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Some more Canon 814 XL-s questions


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#1 Mike Rizos

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Posted 02 August 2007 - 12:55 PM

The manual says the shutter speeds for 150 and 220 shutter at 18fps is about 1/40 and 1/30 respectively. When I calculate the speeds at 24fps I get 1/56 and 1/40 respectively. I would like to use the camera on manual, with an external lightmeter for some shots, and would like to know how much light is lost through trasmission, the viewfinder, and the meter if any, in other words what is the effective shutter speed of the 814 xl-s for the above two shutter angles at 24fps?

I's my understanding that vision stocks 200T and 500T, read as 200ASA and 400ASA. Is this correct?

Why does the internal 85 filter does not engage when a Kodak vision II cartridge is in the camera? This is very strange and the filter engages fine with no film in the camera, and I can see it with a flashlight, and it's effect in the aperture indicator. But not so with either 500T or 200T in the camera.

Thanks.
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#2 Jim Carlile

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Posted 04 August 2007 - 12:07 AM

You're pretty right-on with your calculations for 24fps. The light loss through the aperture is a little more than one f/stop. The best thing to do when using manual exposure is to experiment, bracketing your exposures and keeping a little log so you know how your specific camera handles things. It might take a few rolls. A lot depends on the idiosyncrasies of your meter.

About the VISION 200 stocks:

Kodak designed them to deliberately disable the onboard 85 filter. Your observations are correct. They also set it up so that the film would be exposed at ASA 100, not 200. The reason for this is that they think one-stop overexposure benefits the film.

As a 'professional' film, they also figured that most people would prefer using an external 85 over the lens, which you must do with this film outdoors.

They did this by providing VISION 200 with a 'notchless' cartridge. If you notice, the cartridge is made so that it pushes in the filter pin in the camera, at the bottom of the film chamber. Kodak also speed-notched the film at ASA 160T.

By doing so, the 814XLS-- and many other cameras-- will recognize this as a "daylight" film, and then set the exposure meter for the "daylight" ASA that is associated with the cartridge's particular speed-notch size. In the case of ASA 160T, the daylight speed associated with that speed notch is 100D. This is the technology that was designed into the super 8 system back in the mid-60s, and it's actually very clever and simple.

Of course, VISION 200 is not a daylight film. But Kodak chose to treat it as such, in order to basically "trick" the camera into running it the way they prefer. The super 8 system allows cameras to run "daylight" films at their respectively lower ASA speeds, without the unnecessary 85 filter in the way.

This can be altered. If you take a pair of pliers and snap off a bit of plastic to allow the filter pin to stay out, the 85 inline filter can be used. It won't be disabled any more. Also, in that case, with the pin out, the meter will be set to the tungsten (high) ASA of the speed notch, which is 160. The 814 will then rate the film at ASA 160 instead of 100. That's close enough.

There is no specific ASA 200 speed-notch associated with the super 8 system, so these cameras have to be tweaked a little bit-- by either Kodak, or the user.

As a basic rule, the most common speed-notch associations are: 40T/25D, 100T/64D, 160T/100D, 250T/160D. Each ASA twin has its own size speed-notch. That's how the camera tells the difference. When the filter pin is pushed in, the filter is disabled, and the meter is set to the daylight ASA. Kodak designed their daylight films to have ASA speeds that conformed to this standard.

Not all cameras do this, but the 814XLS does. It will also read higher ASA films than many cameras. If you notice with Tri-X, the same thing happens with the 85 filter, but the 814XLS will also read the film at 160T, rather than 100, because it can read the larger ASA 250 speed-notch.
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