So I am trying to really smooth out this clip that I decreased the speed to 50%. But man, I get this annoying jittery outcome. The footage I am using is 1920x1080p at 24fps. I have already looked online on other sites. The recommendations I get are to select the 'Frame Blend", but does not seem to work at all. Anyone have any other recommendations? Thank you so much.

Unfortunately, 24fps if the worst possible frame rate if you want to do slow mo. Frame blend is the best you can do with Premiere without going to outside third party add-ins, and even those may not give you what you want. There just aren't enough pictures per second to give you nice smooth slomo if you shoot 24p.

All that being said, you may have better luck in AE rather than Premiere.

That's really a challenge.
At 50% slo mo, you have only 12 fps of real data to work with. That is going to be jittery.
At that frame rate, the various blending options will probably soften the image more than smooth it out.
You may have to compromise to 75%, etc. to get an acceptable look.

If you have access to After Effects and the clip you want to make slo-mo isn't too long, there is a way to do it in AE and make it look smooth. Can't recall the name exactly but it was something like "Time Remapping". There are two ways to do it. The cheap and cheerful way is via frame blending, which seems very much identical to how Premier does it. The other one, which I think is called interpolation where it basically makes "tween" frames by computing the different existing frames. It is amazingly slow and cpu intensive. It can work well, but sometimes it looses the recipe and you end up with weird artifacts. You can tune the parameters a bit, which can help some but to get it all right you REALLY have to want to commit the time to make it work right.

I've used it on a couple of 10-15 second clips and did get it to look good.

It's an option.

24p ain't that much worse than 25p that I regulary work with.

Premiere's own slowmotion isn't very good with progressive footage even with frame blending (it's ok when using 50/60i material).

If you have AE you could send the clip there via dynamic link and use timewarp plugin.

Or you could do what I did, just buy the premiere plugin called Twixtor. It has the most painless workflow and yields a great result.

CS5 has frame blending turned off by default (finally). You can try switching it on (right click on the clip, select frame blending), and see if the effect is more satisfying. It probably won't, but you never know.

I've having the same problem with Premiere CS5 and 1080/50i footage.

Using 50% slowmo in CS3 was silky smooth, but I get a jittery effect in CS5 with the same footage. Checking the frame blend option seems to have no difference. Help!

You could also try shooting manually at a faster shutter speed if you intend to slo-mo it. Works much better in post.

I've had good luck with this method.

1. In the project window, select the clip you want to slow down.
2. Right click select modify.
3. Select interpret footage.
4. Select the option to assume framerate and choose 12fps to start.

12fps would be half the framerate of 24p, this equals a 50% slowdown.

Here's what I've got. Don't forget to check out the linked tutorials: Adobe After Effects CS5 * Time-stretching and time-remapping (http://help.adobe.com/en_US/aftereffects/cs/using/WS3878526689cb91655866c1103906c6dea-7d58a.html)