How to create 300x300 thumbnail?

I must be missing something simple because this certainly used to be easy. So I’m trying to convert my code to use the new GetThumbnail. I used to just call GetThumbnail(300, 300) to create a 300x300 thumbnail image. Now GetThumbnail uses a scale factor. So I figured I could just call:

slide.GetThumbnail(300 / slide.Parent.SlideSize.Width, 300 / slide.Parent.SlideSize.Height)


But that returns a thumbnail significantly smaller than what I want. Suggestions?

GetThumbnail was changed in the last hot fixes so to make thumbnail image 300x300 you should write:

slide.GetThumbnail(
new Size(300, 300), // size of the thumbnail.
new System.Drawing.Rectangle(new Point(0, 0), pres.SlideSize), // part of the slide which should be rendered.
null) // collection with shapes which should be rendered. Null means draw all shapes.