What type of roller for this?

[DKAudio]

My first mudding and taping job was doing my downstairs living room ceiling with 5/8" drywall. Many of the joints were butt and not beveled. I did this job around 2 years ago and am actually pretty pleased for it being my first job. I finished the ceiling by spraying it with popcorn. I don't like the popcorn look so I just recently scrapped it all off and am going to do a smooth ceiling. A new layer of mud was put on to try and make my novice job a little better. There are a few spots where it was sanded too low and tape sticks out. I fixed almost everything and it is looking great now. However, it is not perfect, the imperfections are very small though. What type of roller (nap) can I use for the primer to try and hide some of these imperfections?

Thanks

[pushkins]

1/2" with a high hide primer.
After you let the primer dry, come back and apply another layer of mud on the low spots. They are much easier to see with a primer on.
Hint: use a 12" wide taping trowel.