If the quality that you expect on your final product is not quite what you were expecting, this FAQ may help.
1.HD > SD:If the source video or images you are using are in HD format and you export to an SD format, you should not expect the same video quality on this final export. For example, if you import an AVCHD file and then export to DVD, the quality on the DVD will likely be lower than the AVCHD file.
2. Change the presetSome presets will create better quality files or discs than others. Try selecting a higher quality preset and then re-export the project. If you are creating a disc, try selecting the Fit to disc preset. This should create the best quality disc for your project and disc size.
3.Raise the bitrate: If you are using a Custom preset, try raising the bitrate (if applicable to your export format) and then re-export the project.
4. Always Re-encode:If you are exporting to a disc format try selecting Always re-encode entire movie. To do this, click the Advanced button in the Settings section of the Exporter. In the Advanced Settings check Always re-encode entire movie and click Apply.
5.Delete Render Files:Select Setup > Control Panel. Select the Storage Locations category. In this window click the Delete render file button. Click OK and then re-export your project.