I have a Dell P1130 which has a dot pitch of 0.24mm and can display a maximum resolution of 2048x1536.

Now, what I want to know is which resolution can my monitor display without losing any detail in the resolution?

1280x1024? 1600x1200?

Thanks.

It depends on the source and what looks good - just set it to what looks good to you.

It depends on the particular display and how well the beam setup is. There is no universal answer. You should run a bunch of patterns and see. It also of course depends on the refresh rate as well.