I recently found out that color negatives can be cross processed in B&W chemistry, so I thought I'd give it a shot and used a 1:50 dilution as well as a 1:25 one with a 10 and 5 minute processing bath. The 1:50 10 minutes one came out somewhat OK, but with an extremely low contrast, as well as the film came out red instead of purple/blue like I'm used to with Ilford Delta and Kodak T-Max films, I was able to make some kind of a print, but grey and with an extremely low contrast, I used a 24 shot Kodak Gold 400 film so I tried processing it like T-Max 400. The second one, a 1:25 mix with 50 seconds was a slide film: Fuji Sensia 400, this one was even more of a failure since it came out almost completely black with a barely visible image, same problem with the printing, only slightly worse, only able to make prints of extremely low contrast. Is there any list or instructions on how to get a more decent image from cross processing negative or slide film with rodinal? I've seen a few examples out there where people get a rather strong contrast using color films for B&W purposes, so there's got to be a way. I'm slightly new to analog, so I'd like to know a bit on how to achieve a good deal of contrast through both processing and printing even while using normal B&W film - I noticed that using a higher concentrate with a shorter processing time seemed like one way to achieve this, is this correct?