The same picture but with a +2 stop burn to the area around the tunnel entrance through a hole in a piece of card kept moving. Has had a dodge in the lower 1/3 of the picture as well.
It's hard to tell how much is camera shake and how much is lack of depth of field. The lens was set to infinity and wide open. The floor is wet which is also making it less distinct with reflections.
Yes, I like your idea. The burning in I have done here has brought some detail from outside the tunnel -this is unwelcome as it spoils the romance of where the tunnel is going! If I follow your suggestion I would need to mask off the tunnel entrance with a piece of cardboard on the paper and then use the same burning technique as I did to make this print (a hole in a piece of card held in the light path).
I may be able to revisit with a tripod in the next few weeks and I will stop the lens down for better DoF. I took more photos of a similar nature later on in the visit. Still no tripod but less rushed -I was worried that other people were coming into the tunnel behind me.