My bad, I used the wrong term. I meant focus at thr first place. By hard time I meant that the construction of the 4mm is so small that I'm not really able to see anything through it. I have attached an image on the reply where dave replied. Please let me know if you can see it. What I really meant to say is that my 4mm lens has been really not helpful. It's only the 20mm for the moon and not the planets since I can't really see much through it. With the 4mm, maybe it's the construction of the lens that's making it hard for me to see anything through it. I adjust the focus with the knob but it doesn't really help. I would really like to know what should be my next step in seeing planets. That will be really appreciated