I recently purchased a 600mm f4 and am crazy enough to be thinking about using a 2x teleconverter with it. (I have read about the advice of using two tripods with this monster even without the 2x.) My question is will the current model of the 2x Rear Converter accept both inner bayonet mount lenses like my 105mm and outer bayonet mount lenses like my 600mm? (Or is it like the extension tubes that come in either inner or outer bayonet mount versions?) Has anyone used a 2x with the 600mm f4? If so, how were the results? Thanks for any help you can give.

Ken Maher

-- Ken Maher (maherk@iquest.net), July 22, 1999

Answers

Ken: The old T6 2x would accommodate both inner and outer bay lenses. The problem with the 600mm and a coverter would be twofold; amplified shutter shake and color fringing. I would not use the lens at f/4, 5.6 or 8 with the converter in high contrast shots due to the fringing possibility. Your focal ratio would be reduced with the 2x also. So, with the combination of fringing stop down and converter caused focal ratio reduction, the lens would be much limited. A lot depends on what you are going to be using it for. SR

-- Steve Rasmussen (srasmuss@flash.net), July 23, 1999.

Ken: According to the B&H catelog, the 2x can be used on all lenses except the 75 shift and 500mm. In the past there was only the T6 2x and no 1.4x. The 1.4 is a fairly recent addition. I don't think it is called a T6. Animals can be shot with the 600 w/ no 2x hand held with 100-200 film without too much problem. I suggest trying a few shots at f/8 without the converter and you can judge for yourself if the color fringing is acceptable. I have done some Deer, Antelope, Wolves and Bighorn Sheep with this lens w/no converter handheld @ 1/250 with good results. Sometimes the out of focus areas will display fringing. Smaller subjects like Owls will require closer shooting, smaller f-stops for better DOF and a single tripod. If you use a single tripod try to use slow film and f/22-45. Long exposures do better when using a single tripod. If you are shooting at 1/4 to 1/125 sec, it is best to use two tripods. There is no problem with contrast with the 600mm. A 2x will really limit your hand held work with this lens. Try it on some wildlife without the 2x first before you decide. Using two tripods with this lens is very aggravating! I will be away from this forum for one week on a photo shoot(what else). SR

-- Steve Rasmussen (srasmuss@flash.net), July 23, 1999.

Steve: Thank you for your quick response. I am sorry, but I am still confused (a familiar condition for me.) Your reply tells me that the old T6 2X accomodated both inner and outer bay lenses, but I am not sure whether it is implied that the current model 2X rear converter will not, or will also, accomodate both? Since you only mentioned the old T6 2X, I am guessing that the current model will not accomodate the outer bay lenses. Did I guess right? (BTW, was there any such thing as a T6 1.4X?)

As for intended use, I am hoping to try to do something that few other photographers try to do (with good reason :-)) -- I would like to try to get some wildlife portraits on 6x7 chromes. For several years, I have photographed wildlife using 300mm f2.8 and 600mm f4 lenses in the 35mm format. I do not intend to change, but I had a chance to buy the 600mm for my Pentax 67 and recognize that it would provide about the same angle of view and subject magnification as the 300mm in 35mm format and, with a 2X, it would be like a (very tempermental) 600mm in 35mm format. My plan is to take it with me in the car when I am traveling in or to good wildlife locations and, after getting my 35mm shots, in situations in which the subject is relative immobile (certain grazing, feeding or nesting animals) and close to the car, getting the 67 and trying to capture it in the larger format, also.

I had kind of hoped that I could use the lens at f/8 with the 2x, making it an effective f/16 with the 2X. I was thinking of pushing 100 film to 200, adding to the contrast (which I think I read that this lens lacked a little) and allowing me to shoot at a 125th or 250th of a second in good sunlight. Lower light would require faster film (or longer exposures, which could be problematic for shutter shake or subject movement). Now, your response tells me that I should be stopping down to at least f/11. A little more limited, but there still might be some chances for wildlife portraits. A compromise would be a 1.4x, making it like about 420mm in 35mm format, but I do not know if the new 1.4X will accomodate this lens, or if there is an old one that will. Like I said in my original post, I am a little crazy. :-) But if this knowledge of my intended use causes you to think of any comments other than that I am crazy, I would love to read them. :-) Thanks again for your help.

-- Ken Maher (maherk@iquest.net), July 23, 1999.

Steve: Thanks for the information from B&H. After reading your reply, I bought a used rear converter 2x from KEH. It does indeed work with inner bay and outer bay lenses. I have yet to actually shoot any film with it, though.

I had never thought about hand holding the 600mm lens. I know that I cannot hand hold my 600mm f4 Minolta lens for my 35mm system and it is about a pound lighter, but I guess I had not thought about the wider angle of view in the 6x7 600mm making it maybe a little less sensitive to slight motion. With a 2x, I would strictly use a tripod and either a long lens support arm or a second tripod to support the camera. I can understand what you mean about two tripods being aggravating. In fact, I do not think that I will try it.

BTW, hope your photo shoot was enjoyable and a success.

-- Ken Maher (maherk@iquest.net), July 28, 1999.