I t seems to be the single biggest failure of my photographs when using a very long 560mm lens (actual length). I have had mixed advice. One photographer experimented with different techniques and determined that mirror flop was worse with lenses over 300mm, worse if a cable release was used, and worse if the lens was mounted to the tripod by the lens collar rather than the camera. Another person recommended pushing their face against the back of the camera and holding the top of the lens while taking the shot. Can any readers comment on whether these methods do minimise camera shake?

[EcoPix g20-11s] These roosting brolgas in predawn light required a half second exposure through a 180mm lens. Though the birds were mostly still, the mirror needed to be locked up to avoid camera vibration and record a sharp image. Shots made at the time with a 400mm were all unsharp.

Editor - Donald and Molly Trounson, the eminent bird photographers who established the National Photographic Index of Australian Wildlife in the 1970's, experimented extensively with techniques to eliminate camera/lens shake when using long lenses. They found that the worst place to mount a long lens was at the point of balance, which is exactly where the lens manufacturers put the tripod bush.

[EcoPix f28-2s] This resting dingo in the forest evening was still enough to use a slow shutter speed, but in these situations results can still be disappointing due to camera movement. A low tripod, gentle technique and a hands-and-cheek-on approach produced a sharp result, though plenty of frames went in the bin.

They found that the best method is to use two points - one at the camera and one up front, but this can make rapid movements difficult. They developed a complex mechanical arrangement which allowed this while following birds. There is a gimballed tripod mount available now which hangs the lens and is reported to eliminate a lot of shake while retaining smooth manoeuvrability. These are quite expensive. Some new lenses have image stabilisation, which, according to the manufacturers, can give a three stop advantage. Expect an improvement of two stops with these lenses, but availability in really long focal lengths is limited and they only work on the latest camera bodies. Below are a few pointers I have found necessary, and we await keenly your ideas on this important problem.

• Use a solid tripod as low to the ground as possible, without centre extension.
• A fluid head, as used by cinematographers, is better that a normal pan and tilt head. The heavy studio style ball and socket heads are good too.
• Try to work long lenses on a tripod at only the fast speeds, down to 1/125th of a second, and one second or bulb. Expect some degradation at 1/125, and plenty of failures at 1/60 and 1/30. Don't even try 1/15 to 1/2 second exposures on a tripod with very long lenses.
• When following wildlife at moderate shutter speeds, it is generally better to handhold the lens while it is fixed to the tripod, rather than using a cable release and not touching the rig. Your face, hands, arms etc will absorb some internal vibration. I tend to lean quite heavily on the focusing ring and eyepiece, often laying my forearm along the lens.
• Always lock up the mirror when using slower speeds in tele or macro work. (Regrettably manufacturers are now omitting this feature in their cheaper SLR's. They claim mirror vibration has been eliminated but a simple trial refutes this. My F801 gives exactly the same results as my 25 year old Nikkormat - blurred! But I can lock up the mirror on the old dog. A modern body with mirror lock up can give a higher success rate still, because the shutter curtains are so much lighter now.)
• When you have to use slow speeds, place the rig on a flat surface such as a strainer post, car bonnet (engine off!) etc, and shore it up into position with jacket, bean bag etc*. A heavy bean bag placed on top also helps. This is the only way I know to make sharp long telephoto images at the very slow speeds.
• The distinguished Swedish nature photographer Ingmar Holmason developed a technique using lightweight large-diameter plastic drain pipe instead of a tripod. The pipe stands stably on even or soft ground and a v-notch is cut into the open top, giving a four-point support to the lens laid along the notch and held. He claims sharp images down to 1/15th of a second with a 1000mm lens, which is impossible with an ordinary tripod.
• Other causes of degradation in long shots are wind, and atmospheric disturbance, which can degrade images at even close quarters - sometimes down to 10 metres. Calm, cool and clear mornings are best for sharp results.

Of course none of the above solves the problem of subject movement - if you want to stop action, your only recourse is a fast shutter speed, or flash. These flighty pelicans at dusk could only be stopped with a fast lens and 1/250th of a second shutter speed.

[EcoPix g9-6s]