Wildlife Photography across the Water: DOF Calculator App.

Thursday, 7 July 2011

DOF Calculator App.

Well I might be a bit slow, and you might all be aware of these apps but I found one (many available actually) for my Android phone today. I expect those of you with iPhone can find one too via whatever mechanism Apple force you down.

The one I found is pretty good, with specific cameras and lenses being selectable.

You select the camera, then the lens, then the aperture and your subject distance in either metres, feet, inches or cm so useful for macro work too.

Hot the calculate button and it spits out the Near and far limits of focus, giving you the depth of field in the gap.

So for my 5Dmk2, 180 macro at say f11 and 20cm, the available DOF is just 1mm. Moving the aperture to f22, it doubles to a massive 2mm. Moving the subject distance to 30cm, it doubles again to 4mm. So as you can see, when working with things like butterflies, it is not surprising it is not always possible to get things sharp from front to back.

Moving to the 7D and 500 at minimum focus distance, and at f11, the available DOF is only 28mm, so if you are taking images of birds you can see why shooting wide open is not always sensible.

Another feature I like is that you have the option of the longer lenses with converters on as well so you can select 420mm (300 + 1.4TC) or 700 for the 500 +1.4.

Whereas moving to say a landscape, with the 5D and 24mm at f11, with say the horizon at 3km, the near focus limit comes down to 1.72m, so no need for infinity and you can select a much closer distance known as the hyperfocal distance.

Now - my big caveat to working anything photographically with numbers on a technical basis is check and check again with your own experiences, and don't hang your hopes on three decimal places. Techno nerd geekery is all fine and dandy - but check it out for yourself. It couldn't be easier with digital.

But as a quick and easily available aid, it does help to remove some guesswork.

It would be good to hear from you if you have any favourite and useful phone apps that you use. I have previously blogged about sunrise/sunset times and angles, as well as weather and tides.

Exciting day tomorrow for me - might take some images so will share if I do.

Martin

1 comment:

distance calculator9 August 2011 at 12:08
really good and informative blog....Simple DoF Calculator allows photographers to calculate the depth of field and hyperfocal distance for any given settings. The app works on your iPhone, iPod touch and iPad.
It calculates the near limit, far limit, total depth of field, hyperfocal distance, distance in front of the subject and distance behind the subject. The app shows al those calculated values in a simple image without unnecessary information.
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Bio's

David Courtenay, a self taught wildlife and nature photographer, has been capturing images for over 30 years. He has had a passion for wildlife since early childhood and remembers being glued to the television whenever Survival, Wildlife on One and other natural history documentaries were shown. In the 2006 he swapped his established career for the life of a wildlife photographer, such a move demands a measure of uncompromising passion and commitment.

David has travelled extensively throughout Europe as well as spending more than 7 months in India working with local guides and trackers in search of Bengal Tiger, Asian One horned Rhino and Asian Elephant. He has also photographed Wildlife in Australia, Malaysia, Thailand, Sumatra, Africa, Canada and America. Working closely with Conservation companies he tries to raise funds to help Wildlife that has been put on the endangered list by poaching and habitation loss

Martin Dyer has had a passion for avian wildlife since childhood, particularly raptors. Photography was also another keen interest and it was with the specific availability and control of the whole process that digital offers that Martin was then able to combine the two in 2003. Based in the UK, Martin is a regular visitor to Scotland, specifically the Isle of Mull to watch the Eagles resident there. Other trips to Europe and around the UK are usually part of Martin’s agenda in a typical year.

However, as a firm believer on making the most of the local patch, Martin has spent a lot of time and hard work creating a wildlife garden which is reaping the rewards with many new species and varieties of wildlife. A keen member of a number of wildlife photographic groups, Martin is keen to expand his portfolio into other areas of wildlife, and has already established a wide portfolio of images of fungi.