Two steps…

isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size'

You get this output…

Logical block size is: 2048
Volume size is: 1620057

Using this information, we insert the numbers into the dd command..

dd if=/dev/cdrom of=/home/user/iso_files/test.iso bs=2048 count=1620057

And that’s it. Happiness!