Ophrys Photography

Wildlife photography by John Devries, Kent UK. Inspirational images from nature.
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Tips and tutorials
Photographing wild birds Part 5

In my earlier tutorials on photographing wild birds I have covered points 1 to 3 in my list of common errors:
1) Subject too distant.
2) Subject not in focus
3) Blur due to subject movement - motion blur
4) Blur due to camera movement
5) Incorrect exposure
6) Little consideration given to lighting or composition

Let's now carry on moving down the list and finding counters to these issues.

4) Blur due to camera movement

In the last tutorial we looked at the affect of blur due to subject movement. Now let's move onto blur caused by unwanted camera movement and vibration.

Let's face it, nobody likes using a tripod, monopod, beanbag or other means of support as they add extra weight for us to carry and also restrict our movement. What they do achieve though is to eliminate most sources of our own camera shake and vibrations present within the camera.

Is it always necessary to use a camera support ?

The answer is no, but it depends on a number of factors: The magnification (how large the subject is in the frame) and is therefore is related to the focal length of the lens in use, how high a shutterspeed we have available to us, whether the lens has image stabilisation/vibration reduction (IS/VR) and finally the size of the cameras image sensor employed.

Try mounting a recent camera and long lens onto a tripod and view the rear screen in Liveview mode. If you then increase the zoom to around 10x , focus manually and look at the image you will notice that if you so much as touch the camera very lightly the image vibrates wildly on the screen. Imagine what will happen if you were handholding. This is camera shake and we must eliminate it if we are to get critically sharp images, but at what shutterspeed can we safely ignore this issue?

With film cameras, the accepted wisdom was that you can handhold at the reciprocal of the focal length of the lens. In other words if you are using a telephoto lens of 500mm focal length you should ensure that you have a minimum shutterspeed of 1/500 sec. A full frame sensor camera with a 35mm sensor should be equivalent to a film camera with 35mm film fitted so the same wisdom should apply.This guideline is a pretty good rule of thumb, but assumes that we can all handhold a camera and squeeze the shutter gently to the same degree. Of course we can't, so it is worth doing some experiments to determine what you can achieve with your own gear.

The guidance also needs to be updated to reflect IS/VR systems built into cameras or lenses. These can very usefully enable you to handhold at a shutterspeed of between 2 and 4 stops slower than you could without it. A Canon 300mm f4 IS enables you to theoretically handhold at 2 stops lower, so that means you could hand hold it when fitted onto a film or full frame camera at 1/300 sec without IS (so the nearest shutterspeed is 1/250 sec) and 1/60 sec with IS employed. This is a huge advantage and when combined with modern cameras' high ISO abilities a tripod is become less of a necessity unless trying to freeze motion, shoot at small apertures or in low light such as in a forest or on a dull day. You still need to bear in mind though, that although you you may be able to hold the camera to lower shutterspeeds, the subject movement remains the same so motion blur is still a possibility that you need to factor in.

The crop factor of the camera must also be considered. Cameras come with 1.3x, 1.5x or 1.6x crop sensor sizes which increase the effective focal length by the same factor. Our 300mm f4 lens that could just about be handheld at 1/250sec (without IS) becomes effectively a 480mm lens on a 1.6x crop camera so you should not handhold below 1/500 sec.

When I am photographing birds I usually use a 500mm f4 IS lens which I use with or without teleconverters, so the use of a tripod and head is usually essential. The weight of the equipment is such that it can be hand-held if there is sufficient shutterspeed available but only for short periods unless you have the muscles of a weightlifter!

When shooting birds in flight I like to use the Canon 400mm f5.6 lens as it is very sharp, is fast to autofocus and comparatively compact and light in weight. It does lack IS, but as you need to be shooting at high shutterspeeds anyway to freeze subject motion this is not much of a handicap. The Canon 400mm f4 DO IS is even better as its maximum aperture is a stop faster and the IS makes it more versatile for other uses.It is however considerably more expensive and probably has no better image quality than the f5.6 lens.

Camera vibration

If you put your teeth on the hot shoe on the top of the camera and take a picture you will feel a pulse of vibration as you fire the shutter. This is caused by the mirror being flipped up and down when the camera takes the picture. Unlike the low frequency movements of camera shake, this vibration is a very high frequency movement within the camera and can cause softening of the image if not controlled.

You would think that you would get your sharpest images by mounting the camera on a tripod and by using a remote cable release, instead of pressing the shutter button by hand. Thanks to the internal vibrations that I mentioned previously this is not actually the case. The vibrations are in fact amplified by travelling from the camera, up a long lens, through the lens hood and back down to the camera sensor. It is important to damp this vibration by using good long lens technique which is described in the next section.

If you are using incredibly slow shutterspeeds in the order of 1/10 second for some reason, or you are using stacked converters on a long lens to get maximum reach it may be beneficial to lock up the camera mirror (Using Mirror lock-up MLU - usually found in the camera custom functions). An alternative is to use liveview as the mirror needs to be raised to enable you to look at the image straight off of the sensor. If you now use a cable release, the camera operates very quietly and smoothly causing much less unwanted vibration. Camera models can behave differently in liveview, so I recommend you read this excellent article by Juza on the subject if interested.

Long lens technique

When using a long lens on a tripod you need to damp the internal vibrations caused by firing the shutter as follows:

Stand with your feet hip-width apart to get a good stable stance and then grip the camera grip with your right hand as usual with your index finger gently resting on the shutter button.Now look through the viewfinder and press your eyebrow up against the rubber eyecap and press your cheek gently into the camera. Next, place your left hand on top of the lens directly over the pivot point (the ball head). Now lean your weight on your left hand. You are now grounding those vibrations through your body and image sharpness will benefit as a result.If you would like to read more about long lens technique click here: Nature photographers online magazine article

The great American bird photographer, Art Morris has a variation on this method which may be worth trying:
" With the palm of your left hand pointing skyward, put that hand under the front of the lens plate and grab it with the last two or three fingers. With your thumb and index finger, push up forcefully on the lens barrel from below. (No matter how sturdy your tripod head and big lens are, there will always be some play here.) You may have to frame a bit low so that when you "take the play out" you wind up with the desired framing. Hold the camera firmly in your right hand and press your face against the camera back and you will be able to make sharper images at slower shutter speeds than ever before."

Art Morris also uses this technique for the Mongoose 3.5 head and says that it is similar for the Wimberley heads.

Finally, whichever method you choose, when you want to take a shot,don't jab at the shutter button (not always easy when something exciting is happening in front of you). Instead, simply increase the finger pressure until the shutter fires.Some good bird photographers describe using a rolling motion of your index finger.





IS/VR on or off on a tripod ?

On the first generation image-stabilised lenses the manufacturers advise that you switch the IS (VR) off when using a tripod. The reason for this is that the stabiliser can hunt around looking for motion to stabilise instead of just staying still. If you look through the viewfinder you can see this wandering movement if you lock down the ball head firmly.The Canon 100-400mm f4.5-5.6L IS is an example of a first generation IS lens that behaves in this way. I always turn IS off on this lens on a tripod.

In 1999, Canon announced a new generation of super telephotos with second generation IS. The stabiliser used in the 300mm f/2.8 L IS USM, 400mm f/2.8 L IS USM, 500mm f/4 L IS USM and 600mm f/4 L IS USM offers a 2 stop advantage and does not have to be switched off when used on a tripod.

With these lenses it is claimed that IS helps to combat wind or ground vibrations and also mirror slap. The IS should therefore be left on permanently. I normally heed this advice when using a a ball head that is tensioned but not locked down and also when using a gimbal head (which effectively floats weightlessly). However, if you lock the head down tightly you will still see the image wandering around in the viewfinder. It is only moving very slowly, so if you are using a shutterspeed in excess of 1/125 sec I don't suppose this movement is significant, but at lower shutterspeeds I am inclined to turn IS off again.

When working hand-held, off of a monopod or bean bag, I always leave IS on regardless of the lens in use.

Lens IS modes 1 and 2

Finally some image-stabilised lenses have a switch to control whether IS is on in both planes (vertical and horizontal) or just in the vertical plane. The manufacturer advises that position 1 (both planes) is the usual position and position 2 is only used when panning. The idea is to stop the stabiliser opposing your intentional horizontal movement when panning. Some bird photographers claim that position 2 is the one to use all the time as it acts like position 1 until a horizontal panning movement is detected. I am not sure whether this is correct or not. Others claim that position 1 is the one to use for birds in flight (BIF) as the IS works as described by the manufacturer and you are rarely performing a true pan - as birds are either coming towards you or at a forward/sideways angle, rarely do you pan like you would if you were photographing a racing car going past you. You therefore need stabilisation in both planes - so position 1 is the one to use.

Lens switches
The stabiliser mode switch is second from the bottom in this picture


I tend to use position 1 most of the time for BIF and only switch to 2 if I am doing an obvious pan .Having said that, in the heat of battle there is often not time (or the presence of mind) to flick the switch. I am sure I have taken plenty of sharp (and unsharp!) pictures in both switch positions, so I would struggle to make a firm recommendation here.