How many fps are there in 50i? at DVinfo.net

Frank Feijen · June 4th, 2005, 02:26 PM

It may sound like a silly question, but i assumed that 50i meant 50 frames per second interlaced.
However, when i hookup my Sony Z1 to the PC and start capturing with CapDVHS, it tells me it's actually 25fps.
I'm a bit new to HDV, could someone shine some light?

Luis Caffesse · June 4th, 2005, 02:48 PM

Don't worry, it's not a silly question.
The "i" in 50i means it's an interlaced format.

It is referred to as 50i because there are 50 interlaced FIELDS per second.
2 interlaced fields make up 1 frame.

So 50i equals 25 frames per second, or fps.

These designations got popular to avoid confusion once progressive shooting became common. That way we don't confuse 25fps interlaced with 25fps progressive (50i vs. 25p).

Frank Feijen · June 4th, 2005, 02:57 PM

Thanks.

I gues it will take some time before standards become completely standardized, like Avid-editing systems who use 25i instead of 50i.

G's

Dylan Pank · June 6th, 2005, 05:48 AM

It's just the terminology that's confusing. 25i means exactly the same as 50i.

Lorinda Norton · June 6th, 2005, 11:34 AM

I've wondered about this! Thanks for the question and explanation, you guys.

(For Dylan: "You see, my mule don't like people laughing. He gets the crazy idea you're laughin' at him. Now if you apologize, like I know you're going to, I might convince him that you really didn't mean it.") :)

June 4th, 2005, 02:26 PM	#1
Frank Feijen Regular Crew Join Date: Jun 2005 Location: Brussels - Belgium Posts: 36	How many fps are there in 50i? It may sound like a silly question, but i assumed that 50i meant 50 frames per second interlaced. However, when i hookup my Sony Z1 to the PC and start capturing with CapDVHS, it tells me it's actually 25fps. I'm a bit new to HDV, could someone shine some light?

June 4th, 2005, 02:48 PM	#2
Luis Caffesse Major Player Join Date: Apr 2004 Location: Austin, Texas Posts: 704	Don't worry, it's not a silly question. The "i" in 50i means it's an interlaced format. It is referred to as 50i because there are 50 interlaced FIELDS per second. 2 interlaced fields make up 1 frame. So 50i equals 25 frames per second, or fps. These designations got popular to avoid confusion once progressive shooting became common. That way we don't confuse 25fps interlaced with 25fps progressive (50i vs. 25p). __________________ Luis Caffesse Pitch Productions Austin, Texas

June 6th, 2005, 11:34 AM	#5
Lorinda Norton Wrangler Join Date: Nov 2001 Location: Southwest Idaho, USA Posts: 3,066	I've wondered about this! Thanks for the question and explanation, you guys. (For Dylan: "You see, my mule don't like people laughing. He gets the crazy idea you're laughin' at him. Now if you apologize, like I know you're going to, I might convince him that you really didn't mean it.") :) __________________ Lorinda

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June 4th, 2005, 02:57 PM	#3
Frank Feijen Regular Crew Join Date: Jun 2005 Location: Brussels - Belgium Posts: 36	Thanks. I gues it will take some time before standards become completely standardized, like Avid-editing systems who use 25i instead of 50i. G's

June 6th, 2005, 05:48 AM	#4
Dylan Pank Major Player Join Date: Nov 2004 Location: Portsmouth, UK Posts: 611	It's just the terminology that's confusing. 25i means exactly the same as 50i.