I will try 400x when I come to shoot transparencies with that sort of light, as well as an extended wash time. The 500T from my research is more than adequate for my needs for halloween,continuous lighting set up while at a Halloween party would be impossible, at least andec can make a projection print for my needs. As for photos, mainly shoot B&W, this Halloween I am going to do a mixture. I prefer colour for motion pictures. I do shoot some slides now and then, 400X will be next on my list to try once I am settled.