Results 1 to 18 of 18

Thread: Shutter speed for moving MRT Trains?

  1. #1

    Default Shutter speed for moving MRT Trains?

    2 MRT trains are moving past each other. Any idea how fast the shutter speed is needed to freeze the motion?

  2. #2

    Default Re: Shutter speed for moving MRT Trains?

    Originally posted by revenant
    2 MRT trains are moving past each other. Any idea how fast the shutter speed is needed to freeze the motion?
    I think your trying to capture in one of the cabin rite?
    since the speed of those two trains are fast and plus they are
    traveling in different direction which make things worst, my guess
    is to use shuttle speed from 1/250 onwards.

    p/s maybe a smaller F will help to get a brighter pic.

  3. #3

    Default Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by Mickey


    I think your trying to capture in one of the cabin rite?
    since the speed of those two trains are fast and plus they are
    traveling in different direction which make things worst, my guess
    is to use shuttle speed from 1/250 onwards.

    p/s maybe a smaller F will help to get a brighter pic.
    Won't smaller F gives shallower DOF as well which might blur the blackground?
    Last edited by revenant; 28th August 2002 at 12:24 AM.

  4. #4

    Default

    It's gonna be difficult to provide an accurate answer... too many factors come into play here.

    1. Size of MRT trains in the picture (affected by focal length, distance to subject)
    2. Direction and speed of movement in the picture
    3. Degree of sharpness needed

    There's probably tons more.

    I'd say that with 1/500 you should be quite safe... any faster and IMO you're standing too near the trains

  5. #5

    Default

    a larger aperture will render a shallower DOF which could blur the background.

    you could use a wide angle lens to increase DOF

  6. #6

    Default Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by revenant


    Won't smaller F gives shallower DOP as well which might blur the blackground?

    I think you got the wrong facts. The smaller the aperture, the sharper your image, and it will give a good Depth of Field.

    Okay I got a feeling you are not very sure about your apertures. the higher the numeric e.g f22 the smaller the aperture. Which mean a f3.5 is considered big aperture.
    Last edited by excentrique; 27th August 2002 at 11:50 PM.

  7. #7

    Default Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by revenant


    Won't smaller F gives shallower DOP as well which might blur the blackground?

    your object are the trains , wat back ground do you want??? Kranji river?, chinese garden?? do you think you got the luck and patient and wait for 2 two trains to pass by chinese garden??

    I don't think background is necessary in your case, small F number = bigger lens opening = ability to use higher shutter speed.

  8. #8

    Default Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique

    If you have done physics, you would know that a smaller pinhole will give a sharper image than a larger pinhole. well aperture works just like a pinhole.
    This is only true up to a certain (very reachable) limit. Diffraction increases as the pinhole decreases, beyond a certain point, image sharpness is compromised by increasing diffraction.

  9. #9

    Default Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by Lennier


    This is only true up to a certain (very reachable) limit. Diffraction increases as the pinhole decreases, beyond a certain point, image sharpness is compromised by increasing diffraction.

    That why you have a len you make your image sharp pal. The defraction level is no longer affected when you have a len to control it. That's what the focusing is used for.

  10. #10

    Default Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique



    I think you got the wrong facts. The smaller the aperture, the sharper your image, and it will give a good Depth of Field.

    Okay I got a feeling you are not very sure about your apertures. the higher the numeric e.g f22 the smaller the aperture. Which mean a f3.5 is considered big aperture.
    pai sey I should have said smaller F number instead.

  11. #11

    Default Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by ninelives



    your object are the trains , wat back ground do you want??? Kranji river?, chinese garden?? do you think you got the luck and patient and wait for 2 two trains to pass by chinese garden??

    I don't think background is necessary in your case, small F number = bigger lens opening = ability to use higher shutter speed.
    erm.... I scared the cam will take the other train as background and hence blur it? Cause I notice from some micro shots the background is blurred and the distance between the background and cam is not far.

    Sorry, really don't understand on this part.

  12. #12

    Default Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by revenant


    erm.... I scared the cam will take the other train as background and hence blur it? Cause I notice from some micro shots the background is blurred and the distance between the background and cam is not far.

    Sorry, really don't understand on this part.
    Pal, why are you scared? just take the picture and see the results for yourself. This should clear your doubt. Well, there not always a perfect situation to get what you want all the time as outdoor shoot is highly dependant on available light. If the light is super strong, you can go ahead and use smaller aperture with high shutter speed. However, what if the sky is gloomy. You cannot control every situation especially in outdoor. So you have to give and take. If the image is important to you, and the light is insufficient, you have to live with the compensations (be it speed or aperture) . That's why people invent flashlight. But of course that have limtiations too.

  13. #13

    Default Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique


    Pal, why are you scared? just take the picture and see the results for yourself. This should clear your doubt. Well, there not always a perfect situation to get what you want all the time as outdoor shoot is highly dependant on available light. If the light is super strong, you can go ahead and use smaller aperture with high shutter speed. However, what if the sky is gloomy. You cannot control every situation especially in outdoor. So you have to give and take. If the image is important to you, and the light is insufficient, you have to live with the compensations (be it speed or aperture) . That's why people invent flashlight. But of course that have limtiations too.
    That I had some idea. What I'm not very sure is abot DOF. Cause larger aperture ( smaller F number ) will blur background right? And if the light is unsuffificient, we need to use larger aperture so as to use faster shutter speed. But I thought larger aperture also blur background? How to know if the background is not the subject that we want to focus on?

  14. #14

    Default Re: Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?



    That I had some idea. What I'm not very sure is abot DOF. Cause larger aperture ( smaller F number ) will blur background right? And if the light is unsuffificient, we need to use larger aperture so as to use faster shutter speed. But I thought larger aperture also blur background? How to know if the background is not the subject that we want to focus on?
    [/QUOTE]

    Yes, larger aperture will give you a shallower DOF. If there is not enough light, you can only compensate but using a slower spped, of wider aperture. Setback is slower speed cannot freeze moving object. larger aperture gives you shawllower DOF. You just have to pick one to let go. You can't always have what you want in an out door shoot as the light is beyond your control. For this case it make sense to let go the aperture.

    I'm also sure you have a focusing ring at your len right? The focus ring is use to point at the object where you want the image to be at the sharpest. get the focusing right first by pointing your focus ring at the point and adjusting the focus to get it sharp. After which, point your camera back to the angle you want and shoot. This will determine where you want the focus point to be at.

  15. #15

    Default Re: Re: Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique


    Yes, larger aperture will give you a shallower DOF. If there is not enough light, you can only compensate but using a slower spped, of wider aperture. Setback is slower speed cannot freeze moving object. larger aperture gives you shawllower DOF. You just have to pick one to let go. You can't always have what you want in an out door shoot as the light is beyond your control. For this case it make sense to let go the aperture.

    I'm also sure you have a focusing ring at your len right? The focus ring is use to point at the object where you want the image to be at the sharpest. get the focusing right first by pointing your focus ring at the point and adjusting the focus to get it sharp. After which, point your camera back to the angle you want and shoot. This will determine where you want the focus point to be at.
    Is there really no choice for that kinda shot to be perfect / almost perfect?

    oh..... focus on the subject and the background will be blur? How far can the focusing point can be allow?

  16. #16

    Default Re: Re: Re: Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by revenant


    Is there really no choice for that kinda shot to be perfect / almost perfect?

    oh..... focus on the subject and the background will be blur? How far can the focusing point can be allow?
    only if you use an external light source like flashlight. But again you will distroy the natural lightings.

    yep, the focusing point to blurnesss its about 2/3 of the the entire image... it's hard to tell because different apertures will give diffrent depth of field. Why not you test the aperture and see the results for yourself. take 2 can drinks put it at a distance and test shot using diferent focus point and aperture. Will you have a clearer idea then.

  17. #17

    Default Re: Re: Re: Re: Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique


    only if you use an external light source like flashlight. But again you will distroy the natural lightings.

    yep, the focusing point to blurnesss its about 2/3 of the the entire image... it's hard to tell because different apertures will give diffrent depth of field. Why not you test the aperture and see the results for yourself. take 2 can drinks put it at a distance and test shot using diferent focus point and aperture. Will you have a clearer idea then.
    thanx very much

  18. #18

    Default Re: Re: Re: Re: Re: Re: Shutter speed for moving MRT Trains?

    Originally posted by excentrique



    That why you have a len you make your image sharp pal. The defraction level is no longer affected when you have a len to control it. That's what the focusing is used for.
    A lens still has a pinhole at the very centre. All lenses, no matter how "good", work on this same principle. Stop the lens down, and you will get a "pinhole" (may not be technically a round pinhole, but nonetheless it still exhibits diffraction properties of a pinhole)

    For most 35mm lens, diffraction effects can become quite apparent at apertures of f32 and smaller. Again this depends on your subject as well as blowup size.

    http://www.photo.net/bboard/q-and-a-...?msg_id=000427

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
  •