Extenders or Tubes

[thomasryan]

Greetings, and a Happy & Safe New Years to All!
I need some advice. I'm using a 500mm f4 L IS with a 1.4x for most of my bird images. I want to increase the focal length with either a 2x or extension tubes. Losing the AF doesn't matter because the images will be static. I've read mixed reviews about the 2x and I'm totally ignorant about the extension tubes. Thanks for your help...tom

[Doug Brown]

Extension tubes do not increase your focal length, although I believe there is a slight magnification of the image. What extension tubes do is decrease your minimum focus distance; you can get closer to your subject than you can with the lens alone. There is a small decrease in the amount of light reaching the sensor, but not the 1-2 stops that you lose with a 1.4x or a 2x. Extenders do increase your focal length but do not affect your minimum focus distance. You can also use a combination of tubes and an extender.

In summary, extenders bring the action closer to you and tubes let you get closer to the action.

[Cheryl Flory]

Thanks for the clear explanation, Doug! I was wondering that same thing myself.

[Marc Oliver]

In addition to what Doug wrote, using tubes, you will loose infinity focus! With extenders you do not have this problem. I occasionally use a 25mm extension tube and a 1.4x extender on my lens when photographing shorebirds and I don't need to focus on distant subjects, otherwise it's the 1.4x extender only.

cheers,
Oliver

[Alfred Forns]

One other thing to consider You can use extension tubes on the body or in front of the converter which will give you a little closer working distance but loose the AF.