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Thread: more questions about fireworks and lens setting...

  1. #1
    Senior Member erictan8888's Avatar
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    Default more questions about fireworks and lens setting...

    hi,

    been reading a lot of articles on the web on fireworks but none really answered the questions i asking....this is the reason why i asked the following questions here.
    ps: i really go and read up a lot liao.... so pls dun bomb me... hee hee
    just that the articles are mostly talking about what to do but dun really explain why and also did not touch on some of my nagging doubts....

    question 1 :
    just like to check: when would be the best time to close the shutter for a fireworks pic?
    do i close the shutter when
    a. the fireworks is brightest or
    b. when the brightness has all died down or
    c. when i finish counting the seconds eg when time is 3 sec if i want a 3 sec exposure?

    one website said that must close shutter when fireworks at brightest.
    does it matter if i close the shutter when the fireworks is at the brightest or when it is not the brightest?
    i mean when i close the shutter, does it capture the last bright scene on the sky or does it accumulate all the lights that has entered the camera?
    for instance, would it make a difference if the shutter close when fireworks is brightest compared to when fireworks is not the brightest ? assume that aperture size and shutter speed the same.

    question 2:
    if i want the building to be in the picture, eg fullerton hotel to be in the picture, i set focus to fullerton hotel and switched to manual focus to prevent the camera from re- focusing again when i shoot the fireworks.... is this the reason?

    question 3:
    if i dun want to have building in the picture, do i set the focus to infinity and aim at the black sky? sorry... checked the manual but it does not seem to say how to focus to infinity?

    i set camera to autofocus and at f11 (or to about f16).... and focus on fullerton hotel.... is that focus to infinity?
    i look at the lens ring that and see that it is not turned to infinity by the auto focus done by camera. then i switched to manual focus and manually turn ring to infinity.... but now fullerton hotel appear blur...

    how exactly do i focus to infinity?


    question 4:
    if want buildings in the picture with fireworks and set focus to infinity, will outcome be ok?

    question 5:
    if i set to f11 and about 3 sec exposure, this is just about right for the fireworks.... but the buildings in the pic appear to be slightly under exposed....
    can i open the shutter 1 to 2 sec before the fireworks appear and use black card to block the lens... then remove black card when fireworks start appearing. i was thinking in this way, the building gets about 1 to 2 sec exposure more than fireworks... meaning buildings get properly exposed and so do the fireworks....

    is this thinking right or wrong?

    question 6 (last one liao.... sorry):
    was standing at shears bridge on last sat. facing fullerton building, but got street lamps on road behind me. problem is when i placed black card over my lens, because the street lamp is behind me, it shine onto my black card. although the black card is of non refractive black material (can see orange light from lamp on the black card), will the shinning of the light on the black card cause the camera to take in more light when it should not? or does it mean that because the black card is non refractive, although i see the light, to the camera, the black card is black.... ?? dun understand... sorry

    i know that the best way to learn is to experiment and try... but fireworks dun come everyday, so want to get the concepts right before i go and shoot... guess that is better than go and anyhow whack photos...

    "xi er gong ting" (waiting earnestly for advice from anyone)
    thanks
    __________________
    Hope to learn from everyone here....

  2. #2

    Default

    Firstly don't believe everything you read (this included). There are no fixed rules so you need to understand what is happening and what you want to capture.

    #1 - It is difficult to use this recommendation about brightness because you might end up leaving the shutter open for so long that all the different bursts combine and become a big mess. You need to visualise what is being seen and close the shutter when you have got enough. Using a fixed duration is good if you think that you might forget to let go :-) You have more flexibility if using film than digital because longer exposures with digital mean more noise.

    #2 - You should always focus manually when shooting fireworks because you cannot be sure that the fireworks will be in front of the focus sensor. If it is not, then you will either not be able to release the shutter or you will get a badly out of focus shot.

    #3 - How you focus on inifinity depends on the type of camera you are using. Check the manual. From your comments it sounds like you are using an SLR. If so set it to manual focus and turn the focus slowly. Note that many lenses focus beyond infinity so use your viewfinder carefully. But also check that you have set the dioptre correction correctly.

    #4 - The big challenge when mixing buildings with fireworks is to balance the exposure between the two. It is very easy to get one much brighter than the other which I presume is not what you want. If you have been shooting from Benjamin Sheares Bridge, try using ISO 100, f/8 and 4 seconds as a starting point. See how the buildings and the fireworks come out. Note than changing the shutter speed does not change the brightness of the fireworks only that of the building. So get the aperture correct first then adjust the shutter speed accordingly.

    #5 - Since you can't predict when the fireworks will go off you should expose for the buildings after the fireworks.

    #6 - Keep the black card in the shade or better still make it 'L' shaped so that one part of it covers the part in front of the lens.

    Hope this answers your questions.

    Quote Originally Posted by erictan8888
    hi,

    been reading a lot of articles on the web on fireworks but none really answered the questions i asking....this is the reason why i asked the following questions here.
    ps: i really go and read up a lot liao.... so pls dun bomb me... hee hee
    just that the articles are mostly talking about what to do but dun really explain why and also did not touch on some of my nagging doubts....

    question 1 :
    just like to check: when would be the best time to close the shutter for a fireworks pic?
    do i close the shutter when
    a. the fireworks is brightest or
    b. when the brightness has all died down or
    c. when i finish counting the seconds eg when time is 3 sec if i want a 3 sec exposure?

    one website said that must close shutter when fireworks at brightest.
    does it matter if i close the shutter when the fireworks is at the brightest or when it is not the brightest?
    i mean when i close the shutter, does it capture the last bright scene on the sky or does it accumulate all the lights that has entered the camera?
    for instance, would it make a difference if the shutter close when fireworks is brightest compared to when fireworks is not the brightest ? assume that aperture size and shutter speed the same.

    question 2:
    if i want the building to be in the picture, eg fullerton hotel to be in the picture, i set focus to fullerton hotel and switched to manual focus to prevent the camera from re- focusing again when i shoot the fireworks.... is this the reason?

    question 3:
    if i dun want to have building in the picture, do i set the focus to infinity and aim at the black sky? sorry... checked the manual but it does not seem to say how to focus to infinity?

    i set camera to autofocus and at f11 (or to about f16).... and focus on fullerton hotel.... is that focus to infinity?
    i look at the lens ring that and see that it is not turned to infinity by the auto focus done by camera. then i switched to manual focus and manually turn ring to infinity.... but now fullerton hotel appear blur...

    how exactly do i focus to infinity?


    question 4:
    if want buildings in the picture with fireworks and set focus to infinity, will outcome be ok?

    question 5:
    if i set to f11 and about 3 sec exposure, this is just about right for the fireworks.... but the buildings in the pic appear to be slightly under exposed....
    can i open the shutter 1 to 2 sec before the fireworks appear and use black card to block the lens... then remove black card when fireworks start appearing. i was thinking in this way, the building gets about 1 to 2 sec exposure more than fireworks... meaning buildings get properly exposed and so do the fireworks....

    is this thinking right or wrong?

    question 6 (last one liao.... sorry):
    was standing at shears bridge on last sat. facing fullerton building, but got street lamps on road behind me. problem is when i placed black card over my lens, because the street lamp is behind me, it shine onto my black card. although the black card is of non refractive black material (can see orange light from lamp on the black card), will the shinning of the light on the black card cause the camera to take in more light when it should not? or does it mean that because the black card is non refractive, although i see the light, to the camera, the black card is black.... ?? dun understand... sorry

    i know that the best way to learn is to experiment and try... but fireworks dun come everyday, so want to get the concepts right before i go and shoot... guess that is better than go and anyhow whack photos...

    "xi er gong ting" (waiting earnestly for advice from anyone)
    thanks
    __________________

  3. #3

    Default

    Quote Originally Posted by erictan8888
    hi,
    question 1 :
    just like to check: when would be the best time to close the shutter for a fireworks pic?
    do i close the shutter when
    a. the fireworks is brightest or
    b. when the brightness has all died down or
    c. when i finish counting the seconds eg when time is 3 sec if i want a 3 sec exposure?

    one website said that must close shutter when fireworks at brightest.
    does it matter if i close the shutter when the fireworks is at the brightest or when it is not the brightest?
    i mean when i close the shutter, does it capture the last bright scene on the sky or does it accumulate all the lights that has entered the camera?
    for instance, would it make a difference if the shutter close when fireworks is brightest compared to when fireworks is not the brightest ? assume that aperture size and shutter speed the same.
    __________________
    Am not a pro at fireworks, still getting the details down.
    For me, I think I should open the shutter when its dark, aim for streaks that start at the bottom, then when they open fully, close the shutter. Thats to me in theory the best way to capture one 'full' firework.

    I'm using 300D. As for proper exposure, I can do layers to increase the exposure of the buildings while the exposure of the fireworks remains. And even paste several fireworks in one frame. As for film, I've never touched a film SLR, though doing a double-exposure (by shooting and rewinding the film) or using a black card (easier IMO).

    Focusing at inifinity, your cam (DSLR or most P&S), should be able to set manual focus. If its SLR, one way is to AF the buildings, then set to MF, the reading on your lens should be around infinity, or just MF and set to infinity. If its P&S, read the manual.

    Cheers

    Btw, how to get onto sheares bridge from marina side?

  4. #4
    Senior Member erictan8888's Avatar
    Join Date
    Nov 2004
    Location
    Singapore
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    Default

    thanks for advice....
    there is a small stairs up to shears bridge.... walk from millenia BK there... can go together if you dun know how.... i going again this weekend...
    Hope to learn from everyone here....

  5. #5

    Default

    hi, is the entire bridge area accessible? the artillery is firing at the grass patch area, so I was assuming some areas of the bridge might be closed.

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