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Nckcard

macrumors regular
Original poster
Jul 11, 2008
100
0
I'm trying to make a video for a science project with images in it so short only the subconscious mind can notice them (A.K.A. 40 milliseconds), does anyone know how i could make a picture flash for about that long in adobe after effects, or maybe even iMovie HD?
 

bigbossbmb

macrumors 68000
Jul 1, 2004
1,759
0
Pasadena/Hollywood
i doubt you can do it in iMovie.

with video, you're limited to standard framerates... for things shown on typical broadcast TV, that is 30fps. 720p is 60fps which is the highest rate for any broadcast standard. So if you make a 720p comp in AE, a one-frame flash would be as fast as you can get (1/60 of a second).
 

Nckcard

macrumors regular
Original poster
Jul 11, 2008
100
0
i doubt you can do it in iMovie.

with video, you're limited to standard framerates... for things shown on typical broadcast TV, that is 30fps. 720p is 60fps which is the highest rate for any broadcast standard. So if you make a 720p comp in AE, a one-frame flash would be as fast as you can get (1/60 of a second).

But couldn't you time stretch it from there to 1% of 1/60th of a frame?
 

bigbossbmb

macrumors 68000
Jul 1, 2004
1,759
0
Pasadena/Hollywood
you can, but you're output will still be 60fps. ultimately the still will still be there for 1/60 and all the time-stretch would do is probably make it more faint.
 

Nckcard

macrumors regular
Original poster
Jul 11, 2008
100
0
you can, but you're output will still be 60fps. ultimately the still will still be there for 1/60 and all the time-stretch would do is probably make it more faint.

Well is there any way you know of in any kind of program you can think of that I can do this in? I really need to get it done, please help in any way you can.
 

Pikemann Urge

macrumors 6502
Jan 3, 2007
276
0
melbourne.au
Here's what I think you might do. Get yourself a strobe device. I think they are the same thing as flashguns but they have variable timing etc. Channel that through a slide projector and, boom, problem possibly solved. Of course I don't know how many ms the flash bursts are but it's possible that the machine's specification list will tell you.

Sorry I couldn't be of more help.
 

Nckcard

macrumors regular
Original poster
Jul 11, 2008
100
0
Here's what I think you might do. Get yourself a strobe device. I think they are the same thing as flashguns but they have variable timing etc. Channel that through a slide projector and, boom, problem possibly solved. Of course I don't know how many ms the flash bursts are but it's possible that the machine's specification list will tell you.

Sorry I couldn't be of more help.

Are there any other options? i need to have these 40ms frames hidden in a video.
 

Pikemann Urge

macrumors 6502
Jan 3, 2007
276
0
melbourne.au
Hang on a minute here. What's 1 ms? Is it 0.001 sec? What's 40 ms? That's 0.040 sec, right? If that is correct, here are some interesting figures:

25fps: 1/25 = 0.040 sec

29.97fps: 1/29.97 = 0.333 sec

50i: 1/50 = 0.020 sec

59.94i: 1/59.94 = 0.016 sec

So it seems that one PAL frame or two PAL fields are what you want. (?!?!)

EDIT: If I am right you could do this in iMovie.
 

Nckcard

macrumors regular
Original poster
Jul 11, 2008
100
0
Hang on a minute here. What's 1 ms? Is it 0.001 sec? What's 40 ms? That's 0.040 sec, right? If that is correct, here are some interesting figures:

25fps: 1/25 = 0.040 sec

29.97fps: 1/29.97 = 0.333 sec

50i: 1/50 = 0.020 sec

59.94i: 1/59.94 = 0.016 sec

So it seems that one PAL frame or two PAL fields are what you want. (?!?!)

EDIT: If I am right you could do this in iMovie.

Ok, that sounds right. How would i do that in iMovie..?
 

Pikemann Urge

macrumors 6502
Jan 3, 2007
276
0
melbourne.au
Right, here's what you do. Get the clip you want to edit. Make sure it's 25fps ('cos 40 ms is what you want, obviously). Split the clip where you want to insert the single frame. Take the end of the first half or the beginning of the second half of the original clip and remove one frame. Insert a still photo (make sure it's the same dimensions or at least the same aspect ratio).

Drag that photo into the timeline (make sure you select clip view, not time view). Right click on that photo, select Show Info..., then change duration to 0:00:01.

I hope you can follow that.
 

arjen92

macrumors 65816
Sep 9, 2008
1,066
0
Below sea level
Just that you know: 0a:0b:0c:0d
for the letters you can fill in numbers like: 1:15:30:12

the a stand for hours, the b for minutes, the c for seconds and the d for frames, so the d is not for milliseconds or whatever but frames, so it depents on the format you use what d will be.

in the example it's 1 hour 15 minutes 30 seconds and 12 frames (which is almost halve of a second)
 
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