I know this is a bit old now, what with the Mk III being the current model, but I was fortunate enough to get a good price on this extender, as I’d been hankering after trying one out for a while in order to see what difference they actually make.
Out of all of my lenses I knew this would only work with the Canon EF 100-400 mm f/4.5-5.6L IS II USM lens, but I was keen to see what extra reach the extender would give me over 400mm. Because this is being done on a budget, I wasn’t up for spending a huge amount of money just to experiment, so when this came up at a competitive price, I snapped it up.
Now I’m running a Canon EOS70D body, and I knew that I’d lose some features such as auto-focus, but as I’d done my research up front, and knew what to expect, I was confident that I’d suffer no nasty shocks when I came to use it.
In terms of that research, I found this site extremely valuable inhering me out with my decision to buy it. That said, I won’t go into any technical detail as the above site covers it far better than I could ever hope to. My purpose in this article is to give an insight into how I got on with using it for my setup.
Fitting the extender to the lens, and then the camera body is easy; it all slots into place nicely with the usual satisfying clicks that one with attaching any substantial lens gear to your camera body.
Powering up the camera you notice straight away that the camera has defaulted to Manual Focus, irrespective of what you have the lens set to. Secondly you notice you’ve lost 2 full f/stops, so for me I was shooting at f/8 as that’s as low as I could go. You're going to need a tripod. So for this it’s a no brainer that the camera has to be on a tripod as you’re going to struggle to hand hold this and get sharp shots given you need to manually focus. Thankfully the focus ring on the EF100-400 lens is solid and accurate, so minute focussing adjustments are possible with a gentle movement of said ring.
Initial test shots were a little disappointing, but this was mostly down to the weather being misty when I initially tested it, but I was so keen to see the difference it made I couldn’t wait for the weather to clear.
A few days later, when the weather was clearer I tried again, and this time the results were much better. Post processing the images that I had captured, I noted they needed a little sharpening, given they were shot at 560mm. I find the 100-400mm lens needs photos sharpening slightly when shooting at 400mm as this is not the lenses sweet spot, so to adjust sharpening at 560mm came as no surprise. Again, whilst clearer, the weather was not perfect, so I needed to rely on high ISO settings to get some decent shutter speeds (I was shooting in AV mode).
Sadly this is the cost of having to work full time and being in an office when the weather has been sunny, leaving only murky weekends to play with camera kit.
Please note from the test shots below I wasn’t aiming for photography perfection, I was nearly aiming to see what the extender could do in terms of distance. I know that by losing two f/stops I need to increase the distance between the subject and the background to get some decent bokeh, but for these I was happy to lose that.