Thursday, 14 August 2014

Birds in flight with the CX 70-300mm f/4.5-5.6

When Nikon launched the Nikkor 70-300mm f/4.5-5.6 (my review), I thought the Nikon 1 system finally made sense. What they made was one of the most compact lens suitable for bird photography, combined with the very fast and capable PDAF technology and the fast frame rate. This makes the system well suited for photographing birds in flight.

The purpose of this article is to share my experience with using the lens in combination with the Nikon 1 V3 camera. People who consider to buy the lens can see my experience here. And seasoned users can help me improve my technique.



Equipment


Lens wise, this article is about the Nikkor 70-300mm f/4.5-5.6, obviously.

In terms of cameras, any Nikon 1 camera can work with the lens. However, in my opinion, to use this lens, you need an EVF and a proper grip. This leaves you with two choices: The Nikon 1 V2 or the Nikon 1 V3.

The latter of the two has the grip and EVF as user option items, and I would recommend using them. The extra grip is great with a heavy lens, and the EVF makes it easier to track objects, in my opinion. Here is the V3 with the lens mounted:


As far as I know, the V2 and V3 are similar in terms of focus performance, and both are pretty much equally fast in terms of framerate. So the choice between the two comes down to economics (the V2 is much cheaper), and ergonomics preferences. The V3 has 18MP resolution, while the V2 has 14MP. In my opinion, this is not significantly different. 14MP should be enough for most uses.

I have used the lens with the first generation Nikon 1 J1 also, and that works just fine technically. However, with the low resolution LCD and the poor grip, it is not very easy to use.

You'll also need a large and reasonably fast memory card. I'm using the Sandisk 64GB Extreme. It is not the fastest memory card, but in my experience, it is fine for this application.


With 64GB, you can take about 1500 pictures, when saving both JPEG and RAW images.

Finally: Batteries. The Nikon 1 V3 has a somewhat low battery life, but I usually get around 500 images or more on one full charge when birding. Still, this is not always enough, so I recommend bringing extra batteries.

Some have reported a lack of spare original V3 batteries. However, in my experience, other Nikon 1 series batteries work well in the V3, even batteries from the first Nikon 1 camera models.

I have also found that some cheap third party batteries work just well. Perhaps they don't have the life expectancy of original batteries, but they are cheap, they work, and they are available now.

Camera bag


If you are looking for a bag that accommodates the lens with a camera attached, try the Think Tank Digital Holster 10. It just fits the camera with lens, with very little extra slack. If you leave the hood on, in the extended position, you can extend the front end of the lens bag. That way, you can keep the camera and lens in a ready position inside the bag.

Preparation


Eye-hand coordination


The key to photographing birds with a long lens is coordination between the eye and hand. When you see a bird, it is not trivial to find it with the camera. If you have used binoculars, you'll be familiar with this problem.

What you need to learn first, is to be able to pick up the camera, put it to your eye, and point it to a specific object far away. At 300mm focal length, this is not easy.

To practice this, I suggest that you do not start with birds in flight (BIF). That will just be too difficult and frustrating. Rather, start with picking out some small, stationary object far away, and practice pointing towards it with the lens at 300mm. If you want, you can practice with stationary birds, but any object will do.

Once you have mastered this, I find that it is fairly easy to do the same with a bird in flight. As it approaches, try to find it in the viewfinder, and follow it in the flight. Again, this is quite difficult, and requires practice.

When you are following a bird in the viewfinder, you can press the shutter button to start taking pictures. Keep it pressed as you pan, and the camera will take a series of pictures, while it keeps showing the bird in the finder. See the drive mode settings below.

Before trying to find a bird in the viewfinder, make sure the lens is focused at about the same distance as where you expect the birds to be. The distance doesn't need to be exactly correct, of course, that is why you have continuous autofocus. But if you have a reasonably correct focus, that will make the birds easier to see in the viewfinder. If you have the wrong focus, the birds will just be out of focus, blurry blobs.

Usually, you can find some trees or other objects at the right distance, direct the camera in that direction, and half press the shutter release. That will give you a good starting focus which makes it easier to find the birds in the viewfinder.

The birds


For a start, it is best to photograph fairly large birds that have an even and reasonably slow flight path. The larger the bird, the further away you can be when photographing it. And birds flying slowly in a predictable path are easier to follow with the camera, of course.

It is hard to make general comments about the bird species best suited, as it differs a lot from place to place. But generally speaking, seagulls are often present in urban areas along the coast, they are fairly large, and are not afraid to get close to people. So they can be a good starting point for practicing to photograph birds in flight.

The location


To photograph the birds, you will need to find a location where they dwell. Generally speaking, many species of large birds need a closeness to water, so you are often likely to find them around the coast or near a lake.

Here is an open urban park with a river running through. With a lot of people feeding the birds, despite signs discouraging this activity, there are always scores of seagulls here:


Once you have found them, try to observe them for a while and notice their flight pattern. Often they follow the same path repeatedly, which can be helpful when trying to track them.

Don't be afraid of wind. In windy conditions, the birds often fly a bit slower. It is probably their strategy to retain control over the flight path in difficult conditions. This makes it easier for you to capture them.

Camera settings


Focus mode


Here are some tricks to make the process easier. On the lens, set the focus switch to "LIMIT". This means that the camera will not try to focus on close items, and generally speeds up the autofocus. Setting it to "LIMIT" increases the minimum focus distance to about 4 meters, which is suitable for birds in flight.


The focus mode settings are quite important. First of all, you must have AF-C set. Press up on the four way controller to bring up this menu and set continuous AF:


AF-S is commonly used with non-moving objects. This allows you to focus by half pressing the shutter, and then retain the same focus even if you re-frame while half pressing the shutter.

AF-A should in theory work for BIF, as it should switch to AF-C when needed. However, in practice, the camera needs some time to figure out that it needs to switch from AF-S to AF-C, and it is better to avoid this delay by setting AF-C from the beginning.

As for the focus point, all modes could work, but they do slightly different things. In the illustration below, I have chosen the single point:


One could say that this is the choice for expert users. It allows you to focus on the body of the bird, for example, by making sure the body is in the centre of the viewfinder. This is a good thing, as it means that you don't accidentally focus on a wing tip, throwing the body slightly out of focus. However, the downside is that if you lose the bird from the centre point, the camera will try to focus on the background, and a some of your frames will become totally out of focus.

Using the auto area, the top mode, is usually better for beginners. It makes it easier for the camera to keep the focus on the bird, even if you lose it from the centre point as you pan.

Drive mode


One of the big advantages of the Nikon 1 series, is the ability to take up to 60 frames per second, at full resolution, and while saving the RAW files. With the Nikon 1 V3 camera, you can take up to 20 frames per second, while still getting a good AF-C performance. If you select 30 or more FPS, you will not be getting autofocus between the frames, so set at most 20 for BIF:


You find these setting in the drive mode menu, by pressing left on the four way controller. These high frame rates require that you have set the electronic shutter mode (not the mechanical shutter).

I have often set 10 frames per second. This allows me to pan and shoot a bird during a slightly longer duration than when setting 20 frames. The camera buffer is good for about 40 frames, so that equates 4 seconds at 10 FPS.

Exposure


To keep a bird sharp as it flies, you generally need a quite fast shutter speed. Around 1/1000s or more is usually needed. I would set the camera in S-mode (shutter priority), set the shutter to 1/1000s, and set auto ISO, for example the A3200 mode.

That way, the camera will usually set the maximum aperture, and select an appropriate ISO for your scene. On a bright day time, you may get a low ISO like 160 or 200, but often you will end up with ISO 400 or more.

Often, a bit of positive exposure compensation is good to apply if you are photographing birds against a bright sky. About +0.3 to +1.0 depending on the conditions. Test to see what you prefer.

Electronic shutter and rolling shutter


To get the fastest framerate, you must use the electronic shutter. The Nikon 1 cameras read the sensor values sequentially, row for row, in about 1/80s. This is much faster than the electronic shutter of Micro Four Thirds cameras. For example, the Lumix GH3 has a readout speed of 1/10s, which causes severe rolling shutter issues.

Still, 1/80s is much slower than most mechanical shutter. Anything moving during the exposure can be skewed. So is this going to be any problem?

If you are panning while photographing, you will get some rolling shutter effect in the sense that the background will be skewed. Here is an example, where I photographed a seagull in flight at 1/1250s, f/6.3, 300mm, ISO 400:


As you see, the tent in the background is skewed. In the reality, it is square. This is because I was panning to follow the seagull in flight. The seagull itself is not affected by the rolling shutter, as I was following its path during the shutter readout.

Rolling shutter can be an issue if you have urban architecture in the background, in which case you may notice that it becomes skewed during panning. However, most of the time you do not have any square objects in the background, and you can ignore rolling shutter artefacts, as they will probably not be noticeable.

Setting a faster shutter speed is not going to help: The sensor readout is about 1/80s irrespective of the shutter speed.

This can also be a problem when photographing rotating propellers. Here is a helicopter, photographed using the electronic shutter:


As you see, the rotor blade appears a bit skewed, due to the rolling shutter effect. However, the effect is barely noticeable. Using the non-silent mechanical shutter, the blades would be almost completely straight.

So my advice is: Go ahead and use the electronic shutter, which is denoted the "silent shutter" in the camera menu.

ISO choice


For the best image quality, you'll want to keep the ISO as low as possible, of course. But how high can you set it?

Here is a series of images taken at different ISOs:

ISO 200
ISO 400
ISO 800
ISO 1600
ISO 3200
ISO 6400

And 100% crops from the images at different ISOs:


I think it looks like ISO up to 800 is fairly safe. At 1600, the details start to go away, and ISO 3200 and 6400 are quite poor.

Example BIF pictures


Here is one series of pictures taken at 300mm, f/5.6, 1/4000s, ISO 800. I used 10 FPS, and the auto area focus mode. I used +0.3 exposure compensation. You can click on a picture to see a larger resolution version:


Since I used the auto area AF mode, the camera keeps the bird in focus, even if it escapes the centre point of the image frame. All these pictures are well in focus, and the fast shutter speed freezes the animal so that it is very sharp.


In the next example series, I used ISO 400, 300mm, f/6.3, 1/1250s. And thinking I would be able to follow the bird exactly, I set the centre spot autofocus mode.

However, I was not able to follow the bird, and the camera has focused on the background most of the time, leaving me with a series of out of focus images. It would have been way better to use the auto area autofocus mode, the default choice:


Only the two first pictures are sufficiently in focus. Here is the first one, cropped. With the evening light, the colours are rather pleasing:


The lesson learnt here is to not select the centre spot autofocus mode unless it is absolutely needed. The auto area autofocus mode would have given me better focus for most of these images.


Finally, here I used the S exposure mode, and set 1/1600s. The exposure used was f/5.6, ISO 450, f=300mm. I was following a seagull as it lands. I used the auto area autofocus mode, which keeps all the photos in very good focus:


Some of the pictures are unusable, but that is only due to poor framing. Apart from that, the camera keeps the seagull well in focus all the time.

More interesting pictures


While the example images above are sharp, they are also quite boring. To take more interesting pictures, here are some ideas:

Find more exotic birds!

Try to find the birds early in the morning, or late in the evening. Then, the light is warmer, which will give you more pleasing colours.

Photograph the birds while they do something interesting. For example while landing, while grabbing food from the water or from the land, while quarreling, while feeding infants, or something else. Photographing them while flying close to the water or the ground can also be interesting.




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