Day: January 17, 2025

The past few weeks, I’ve seen a number of the photo websites I follow turn their attention to the ‘background’ of birds photos.
I’m not going to rehash it here, but it was intersting that we have been working close quarters with a pair of Sacred Kingfisher hoping that among the busy realestate in the river flat forest that they might find a suitable nesting site. Many of the holes are already taken by a range of Rainbow Lorikeets, Red-rumped Parrots and sadly Common Mynahs.

The forest has some old growth Red Gum, but mostly a mix of younger trees. Each is strugglling to get as much of its canopy into the sunlight and the sun only pentrates in tiny, thin fingers though the covering.

Result for your photographer is little real bright light, so its high ISO speeds, slower shutter speeds and wide open lenses.

So I’ve been able to experiement with those dreamy soft backgrounds that the photo-info/influencer-sites have been lauding as the ‘new’ look. Funny how things seem to go round in cycles.

And apart from lots of mis-information the simple physics of it all seems to escape most of them.
As “Scotty” of “Startrek” fame was want to say, “Ye Cannae change the Law of Physics”.

Depth of Field has three basic principles and a k=Constant to work this stuff out.
Here they are. Lens focal length, Lens Aperture, Subject distance. And depending on how well corrected said lens is in design and manufacture will also influence the softness of the result. Lenses like the 70-200 f/2.8 and 300 f/2.8 series are cracking examples of how soft and milky those out of focus bits can become. Similarly, the 105mm f/2 and the wonderful 200mm f/2 have to be used to be appreciated.

Oh. The K?? Well in the calculation K has a value that represents:-“The Circle of Confusion”. And as every student who has had to make those calcs will tell you, “What an appropriate name!!!!”

The softer lighting in the forest has helped reduce some of the harshness and two very cooperative Sacred Kingfishers who don’t seem to mind at all landing close by where I’m standing have given me some lovely soft out-of-focus-fuzzy bits.
For the record, most of these shots were taken with the 500mm f/5.6 or 700mm f/8 (the 500mm with converter) or I even stuggled down with the 300mm f/2.8 and converter for 420mm f/4

Enjoy
Its a Gallery so click on an image for a larger view.

And for bonus points. Both decided to show of their lunch on the same branch.