I am changing the footage speed in Premiere Pro 1 to create a slowed down effect. The problem is, every time I render it, it looks jerky and is not smooth. I am using speed/duration and changing the speed percentage (which effects the duration too). The un-rendered footage plays back perfectly on the timeline, it's just the slowed down parts are jerky when rendered.

Some parts are speeded up to 115% but these are ok once rendered.

Can someone help me overcome this problem?

I'm assuming you do not have any plugins that effect the speed/duration altering part of Premiere. Some do.

As far as I can remember what comes into vanilla Premier Pro 1 is nto even a frame blend speed change. All it does is repeat frames as necessary to give the duration you ask for. There's no alternative tot he jerky motion you are seeing unless you get some sort of plugin.

It's ;less than usefull isn't it? Even the blend mode that I see from my Matrox card is really poor. It simply blend one frame into the other over the extra frames that get added. No good at all really for a decent slo-mo.

What you need is a good plugin. I understand Twixtor is a good one. Or, if you have it, you might get better results out of After Effects. You can ramp the speed changes in AE as far as I know.

__________________
I'm not young enough to know everything!