Hi Vicki and welcome to the group.
You asked what lens to use! possibly the question is which camera should I use? I am not into ghost hunting however I would have thought seeing paranormal TV programs they seem to prefer video cameras with infrared lenses to "see " in the dark.
Now I don't know if your camera can be adapted to do infrared photography, if not maybe it would be worth investing in an adapted camera with this facility.
As a matter of fact where I live sightings by several people have seen the "image" of a cowled figure around the place. Not suprising as it used to be owned by the church under the Lichfield diocese. The previous owners daughter was heard talking to someone in the bathroom- my wife once raced out the back door thinking we had an intruder and nobody was there. That was ontop of varies claims she made of seeing an "image pass the windows.
Also my youngest son saw a young girl sitting on our now gone/replaced front gate, strangely enough this was exactly the same he saw as in an old photo when it used to be a farmhouse with people sitting outside. So the story goes a young girl got killed by accident in the milking parlour and the girl seen by my son was that girl.
Going way way back I did also have a really scary episode, I have to stop here for a moment to say after this incident it has left me with a very open mind about the paranormal, some may well scoff at the very thought which I can well understand, but for me it was real enough to remember it 50 years later as if it happened yesterday.
I was driving across the goss moors in the west country very late at night in my minivan, those days one didn't need a centre rear view mirror just wing mirrors. This particular stretch of road was a "roman road" about 7/10 miles dead straight. I saw in the wing mirrors headlights in the distance which rapidly came up behind me. They actually blinded me so I stopped got out of the van and there was absolutely nothing there. Make of it what you will, but for me it scared the pants off me which is why as I said I have a very open mind on the subject. Yes it may well have been tiredness and the brain playing tricks and I well understand that is what might be going through peoples minds, it has mine as well.
Yes I know many don't believe and I thought what a load of old rubbish as well, infact I thought also they had something loose up top, to be honest.
I have suprised many who don't believe by giving this example. You are driving down a road and approaching a bend, how often do you know there is a car comming the other way without seeing it so keep well over to the left. Is it premonition -experience or what, makes you stop and think doesn't it?
To end up saying I have never indulged in any form of paranoral investigation- joined any groups -or gone to a seance or taken drugs. I just don't believe in them and have absolutely no interest in the subject, (apart from watching TV programs) however when something actually happens it is very hard to try to get people to understand and unless something happens to them personally I can accept their disbelief.
Realspeed