Thanks all for good informative comments and advices.
I have taken a few photos yesterday with new 'holes' of varying sizes of 0.4, 0.5 and 0.6 or there about.
To me they all produced same blurry un-interested images.
Maybe I am expecting too much from the pinhole.
Maybe I need shorter focal length to accentuate distorsions and/or vignettes to make the images interesting.
I had a good fun building it so don't mind going back to my working shed.
Any good or interesting focal lengths for 4x5?