How often do you use f2.8 or f3.5 for mammal photography?

I'm still choosing what will be the best lens for my porpouses, the 70-200mm f4 IS or the 70-200mm f2.8 IS II.
The advantages of the f4 IS are clear, less weight and less money to spend, but I'm loosing something????

I already have an 300 mm lens plus teleconvertors, but I need a zoom like that for big mammals or close animals.

So my question is basicaly, do you need to use f2.8 or 3.5 very often when shooting wildlife? Or is f4 the minimum aperture to get at least the head an half the animal body in focus?

What are your experiences about this?

best regards,

paulo anjo

Paulo,

Not often. I shoot big mammals a lot and most of the time I use 5.6 and above depending on ambient light. Unless you are specifically looking for those shallow DOF shots, shooting at F2.8 does not provide enough DOF IMO. I use 70-300mm F4-5.6 L IS lens now and used 100-400mm in the past for big mammals. Never felt the need for 2.8.

-Sid

This may or may not be relevant depending on the situation but keep in mind that regardless of what aperture you are using for the actual image, the f/2.8 lens will still give you a brighter viewfinder and should allow better AF relative to the f/4 since AF is done with lens wide open and the f/2.8 will have more light to work with.

Another thing to consider is the option of using teleconverters which is more practical with the 70-200 f2.8.

f/2.8 AF also results in more accurate focus (Canon's documentation).

On my last safari in Tanzania I took my 300 f/2.8. Here is the distribution (includes all lenses used, some f/4 like the 70-200 f/4):
8427 total images
99 images at f/2.8
236 images at f/3.2
99 images at f/3.5

Thus, 5.1% of images were at faster than f/4.

Of those images, I took 1998 images with the bare 300 (no TCs),
88 images at f/2.8
236 images at f/3.2
76 images at f/3.5

Thus 20% of bare 300 images were at faster than f/4.



Roger

Another point to consider is that most lenses (especially zooms and when using TCs) are sharper at least one stop down from wide open so the f/2.8 has the advantage that you would still be at f/4 vs. f/5.6 which will help when shutter speed is an issue.

It really depends. As mentioned - f2.8 and f3.5 are REALLY shallow if you are working with any decently sized mammal close up (say bigger than a small deer fawn and closer than 20 meters).
I try to stop down if the light allows. With new ISO tech on the cameras I would often rather sacrifice ISO than aperture. Even f4 or f5.6 on a prime lens can be quite shallow for close-by mammals.

I don't have a 2.8 lens (except for the 100mm Macro) but sometimes I wish my 4/300L were a 2.8 to get a very limited DOF.
I am currently reading the wonderful book "Captured" by Moose Peterson (I highly recommend reading it!) and there he mentions that
he likes using a 2/200 Nikon lens for mammals.

Markus