William wrote: Shooting in the morning sun the past two days revealed no difficulty focusing a f5.6 or f8 (with a Kenko 1.5X TC), and I do plan on getting the Pentax 1.4X-L TC for the superior compatability, but I wonder about a 2X TC, going to F11. Will I need a searchlight to focus in cloudy weather? Your experiences?
REPLY: My advice is to forget using a 2X converter with a 600mm lens. One thing is that no lens will give good result with a 2X converter (in spite of what some people claim, no good 2X converter has ever been made - you get visible image degradation with all 2X converter + lens combinations known to man), another issue is that a 1200mm lens is virtually impossible to support. In addition, you need to stop down at least two stops to get even half decent results from a 2X converter something that gives you a shooting aperture of F:22. You are going to be constantly plagued by vibration problems and can only shoot still life. The Pentax 2X-L converter doesn't really work with the 600/4 if you are even the slightest quality concious, at least you need two tripods, so I doubt it will work any better with the 600/5.6. The 1.4X-L converter should work great though. - 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 .
