When I started B&W photography in the 1970's and for many years thereafter I Have from time to time compared the effects of using either yellow, orange or red filters, generally the results of these comparisons were disappointing except that red filters always made the shadows very dark (shadows being blue). Recently I have been using folding cameras without filters of any kind and find that the sky does not just go white as the popular wisdom of the 1970's and earlier suggests, this is likly to be as a result of modern films having a more extended red sensitivity? I have even gone to the extent of trying my Canon lenses on FTb with a UV filter only with good results, good shadow detail and enough detail in the sky. I am not in a position at the moment to do much photography but this requires more trial to make any constructive opinion possible. I wonder I anyone else has tried B&W film without filters or with only a UV and their opinion of the result?