How to get better results with ImageMagick and convert

How to get better results with ImageMagick and convert

In last two days I’m trying to find best way to convert PDF files to good quality JPEG files. Of course size does matter, not only in case of women breasts.

When I was trying to convert files directly from PDF to JPEG results was pretty scary:

convert myfile.pdf[1] dc.jpg

number 1 in brackets means only one(second) page to process.
As I result I get file with pretty huge size: 496.8K
but… if we do this in two steps:

convert myfile.pdf[1] dc.png
convert -filter Gaussian -quality 85 dc.png dc.jpg

file is much smaller 170.3K
somebody could point me that I can do this in one line… but unfortunately it’s not giving same results.