 Stefanie Gibson |
Problem w/auto focus on D80 w/Opteka macro lens I purchased a set of Opteka macro lens (+1 to +10) and attached them to my nikkor (AF-S) 18-135mm f/3.5-5.6G ED lens and now I cant seem to get auto focus to work. I have tried changing all the settings assoc. w/ this (like single serv, ect. I even tried to go completely manual and still cant seem to get anything up close to focus properly. any ideas?
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- Gregory LaGrange Contact Gregory LaGrange Gregory LaGrange's Gallery |
Having something attached to the lens can prevent auto focus from working. If the camera body uses an infra red beam to auto focus, an extra glass element that does any diffracting of light might make the infra red focus function not perform correctly. Super technician Jon Close or super analyst Alan Marcus might be able to delve into that more deeply. If things look out of focus with manual focus, you could have a low quality add-on, or the depth of field could be so narrow that you have to be extra precise.
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Christopher A. Vedros |
Stefanie, Try this - set your lens to manual focus, zoom in all the way, then turn the focus ring all the way to the "close focus end", not the "infinity focus end". Then look through the viewfinder and move the camera in closer to your subject until you find the plane of focus. You may still need to use a tripod to get a sharp picture, but at least this method will show you how close you need to be to focus with that particular attachment. Chris Vedros
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Stefanie Gibson |
Thank you both. I will try what chris said and see if that works.
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Alan N. Marcus |
Hi Stefanie, First I am flattered! Mr. La Grange called me a “super analyst”. Likely I don’t deserve the title. Especially in this case as I truly don’t know the answer. If we were face to face over coffee, I would toss out a thought or two. Customary for me, I dispense marginal technical stuff. That being said, here’s the stuff. Mr. Vedro is spot on when he advises moving the camera. This is true because when working in close, focusing by racking the lens is less decisive. Now the real question is; does mounting a supplemental close-up lens mess up the camera’s auto focus logic? I think not. I would suggest practicing using a printed page as the target. Also, I think the IR (infrared) focusing aid lamp is not a factor. Perhaps the natural high contrast of something like newspaper print will demonstrate that the camera’s focusing mechanism is working just fine. Maybe this is a case of insufficient illumination on the subject to allow the automation to take off. Additionally, maybe this is a case whereby the expectations exceed reality. Good supplemental lenses must be achromatic, a two element design. A single element supplemental is always substandard due to induced chromatic aberration i.e. color fringing happens. Also the figure (lens shape) of supplemental lenses is poor at the edges. Thus it is necessary to stop down to f/8 or f/16 to achieve sharp focus. Bottom line is: I think these buggers will work once your technique is perfected. Lots of luck, Alan Marcus
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Jon Close |
The close-up lenses lessen both the minimum near focus distance possible, and the far focus limit. The greater the diopter power of the close-up lens, the narrower the focus range, and the possible range of focus will be different at different zoom settings. By itself the 18-135 will focus from 18 inches to infinity. With a +1 diopter close-up lens attached and the lens set for 135mm, the focus range is reduced to about 4 inches to 45 inches. With the +10 the range of focus is only from 2 inches to 9 inches. Since the lens is as long or longer than the minimum focus distance, with the higher diopter powers you need to set it for infinity focus, then move the camera closer to your subject until it is in focus, then use the focus ring (manual focus only) for very fine adjustment. Obviously a tripod is needed, and it helps tremendously to use a macro focusing rail head that moves the camera and lens forward/backward several inches.
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Stefanie Gibson |
Thanks to all, I havent had time to play with it some but will have a chance next week. I really appreciate all this input as I have learned quite a bit.
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