Is 60i really not 60fps?

Janson Williams · January 26th, 2009, 09:05 PM

haha, im confused... 1/120's or shorter refers to 1/120 - 1/150 and so on??

1/60 and longer refers to 1/60 - 1/30 - 1/15 and so on??

the longer b/c the longer time the shutter open and closes, causing a kindo ghost effect?

Curt Fargo · January 26th, 2009, 09:14 PM

Yes 1/150 is faster than 1/120, therefor open for a shorter period of time.

1/60 is slower is slower which means that it is open for a longer period of time.

If you are exposing the sensor to light for 1/120 of a second, doing it faster (1/150), exposes the sensor to light for a shorter period of time and doing so for 1/60 exposes the sensor to light for a longer period of time.

Petri Kaipiainen · January 28th, 2009, 01:56 AM

jumping in a bit late, but I still sense some unclear points here...

Shooting 60i and deinterlacing it does not produce exactly the same thing as shooting 30p. The reason is that the first and second fields are exposed 1/60:th of a second apart, but in 30p the whole frame is exposed at the same instant. For that reason 60i actually has twice as many pictures, even though they are only half resolution each. For that reason 60i is better for doing slow-mo as you actually have twice the frame rate to work with (but only half resolution). It would totally defeat the purpose to shoot 60i and deinterlace it and then do a slow-mo out of that. Why destroy the "double cranking" so desparatelly needed?

For the same reason 60i looks smoother than 30p. All tv broadcast systems use interlaced video (60i or 50i) and I fond no reason to use progressive for anything, as I do not do film transfers.

January 26th, 2009, 09:14 PM	#17
Curt Fargo Regular Crew Join Date: Jan 2009 Location: Vacaville, CA USA Posts: 83	Yes 1/150 is faster than 1/120, therefor open for a shorter period of time. 1/60 is slower is slower which means that it is open for a longer period of time. If you are exposing the sensor to light for 1/120 of a second, doing it faster (1/150), exposes the sensor to light for a shorter period of time and doing so for 1/60 exposes the sensor to light for a longer period of time. __________________ Curt Fargo Last edited by Curt Fargo; January 26th, 2009 at 09:17 PM. Reason: correction

January 26th, 2009, 09:05 PM	#16
Janson Williams Regular Crew Join Date: Jul 2008 Location: Pittsburgh, PA Posts: 101	haha, im confused... 1/120's or shorter refers to 1/120 - 1/150 and so on?? 1/60 and longer refers to 1/60 - 1/30 - 1/15 and so on?? the longer b/c the longer time the shutter open and closes, causing a kindo ghost effect?

January 28th, 2009, 01:56 AM	#18
Petri Kaipiainen Major Player Join Date: Apr 2007 Location: Espoo Finland Posts: 380	jumping in a bit late, but I still sense some unclear points here... Shooting 60i and deinterlacing it does not produce exactly the same thing as shooting 30p. The reason is that the first and second fields are exposed 1/60:th of a second apart, but in 30p the whole frame is exposed at the same instant. For that reason 60i actually has twice as many pictures, even though they are only half resolution each. For that reason 60i is better for doing slow-mo as you actually have twice the frame rate to work with (but only half resolution). It would totally defeat the purpose to shoot 60i and deinterlace it and then do a slow-mo out of that. Why destroy the "double cranking" so desparatelly needed? For the same reason 60i looks smoother than 30p. All tv broadcast systems use interlaced video (60i or 50i) and I fond no reason to use progressive for anything, as I do not do film transfers.