does the nikkor VR help in case ...

Discussion in 'Lens Lust' started by bkaushik, May 24, 2007.

  1. Hi,

    Does the Nikkor VR help to reduce vibrations of following kind:

    1) mirror slap
    2) shutter release and close
    3) minor vibrations while we press the button down to click the snap

    I ask these questions because I was wondering as to what difference VR can make on long tele lenses (600mm f/4, 400mm f/2.8, 500mm f/4 types) which however need a tripod to shoot.
    If it helps reducing the vibrations of the above kinds, then it would be of great help.

    Please throw some light on this...

    rgds,
     
  2. I'm not convinced so since the stabilisation takes place before the mirror flip up and the shutter release. But I could be wrong. I have done some quick tests with my friend's Canon 500mm IS with and without mirror lockup and remote release. The image sharpness do show improvment with the mirror up and the use of remote release.
     
  3. InitialD

    InitialD

    151
    Mar 12, 2007
    Malaysia
    I thought I came across somewhere that the Canon IS in the 500mm does indeed compensate for mirror slap. I could be wrong though.
     
  4. I came across this article which said the optical stabilization isn't the answer to mirror slap (last line of the first paragraph)
     
  5. cadman

    cadman

    301
    Dec 4, 2006
    Johns Creek, GA
    Nikon says if you are on the pod turn VR off. If you are handheld you got a hell of a lot more to worry about than mirror slap.

    JMHO
     
  6. For me, I'v been using a monopod with my 70-200 VR with the VR on. I'v been setting the VR off these past few outings and my picture is WAY better and WAY WAY sharper than before.

    I don't know maybe its just me and my monopod technique but now I won't be using on VR on my monopod ever again.
     
  7. cadman

    cadman

    301
    Dec 4, 2006
    Johns Creek, GA
    I think that indicates good monopod tech - the more stable the platform, the more VR will negatively affect sharpness.
     
  8. fishlips

    fishlips

    69
    Apr 20, 2007
    Puyallup, WA
    Garry is correct.
    When I am on a pod with VR on, I have noticed that I can get better images with VR off. The VRII is suposed to recognize this and self-correct but that could be vapor-ware.
     
  9. jfriend

    jfriend

    313
    Nov 11, 2005
    SF Bay Area
    My understanding of VR is that it works by counteracting detectable and moderately regular shake frequencies. Apparently, the shake from hand-holding is actually fairly regular. I do not believe it is quick reacting enough to handle one shot perturbations like mirror slap or a wiggle from pressing the shutter.

    With the long lenses, VR enables handheld use or even monopod use in some circumstances that they could not otherwise be used. And, it's my understanding that there are some cases where the latest versions of VR can even occasionally help on a tripod when there's some sort of regular vibration (e.g. tripod not that sturdy, windy conditions, etc...).

    In all cases, I know of no reason why you shouldn't just eliminate mirror slap and shutter press wiggle from the equation when shooting on a tripod. They are usually simple to eliminate and it will make better pictures to eliminate them.
     
  10. Thanks everybody for loads of input.


    jfriend, any tips/techniques on how to eliminate mirror slap vibrations ?

    rgds,
     
  11. jfriend

    jfriend

    313
    Nov 11, 2005
    SF Bay Area
    Some ideas

    Unfortunately, the D70 doesn't have mirror lock up because that's the best way. You lock up the mirror, then trip the shutter.

    Without mirror lock, your options are:
    • Avoid the shutter speeds that are most affected by mirror slap. What that shutter speed is depends upon your setup, but I've often found it to be around 1/30th. At speeds significantly faster than that, the shutter is fast enough that it isn't affected as much by the slap vibration. At speeds significantly slower than 1/30th, the vibration damps out during the shot and more light hits the sensor after the vibration has slowed down so you don't see it's effect a much. You could test this out with your specific setup by taking shots at a whole bunch of speeds to see which shutter speed has the worst performance.
    • Go for the firmest tripod setup you can get. Beefy tripod, strong head, strong foot, hang weight on the tripod hook, don't extend the tripod column, keep the tripod legs as short as you can, balance the camera/lens well on the head, etc...
    • Use some sort of cable release so there's no vibration from the shutter trip.
     
  12. genera

    genera

    Oct 6, 2005
    California
    Balakumar,

    I think that VR relies on optical feedback to correct for movement so it makes sense that it can't help when the mirror is up and slapping happily away.

    John's recommendations are good but I'll add a couple of comments.

    1) When used in conjunction with your sturdy tripod and head, try pressing down on the top of the lens, directly over the head, as you press the shutter release. Personally, I've never found this to be useful but some say it does help to dampen vibrations.

    2) I did a test similar to what John recommends in his first point. I found that the blur from mirror slap, on my D70, was worst at about 1/4 sec. and that it got linearly better with each doubling of the shutter speed until at about 1/125 sec. it's no longer noticable. I have some test photos that illustrate this but SmugMug is doing some maintanence right now and I can't upload. I'll add the photos in the morning.

    3) Buy a camera with a mirror lock-up function :eek::biggrin:. It's the only way to totally eliminate it.
     
  13. You will be amazed how much vibration you get through the long glass even when tripod mounted!
     
  14. Thank you very much John and Gene for the tips. I shall keep them in mind.

    Gene, I shall look forward to viewing your experimental shots. Please let me know (on this forum or PM) when u upload them.

    rgds,
     
  15. genera

    genera

    Oct 6, 2005
    California
    Blur from mirror slap

    These photos were taken using a sturdy tripod and head using a remote shutter release. The head was clamped down tight. I allowed a couple of seconds for any motion to die down after making adjustments and before pressing the shutter release.

    A larger version is available here.

    In photos 1 and 3 the distance between the ghost image and the primary image is proportional to the reduction in shutter speed. I stopped at 1/4s so I don't know if it got worse at slower speeds. You can see that there are both vertical and horizontal components to the movement (this may be easier to see if you follow the link to the larger image). In 1 the movement is mostly upward with a little movement to the left. In 3, which was taken in portrait orientation (and later rotated to match the other photos) the movement in mostly to the right with a small upward component. When I took these I was skeptical about how badly IQ could be degraded by mirror slap, but not any longer. Tips on avoiding mirror slap: Keep your shutter speed up if you can. Use mirror lockup if you camera has it. Don't use telephoto lenses. :smile:

    BTW, can anyone tell me why there is movement both left/right and up/down? My guess is that the larger movement is from the mirror and the smaller is from the shutter.

    [​IMG]


    Sorry, I no longer have any of the intermediate photos, just these composites.
     
  16. gvk

    gvk

    388
    Jun 17, 2005
    Mystic, CT
    According to Nikon's description of VR technology at
    http://www.nikon.co.jp/main/eng/portfolio/about/technology/nikon_technology/vr_e/index.htm

    1. VR uses angular velocity sensors for yaw and pitch due to camera shake (I think that these are likely acceleration sensors and velocity tracking is actually calculated via the built in microcomputer).

    2. This angular velocity is sampled every 1/1000 second and the microcomputer calculates the required position of the movable VR lens to compensate for camera movement, and updates its position by pulsing voice coil motors.

    3. VR does not compensate for camera movement during recomposition (I would guess that recomposition is typically slower and larger in amplitude than camera shake).

    4. VR changes its operation algorithms during exposure and compensates more agressively for smaller movements. The movable VR lens is also re-centered when the shutter is released just before exposure to avoid dependence on its previous position of VR lock with shutter release partially depressed.

    5. In normal VR mode "slow and wide camera movement" is considered recomposition and ignored (Although not mentioned on this page, they specify elsewhere that panning is also detected in normal mode, and my experience confirms this). In active VR mode "even large amounts of camera movement are compensated."

    6. "A tripod is generally believed to prevent image blur, but camera shake can occur due to the movements of the quick-return mirror or shutter curtain, or winds. This camera shake movement has different characteristics compared to normal camera shake caused by handheld shooting. Nikon's VR technology makes it possible to detect and compensate this type of camera shake, as well. (Note: Some VR lenses do not have this function.)" The only lenses that I know of that Nikon explicitly states have tripod mode VR are the 200 mm f/2 VR, 300 mm f/2.8 VR and 200-400 f/4 VR.

    Interesting reading that seems to contradict some of the speculation earlier in this thread, even if most of the info on that web page was probably written by their marketing department. :smile: I am also skeptical about how much VR actually can help with mirror and shutter induced vibration, although Nikon clearly claims it can. I have used VR on my 300 mm when mounted on a tripod (Gitzo 1325 with Arca Swiss B1 and Wimberly sidekick), but rarely at shutter speeds below 1/100 second.
     
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