Pam-Richards

Hello all When I was trialling VideoPad I would export my videos into MP4 & they would be as I recorded them quality wise. Since buying it, when I export to MP4 they are grainy after & definitely not what I expected. The only difference is that it's now paid for, which surely cannot be the issue?. Any ideas as to what is going wrong? as I am left having to use my old editor as before, so, so far money wasted. Pam