With all due respect, this should not have to be addressed with a "workaround" ... it defeats the whole purpose of using Lightroom as the centerpeice for a RAW image workflow, if one must export or create additional copies of images in order to maintain sharpness for the creation of a slideshow ... For myself, this could add up to many thousands of images per year that must be generated to perform such a trivial task that should have been addressed long ago ... Adobe should have paid more attention to this module over the past several iterations and improved it to the point where the user could apply sharpening to the images as a part of the process of creating a slideshow. Otherwise, how is Lightroom to be considered a workflow solution ... when all it does is create more work for the user to accomplish their tasks? Unfortunately the Slideshow module has lingered in obsurity since v1 with hardly any consideration by the development team whatsoever.

Do realize that burning to a DVD you get very low resolution images as DVDs are only 480p so your DVD burning software has to scale the exported video down by a very large amount. If the scaler in the DVD burning software you use is not very good, you'll get very soft results. Let alone that the pixels in a standard video DVD are not even square! Even if the scaler is very good you'll never get very good results as 480p is just not very low resolution for still images and you'll always see pixellation or very soft images. Ian's response up there is very good advice and probably gets you fairly good quality when burning DVDs from the final files. That said, my experience is that you're often best of just burning the 1080p files to a data DVD with the files and hoping that your client has a BluRay player that can play these files (very hit and miss unfortunately). So don't let it get touched by and video DVD authoring software. You can also dump it on a USB stick. Many TVs and BluRay players nowadays have USB slots from which they will play the H264 encoded files Lightroom generates.

The reason is that your eye is much less discerning for moving images. You are much more likely to see limited resolution issues on still images. Movies are much less critical and many people do not notice the difference between a DVD (maximally 480p) and a 1080p BluRay except in still images even though the BluRay disc has 6 times the number of pixels.

>Isn't burning to a DVD/data DVD exactly the same? I am confused by what you mean to try here?

Video DVD is a different thing from a dataDVD. To be able to play on a standard settop box DVD player, the video has to be transcoded to standard definition mpeg2. The maximal resolution for standard video DVDs is a pityfull 720x480 pixels (for the Northern American NTSC standard). It is slightly higher in Europe (but not much). Burning a data DVD (or CD) is just what the name implies, it creates an exact copy of the H264 mpeg4 high def file that Lightroom outputs. The problem is that not many players play such files or can read data DVDs/CDs and you basically need a good BluRay player to play these. But if they do, you'll get full 1080p quality and in general you will not be able to see any softness except on absolutely gigantic TV screens.