best 8mm camera!?

[tom hardwick]

As movies chop each second into so few frames (let's take 18 per second) it becomes more important that slow shutters are used to give fluidity to movement within the frame.

Movement within the frame can be the obvious, like a footballer running from L to R, or a pan across a static subject - the effect is the same.

This is why the XL cameras of the early 80s are so much better at displaying smooth motion; they film at very slow shutter soeeds per frame. The 220 degree shutter gives an exposure of 1/29th sec at 18fps and this makes for very smooth subject movement.

This is the main reason why Beaulieu constantly recommend you shoot at 24fps with their oscillating shuttered cameras. At 18fps they were exposing each frame at 1/64th sec and producing movies that were too sharp and gave rise to the "shutter stutter" that a lot of people object to. At the same time they went on about 100% of the light reaching the gate (true) convieniently forgetting that with such high shutter speeds necessary to oscilate the shutter mirror, less light was getting through anyway.

100Hz TVs are a bit like this too, and for fast action sport the picture looks smoother at 50Hz.

tom.

[#Pedro]

I think you are mixing up the framerate which defines the resolution of the movement and the flicker frequency. A 100 Hz TV ONLY doubles the flicker frequency from 50 to 100 Hz, but the framerate, the number of DIFFERNT frames per second, keeps the same as with a 50 Hz TV, always 25 fps. The result is, that a 100 Hz TV reproduces less flickering when all the screen is bright and white and gives a more smooth impression, less headake even with large screen diameters.
Tom, I am using 2 cameras, my favorite one is the Beaulieu with it?s very short shutter times and it?s sharp frames. The second one, which I use when "filming is forbidden" or too dangerous (cities in South America...), and it?s an Canon Autofocus XL camera. Sometimes I splice footage from both cameras together. But as a matter of fact, the Beaulieu footage looks so much sharper projected on my 1,5 m screen, that there is no comparation, the Canon is only a compromise. If you shoot quick movements with the Canon, the moving objects get "wiped", due to the long shutter times. But my (subjective!) impression of this result is not a smoother movement, it?s lack of sharpness. I?ve no problems with Beaulieu films taken with 18 fps. Yeah, as my budget is very limited, I?m using 18 fps! And I don?t think the movements less smoother as the ones taken with the Canon. The only way for my opinion, to get even smoother results, is to spend more frames per second, capturing more different positions of a movement. Analouge to the optical resolution of the film surface: More grains per mm, more details. More fps, smoother movements. Wiping the movements with a long shutter speed does only give a very first impression of smoothness, after a few seconds you recognize, that it?s lack of sharpness.
puh - thats it, my point of view, excuse my English...
Pedro

[tom hardwick]

Excellent English Pedro and I understand every word, no worries.

No I'm not mixing up frame rates with projector shutter frequencies, though I'm sure many do. I agree with your explanation of 50 and 100Hz by the way, and for me 100Hz TVs look a lot better.

But when I film with my 1014 at its highest shutter speed (1/160th sec per frame at 18 fps) each tiny picture is indeed sharper but the fluidity of motion is completely lost. Zooms "stutter" and pans are jerky looking.

You're right that more fps is the real answer, but a 54Hz projection of 18 fps is not a bad compromise, and works well.

I'm surprised to hear the Canon lens is so dissapointing against the Beaulieu. In the same lighting conditions, what respective apertures are both cameras working at? I'd expect the Canon to be at f5,6 when the Beaulieu needs f4, but tell me what you know.

tom.

[#Pedro]

Hi Tom,

Thank you for your nice comment concerning my language...

Indeed the 100 Hz TVs provide a better image, my next one will be a 100 Hz model, but it?s only the flicker, not the framerate. I think, you in USA have 30fps in TV???

I will check it out focusing the same object with the same zoom angele with both cameras.
My only problem is, that I?m not shure if the displayed stop is comparable with the real photografic stop, as there is that prisma inside the camera which takes the half of the light away to feed the viewfinder. The stop of the Beaulieu is exacly the same as the stop on my 35 mm still camera (at same film speed).

My Canon is that model with the 1:1,0 lens. The reason for a less "sharp" image is the lower contrast reproduction of this lens, the slower shutter speed which wipes the movements, the tendency to overexpose automatically every shot (no way to correct it manually) and the prism which divides the light for viewfinder and film. But it?s very good for "hided" filming at bad light conditions, without doing any adjustments at the camera, just press the button...

In contrary, the Beaulieu is adjusted exactly to the specified light sensibility, has a bottom-weighted TTL measurement system (1 stop more sensitive at the bottom of the viewfinder) which gives in nearly all cases crisp and sharp pictures.

To input some facts in our discussion:
The Beaulieu exposes with the following shutter speeds (18 fps):
1/72 s in normal position
1/40 s in LowLight position (= ca. 180?)

Pedro

[tom hardwick]

Yes, they have 60Hz mains in the USA but I'm in England, UK, where it's 50Hz. And PAL is so much nicer than NTSC (there - that should start an argument). Yes, my next TV will be a 16:9 100Hz widescreen model, but till then the lovely Sony 34" will have to do = sigh =.

I have a Canon 310 XL with that magic engraving around the lens 1:1,0 Lenses don't come much faster than that. I agree that the tiny periscope prism takes a small amount of light away from the gate, and it's interesting hearing you say how accurately your Beaulieu follows your still camera as regards exposure readings.

tom.

[Alex]

Ironically, what makes for a "sharper" motion shot with a faster shutter speed...

...does make for a strobier shot when motion is captured moving in a left to right or right to left manner.

And, ultimately, it makes the camera have less sensitivity in low light situations.

a 180 degree shutter is normal at best.

Yet Beaulieu calls that "low-light"

True low light super-8 cameras have a 210-220 degree shutter.

[#Pedro]

Alex:
180? is called "LowLight" at Beaulieu cameras, because the amount of light on the film surface is higher as at 220? cameras with a conventional viewfinder system (with prism). Therefore 180? is enough. The LL shutter of amateur cameras is to slow for really sharp results. You cannot compensate missing frames per second (for a smooth panoramic movement) with wiped frames. The panorama movement will appear less stroboscopic but it won?t show the details of the landscape, as they are not reproduced in a sharp way. The only thing what helps, is to make the panoramics very slow, and use a slight slow motion framerate. When i make a film with 18fps and I decide to include a panoramic, I always shot it with 24 fps (and project it with 18 fps). Panoramics I made with my Canon LL-camera, I never included in any final cut version of any film, as they only disturb the eye of the audience.
Pedro