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narrow aperture shots ... getting it all in focus

  • 01-03-2009 6:39pm
    #1
    Closed Accounts Posts: 1,788 ✭✭✭


    Hi
    I've tried some shots to get everything in focus, foreground and background .... but even at apertures like f22 .. if the object is close enough
    the background will still be a little blurred (a lot less of course then when it is a f f2.8) ..

    I see in Petersons book on Exposure that he has some photos of his daughter and the background (and her) in perfect focus .. maybe this is because he is using series 1 camera with such a large AF range .. (I have the 5D II) the AF range is not the best on it ... same as the 400D ...


Comments

  • Closed Accounts Posts: 6,281 ✭✭✭Ricky91t


    Is this a question on how to do it,or just a rant about the 5D's af system?


  • Registered Users, Registered Users 2 Posts: 4,699 ✭✭✭ThOnda


    It depends also on focal length of your lens. The longer lense the narrower DoF. You have full frame camera, so there should not be a difference between your and his picture, if you both used the same lens (focal length).


  • Registered Users, Registered Users 2 Posts: 6,713 ✭✭✭DaireQuinlan


    jackdaw wrote: »
    Hi
    I've tried some shots to get everything in focus, foreground and background .... but even at apertures like f22 .. if the object is close enough
    the background will still be a little blurred (a lot less of course then when it is a f f2.8) ..

    I see in Petersons book on Exposure that he has some photos of his daughter and the background (and her) in perfect focus .. maybe this is because he is using series 1 camera with such a large AF range .. (I have the 5D II) the AF range is not the best on it ... same as the 400D ...

    The normal way of doing something like this (trying to get everything into focus as much as possible ) would be to focus at the hyperfocal distance for a particular focal length and F-Stop. As Thonda points out its heavily dependent on the focal length of your lens. For example, I have a 20mm which I use quite a bit this way. Stopped down to f/16 and focused at 5 feet then everything from about 2+1/2 feet to infinity will be acceptably* in focus. I have the values printed out and pasted onto the lens for several combinations of f-stops, focal lengths (its a 20->35 zoom) and coc figures.

    google for hyperfocal distance for more info, and check out the online DOF calculater for specifics: http://www.dofmaster.com/dofjs.html

    *for some value of the word 'acceptably', this is a whole other discussion.


  • Registered Users, Registered Users 2 Posts: 16,624 ✭✭✭✭Fajitas!


    That:

    a) has nothing to do with the 5D's AF system, which, believe it or not, is better than the 400D's AF.

    b) has to do with controlling your depth of field and distance from subject, as opposed to your AF. Look up "hyperfocal distance" and see if that helps you.


  • Registered Users, Registered Users 2 Posts: 6,393 ✭✭✭AnCatDubh


    for DOF, its necessary to understand the effect of all the parameters. Some time ago I thought my bridge camera wouldn't produce good depth of field and I needed to get a DSLR. I got the DSLR and began to try to find more depth of field (what i was actually looking for was smaller depth of field / more bokeh - lol). Then I read that smaller aperture = more blurry bits so i tried that and yes it certainly helped greatly. Next, I got a 70-300mm lens and happened to notice wonderful bokeh at the 300mm end of things at f5.6 - and thought wow, how'd I do that for not a particularly low aperture value. In reality it wasn't the aperture at that point but the focal length. But I also noticed that it wasn't exactly true that it only happened at 300mm, and this is where distance to subject came in. I don't have a full frame camera yet but crop factor I understand will also have an effect.

    Anyway the purpose of the above is to illustrate that the control of bokeh and the other side of the coin the depth of field is a combination of a number of photographic parameters and to fully understand how to control it requires you to understand the effect of each parameter as each parameter will effect the depth of field. A single parameter taken in isolation will have consequental limited control over either your desired depth of field or the resultant bokeh.


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  • Closed Accounts Posts: 1,788 ✭✭✭jackdaw


    Ricky91t wrote: »
    Is this a question on how to do it,or just a rant about the 5D's af system?

    Is this necessary ?

    thats what i hate about forums ... the sarcasm ...
    its a how to do .... not a RANT !!!


  • Closed Accounts Posts: 6,281 ✭✭✭Ricky91t


    jackdaw wrote: »
    Is this necessary ?

    thats what i hate about forums ... the sarcasm ...
    its a how to do .... not a RANT !!!

    People do come on forums just to rant,And the fact people tend to use question marks when they have a question is a bit of help.

    That's what I hate about forums you can't hear the person tone of voice and therefore you can't tell if it's a question or not.Hence the fact a question should be used

    For me whenever something is up close no matter how low the aperture is,you'll always have some bit of background blur


  • Closed Accounts Posts: 1,788 ✭✭✭jackdaw


    Ricky91t wrote: »
    People do come on forums just to rant,And the fact people tend to use question marks when they have a question is a bit of help.

    That's what I hate about forums you can't hear the person tone of voice and therefore you can't tell if it's a question or not.Hence the fact a question should be used

    For me whenever something is up close no matter how low the aperture is,you'll always have some bit of background blur

    Good point .... Thanks all for that link ... I learned a lot about Depth of field calculating...

    cheers


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