I think that's called blooming. No I haven't encountered it, but I'm not exposing for greater than 4-seconds on the slice and most of the time between 3 and 3½ seconds. Usually my problem is that I have to increase the exposure time because some smaller features either don't render or are warped. The light blue NYC Canstock boxcar above is an example. The X58 stand-alone underframe detail was either flimsy or didn't render at 3½ seconds. At 4 seconds, it rendered perfectly and the larger relief was not adversely affected by the extra ½ second exposure rate.