Great Blue Herons are notoriously skittish birds and will take flight if you approach them directly. This is one of the reasons why most non-masochistic photographers will use a super-telephoto lens to get the reach to get photographs of them. I don't have that luxury at least until I can put together three years of saving for a 600mm f/4 super-telephoto lens. Which means I won't have a 600mm in hand until about May or June of 2015. Which means, I'm stuck with the 70-200mm f/2.8 VRII. This means having to utilize my grey matter in between my ears to take advantage of ways to get "closer" to the GBH subjects. To give you an idea. Here's three images that I took this past August 26, 2012 at False Creek. And I'll give you an idea of what it took to get those images.
Image 1 =
Image 2 =
Image 3 =
I'm having to learn the places where I can get close in order to take advantage of the better focus resolving power of the 70-200mm f/2.8 VRII. I have the original 70-300mm G (Non-VR)...but I prefer the 70-200mm, despite the loss of the extra 100mm. Which means really having to get close to get a better focus on the head. Ain't easy to get close, but the positioning of the GBH allowed me to use the manmade topography of the area to get really close without letting the GBH see me.
To give you an idea of where I was shooting from. These were the positions from 1st shot through the third shot.
My approach towards "Henry" the heron.
Taking advantage of your topography and knowing the characteristics of the animal that you are seeking to take a photograph of is essential to getting close to an animal. However this further illustrates the need for the right equipment. I would not recommend using this technique of getting close on photographing the North American Grizzly or Elk. They will charge you if you get close. If you can't buy the right equipment for the photographic job at hand, then rent it. The reason I'm shooting birds, is because I enjoy doing so. And these subjects will not kill you if you don't exactly have the right equipment at the time. There is no point in putting yourself in a bad situation. The photograph is not worth your life.
Stay smart; stay safe...
Happy Shooting