I needed to convert some old cds to isos, this worked like a charm
$ isoinfo -d -i /dev/cdrom | grep -i -E 'block size|volume size'
Logical block size is: 2048
Volume size is: 1439856
Then take the blocksize and pass it to dd
$ dd if=/dev/cdrom of=~/ISOS/marvel_ultimate_alliance.iso bs=2048 count=1439856 status=progress
2943076352 bytes (2.9 GB, 2.7 GiB) copied, 224 s, 13.1 MB/s
1439856+0 records in
1439856+0 records out
2948825088 bytes (2.9 GB, 2.7 GiB) copied, 224.303 s, 13.1 MB/s