Sharpness issues

I have recently been having real difficulties with getting really sharp images with my 500mm f4 lens. I have tried different camera bodies and re-calibrated the lens using Lens align with Focaltune software, with each of them, both with and without the TC-14 teleconverter I regularly use, with no real sense of the problem.

Then I spent a couple of hours on Cherry Beach shooting shorebirds, both foraging along the tide line and birds in flight at varying distances. On examining the images in Photomechanic the light suddenly went on! All the images shot at closer distances were sharp, most of those beyond about 40 feet were decidedly not, yet occasionally even an image further out would be sharp as a pin.

 

Semipalmated Plover (Charadrius semipalmatus) grabs a worm while foraging on beach, Crescent Beach, Nova Scotia, Canada

Nikon D3s, Nikon 500mm f4, Gitzo tripod with Flexshooter head. 1/1250th @ f5.6, ISO 400

Obviously the issue was not with the camera bodies but decidedly funky behaviour form the lens, so it’s on it’s way to Nikon service in Toronto.

This left me with a problem as I have been waiting several days watching a nearby Osprey nest as the youngsters were obviously very close to taking their first flights. Not wanting to miss out on the opportunity yesterday I grabbed the 200-400mm f4 zoom with the 1.4 converter and hoped that I would have enough reach if there was any action.

Sure enough almost as soon as I arrived I could see the two youngsters were testing their flight skills, launching themselves a few feet above the nest and hovering on outstretched wings before landing neatly back on the nest. By adding the TC-14 converter, zooming in to the 400mm setting I was able to get a focal length of 560mm and by stopping down to f8 to give me a little more depth of field and sharpness came away with a good set of usable images.

Young Osprey (Pandion haliaetus) tests it’s wings while learning to fly at nest on artificial nesting perch, Petite Riviere, Nova Scotia, Canada

Nikon D3s, Nikon 200-400 f4 zoom + TC-14 converter (effective focal length 560mm), Gitzo Tripod with Flexshooter head, 1/1600th @ f8, ISO 320

To see a wider selection of new photos go to the Recent Images gallery. This is updated regularly.

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Attila the ‘Hum’ – how to photograph hummingbirds

Since being back in British Columbia we have had our hummingbird feeders out and have seen more of these mini wonders than in any previous year. We have been filling the feeders every day and if we are a little late the birds soon mob us as soon as we go outside and let us know.

Female Rufous Hummingbird
Female Rufous Hummingbird (Selasphorus rufus) in flight at a feeder

One feeder is situated on our upstairs deck, overlooking the garden and this is jealously guarded by one male Rudous Hummingbird who sits nearby waiting for intruders. As soon as another hummer appears anywhere near the feeder he rockets across the garden and there ensues a round of astonishing aerial combat – this is ‘Atilla the Hum’ who terrorises the rest of the hummingbird flock. However as soon as he is otherwise engaged other birds will rapidly take the opportunity to visit the feeder.

Male Rufous Hummingbird
Atilla the Hum – Male Rufous Hummingbird

Photographing hummingbirds can be a little challenging – their wings beat at some 60-70 times per second, and can fly at 25-30 mph in normal flight and attain 60 mph when they make their spectacular dives. Fortunately they are also able to hover virtually motionless when feeding and are the only bird that can fly backwards.

Even with today’s modern DSLR’s and their ability to shoot at shutter speeds of up to 1/8000th sec this will still not be fast enough to get those wings completely frozen. In addition to obtain these fast shutter speeds you will often need to dial up the iSO setting resulting in  loss of image quality, and open up the lens to it’s maximum aperture resulting in limited depth of field.  The answer is to use high speed flash to freeze the action.

My technique for high speed flash

There are number of ways to set up for high speed flash, but here is my method. (When I talk about high speed flash I am using regular camera speedlights, not studio strobes)

Flash settings

I set all my flashes to manual. Some photographers use TTL but I find that for this sort of work I prefer to have complete manual control. The main reason for this is that flash is providing 100% of the illumination for the photograph, therefore, once you have your camera and flash settings giving a correct exposure, you are not subject to any changing light conditions so you can be guaranteed that every exposure will be the same.

Flash duration is directly related to the output setting on the flash. The table below gives the power output and corresponding flash duration for settings with a Nikon SB910 Speedlight. Other Speedlights will be broadly similar including those by other manufacturers.

1/1 (full) output = 1/880 sec
1/2 output = 1/1100 sec
1/4 output 1/2550 sec
1/8 output = 1/5000 sec
1/16 output = 1/10000 sec
1/32 output = 1/20000 sec
1/64 output = 1/35700 sec
1/128 output = 1/38500 sec

As you can see, when you dial down the power, the flash duration gets progressively shorter, and these durations are way faster than any camera shutter. So how to put this to good use.

Camera settings

I also set my camera to manual mode when using high speed flash. Again, once you have a correct exposure there is nothing to change and you need to gain complete control for this first stage.

You need to determine a base exposure – this is an exposure at which the camera will register no ambient light in the image. (To help with cutting out ambient light it is helpful if your subject area i.e. the feeder and background are in a shady area rather than full sun). Start by setting your camera to it’s lowest ISO setting, which will additionally give the best quality in your file and the fastest flash synchronization speed. (Nikon and Canon users should not use high speed flash settings as, to achieve these fast synchronization speeds, the flash emits multiple burst of light that will have a slightly stroboscopic effect and result in blurring of the wings – the very thing we are seeking to avoid). Turn off your flashes, focus on the feeder and take images adjusting your camera aperture until you get a completely black frame, i.e. no image registering at all. I generally find something in the order of ISO 200, Shutter speed 250th (my fastest sychronization speed) and an aperture of around f11 does the trick in a shady location.

With regard to lenses you need something that focusses relatively closely whilst allowing you to remain far enough form the feeder to not disturb the birds. Something in the 300mm to 400mm range is ideal. I pretty much always use my 200-400mm f4 for these shoots as it focusses right down to 2m (6.2′) allowing frame filling shots of these tiny birds.

Finally – use a tripod! You cannot possible hand hold a long lens, focus and frame the birds with any degree of accuracy.

Placement of the flashes

Note that I say flashes – you need more than one flash for a number of reasons. First, the output is going to be dialled right down so output is going to be low (although we are going to compensate by placing the flashes close to the subject area). Second we need to light from multiple directions to avoid shadows, and third we are going to need to light the background otherwise it will register as jet black (although this in itself can lead to interesting photographs).

Rufous Hummingbird (Selasphorus rufus) in flight
Rufous Hummingbird (Selasphorus rufus) in flight – no background

Many articles will show setups with between five and seven flash heads but you can certainly get great photos with as few as three as I will demonstrate. (Note that because you are using fully manual settings you do not need thousands of dollars worth of camera brand flashes – a few cheaper models with manual settings will easily suffice such as those made by Vivitar and others).

Your flashes do need to be close to the subject area as your flash output is going to be low and will not have a lot of reach, around 12″ to 18″. To use a three light set up I place two of the flashes at around 45º with one set slightly higher than the other to give a balanced light, and a third above the background pointing straight down.

Set up using three flash heads
Set up using three flash heads

Most modern flashes also have a zoom setting. I set the two flashes in front of the subject to their maximum zoom settings to concentrate the throw of light and the background flash to 50mm to give a bit of spread over the background.

I generally start with an output setting of 1/32 or 1/64th, either of which will give an action freezing flash duration for a hummingbird wing. Take a photo, doesn’t have to have a bird in it, simple image of feeder or a flower head in the correct location will do just fine. Check the exposure on the camera and watch for flashing highlights and blown out area on your histogram. Adjust your camera aperture (never the shutter speed) until you have a spot on exposure.

Female Anna's Hummingbird (Calypte anna) feeding at a Hosta flower
Female Anna’s Hummingbird (Calypte anna) feeding at a Hosta flower

You are going to need a method of firing the flashes. I use Pocket Wizard Radios along with some flashes set to fire  using IR slave. You can also use a sych. cord to one flash and set others to fire using either built in optical slaves or cheap add on optical triggers. Check your manuals to see what works for you.

Feeder set up

To attract the birds it’s best to set up at a feeder station they have already been habituated too. Hummingbirds are remarkably tolerant, allowing you to be very close whilst they feed. When you start shooting don’t simply fire away every time a bird arrives at the feeding station. Give them a break once in a while and allow them to feed without the flashes popping of every time they get near. It is amazing at how quickly they will get used to the flashes and other ‘stuff’ you have placed near their feeder.

Start by placing the feeder to one side of the frame. Cover any feeder holes you don’t want them to visit. If your feeder has perches remove them as the hummingbirds will provide better subject material as they hover rather than sat on a plastic feeder.

Once the birds are habituated you can start changing things up. I usually start by placing  suitable flowers close to the feeder which can give the illusion of the birds feeding on the flowers. (Make sure you only use flower heads that the hummingbirds would normally visit to avoid a false looking image). The ideal way to position your blooms is to use a Wimberley Plamp. (http://www.tripodhead.com/products/plamp-main.cfm) The next step is to remove the feeder completely and replace it with a suitable tubular shaped bloom. Grab a syringe (I have often been described as a photo junkie!) and some sugar water and ‘inject’ the flower bloom with sugar water. They may be confused for the few few visits but will soon latch on to the idea that the bloom is fill of nectar. Regularly re-fill the bloom to keep them coming.

Sit back and wait for the hummers to arrive and make great images.

Female Rufous Hummingbird (Selasphorus rufus) feeding at a Petunia flower
Female Rufous Hummingbird (Selasphorus rufus) feeding at a Petunia flower

Back to the birds

This week I am going to return temporarily to a bit of wildlife photography with a visit to The Isle of Sheppey  RSPB reserve at Elmley Marshes, with my friend David. There is a 2 mile drive into the reserve proper that is managed by the Elmley Conservation Trust so the photo opportunities regularly start long before you get to the reserve proper, and this was exactly the case on this trip. If ever you go here on a photography trip make sure the camera is right beside you before you enter the reserve road.

Only a few hundred yards into the reserve I got some great shots of a kestrel perched on a post, just a few yards from the road. Unfortunately David was not quite as ready as I was and missed a golden opportunity as the bird took off just as he got the lens out of the window!

Kestrel (Falco tinnunculus) female, perched on a post, Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn
Kestrel (Falco tinnunculus) female, perched on a post, Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn

Nikon D3, AF-S VR Nikkor 500mm f4G ED lens, 1/1000 at f6.7, ISO 500, aperture priority automatic, lens supported on window ledge of car.

Birds are unpredictable, particularly in their sudden and very rapid movements so even though a bird is perched on a fence post and is relatively still I will still try and keep the shutter speed high enough to accommodate these sudden bursts of energy. With today’s cameras capable of producing such high quality images I am not afraid of pushing the ISO a little higher  to ensure the shutter speed is at least 500th/sec and preferably 1000th or better. This doesn’t mean you simply push the ISO to the highest value your camera goes to, it’s still a balancing act between quality of file and the settings you need.

Curlew (Numenius arquata), Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn
Curlew (Numenius arquata), Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn

Nikon D3, AF-S VR Nikkor 500mm f4G ED lens + TC14 converter, 1/800th at f8, ISO 500, aperture priority automatic, lens supported on window ledge of car.

You cannot get out of your car on the entrance road but this really does not present an issue. The birdlife is so used to seeing vehicles that your car makes an ideal mobile hide. Make sure that on stopping you turn off the car engine. The vibrations from an idling car are still enough to affect your images.

I always recommend that you use a sturdy tripod and proper tripod head when shooting wildlife images, but here in London I don’t have my tripod with me.  As I am shooting predominantly sport and tripods are usually banned (in fact throughout the Olympics tripods are not allowed due to the extremely limited space in the photo positions), and there is only so much I have been able to bring to London, I am mostly using a monopod. However, if you ensure you keep the shutter speed high enough, and use good technique, it is possible to handhold for short periods of time, which I do often with the 500mm f4 for flight images. (I wouldn’t attempt this with the 600mm, just too heavy!)

Black-headed Gull (Larus ridibundus) in flight, Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn
Black-headed Gull (Larus ridibundus) in flight, Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn

 Nikon D3, AF-S VR Nikkor 500mm f4G ED lens + TC14 converter, 1/2000th at f8, ISO 500, aperture priority automatic set to -2/3 stop to retain detail in white feathers, hand held.

Ethics

Finally a word on the ethics of photo manipulation. I am often asked what I think it is reasonable to do to a photo in our digital world and what it is not. The answer is not entirely straightforward as it depends so much on what the subject material is and what you are trying to portray. For example in my sports photography it is essential that I do not materially alter the content of an image. In other words I am restricted to simple colour correction, cropping and removing any sensor dust – and that is about it. I cannot for example, clone out a distracting spectator from the background of an image as I would be materially altering reality, even though the image would be more pleasing if I did so. However in the natural history photo it is perfectly acceptable, in my opinion, to remove a distracting branch, for example, as I have not altered the reality of that particular image.

So long as I am not attempting to fool the viewer of an image into believing that something happened that was not really there – for example combining an image of a sparrow and a parrot sitting on the same branch and then portraying it as reality. If I do it as an exercise in digital manipulation and inform everyone that that is what I am doing it is fine. The classic example is when National Geographic Magazine moved the Pyramids to make an image fit the front cover – not cool!

Mute Swan (Cygnus olor), Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn
Mute Swan (Cygnus olor), Elmley Marshes RSPB Reserve, England, Original image: Photo by Peter Llewellyn

Mute Swan (Cygnus olor), Elmley Marshes RSPB Reserve, England, : Photo by Peter Llewellyn
Mute Swan (Cygnus olor), Elmley Marshes RSPB Reserve, England, Finished image after cropping, correction and clean-up : Photo by Peter Llewellyn

Nikon D3, AF-S VR Nikkor 500mm f4G ED lens, 1/2000th at f6.3, ISO 500, aperture priority automatic, lens supported on window ledge of car.

The second image above has the distracting branch removed and some additional exposure and contrast work, which I regard as perfectly acceptable. Here I have used the Quick Mask technique in Photoshop, one of the few tasks I still use Photoshop for. For details of how to do this see the e-book, Photographers Workflow available from the site. The book will soon be updated to account for some major changes in the way I handle my images. Anyone purchasing the book now will get the update free when it comes out.