How much of a disadvantage is 3 focus focus points ?

  • Posted by jane on March 18th, 2010 filed in portal.jsqf.com

  • I've recently treated myself to a DSLR - I got the D40X as I liked the feel of it. Anyway, it only has 3 auto-focus points and I remember one member saying this will make sports photography difficult. Thankfully i'm not interested in sports photography or sports anyway :-P But...will the same aply to wildlife photography ? Can I still capture a bird in flight ? Before splashing out on a telephoto lens it would be good to know if i've bought myself the right body, as the camera shop has a 30 day exchange policy, and I could swap it for a rebel XTi. But I don't want to, unless this auto-focus thing really is a problem...

    Pressumably I can just manually focus on the areas not covered by auto focus ?

    Thanks :meh:


  • Why is that? Are you suggesting that photographers that worked prior to the invention of auto focus didn't photograph moving subjects?

    it may not be an option because DSLRs, especially the entry level models, have very small and dim viewfinders that make MF much harder than the large bright finders in 35mm cameras.


  • Depends on what you shoot. If shooting portraits in a studio - I'd only use one focus pooint. If shooting a moving subject (wedding, sport etc, then it's a huge disadvantage.

    I struggle with the 20Ds 9point AF. I want the 45 point AF of the 1 series :)


  • I always use the center AF point on my body and recompose. It's the most sensitive and most accurate sensor. I never usually use the other points unless i can't move the camera, which isn't often.

    I do the same thing for most of my shooting. I haven't yet used this method for anything moving so I'm not sure how lets say a bird might be. It could be difficult to focus and recompose before it flies away.


  • Why is that? Are you suggesting that photographers that worked prior to the invention of auto focus didn't photograph moving subjects?

    they certainly did :) .. and they were better at focusing manually than most of us today ;)

    Just multiple AF sensors can make life easier in those situations, but not having them does not make things impossible.


  • 1 series 45 focus points rocks in a lot of situations... especially with moving objects.

    My first EOS camera was an Elan IIe with three focus points and eye control. Used both to their fullest extent. I was happy with it.

    I also manually focus with SLRs and Rangefinders. I enjoy both but actually find rangefinder's easier than split prism SLRs.

    Its a personal preference and I see neither an advantage nor disadvantage.


  • I focus manually.


  • Thanks so much for the replies.

    It's interesting to read how much of a personal thing this is - one member saying 3 is too many and it clutters up the viewfinder, another saying it's not nearly enough.


  • On the more expensive Canon cameras, I think I read that in certain modes for moving subjects the sensor points will hand off focus from one to another ... so not only are you following the subject but the camera does what it can to maintain focus.

    I shoot a ton of sports and I use center focus only for sports. On other shots, especially wide angles, I still only use one point but I will select a focus point closest to my subject to minimize repositioning. I get sharper results that way when I shoot with larger apertures.

    Gary

    Indeed, Nikons have that tracking feature too - and it can do some interesting things. I was messing around with it at a Rollergirls game, and, well I call this a perverted selective focus!

    http://farm1.static.flickr.com/81/245096459_7ff5fc28d5.jpg


  • haha, i see you have a sence of humor. ok lets get back on topic here.


  • errr....i dont use them, i dont shoot automatic.

    So you only use a pinhole? Otherwise I'm guessing you have some automation ;)


  • errr....i dont use them, i dont shoot automatic.

    and your point?


  • errr....i dont use them, i dont shoot automatic.


  • Viewfinder brightness is a function of the maximum aperture of the lens in use. The new viewfinders are 2/3 the size of the 35mm ones. Not much of a problem. Try tracking action through a rangefinder camera viewfinder or an old TLR with a waist level finder where everything is upside down and backward or a 1940's vintage press camera with a snap on viewfinder. Trust me they would make a DSLR seem like a piece of cake in comparison and yet all of those cameras were used to track moving subjects for years and years. No, it is very much an option.

    and the type of focussing screen that is in use, fit a Beattie intenscreen and you will gain around 2-3 stops of viewfinder brightness


  • Most of the time I use 1. But when tracking a moviong subject the 45 point AF of the 1 series cannot be beaten


  • The disadvantage of 3 focus points vs a single one is that it clutters up the viewfinder unnecessarily. One focus point would certainly be better.


  • for wildlife I always use all 45 of the focus points if I'm following the movement of say a bird in flight as you never know just where its going, I also use the SERVO mode for focus so the camera can keep track of the subject


    For portraits of animal then I use the one of the off centre focus points, whichever one covers the subjects eyes and I set the focus mode to ONE STOP


  • it may not be an option because DSLRs, especially the entry level models, have very small and dim viewfinders that make MF much harder than the large bright finders in 35mm cameras.

    Viewfinder brightness is a function of the maximum aperture of the lens in use. The new viewfinders are 2/3 the size of the 35mm ones. Not much of a problem. Try tracking action through a rangefinder camera viewfinder or an old TLR with a waist level finder where everything is upside down and backward or a 1940's vintage press camera with a snap on viewfinder. Trust me they would make a DSLR seem like a piece of cake in comparison and yet all of those cameras were used to track moving subjects for years and years. No, it is very much an option.


  • lol well atleast zaphod had something funny to say about my usless post. see i like throwing things into conversations that have little or nothing to do with them, a pinhole camera would be fun though ;D
    yay for shutter speed priority!


  • I always use the center AF point as well.


  • On the more expensive Canon cameras, I think I read that in certain modes for moving subjects the sensor points will hand off focus from one to another ... so not only are you following the subject but the camera does what it can to maintain focus.

    I shoot a ton of sports and I use center focus only for sports. On other shots, especially wide angles, I still only use one point but I will select a focus point closest to my subject to minimize repositioning. I get sharper results that way when I shoot with larger apertures.

    Gary


  • see i like throwing things into conversations that have little or nothing to do with them,

    Great!!! hopefully the rest of the community doesn't pick up your habit.. since useless posts are PITA.


  • That may not be an option when tracking a moving subject.

    Why is that? Are you suggesting that photographers that worked prior to the invention of auto focus didn't photograph moving subjects?


  • i agree with what others say in here, unless your focus has to follow fast moving objects, the central AF is sufficient. In wide angle photography with shallow DOF having some off centre AF points may help. but then again I would maybe focus manually then
    .


  • Thanks for the replies so far.

    Deepspring - I guess as long as I am following the subject ( the bird ) there shouldn't be a problem focusing. I would have thought the difficulty would be when the subject is moving quickly within the frame ?


  • I always use the center AF point on my body and recompose. It's the most sensitive and most accurate sensor. I never usually use the other points unless i can't move the camera, which isn't often.


  • I focus manually.

    That may not be an option when tracking a moving subject.







    • #If you have any other info about this subject , Please add it free.#
    Your name:
    E-mail:
    Telphone:

    Your comments:


    If you have any other info about How much of a disadvantage is 3 focus focus points ? , Please add it free.