Page 1 of 2 12 LastLast
Results 1 to 20 of 36

Thread: Handshake

  1. #1

    Default Handshake

    At telephoto, handshake becomes more pronounced. But is it because of the slower shutter speeds usually associated with small apertures at long focal lengths or is it also because of the fact that a long focal length WILL make handshake more obvious?

  2. #2

    Default Re: Handshake

    try this:

    take a laser pointer.
    stand 0.5m away from a wall and point the laser at any spot, trying to keep it stable

    now try standing 6m away from the wall and point the laser at the same spot

    what do u notice?
    at 6m, a small movement of ur hand will shift the laser else where from the spot

    same theory when shooting with telephoto. hope the explanation helps
    Photo Album - Photo Album

  3. #3
    Member
    Join Date
    Apr 2005
    Location
    Sengkang
    Posts
    394

    Default Re: Handshake

    Quote Originally Posted by megascriler
    At telephoto, handshake becomes more pronounced. But is it because of the slower shutter speeds usually associated with small apertures at long focal lengths or is it also because of the fact that a long focal length WILL make handshake more obvious?
    your shutter speed must be at least 1/focal length.

    for example, if your focal length is 200mm, you need at least 1/200 sec to minimise camera shake.

    sometimes you need to push up the ISO or ASA if you are using AP mode

  4. #4
    Senior Member sammy888's Avatar
    Join Date
    Sep 2004
    Location
    Singapore, Singapore, Singapor
    Posts
    1,568

    Default Re: Handshake

    Quote Originally Posted by Zaknafein
    try this:

    take a laser pointer.
    stand 0.5m away from a wall and point the laser at any spot, trying to keep it stable

    now try standing 6m away from the wall and point the laser at the same spot

    what do u notice?
    at 6m, a small movement of ur hand will shift the laser else where from the spot

    same theory when shooting with telephoto. hope the explanation helps
    That's a good analogy man!.. heh

  5. #5

    Default Re: Handshake

    heee thanks! just trying my best to explain better
    teaching is a good way to learn
    Last edited by Zaknafein; 28th January 2006 at 11:29 PM.
    Photo Album - Photo Album

  6. #6

    Default Re: Handshake

    Thanx everybody. I've thought about it too, using pendulum oscillation as an analogy. But just to make sure so asked you guys.

  7. #7

    Default Re: Handshake

    Quote Originally Posted by vincenthau
    your shutter speed must be at least 1/focal length.

    for example, if your focal length is 200mm, you need at least 1/200 sec to minimise camera shake.

    sometimes you need to push up the ISO or ASA if you are using AP mode
    Heh, don't forget the crop factor if you using dSLRs!

  8. #8

    Default Re: Handshake

    And why is it so important to be more steady that regular shots for macro?

  9. #9
    Senior Member
    Join Date
    Jan 2003
    Location
    Dry cabinet!
    Posts
    1,757

    Default Re: Handshake

    Quote Originally Posted by drake336
    Heh, don't forget the crop factor if you using dSLRs!
    Actually need not include the crop factor.
    The crop factor does not change the distance of your focusing. The crop factor is due to the fact that your DSLR sensor is not big enough to capture the full image but capture part of the section. This will cause you to capture a zoomed in section of the image whereby "enlarging" it.
    Just like when you have a photo but you crop towards the center, then your overall photo appears bigger.
    Dreaming... 14mm f2.8, 16-35 f2.8 mkII, 85 f1.2 mkII

  10. #10
    Member
    Join Date
    Jul 2005
    Location
    Bt Batok
    Posts
    768

    Default Re: Handshake

    Quote Originally Posted by gryphon
    This will cause you to capture a zoomed in section of the image whereby "enlarging" it.
    the blur is enlarged oso this is different from cropping. try this, shoot at ur camera's max zoom at 1/20sec. then shoot at ur camera's widest end at the same shutter spd and crop to simulate ur max zoom. u'll see the difference in motion blur.

  11. #11
    Member
    Join Date
    Jul 2005
    Location
    Bt Batok
    Posts
    768

    Default Re: Handshake

    the 1/focal [rule] is conservative. with experience its possible to constantly shoot at half of tt [suggested] spd(not counting IS/VR).

  12. #12
    Senior Member
    Join Date
    Nov 2004
    Location
    Tampines
    Posts
    8,167

    Default Re: Handshake

    Quote Originally Posted by drake336
    Heh, don't forget the crop factor if you using dSLRs!
    This was in my mind too..
    So if 500mm on 1.5X Crop = 750mm, so shutter must be 1/750 at least?

  13. #13

    Default Re: Handshake

    Quote Originally Posted by donchua
    This was in my mind too..
    So if 500mm on 1.5X Crop = 750mm, so shutter must be 1/750 at least?
    The focal length of a lens does not change with the crop factor, neither does perspective. The only that changes is the field of view (FOV), i.e. you see less of the image projected from the back of the lens. so for a 500mm lense, RoT is 1/500sec.

  14. #14

    Default Re: Handshake

    Correct, focal length and perspective doesn't change, but the image is nonetheless enlarged right?

    A small blur which is acceptable in full frame will be magnified by the crop factor right. As such after cropping, you have a smaller image with the blur relatively more distinct, isn't it?

    Anyways, I have been using 1 / (FL x cropfactor) all this while for hand hold

  15. #15
    Member
    Join Date
    Jul 2005
    Location
    Bt Batok
    Posts
    768

    Default Re: Handshake

    Quote Originally Posted by donchua
    This was in my mind too..
    So if 500mm on 1.5X Crop = 750mm, so shutter must be 1/750 at least?
    lol if like tt u can only use ur bigma at 12nn or iso1600 w/o support

  16. #16
    Senior Member
    Join Date
    Jan 2003
    Location
    Dry cabinet!
    Posts
    1,757

    Default Re: Handshake

    Quote Originally Posted by cyber_m0nkey
    The focal length of a lens does not change with the crop factor, neither does perspective. The only that changes is the field of view (FOV), i.e. you see less of the image projected from the back of the lens. so for a 500mm lense, RoT is 1/500sec.
    Yup thats right... now i know wat term to use "FOV"
    Dreaming... 14mm f2.8, 16-35 f2.8 mkII, 85 f1.2 mkII

  17. #17
    Senior Member
    Join Date
    Nov 2004
    Location
    Tampines
    Posts
    8,167

    Default Re: Handshake

    Quote Originally Posted by roti_prata
    lol if like tt u can only use ur bigma at 12nn or iso1600 w/o support
    Ok lah, 2 days ago I taken test pic of a airplane letting go white smoke flying
    past my flat around 5plus pm at 500mm ISO400, f8, 1/1600.

  18. #18

    Default Re: Handshake

    Quote Originally Posted by cyber_m0nkey
    The focal length of a lens does not change with the crop factor, neither does perspective. The only that changes is the field of view (FOV), i.e. you see less of the image projected from the back of the lens. so for a 500mm lense, RoT is 1/500sec.
    Agree that the guide is still 1/focal length and don't have to take the crop factor into account.

    For e.g., my Nikon Coolpix 5700 at max. 8x optical zoom has a focal length of 71.2mm which is equivalent to 280mm on the 35mm format. This is similar in calculation to how the focal lenght of lenses on DSLRs with APS sized sensors are multiplied by the crop factor to arrive at the 35mm format equivalent focal length. The crop factor on my camera is actually about 4x. I could easily shoot at 1/60 handheld fully zoom in since the actual focal is only 71.2mm. If the crop factor really needs to to taken into account, then the guide give 1/280 already at full zoom and shooting at 1/60 handheld at full zoom to get steady shots would be unthinkable already.

    The crop factor only affects how large the image will appear on the frame (i.e. because of the difference in FOV). How the rays of light in the camera and lens will vary to cause handshake-blur images is only affected by the amount of handshake and the focal length (how long light have to travel in the lens and camera to reach the sensor) but not the crop factor.
    Last edited by Clockunder; 5th February 2006 at 10:28 AM.

  19. #19

    Default Re: Handshake

    Ok, we really need to confirm this... cos I am quite convince crop factor should be considered... here's my reasoning...

    Picturing how light passes through the lens and get focused on the back (film or CCD/CMOS).

    If we fit the same lens to both film and digital body and shoot the same object, light from the same point of an object will fall on the same position @ the back since focal length is the same.

    Ok, now if our hand shake an equal amount during both shots, the point of light focused @ back will also be shifted equally for both shots, let's say X mm.

    But when you consider, X mm on 35mm film and X mm on APS-size will mean different proportion of the entire image (i.e. smaller area = bigger proportion of blur), I really fail to understand how you can use the same guide line for 35mm film and smaller CCD/CMOS...

  20. #20
    Deregistered
    Join Date
    Dec 2002
    Location
    Planet Nikon
    Posts
    21,905

    Default Re: Handshake

    Use a tripod...

Page 1 of 2 12 LastLast

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
  •