Premiere pro - Speeding footage = "lag"

[FlaFla]

Hi,
I've tried various time to speed up my footage (4k) in premiere pro (120%).
When I render the footage, I see that it's laggy.
Is it to due to highj shutter speed / fps issue or something else ?

Can I arrange this in post prod ?

Thank you

 

[blacksheep]

I am guessing the reason nobody has responded to you yet is we can't figure out what this lag you mention is. Can you post a video example? Also what do you mean by lag?

 

[Qoncussion]

Are you sure it's not your computer hardware? Have you tried it on a more powerful computer?

 

[4wd]

As soon a you start making adjustments the RAM Preview hast to do a great deal of work to let you see the result a live preview.
Changing speed is especially demanding. You can change the preview to half quarter or lower resolution which will help somewhat.
Other changes can be put on an adjustment layer which can be toggled on/off so that you can still play through to check for goofy mistakes.
The result after export rendering won't be affected by any lagging in preview but the time take will increase proportionately.

If timings need to be exact with the speeded up footage you could render that section in advance and re-import.

 

[Kilrah]

Probably too much processing for your computer to handle real time, jsut do a render (press enter, or sequence->Render all or jsut the selection depending on your choice). Wait until it's done and it'll play smoothly.

Note that speed adjustments other than multiples of 2 will casue either some sort of stuttering or blur in any case. There are 3 different modes for processing speed adjustments, you can try them all to see what looks best.

 

[FlaFla]

Hi,
Thanks guys for the answers.
Yes, the problem is also when the video is rendered totally.
I think that kilrah pointed the problem. Lagging wasn't the good term, it's more a shuttering effect .

So basically I could speed up the footage dans 120% and check the 3 différents form of rendering?

Thanks all for the help (and yes, computer is getting older, at least in 4k it is working hard!)

 

[jotka]

Hi,
Lagging wasn't the good term, it's more a shuttering effect .

I have the same issue basically. I fly slow and steady, to have a nice, cinematic movements, but then sometimes i would like to speed things up in the post processing.

Have you managed to deal with it in Premiere?

best
Jarek

 

[gnirtS]

Impossible to help without seeing footage and the settings used.

It its a render issue then use a proxy or pre-render clips to edit.

If its an output issue what do you mean by lag? If you're changing speeds you might get dropped or duplicate frames, the output format might be too much for the computer to display and so on.