I'm considering buying the outer bay extension tube for my 600 f/4 and was wondering if anyone knows the close focus distance using these two? Also, I've noticed that in Pentax's new manual for its lenses, they show the 600mm having seven elements. Anyone know of a design change with this lens? Mine has six elements. Thanks, Steve

-- Steve Rasmussen (srasmuss@flash.net), December 14, 1998

Answers

Thanks Jim: Your info makes it easier for me to make my decision about the outer bay tubes. Concerning your interest in the 165mm for macro work; I have used the 105mm and helicoid ext tube for years with excellent results with no flash. Maximum mag is .63x. The inner bay tube set provides more mag than the helicoid though. The helicoid does not maintain automatic metering ability, which I discovered the hard way. Have used the 200mm new version(same design type as 165LS) with the helicoid with good results. This is not quite as sharp as the 105 though. Steve

-- Steve Rasmussen (srasmuss@flash.net), January 04, 1999.

Steve,

I dont know if you found your answers yet, but the brochure I have indicates the close fucus distance with the outer tubes is 9 feet. I assume this is with both tubes. Since I do not have any of this equipment, I cannot verify first hand. Hope this helps.

-- Jim Korczak (korczaks@ptdprolog.net), January 01, 1999.