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Thread: A thought about focusing...

  1. #1
    rpcrowe's Avatar
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    A thought about focusing...

    I attended an excellent presentation by an accomplished local bird photographer who uses a Nikon D300 with Nikon's 200-400mm f/4 lens + the 1.5x TC. The lens will autofocus with the 1.5x TC and he stated that for a local lake and species of bird he shoots (grebes), that he absolutely needs the 1.5x TC on his lens.

    I shoot with Canon and have a 400mm f/5.6L lens and a 7D. Obviously I cannot use my 1.4x TC and expect to autofocus.

    It just came to me that when I first worked in photography, I did not have a camera/lens with a built-in rangefinder. Instead, I guestimated the distance and set that on my lens.

    Obviously, I wasn't shooting with a 400mm lens wide open at f/5.6 which produces rather thin DOF.

    Getting a 500mm or 600mm lens is price prohibitive. for me. IMO, the ideal lens for birding and general wildlife would be the new Canon 200-400mm f/4L IS 1.4x but, I really don't want to sell my kidney for the price of a lens. Possible, one of the big Sigma lenses would do the trick but, that would still mean a considerable expenditure.

    I am wondering if an auxillery rangefinder such as this might not do the trick for a little over a hundred bucks...

    http://www.amazon.com/Wildgame-Innov...7608837&sr=8-9

    I could find the distance of my subject and then manually select that distance on the distance scale of the lens. Obvously, it would be slower than an autofocus lens and I probably could not use it for birds in flight but, it might be just the trick for swimming and nesting birds.

  2. #2

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    Eugen

    Re: A thought about focusing...

    Hi Richard,
    I don't know how detailed the distance scale is on your lens (I've only worked with cheap lenses so far and the distance scale is at least poor; only a few marks 1,3,5,8 and infinity). If your scale is much better then the rangefinder would be a good bet but if there is nothing between 8m and infinity I don't think the range finder could help you much - you might be better with manual focusing and saving the $100.
    Basically you will be doing manual focusing anyway.

    Personally, I think it will be much faster to use manual focus all the way; using the range finder, setting the distance on the scale then fine adjusting the focus to me appears like you are losing precious time. But that's only me (a newbie ), others might think differently.

  3. #3
    herbert's Avatar
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    Re: A thought about focusing...

    Hi Richard,

    I know that you can cover some of the contacts on the lens and the camera then doesn't know the lens aperture. This prevents it from disabling autofocus. Apparently it can work if you prefocus the lens manually in approximately the right position. The autofocus can then have a go at locking on.

    A quick search found this thread explaining how to do it:

    http://photo.net/canon-eos-digital-camera-forum/00H102

    I quote, "Looking at the lens side of the extender with the pins at the top, tape off the three left pins."

    You could try this. It may be worth a go. But only if you already have an extender. I would not buy one for this purpose because you will probably be disappointed.

    Alex

  4. #4
    rpcrowe's Avatar
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    Re: A thought about focusing...

    I already have the extender which I normally use with my 300mm f/4L IS lens anI originally bought it for my my 70-200mm f/4L IS lens befor I got a wonderful deal from a friend on both the 300mm f/4L IS and 400mm f/5.6 lens..

    I will ty just guestimating the distance at first using the lens in manual focus mode....

    I don't want to put a lot of money in this because I am certainly not a dedicated wildlife photographer. There however are a couple of shots of the grebes (a water bird that seldom flies) of Lake Hodges that I want to capture. In their mating ritual, they "run" across the water in pairs. They also ferry around their young on their backs. These little downey chicks look cute as heck on their parents backs.

    You never know, I may enjoy wildlife photography and since there are some pretty good areas fairly close to my home, it might be fun to start.

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    Re: A thought about focusing...

    Teleconvertors are not the only way to technically get more reach.
    The new Nikon V1 and J1 have a 2.7 crop factor, automatically giving a significant improvement in reach (500mm becomes equivalent to 1350mm).
    Plus a camera with more pixels produces more pixels on target for the same composition. (Yeah, also bearing in mind quality of pixels, but that depends on size of print/viewing).
    There are also mirror lenses out there (usually, but not always) manual focus. Somewhat lower quality, but again a lot of that is mitigated if you are printing at less than A3 (around 11"x16").
    Graham
    trying to think outside the box

  6. #6
    rpcrowe's Avatar
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    Re: A thought about focusing...

    Sometimes I get a stupid idea which after thinking about it seems even more stupid. I did not look at the distance scale of my 400mm f/5.6L lens. My idea just would not fly because the distance scale is not as comprehensive as I thought.

  7. #7
    Moderator Dave Humphries's Avatar
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    Re: A thought about focusing...

    Quote Originally Posted by GrahamH View Post
    The new Nikon V1 and J1 have a 2.7 crop factor, automatically giving a significant improvement in reach (500mm becomes equivalent to 1350mm).
    Plus a camera with more pixels produces more pixels on target for the same composition. (Yeah, also bearing in mind quality of pixels, but that depends on size of print/viewing). ~

    Graham
    trying to think outside the box
    This is an interesting concept Graham, and one I have been toying with for getting more wildlife reach - although probably not by going with a V1, but instead something cheaper.

    It was one of the deciding factors in Rebecca (Becky Humphries) starting her 'DSLR addiction' with micro 4/3 format and a Panasonic GH2 and the 100-300mm (crop factor 2x giving 200-600mm) instead of Canikon 1.6x/1.5x crop factor bodies.

    For myself, I am vaguely considering whether a RAW shooting bridge camera that reaches somewhat over 700mm with IS, is a cost effective answer - the smaller sensor/greater DoF will be a benefit at those focal lengths and you have the benefit of a spare body to boot.

    The alternative is, as has been said, the Sigma 150 - 500mm at about 850 (UK) or a Nikon long lens at several thousand notes

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