Page 2 of 2 FirstFirst 12
Results 21 to 40 of 40

Thread: OOF blur/bokeh quality when focusing to infinity

  1. #21

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Quote Originally Posted by ijnek View Post
    my concern is every lens has a focusing distance range before it reaches infinity....
    Yah, so? I don't see your issue or why you keep on wanting to focus at infinity for a portrait shot. I think you're missing some basic fundamental skills.
    Alpha

  2. #22
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,901

    Default Re: OOF blur/bokeh quality when focusing to infinity

    what is your real question??
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  3. #23
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    no, i do not want to focus to infinity .

    eg.
    if i want to take a portrait and the focusin distance is at infinity(due to lens focal length), will i still get background blur.

    if u tell me i can use a 50mm and still go for full body shots with sweet background blur n good bokeh quality, then y should i need to get a 85mm or 135mm for the job?

    damn, i feel tat i can't get my question across in words...lol....any hotline to dial for help?

    btw, thx. i really appreciate u guyz helpin me out here with a dumb Question.
    i think i should try to get my hand on a 85mm prime to c if it makes a difference
    Last edited by ijnek; 8th January 2013 at 12:01 PM.
    Stirring up emotions with pics - cyliew

  4. #24

    Default

    Quote Originally Posted by ijnek View Post
    if i want to take a portrait and the focusin distance is at infinity(due to lens focal length), will i still get background blur.

    if u tell me i can use a 50mm and still go for full body shots with sweet background blur n good bokeh quality, then y should i need to get a 85mm or 135mm for the job?
    ...what on earth makes you think the lens will focus at infinity, or what on earth that has to do with focal length? Sounds like you think there is a connection where there is none.

    A higher focal lenghth will give you a different background perspective and thinner dof. But again, zero link to your bizarre "focusing at infinity" idea.

    Fyi, as previously stated, lenses can have slack - you may look at the lens focus scale and think it's focused at infinity, but that is clearly not the case.
    Alpha

  5. #25
    Senior Member shierwin's Avatar
    Join Date
    Dec 2008
    Location
    East Coast
    Posts
    3,368

    Default Re: OOF blur/bokeh quality when focusing to infinity

    I never realise that the lens will focus to infinity when you're shooting a portrait!
    The subject must be very very far away so much so that the lens needs focus to infinity.

    Once you select infinity focus you'll get, instead, foreground blur
    BTW when you shoot did you select single point focus?

  6. #26
    Member
    Join Date
    May 2006
    Location
    Taman Jurong
    Posts
    114

    Default Re: OOF blur/bokeh quality when focusing to infinity

    TS, what do you mean by "focusing range"? You mean min and max focusing distance? Are you confused because you think that the max focusing distance of a lens is not at infinity? So you are asking if you place your subject at the max focusing distance, will you get a good background blur at infinity?

    For your info, most lenses have max focusing distance practically at infinity. Unless you are talking about adding extension tube/ close-up filter to turn the lens to macro. In that case, you will lose infinity focusing.

  7. #27
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,901

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Quote Originally Posted by ijnek View Post
    no, i do not want to focus to infinity .

    eg.
    if i want to take a portrait and the focusin distance is at infinity(due to lens focal length), will i still get background blur.

    if u tell me i can use a 50mm and still go for full body shots with sweet background blur n good bokeh quality, then y should i need to get a 85mm or 135mm for the job?

    damn, i feel tat i can't get my question across in words...lol....any hotline to dial for help?

    btw, thx. i really appreciate u guyz helpin me out here with a dumb Question.
    i think i should try to get my hand on a 85mm prime to c if it makes a difference
    you can use a longer focal length lens like 200mm, shoot with wide open aperture, of course, the background should be far far far far far away from the subject.

    if you want to use 50mm lens to shoot full body shots with background blur, also can, just find a model same size as your toy figurine.
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  8. #28
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    yes, i might be confused...
    apprecialte the effort....

    when i look at the lens, it has the focus distance range markin.
    from there can c the range from min focusin distance to the infinity mark.

    the 50mm/85mm might not b a good example for what i'm tryin to figure out...

    let's look at this example instead.
    group pic...normally should use a wider angle lens to fit every1 in.
    but say i only have a 85m, i would thus need to stand back quite a distance to fit every1 in the pic.
    this would then increase the focusin distance(distance between group and photographer).
    by any chance the distance range(indicated on lens range) becomes(or shown as) infinity, can i expect to see any background blur?
    Stirring up emotions with pics - cyliew

  9. #29
    Moderator catchlights's Avatar
    Join Date
    Sep 2004
    Location
    Punggol, Singapore
    Posts
    21,901

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Quote Originally Posted by ijnek View Post
    yes, i might be confused...
    apprecialte the effort....

    when i look at the lens, it has the focus distance range markin.
    from there can c the range from min focusin distance to the infinity mark.

    the 50mm/85mm might not b a good example for what i'm tryin to figure out...

    let's look at this example instead.
    group pic...normally should use a wider angle lens to fit every1 in.
    but say i only have a 85m, i would thus need to stand back quite a distance to fit every1 in the pic.
    this would then increase the focusin distance(distance between group and photographer).
    by any chance the distance range(indicated on lens range) becomes(or shown as) infinity, can i expect to see any background blur?
    do you know how far is infinity?
    Shoot to Live, Live to Shoot
    www.benjaminloo.com | iStock portfolio

  10. #30
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: OOF blur/bokeh quality when focusing to infinity

    TS,

    A couple of examples for you.


    If I shoot this in portrait orientation, I can wait for the subject to walk in more and still get a full body shot and get even more background blur.
    Focal length 200mm, uncropped
    Aperture F2.8,
    Approximate subject distance from camera = 20m (If you look at the lens markings, it will almost be at "infinity", just like your case.. but focus is at 20m, not infinity)
    Is there background blur? = YES


    This is shot in landscape orientation. If I shot this in portrait orientation, the subjects will be full body.
    Focal length 85mm, uncropped
    Aperture F1.4
    Subject distance: 4m
    Is there background blur? = A Lot.


    Please note, both these pictures are shot on full frame cameras. So, on a APS-C cropped camera, you will have to step back slightly more to get the same framing, and your DOF will be slightly deeper.
    For example, for the 2nd pic, the DOF is 0.18m. If you use a DX cam like D7000, you will have to step back around 2 more meters to get the same framing, your DOF will become 0.28m.

    BTW, when choosing focal length as a creative choice, the thing you want to think more of, is not amount of blur, but rather the amount of compression you want in the picture. What is compression, you might ask? It means how large(close) the background will look in relation to your subject.

    Hope these examples help.
    Last edited by daredevil123; 8th January 2013 at 05:17 PM.

  11. #31
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    catchlight, i think i'm confused here with the infinity marking on the lens and the actual infinity distance...

    i use nikon lens(doesn't matter the brand) and i remember for the 70-200 f4, the range on lens is 1m to 5m, beyond the 5m it shows an infinity mark....u know...the little scale that changes accordin to the focusin distance....

    appreciate the help given n tolerance too...
    Stirring up emotions with pics - cyliew

  12. #32

    Default

    Quote Originally Posted by ijnek View Post
    yes, i might be confused...
    apprecialte the effort....

    when i look at the lens, it has the focus distance range markin.
    from there can c the range from min focusin distance to the infinity mark.

    the 50mm/85mm might not b a good example for what i'm tryin to figure out...

    let's look at this example instead.
    group pic...normally should use a wider angle lens to fit every1 in.
    but say i only have a 85m, i would thus need to stand back quite a distance to fit every1 in the pic.
    this would then increase the focusin distance(distance between group and photographer).
    by any chance the distance range(indicated on lens range) becomes(or shown as) infinity, can i expect to see any background blur?
    Stop fixating on the lens marking. Consider what infinity truly means.

    And yes, you can have background blur depending on your aperture and the distance between the subject and the background.

    Any online dof calculator could have told you that.
    Alpha

  13. #33
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    yes rashkee, i'm aware of my mistake now. the actual infinity distance and the little infinity mark on the lens scale.

    thx for the help.
    i will google to see if i can find more info.

    thx....and sorry if i frustrated some.
    Stirring up emotions with pics - cyliew

  14. #34
    Moderator daredevil123's Avatar
    Join Date
    Oct 2005
    Location
    lil red dot
    Posts
    21,627
    Blog Entries
    1

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Quote Originally Posted by ijnek View Post
    yes rashkee, i'm aware of my mistake now. the actual infinity distance and the little infinity mark on the lens scale.

    thx for the help.
    i will google to see if i can find more info.

    thx....and sorry if i frustrated some.
    don't be sorry. you ask questions, we try answer. and some people with the same questions may search and find this thread.

  15. #35

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Quote Originally Posted by ijnek View Post
    yes rashkee, i'm aware of my mistake now. the actual infinity distance and the little infinity mark on the lens scale.

    thx for the help.
    i will google to see if i can find more info.

    thx....and sorry if i frustrated some.

    i think u should go back and try out the lens again before posting of such infinity issues.
    i see your concern is about background blur.
    this has nothing to do with lens focus to infinity or not.

  16. #36
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    hi turbonetics, i read ur post n i get a hint of fire.
    if u gone through the whole thread, u would know that i'm relating background blur to infinity distance focus.

    but my mistake was to assume the actual infinity distance to the infinity mark on the distance scale on the lens.

    sorry if i step on ur toes
    Stirring up emotions with pics - cyliew

  17. #37

    Default

    Quote Originally Posted by ijnek View Post
    if u gone through the whole thread, u would know that i'm relating background blur to infinity distance focus.
    Which is also wrong if you're shooting a subject. Stop trying to link them if you are shooting a model
    Alpha

  18. #38

    Default

    Quote Originally Posted by ijnek View Post
    catchlight, i think i'm confused here with the infinity marking on the lens and the actual infinity distance...

    i use nikon lens(doesn't matter the brand) and i remember for the 70-200 f4, the range on lens is 1m to 5m, beyond the 5m it shows an infinity mark....u know...the little scale that changes accordin to the focusin distance....

    appreciate the help given n tolerance too...
    Depending on the lens design, the difference between infinity focus n smth like 5m may be very small, its optical physics.

    Practically, when your lens is focused at infinity according to the scale, it probably is (or v far away, give n take) unless u gt a badly calibrated one.

    Again, if u are focused at infinity (and your subject is sharp), chances are u will not get bkgd blur. Similarly, if u r focused at a subject that is v far away (in order to fit the whole body) u may not b able to get bkgd blur if ur bkgd is not far away or aperture not big enuff...

    Lastly, why so bothered about this? Just shoot your subjects in focus, and then recompose n reposition if u can't get your desired bkgd blur. Learn the limitations of the lenses u have first and work around it.
    hi

  19. #39
    Senior Member shierwin's Avatar
    Join Date
    Dec 2008
    Location
    East Coast
    Posts
    3,368

    Default Re: OOF blur/bokeh quality when focusing to infinity

    Dear TS. Don't be fixated by the infinity scale on the lens. Just focus on the subject you're shooting and let the lens does the rest.
    Look at the lenses you have; notice that the last marked distance scale to the infinity mark constitutes a very very limited segment of the scale ring.

  20. #40
    Member
    Join Date
    Feb 2008
    Location
    Johor Bahru, Malaysia
    Posts
    1,764

    Default Re: OOF blur/bokeh quality when focusing to infinity

    thx for the help n effort
    appreciate it guyz
    Stirring up emotions with pics - cyliew

Page 2 of 2 FirstFirst 12

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •