High school graduation: 24p or 30p HDV?

[Stan Harkleroad]

Just curious about some opinions. I'm filming high school commencement ceremony tomorrow night with 2 HV40's. I'm torn between 24p and 30p. It will be a relatively low motion event with no fast pans or unexpected movement. I will also be taking a Power Point slide show that is being shown and making it part of the finished video by outputting the individual slides and using them in Vegas.

So I can't decide which to use. What would you guys do?

[Garrett Low]

I usually shoot events like that in 24p. A lot of times the light levels get a little low and being able to shoot at 1/48th as apposed to 1/60th is a great help. Just have to keep those pans slow and smooth.

-Garrett

[Steve Struthers]

If you're going to post the resulting video to the web, 30p would work well. If your proposed method of distribution doesn't matter, 24p would work well too, but it's not the very best choice of you change your mind and distribute it to the web.

If you're going to hand out DVDs of the event, 60i would work best, although you'll give up a more film-like look to your video, if that's one of your aims.

[Garrett Low]

Originally Posted by Steve Struthers

If you're going to post the resulting video to the web, 30p would work well. If your proposed method of distribution doesn't matter, 24p would work well too, but it's not the very best choice of you change your mind and distribute it to the web.

If you're going to hand out DVDs of the event, 60i would work best, although you'll give up a more film-like look to your video, if that's one of your aims.

I'd actually argue that 24p is better for web distribution. Save on bandwidth. In actuality, if you shoot 30p you can easily create DVD's. The 30p files will easily be converted to 60i and you won't get those wonderful interlace jaggies or loose resolution. Going from 60i to 30p doesn't give you that.

The only reason I capture anything in 60i anymore is because my old HV20 doesn't have 30p. But then I take the HDMI out into my nanoFlash and record progressive for total overkill. ;-)

Garrett

[Stan Harkleroad]

Eventual distribution will be DVD and web. We sell copies to parents on DVD and I'll also put some clips on our site for self-promotion.

Like I said, it will be a low motion, very predictable event where I won't need to pan fast.

My only concern is that both cameras will also be hooked to a projection system that will shown live. I'm thinking maybe 30p would be better for that reason?

[Garrett Low]

It really depends on the projector but definitely go with a progressive format. Interlaced looks horrible when projected on a big screen from my experience. If it is a typical computer projector it also won't make much of a difference. It really comes down to your taste for the look except as mentioned earlier that 24p allows you to shoot a little slower shutter speed. At least that's what I've experienced. Others may have different takes and experiences.

-Garrett

[Jon Fairhurst]

24p tends to have a dream feel. 30p tends to have a reality feel. What feel do you want to present?

If shooting a linear, end to end video with standard colors on a HDV camera, I might go for 30p. You're likely to have oversharpening, blown out highs and other clues that this is video, rather than film. Might as well embrace the 30p reality video look.

On the other hand, if you will cut and edit the film creatively, use interesting colors, control the lighting, show some clips at slow speed, etc, then produce in 24p. With that style, you can shoot some stuff at 30p and slow it down to 24p for a dreamy feel.

Technically, neither is wrong. It really depends on the style that you want to deliver.

[Taky Cheung]

I would like to add... 60i gives the home video-ish feel and 24p is more film look. Thus 30p would be a great choice. It's not easy to shoot 24p that you need to plan ahead. Fast panning will look stuttering in 24p. If you are going to do slow mo, 24p would not be a good choice too.

When it comes to bandwidth, 24p and 30p consumes the same bandwidth as data rate is calculated as kilobits per second but not frames per second. Some would argue 24p gives better result as there're more bandwidth allocated in each frame, but from my experience, there isn't much difference.

I think the best way for you to go with is to shoot some sample run, edit and export to see which frame rates give you the result you like. =)

[Stan Harkleroad]

I don't need any slow motion clips. The fastest thing at the whole event is a student walking from one side of the stage to the other to receive their diploma and exit the stage. I've shot the same event for a few years with Panasonic SD cams and I have Canons now. Luckily it's an event I know well and either way I go it will work well. I just didn't know if one frame rate would have an advantage over the other in this particular situation.

I think I'll stick with 30p to have a nice middle ground. This is a really important event and they've been pleased with what I've done in the past in SD. I should also add that I'll be taking a lot of SD footage that the school will give me and putting it on the same disc. I usually do this by using DVD Lab Pro and using multiple VTS and the commencement goes on one VTS with the rest on another. In years past I'd film in wide screen and the footage they give me is in full screen so I'd have to use that method to get it on a single disc, which is their request BTW. This year I'll have to fit down-rezed HD wide screen and SD full screen so this method will come in even handier.

[Garrett Low]

Originally Posted by Taky Cheung

When it comes to bandwidth, 24p and 30p consumes the same bandwidth as data rate is calculated as kilobits per second but not frames per second. Some would argue 24p gives better result as there're more bandwidth allocated in each frame, but from my experience, there isn't much difference.

You are correct Taky, I should have elaborated and said that 24p allows you to lower the bitrate without degradation to the picture thereby lowering the bandwidth required. There seems to be a threshold minimum bitrate which material start to fall appart. As long as you are above that threshold the difference between 24p and 30p is not noticeable. I've just had instances where 24p streams better at lower bitrates.

But I agree that it is more about the look you want.

-Garrett

[Taky Cheung]

Thanks Garett... I also heard of another saying, that 30p is actually more effective in codec usage in online streaming. It was because all modern codec makes use of inter-frame compression. The more the number of frame in a second, the less difference between frames, thus more bandwidth is allocated for the "difference".

I'm not a codec expert... so I can't comment how accurate it is. As long as it looks good on Vimeo, I'm happy =)

[Garrett Low]

I've also heard that too. Funny thing, when I create the mpg file for DVD using variable bitrate and multi-pass the 24p came out with a smaller file than the 30p. Max, min and average setting were the same. I'm not sure if that was because I started with 30p material and was just experimenting or what.

-Garrett

[Buba Kastorski]

Originally Posted by Stan Harkleroad

Eventual distribution will be DVD and web.

if you're not transferring it to film - 30p

[Jon Fairhurst]

Early on, I did an original video website where we published at 15 fps for dialog-based stuff and 30p for action stuff - especially when there were gun flashes. At 15 fps, we would have a 50% chance of hitting or missing each flash.15 fps for low motion stuff definitely saved bits and it still looked good.

[Stan Harkleroad]

I ended up going with 30p HDV. I could have gotten away with 24p but I played it safe since this is an important project.

I switched between 24 and 30 while the live feed was going and didn't notice a difference as far as brightness.