Is it sharp? It is an unbelievably sharp lens, but this photograph isn't. I scratched my head for quite a while, trying to work it out. I was using Canon's new EF 600mm F4L IS II USM lens and although it has image stabilisation, it was tripod mounted for this frame. The shutter speed was reasonably fast - 1/1600 second - and I took several shots so the autofocus had plenty of opportunities to nail the distance... what could it possibly be?
Chris Macleod from Canon was showing me the new EOS M camera when he snuck the 600mm into the conversation. Would I like to try it? Could I take it to Central Australia with me? Tony Hewitt and I were just about to leave on our Adventures In Oz expedition (and I promise to post more about this shortly), so it was an opportunity too good to pass up.
I was shooting on a Canon EOS 60D, so with the smaller format, I figured I had the equivalent of a 960mm super telephoto. And I was able to hand hold it and get a sharp shot. I say 'able' advisedly, because I certainly did on many occasions, but you would be much more sensible to use a monopod as it is a weighty unit. Mind you, Canon will probably object to this comment. Yes, it's weighty in comparison to a 50mm lens, but for a 600mm, the new model is incredibly light at 3920 grams. It's also a good deal smaller than its predecessor, plus faster and sharper and cheaper! I want one!
So what was the problem? Heat haze. Although it was winter, it was a reasonably warm day, but not oppressive like summer. Even so, looking across the hills, I figure there would have been quite a deal of heat over the ground and the 'watery' rendition of the file when you enlarge it up bears this out.
Sort of defeats the purpose of having a really sharp lens to create watercolour effects, I guess! But what I love about telephotos for landscape photography is the opportunity to isolate subjects. If only they made lenses this long for medium format as well!
The photo is taken at Tylers Pass, around 40 kilometres from Glen Helen. Tony and I are planning another trip there next year in July or August. Details will follow.
UPDATE - Image Stabilization
A reader 'fiennes' asked if Image Stabilization was turned on or off. It was probably left on. With the latest IS systems, I'm told this isn't generally a problem, but it certainly was a recommendation with earlier lenses when Image Stabilization was first released. There were clear recommendations back then to turn it off when the camera was tripod mounted.
Later recommendations are not so black and white. The manual for the older 600mm Canon says, "When you use a tripod, the Image Stabilizer should be turned off to save battery power". It didn't seem to be an issue in terms of quality.
In the manual for the current 600mm lens (which I didn't read beforehand), it says, "Using a tripod also stabilizes the image. However, depending on the tripod and shooting conditions, sometimes it may be better to turn off the Image Stabilizer function." This could be read both ways and so maybe the image would have been clearer if it were turned off.
However, returning to the image itself, it looks more like a heat haze effect than camera shake. And I have lots of other images taken on a tripod in different conditions with the same lens which are tack sharp.
So, point taken and fiennes may be correct. Next time, I'll do it both ways and test!