How did they fake the zooms in this music video?

[Ryan Elder]

I want to do fast zoom effects for a project, but do not have a constant aperture lens that can do that, but I wonder if I could fake it when I saw this video do a zoom but it doesn't look like they use an actual zoom lens. They do it at 0:48 into the video:

Britney Spears - ...Baby One More Time (Official Video) - YouTube

But I am wondering how that faked zoom was done. I tried going through it frame by frame but was not able to on youtube so far. Do they zoom in post? But if they did, that would cause resolution loss? But maybe resolution loss for an effect is okay and no one will notice, if that's what they did?

Thanks for any advice on this! I really appreciate it!

[Doug Jensen]

If you have a zoom lens where the maximum aperture is limited by the focal length, such as a lens that has f/4-f/5.6 printed on it, then set the aperture for the smaller of the two numbers and it will be able to keep that aperture constant throughout the zoom range. In this example, set the lens for f/5.6 and it will be f/5.6 no matter the focal length. Problem solved.

[Ryan Elder]

Oh okay thanks. But the amount of light coming in still changes though. I think it's because the light is coming in at a slower right if the lens is longer, even if the aperture is the same setting throughout. It doesn't matter if the setting is the same throughout, if light cannot travel through lens as fast if it's longer?


But another thing is, my lenses are also not parfocal, and goes out of focus during the fast zoom, so I would still need to find a way to fake the zoom other than using a zoom lens, if I do not have any parfocal lenses, wouldn't I?

[Doug Jensen]

You are either incorrect about the light changing as you zoom, or you have the world's worst lens. If the maximum possible aperture when the lens is zoomed in is X, then the lens must be able to hold that same aperture when zoomed out.

[Ryan Elder]

It seems to me that the exposure changes during the zoom if I am at the same aperture, but I can keep trying. However, I still have the non-parfocal issue where it goes out of focus during the zoom as well though. This is why I thought doing the zoom with other effects, other than the lens is better perhaps.

[Pete Cofrancesco]

Crash Zoom rears its ugly head. Good god man you've dwelling on this for as long as I can remember you posting here.

2019!
https://www.dvinfo.net/forum/open-dv...ml#post1948473

[Ryan Elder]

Oh yes, it's just now that I see this way of faking the zoom, I figure it's a game changer now that I was not aware of before.

[Ron Evans]

Today I would just shoot in higher resolution and do it in editing. If your output is 1920x1080 shoot UHD. That video was clearly shot with many takes. It is film style not continuous video shoot so likely a fixed lens shot and two takes.

I shoot UHD these days but edit 1920x1080. This effect would be easy.

[Doug Jensen]

If it was up to me, I'd use a real lens and do a real snap zoom. The depth of field change that occurs from the changing optics will add to the effect in a way that can't be duplicated just by zooming out from a 4K or even 8K image. It's not the same thing at all.

[Ron Evans]

It could still be faked in Resolve. However I do not think they used a zoom. I think it was multiple takes. Pure film style. Just synced just like the rest of the video.

[Doug Jensen]

Something could be done i post but it wouldn't look the same and it would take a ton more time and effort.

[Ron Evans]

The closeup of Britney would not be too difficult to mask with Magic mask in Resolve and just put a little blur on the outside.

[Ron Evans]

This is the approach. It is possible to be a lot more careful with the mask too.

How To Create Depth of Field Effects Using The Magic Mask - YouTube

[Paul R Johnson]

First thing is try your zoom - I'm amazed after all the grief in the past three years you have had with it you still keep trying to use it.

Try the crash zoom at the full range of apertures, and then zoom in in the editor and try the zoom out in that. Then try it in 4K and see if that works better than 1080. See which looks best. You are going to talk about this for months when you could spend an hour trying these things out, sort it and move on.

If you have tried the techniques for crash zooms and they don't work for you, then maybe you should just buy a second hand lens that stays in focus!

[Doug Jensen]

Originally Posted by Ron Evans

The closeup of Britney would not be too difficult to mask with Magic mask in Resolve and just put a little blur on the outside.

Seeing is believing, so please produce a demonstration shot of your own to show us how it would look. :-)
And while you're at it, please keep track of the time it takes.