Originally posted by Kinciad
been playing around with my 75-300 lens. mounted on some tripod and noticed that the whole setup (lens and cam) shakes (very slightly) when the shutter opens n closes.
1) at 300mm, will the slight 'vibration' caused by the shutter blur pictures?
There's a couple of causes for blurring of images when mounted on a tripod and these are:
1) Tripod too lightly constructed (ie: flimsy)
2) Ballhead/Panhead not locking down correctly
3) Poor tripod collar design that doesn't hold the lens/camera rigidly.
4) Poor trigger release method (the finger should be rolled gently over the shutter release, not stabbed, poked or otherwise violently pressee.
5) Mirror slap. Not much you can do about this one as it's an inherant design flaw in many cameras (caused by having light camera chassis, insufficient damping and cost cutting in general).
Mirror slap occurs when the reflex mirror movement is activated. If the mirror isn't well damped then the voilence of the movement sets up a vibration in the camera body that can last upwards of 1/4 second in severe cases.
Originally posted by Kinciad
2) i dont have a remote release yet, so i used timer instead... any use?
It depends on how your camera implements the self timer function. If the reflex mirror is moved 'up' at the start of the self timer cycle then it will help a lot in reducing vibration. If however the mirror is moved just before the shutter is actuated then it's of little use. You can test this function by simply watching through the viewfinder and seeing if when in the self timer cycle the image through the viewfinder goes blank (black).
Originally posted by Kinciad
3) will more expensive tripods prevent this? "note the vibration is caused by shutter movement and not by shaky tripod - i think!" :dunno:
Generally you get what you pay for with tripods. Light tripods (with the exception of carbon fibre and composite fibre tripods) tend to be extremely prone to vibration with long lenses.
A few tips however.
The use of a 'rock bag' or sling is an old trick that Streetshooter has mentioned. It involved using a sling between the tripod legs and filling it with a couple of kilos of rocks, gravel, sand etc. However you have to be careful that you don't overload the tripod. this method is greatly favoured by European wildlife photographers and those working with prime lenses over 600mm
Get a heavy tripod - For pure stability nothing beats mass and good old weight. Heavy tripods are far more stable than light tripods. The downside is that they can be back breaking to carry. (Try lugging a 8+kg tripod/head combination around and you'll know what I mean).
Try placing your hand over the tripod collar. Again this is a standard long lens technique and damps vibration very well for shots over 1/60th of a second.
Avoid the infamous 1/30th to 1/8th or thereabouts 'blur zone'. A lot of zoom lenses have insubstantial tripod collars and are prone to image blur between about 1/30th and 1/8th second shutter speeds. Avoid this speed range where possible.
Lock all controls on the tripod down tight!
Hope this helps.
