i-link

Hi guys,

I use a sony HDR-FX1000 and i have a macbook pro, which i use final cut pro with. Just wandering, do i need an i-link cable to maximise the quality of the hd footage, or will a fire wire be fine?

Also, what is the main differenece between progressive and interlaced footage?

Thanks very much

"iLink" is just Sony's trade name for a four-pin Firewire connection. For a while, back in the day, Apple defended the "Firewire" trademark, so Sony decided to come up with their own name. These days the "Firewire" name and logo are free for anybody to use without a license, so the whole thing seems kinda silly in retrospect.

They also call the 6-pin FireWire and the 4-pin to 6-pin "i-Link" as found on some of the SONY professional Decks like the J30 Digibeta.

I am not aware of any Sony kit that uses FireWire 800 connectors but obviously you can connect "i-Link" to it with no issues as long as you have the correct leads.



For instant answers to more than one hundred common FCP questions, check out the LAFCPUG FAQ Wiki here : [www.lafcpug.org]

"Also, what is the main differenece between progressive and interlaced footage?"

The main difference is the way how pictures are built on your screen.

Progressive, like your computer display, starts to be drawned like a printed document from top to bottom. The way that your sheet of paper cames out of the printer.

Interlaced, like your TV display, prints the same picture twice. It slips the same picture in two by drawing the first upper lines and then the Lower lines, on SD, DV does the inverse.
PAl Systems have 625 lines so a frame is first built with 312.5 lines from left to right, then the next 312.5 are built to finalize the picture .

With the printer example you have to print twice on the same sheet for your final picture.

This question is answered on the FCP Manual.

Rui Barros
Editor Colorist Trainer
Lisbon, Portugal
RTP Post-Production
Apple Certified Trainer FCP 7
Apple Certified Pro FCP 7

Well ? kinda. Not really. It's not related to how the image is drawn on the screen; it's related to how the image was recorded by the camera. The format people call "30p" is exactly the same as normal NTSC 60i in every respect except how the shutter on the camera was operated.

"Well ? kinda. Not really."


Read the FCP manual or TDFB

Rui Barros
Editor Colorist Trainer
Lisbon, Portugal
RTP Post-Production
Apple Certified Trainer FCP 7
Apple Certified Pro FCP 7

Right, and I'm saying that both of those references are misleading oversimplifications. The way you summed it up ? and I say this with all due respect and deference ? was particularly misleading, because interlaced footage has no frames at all. A "frame" of interlaced material can be created from any pair of fields, which becomes a serious issue when you're dealing with different digital video systems that have different assumptions about field dominance.

If you want to put it really, really simply, say this: Progressive footage is any footage where all scan lines are recorded each time the shutter opens, and interlaced footage is any footage where half the scan lines are recorded each time the shutter opens.

Dear Jeff,

I'm very sorry for my poor english and thank you very much for your good explanation.

"interlaced footage has no frames at all."
So what does it means 25 or 29.97fps?

Rui Barros
Editor Colorist Trainer
Lisbon, Portugal
RTP Post-Production
Apple Certified Trainer FCP 7
Apple Certified Pro FCP 7

It means the camera shutter was opening once every 25th or 29.97th of a second. When you shoot interlaced, at (say) a 50 Hz clock rate, the shutter opens once every 50th of a second and the camera records one field. If you shoot one of the NTSC or PAL "progressive" formats, the shutter will open once per 29.97th or 25th of a second and record both fields.

I put "progressive" in quotes because those formats are still played back interlaced on your television. So they're recorded progressive, and played back interlaced.

In other words, when people say "25 frames per second" or "29.97 frames per second," they're simplifying. There's really no such format that is both recorded and played back at either 25 or 29.97 frames per second. Both PAL and NTSC "progressive" formats are played back as either 50i or 60i.

This confuses a lot of people when they go out and shoot "25p" or "30p" and notice that the motion seems really stuttery on their televisions or broadcast monitors. That's why I'm making a big deal about it here. Because understanding how these formats work is key to understanding why they work.