compatibility - the older films can be developed using the new chemical formulas, and the new films can be developed using the old classic formulas. However, it is important to note that both the new and old Plus-X films are to be exposed at 50 ASA (daylight) when being developed in the old chemistry, and 100 ASA when developed in the new chemistry. There is no change with the Tri-X films, as far as I am aware from Kodak's information.

Most laboratories intend to switch to the new process on October 1st, 2003. If you have Plus-X film that has been exposed at 50 ASA, and have not processed it yet - either get it to a lab that still uses the old process, or develop it yourself using the Kodak specifications below or any of the other classic formulae on the net.

I have not tested these new films or process combinations, nor do I currently have the new formulae (the Kodak D-94a developer and the R-10 bleach) - but Kodak said that it would be releasing the formulas around December of 2003 on their webpage. The processing information I have on this webpage does not yet reflect the new process. Check the Kodak webpage (cinematography section) and the Kodak FAQ on these two new films for more detailed information.

INCREASING DYNAMIC RANGE IN A KINESCOPE SYSTEM

I have for a long time thought of the concept that a limited dynamic range could be cured by way of doing two separate passes to capture highlights and shadows. As we have heard, there are such devices with columnated CCD's that scan film effectively twice, once for each region. The effect is an increase in captured dynamic range which bypasses a devices' own limitations.

I have thought of a similar process for shooting off of a computer monitor. Computer monitors have poor dynamic range, this is no secret. This is one of the main reasons why kinescopes are inferior to laser recorded output. However, they do have fairly decent resolution, over 1000 lines in many cases, and they are, compared to laser recorders, very inexpensive.

Here is an image off of DV. Not like this example will help us improve dynamic range, as this image doesn't have much range to speak of, but it's just for illustration...

If we pointed a film camera at a CRT screen (eg. a computer monitor) and exposed this image at exposure N onto film, we would get a middle 18% grey reproduced exactly.

However, we would only get black into the shadows to a certain point, let's say 20 points RGB as an example. The last 20 points of the image file are virtually the same as 0 points when the camera looks at the monitor, as the monitor's phosphors are unproportionately dim or simply off.

Now, we want to first see if we can capture the shadows as best as possible, so points 0 to 20 will register. So we take the image and remove all values 128 points of RGB and up, and we get this image, which displays every point from 0 to 127 RGB:

If we expose this image off the CRT at N, we will get the same output that we would have if we photographed the entire frame at N, meaning we wouldn't get any extra shadow information that we want - the monitor is hiding that because any value below 20 won't adequately light up any of its phosphors anymore.

So in order to accomplish this, we have to raise the base shadows for the monitor can actually display the last missing 20 points properly, and so the film will be able to record it. To accomplish this, we raise the overall brightness of the image by 20 points. We get this:

But now we have a problem, because if we expose at exposure N, all values that are at 127 points RGB (our 18% middle grey reference, in photographic terms) are now shifted up to 147 points.

To keep our middle grey where we want it, we now have to underexpose the image by N-X, to the point where 147 points will register at middle grey. We still haven't lost the values below 20 points RGB, as film has a greater dynamic range and can read the phosphors that are burning that low without problems. We have now captured an extra 20 points of dynamic range in the bottom part of our image!

Now, to capture the highlights we start by taking the original image again. This time we remove all shadows, in other words anything lower than 128 points of RGB becomes monitor black. Now we have this image, which displays RGB points 128 to 255:

If we recorded this image at exposure N, our highlights would be too bright, the monitor's phosphors would be at their brightest after a certain amount of points, let's make the math even and say it's after 235 points (the same 20 point offset as with the shadows). To gain back those extra 20 missing points at the high end, we have to dim down the monitor's phosphors so they can resolve the extra 20 points of RGB correctly. We make the image 20 points darker. In order for RGB 128 to perfectly "meet" value 127 from the first exposure on film, we have to also compensate our exposure by increasing it to N+X. We now make the second exposure onto film.All the black regions on the two files A and B are going to work as a matte, they prevent double exposure so we can have a composite image made of two images that look like one.

The key trick here is getting levels 127 of exposure A and 128 of exposure B to perfectly line up on film in a linear manner, which must be accomplished through testing. This is also assuming the monitor is linear in its toe and shoulder, and displays at a gamma of 1.0. If the monitor has a non linear behavior then more complicated image manipulations may be necessary, such as adjusting the file's curve.

Also, if we wanted to be picky, or if our tests suggest it as a good idea, upon raising the brightness of the shadows image we could make sure that all 0 levels stay at 0 and make only levels 1 and up are boosted in brightness. This can be done in order to keep the black matte as dark as possible, to prevent a small fogging exposure falling upon the second exposure in case there are still phosphors dimly burning below 20 points RGB.

I have also thought of an automated way of doing this dual stage kinescoping.

A film camera is pointed at the CRT screen (16mm or 35mm, cameras like a Bolex or Eyemo would be fine). The camera is hooked up to a computer controlled intervalometer. Before the lens of the camera is a special secondary butterfly circular shutter (just like the one in the camera), with two openings of different sizes.

The first frame, for the shadows (A) comes onto the CRT. The intervalometer is triggered to open the camera's internal shutter and to keep it open. Then, the secondary, external shutter makes one half turn, making one exposure onto the film at N-X. After the secondary shutter closes, the intervalometer still keeps the camera's internal shutter open - the frame does not move anywhere. Then frame B for the highlights comes onto the CRT. The secondary shutter then makes another half turn, this time exposing the film with its second opening which is calibrated at N+X. The intervalometer then closes the camera's internal shutter, and the film is advanced one frame.

The process repeats.

Registration is good as there is no chance of film movement in between the two exposures - the shutter and film stay stationary thanks to the programmed intervalometer.

This is an untested hypothesis. You are welcome to experiment and share your results in the Movie Processing Group above if you so wish.

- George Selinsky

A GRAPHIC ILLUSTRATION Depending on your specific monitor, results might be different. In A, one side of the rectangle is at 0 points RGB. The other is at 5 points. You can't tell the difference between them.. However, when you brighten them by a certain percent (in B), notice how they begin to become distinct. In C, square one is 250 points RGB while 2 is at 255. It is almost impossible to tell them apart. When you see them with the brightness lowered in D, you can see the difference more clearly.