My lead photographer was working with me this weekend at a wedding. I was shooting TTL. He likes to go full manual and get the exposure with a meter for ambient light then set his flash one stop down from that reading for fill and shoot. He told me, "set your flash on f/8". I am looking at the flash unit and the book. I have 1/1 power, 1/2, 1/4, 1/8, 1/16, 1/32. I have no idea how to set it to a specific f/stop. The owner's manual only has a table of guide numbers for 100 and 400 speed film. I know that every other stop (i.e. 1600, 6400, etc.) doubles the guide number. Is there a chart or calculation whereby I can figure out the GN for any speed film. This is basically what I am trying accomplish with the guide number chart. Any help anyone can give would be very much appreciated. By the way, using the TTL with the new 645n produced some very pleasing images, but he is right, the background could have not been so dark.
Thanks, Glen (in Kansas City) - This message is from the Pentax-Discuss Mail List. To unsubscribe, go to http://www.pdml.net and follow the directions. Don't forget to visit the Pentax Users' Gallery at http://pug.komkon.org .
