AF100 Recording in 30i instead of 60i

[Dillon Exner]

I was not able to get the upgrade to record in 60p, so I can only set my framerate as high as 60i. However, when I imported my footage, I noticed it was in 30i.



I went into Quicktime, and the metadata says it's 59.94i, but its info says it's 29.97i.



(these ARE the same clip; naming convention starts at 1, the other starts at 0)

This is particularly weird, because I don't even have the option to record at 30i (initially, I thought I had it on the wrong setting).

 

[David Jimerson]

That's because your software is using the archaic and confusing OLD term, "30i" -- a term which should be stricken from memory.

"30i" and "60i" are the same thing. "60i" is the superior, more-accurate term.

What's the WORST is when software uses BOTH terms.

 

[Barry_Green]

David is correct. Well, if we want to be extremely picky, we should be calling it 59.94i, but the term in general use is "60i".

There are some who insist on calling it "30i", but all the camcorder manufacturers have standardized on calling it "60i" or "59.94i".

In the world of NTSC-territory interlaced video, there are not two separate things (60i and 30i). There is only one standard, which is 59.94 interlaced fields per second. When someone calls it "30i", they're taking the notion of two fields and combining them together into a "frame", but it's not changing what the underlying video is - 59.94 half-frames (aka "fields"), one displaying the odd lines on the screen, the next displaying the even lines. So whether they call it "30i" or "60i" or "29.97i" or "59.94i", it's all referencing the exact same thing.

 

[Dillon Exner]

David is correct. Well, if we want to be extremely picky, we should be calling it 59.94i, but the term in general use is "60i".

There are some who insist on calling it "30i", but all the camcorder manufacturers have standardized on calling it "60i" or "59.94i".

In the world of NTSC-territory interlaced video, there are not two separate things (60i and 30i). There is only one standard, which is 59.94 interlaced fields per second. When someone calls it "30i", they're taking the notion of two fields and combining them together into a "frame", but it's not changing what the underlying video is - 59.94 half-frames (aka "fields"), one displaying the odd lines on the screen, the next displaying the even lines. So whether they call it "30i" or "60i" or "29.97i" or "59.94i", it's all referencing the exact same thing.

And that's where the confusion had come in. I had been taught that the number when referring to interlaced video referred to the number of frames, rather than the number of fields (in other words I learned 30i has 60 fields, 24i has 48 fields, etc.).

By the way, I have since switched my camera to 30p and kept it that way.

 

[groveChuck]

While you can't "record" (as in with sound), you can overcrank in 60p for slo mo (edited in a 24p timeline). Don't know if this helps...

As for 30p, most avoid it as it's less film-like motion (if that's the look you're going for) than 24p. I might suggest (should you be curious), a comparison test between 24p and 30p, of both subject motion and camera motion (not panning aggressively, of course) and see what you think?
If you're shooting something like sports, 30p might be slightly better, but that could be tested, too.

Also- there's no 24i, just 24p. And 30p, 60p, etc., p denoting progressive, which is each frame being a discrete frame unto itself, not a combination of 2 fields scanning every other line like Barry said, which would be interlaced... But think of it as 24p, 30p, 60p and 60i. HTH...

 

[Rainer]

So, to summarize, not incorrect, just imprecise. 60i fields = 30i frames. And of course camera manufacturers prefer just to say 60i. Which you gonna buy if you got no idea? 30i or 60i?