PAL 25 fps + shutter speed question

[Daniel Chan]

I have a PAL version of the XL1S and is having trouble understanding the shutter speed differences and frames per second. I understand that Pal records in 25 fps, NTSC records in 30 fps and film is 24 fps.

Now what I am still shaky on is the whole thing about shooting in frame mode.

Some threads say that if the camera has the factory preset of 1/50 shutter interlaced, when shooting in frame mode, it is somehow halfed to create the 1/25 shutter look that is close to film. Now I may be the only one who doesn't understand the process being explained and the math behind this. Is there a different between the look of a PAL in 1/50 and an NTSC in 1/50? And how does manipulating the shutter speed help achieve the film look?

And that magic number 25, does it refer to the fps or the shutter speed?

Now I understand to emulate the film camera look, a PAL(25fps) is closer to a film camera, what about the shutter speed? beside the lesser light going to the ccd's, how does it actually affect the look of the images?

Sorry for the beginner's question, but it seems everywhere I look, there is a different explanation, I read Adam Wilt's take and it is different from some of the threads....

Thanks guys.

Daniel from Hong Kong

[B. Moore]

fps (FRAMES PER SECOND )is not the same as shutter speed. If you go to lets say 1/60 or 1/125 shutter speed, your camera still and always will be 25 frames per second (PAL) or 30 frames per second NTSC.

Bruce

[Rob Lohman]

First of all, NTSC and PAL camera's have DIFFERENT shutter
speeds. NTSC does not have 1/25th or 1/50th... They have
1/30 and 1/60. As Bruce said, you will ALWAYS record at
25 frames / 50 fields per second.

Second: difference between interlaced and frame mode.
The only difference (basically) is that half of the picture is taken
1/50th of a second (or 1/60th if your NTSC) later than the other
half. The camera than assembles this in one frame and stores
it in THE EXACT SAME WAY as a progressive image. The two
halfs originated at two different points in time though (more
compatible with old TV's). In frame mode all of the image is
captured simultaniously. With the XL1 you will loose a bit of
color resolution here due to the way this is achieved.

Third: shutter.... now I cannot tell you how this works on a digital
camera like ours. But on movie camera's this is a physical disc
that spins after the lens to allow the correct exposure of each
frame of film (so that you do not get half exposures or exposures
on seems etc.). Changing the shutter speed on your camera
has direct impact on the amount of light hitting your CCD (why
exactly is still a mistery to me, but it does) and changes the
way motion is shown. A low shutter speed of 1/25, 1/10 or lower
creates very "slow" and motion blurred images. A high shutter
speed like 1/1000 creates very sharp images which can be nice
to create a slow motion effect where you still see everything...

Hope this explains everything a bit better.

[Daniel Chan]

So what should I use if I want the best quality images in terms of sharpness and detail, should I sacrifice the filmlook with 1/25 and instead use higher like 1/500 or 1/1000 and light the scenes brigter with lights myself? cos 1/25 does look rather blurry and slow to me... and there is also a delay in the pictures sharpening when I stop moving the camera... which to me looks not a whole lot like film.

I have read that to get the film look you should use 1/25, but is there a way to compensate the blurr and still get the same flicker effect?

Thanks

Daniel

[Rob Lohman]

You can try to use 1/50th.... which has a bit of both. Basically it
boils down to what you find pleasing. Not me. Expirement a lot
and see what you like.