mixed frame rates on HDV tape...
 

hey everyone,

Okay, so I just started shooting with my HV30, I love it so far, but I had a quick question about mixing frame rates on HDV tape. I know it can be done, but is it reccomended? example: I shot some 60i footage of a birthday party over the weekend, now I'd like to shoot 24p and 30p footage to see how those look, can I record these frame rates on the same tape that I shot the 60i footage consecutively??

As far as capturing goes, I am using FCP 5...no open timeline, so I assume I need to set up seperate projects to capture the footage with different frame rates??
I'm new to HDV so any clarification would be appreciated, thanks in advance.

~brendan

Everything you record to tape is actually a 60i stream so you won't have any issue recording different frame rates.

You can film them all in the same tape, but you would need to know which one is which because they all are written down as 60i. Some people put two fingers in front of the lens at the beginning of each PF24 recording, one finger in front of the lens for 30p recording, and nothing for 60i. This way they can easily recognize them on post.

great suggestion Eugenia! and thanks for clarifying Wes.

Eugenia,

I still don't understand why it makes a difference? Just for capturing to computer? If so, why would the capture software care? Wouldn't it be able to tell? Do the clips need to be captured separately?

This may be slightly off topic, but as far as recording to tape goes, is it a bad idea to reuse the same HDV tape after capturing? Example, I fill up a tape with film footage and capture it. After, should I reuse the tape, or will it dull the quality?

Scott

>If so, why would the capture software care?

The "capture" software doesn't care, but the editor does.

>Wouldn't it be able to tell?

No, it wouldn't. Vegas for example can't tell the difference between PF24, 30p and 60i from the HV20/30 cameras. And other editors must be explicitly told that this or that clip is one format or the other in order to use their built-in support for e.g. pulldown removal (e.g. After Effects).

Since you're only recording 1s and 0s the quality won't change. What will change is susceptibility to dropouts, errors or transport malfunctions. Every pass of the tape over the heads wears some of the magnetic particles off and stresses the tape. Constant reuse will make the tape less reliable. You might be able to get away with 2-3 uses, but with tape as cheap as it is and the consequences of problems as large as they are, why risk it? Shoot it, capture it, store it. That's the best advice I can give you.

Cool, good to know. Thanks man,

Scott

When the data is coming off the camera....
60i
30p
24p ....They all look the same to the computer. They all look like 60i. Because HDV is really based around 60i.

In 60i you see a 30 frames per second. But each frame is made up from two interlaced fields. Each field comes from a different moment in time. If stuff is moving you see "mouse teeth"

In 30p you get exactly the same thing, but the two fields come from the same moment in time. No mouse teeth here.

With 24p - you have to run a reverse-telecine process to take the 60i container and extract those 24p frames.

You make it sound so easy!!

Scott