Jorma is spot on.
HIGH Bitrate creates LARGE File size
For the same duration, MPEG2 size is dependent on BITRATE (BR). The larger the BR the larger the final render.
Visually noisy video requires high bitrate. So, fireworks, smoke particles, that you want to see nicely, needs high bitrate. Noisy video due to badly lit footage that is then boosted creates unnecessary noisy footage, this needs to be smoothed. I use NEAT Video to smooth “noise”.
Stop using delivery formats, WMV or MP4, to then re-render. Stop.
This is what I do:
1] Render Project to MXF, say the SONY one and use a BITRATE that you can balance between SIZE and QUALITY. It is very straightforward.
2] Use that for rendering to MPEG2.
That is what I do. As to then creating the 150 minute DVD here is the suggestion from Mark’s BitRate calculator:

3] Use BitRate Viewer to analyze just where I have Peaks of BitRate and I can then make further adjustments.
The bottom line for you and others are that you are delving into a procedure that has had many many user perplexed – myself included.
So, to recap:
A] For the same duration, HIGHER Bitrates create LARGER files.
B] Treat your project analytically until you get that balance between QUALITY and BITRATE you will then get a file size that will fit onto a 4.7gb.
Ahem: The dirty lil secret – DVD encoding is a process that forces us to use a technology that is in itself restricted to the means of delivery (a 4.7gb platter). I’ve just purchased an iPad Air 2 with 132gb of memory. Why do I need to restrict myself to 4.7gb just to produce a DVD? Yes I will still produce DVDs. I do this for my client who wants me to do it, although that DVD is ignored as his Presenter will ONLY use my MP4 or WMV output for the Presentation. Why? ‘cos her laptop doesn’t HAVE a ?”%^” DVD player – douh……
Have fun with experimenting in getting the balance right.
* Grazie
Video Content Creator and Potter
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