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Thread: My first pic posted: Singapore skyline.

  1. #21
    Senior Member Kit's Avatar
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    Default Re: My first pic posted: Singapore skyline.

    BTW, if you want to show an example, at least find something similar. The one you provided was shot at a much higher level than the horizon, how to compare???

    Objects on the same plane but further from the camera will only appear smaller, they don't tilt upwards.

  2. #22
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    Default Re: My first pic posted: Singapore skyline.

    The London Eye example is to show that the riverbank cannot be used to judge if the horizon is tilted, this exagerated example is to show it clearly......I think the TS pic may suffer the same situation, slightly, so the riverbank is not horizontal......

    A more subtle and similar example is below, do you think it has tilted horizon? It will be if you draw a horizontal line against the riverbank...

    http://www.flickr.com/photo_zoom.gne?id=17002457&size=l

    To me, based on the vertical of the flat in the middle, it has tilted to the clockwise direction a little, but if I use the riverbank, it is the other way round....

    TS, hope you dun mind me discussing this....I usuall learn and confirm concept from discussion.

    Quote Originally Posted by Kit View Post
    BTW, if you want to show an example, at least find something similar. The one you provided was shot at a much higher level than the horizon, how to compare???

    Objects on the same plane but further from the camera will only appear smaller, they don't tilt upwards.

  3. #23

    Default Re: My first pic posted: Singapore skyline.

    i think we should just move on, and leave it at that
    some people are just like that, you clarify they will just do their own thang, insist that they're right
    and ignore pointers as to misunderstandings, no remorse to the max
    i think the important thing is that the ts has learnt something
    as to which is the proper way to correct the picture, i think we all know - it's pretty clear, i will not state any explicit stand or else later i get dragged into the argument, which is very unsightly
    since it has become so technical and obtuse that it has nothing to do with the critique anymore

    ts - if you feel that you have anything more to add, you may do so
    else my advice is to close the thread
    no point letting this build up until it becomes something uglier than what it is already
    cheers

  4. #24
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    Default Re: My first pic posted: Singapore skyline.

    I am sorry if it looks like a argument and has turned ugly. I was just trying to discuss constructively and hope to verify my knowledge. I will leave this thread alone now.

    Apologies.

  5. #25
    Senior Member Kit's Avatar
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    Default Re: My first pic posted: Singapore skyline.

    Chose what you want to believe, I really can't be bothered talking to people who don't listen...

  6. #26

    Default Re: My first pic posted: Singapore skyline.

    i feel that the photo consist a little too much grass...

  7. #27

    Default Re: My first pic posted: Singapore skyline.

    Hi..

    I am also very interested in the titled problem.
    Can anyone please tell me is the picture bwlow tilted?





    Look at the UOB Plazza. Looks verticle in the second picture but the horizon seem to tilted liao.

    How?? Which picture is not tilted? Or both also titled?
    Last edited by Silence Sky; 19th September 2007 at 11:52 PM.

  8. #28
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    Default Re: My first pic posted: Singapore skyline.

    please keep the discussion here focussed on TS's picture.

  9. #29

    Default Re: My first pic posted: Singapore skyline.

    Quote Originally Posted by Silence Sky View Post
    Hi..

    I am also very interested in the titled problem.
    Can anyone please tell me is the picture bwlow tilted?

    hey silence sky

    yes, one look can tell that the picture is heavily tilted to the left
    there is also lens distortion problem
    not sure about keystone, will have to see, but probably has too

    i usually just try lens distortion of +6 correction in ps, which i did here
    rotate 1 degree clockwise, - now to check whether the picture is correctly verticalled, the easiest way is to just check the building in the centre
    if don't have then suck thumb, but here have, the one with the blue logo in top right
    after rotation i based using the rectangular marquee tool as straight edge
    then now, vertical perspective correction of about -15

    after cropping, result:


    still not very well adjusted but smaller pictures very hard, i have to base it on eye, cannot zoom in to be exact
    so the building on the right still not very straight, hrm
    so this was a very botched job but i guess you will get the exact order in which you need to correct the picture

    1) lens distortion correction if any, you should always make a mental note of how much is optimal so you don't have to waste time, this is the easiest step to go wrong
    2) rotation correction if any
    3) vertical perspective correction if any

    usually you would not require much horizontal perspective correction for landscapes/wide scenes, unless you have done a very bad job when shooting; vertical perspecitve is the main thing - try not to do BOTH horizontal and vertical perspective correction, not sure if it works but i always end up with really screwed up results so i avoid it these days

    please note that not all the time die die must correct distortion
    or vertical perspective
    or horizontal perspective
    especially if you intend it as effect, artistic license is up to you
    a rough guide when you are overdoing it is when people start commenting that the picture looks too weird, etc
    Last edited by night86mare; 19th September 2007 at 11:58 PM.

  10. #30

    Default Re: My first pic posted: Singapore skyline.

    Quote Originally Posted by night86mare View Post
    hey silence sky

    yes, one look can tell that the picture is heavily tilted to the left
    there is also lens distortion problem
    not sure about keystone, will have to see, but probably has too

    i usually just try lens distortion of +6 correction in ps, which i did here
    rotate 1 degree clockwise, - now to check whether the picture is correctly verticalled, the easiest way is to just check the building in the centre
    if don't have then suck thumb, but here have, the one with the blue logo in top right
    after rotation i based using the rectangular marquee tool as straight edge
    then now, vertical perspective correction of about -15

    after cropping, result:


    still not very well adjusted but smaller pictures very hard, i have to base it on eye, cannot zoom in to be exact
    so the building on the right still not very straight, hrm
    so this was a very botched job but i guess you will get the exact order in which you need to correct the picture

    1) lens distortion correction if any, you should always make a mental note of how much is optimal so you don't have to waste time, this is the easiest step to go wrong
    2) rotation correction if any
    3) vertical perspective correction if any

    usually you would not require much horizontal perspective correction for landscapes/wide scenes, unless you have done a very bad job when shooting; vertical perspecitve is the main thing - try not to do BOTH horizontal and vertical perspective correction, not sure if it works but i always end up with really screwed up results so i avoid it these days

    please note that not all the time die die must correct distortion
    or vertical perspective
    or horizontal perspective
    especially if you intend it as effect, artistic license is up to you
    a rough guide when you are overdoing it is when people start commenting that the picture looks too weird, etc
    First of all, thanks Nightmare for your explanation.
    Very heavy stuff, let me try to digest first.
    But I find the horizon of the first picture very straight. That's the base i used to framed the shot and building turned out to be titled.

    Apology to TS for sharing your tread, but i find it a good opportunity to field my question here which has bother me for quite some time.
    Last edited by Silence Sky; 20th September 2007 at 12:11 AM.

  11. #31
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    Default Re: My first pic posted: Singapore skyline.

    Kit is correct in pointing out the slant in TS's picture. regressing shoreline do cause perception of slanted line of horizon, but it's dependent on the alignment of camera in terms of height above ground and angle to/from horizontal. in TS's picture's case, the camera is relatively close to ground (eye level) thus it is not incorrect to use the distant shoreline as a guide.

    lastboltnut, the red vertical line you drew in the middle of the picture is incorrect, you can observe the angle of slant more closely to pick up the mistake. (refer to pm)

    i'll just add that Kit's use of the green vertical line can be misleading. lastboltnut was correct in using the vertical centre line as indication of tilt, which in this case shows a tilt. Kit's green line is placed far off the centre, unless the lens is exactly perpendicular to the true horizontal (i.e. the direction of the shot is exactly parallel to true horizontal) the building will be distorted even if the horizon is horizontal.



    let's end the issue on line of horizon here, i'm sure TS will like to see more comments in other areas as well.
    Last edited by eikin; 20th September 2007 at 12:34 AM.

  12. #32
    Senior Member Kit's Avatar
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    Default Re: My first pic posted: Singapore skyline.

    The vertical green line wasn't meant to emphasize the horizon tilt, I used it to single out the keystone effect of the buildings. Anyway, good to see that you can explain this concept to the 3-dimensionally challenged better than I do.

  13. #33
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    Default Re: My first pic posted: Singapore skyline.

    Quote Originally Posted by sexalicious View Post
    thanks for all the comments. will take note on the horizon and distortion. As a newbie(3 mths) to photography. i wish to strive too, =)

    actually i still dont understand something nightmare.
    what these means?
    1) there is tilt in the horizontal plane in the first place, hence the verticals might not be correct in the first place
    2) then there might also be keystone effect, i.e. converging or diverging verticals, depending. in this case converging verticals
    find in the following 3 rather ugly diagrams i came up with 2.30am in the morning, hope they explain the idea of distortion. try it yourself to see the effects.

    up-down movement


    left-right movement


    rotation


    human beings are not robots, our movements are never precise and occur in 3-dimensions simultaneously (which is why pan-tilt tripod heads are useful for landscape) but once you understand how each distortion originates, it's not difficult to single out the problems.
    Last edited by eikin; 20th September 2007 at 01:37 AM.

  14. #34

    Default Re: My first pic posted: Singapore skyline.

    so best would be to carry a tripod for landscape photography. be it night or day. plus a level bubble too. but thanks for all the feedbacks. learnt sumthing from this thread. don't mind the arguments but let's keep a healthy discussion

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