No, you can’t simulate the fast-focus or weather-sealing of the pricey big glass. But you can simulate the ‘look’ of those expensive telephotos with a modestly-priced telephoto lens.
The reason big telephotos have their signature ‘look’ is largely their de-focused backgrounds. The subject is the only thing in focus, and everything else just melts away when those lenses are shot wide-open.
You still need a lens that has the reach of big telephotos, but you can easily de-focus the backgrounds with software. The best way to do this is with a mask. What you need is a program that lets you select the background, and then use Gaussian blur to make that background melt away.
Keep in mind that sometimes you stop down a lens because you want the extra lens resolution it gets you, but you pay the price by ruining the background. It’s totally amateur to let power lines and chain-link fences remain visible in the background. If you blur the background after the fact using a photo editor, you can get the best of both worlds. That annoying background clutter can magically disappear.
There’s another problem that many photographers often encounter. If you’re at a zoo that uses mesh or bars around their enclosures, you’ll discover that the backgrounds of your photos have a nasty repeating pattern to them, even though the subject is sharp and the backgrounds are (mostly) out of focus. This is what’s known as ugly bokeh, although this kind it isn’t caused by your lens optical design. Maybe you can’t see the mesh itself, but its effect is still felt. Your first inclination is probably to either reject the photo or try to use a healing brush to fix the background. Wrong on both counts.
Healing brush tools are very labor-intensive, and often involve a considerable amount of skill to use them well. You can usually get rid of irritating background details with considerably less effort via the “Gaussian blur” effect instead.
Many editing programs offer masking features, and nearly all of those same programs offer the Gaussian blur effect. I used to think that the last thing I wanted was to blur my photos; it didn’t occur to me that Gaussian blur is virtually never used outside of a masking operation (they’re not applied “globally”).
Big, expensive, 600mm f/4 lens “look”
The shot above doesn’t have any obtrusive background detail to spoil the scene, but that’s not how the original shot looked. I wanted the two tiger faces to be in focus, but they weren’t both at the same distance. I stopped the lens down a bit to get sufficient depth of focus, but that also caused the ugly background to just look worse and worse.
The cold cruel reality of the original shot
I knew when I took the shot that it could be improved in an editor, but I have to admit that I wasn’t sure if it could be turned into a ‘keeper’. You don’t always get to maneuver into a position where you can control both the main subject and the background, although you should always strive to do so.
The mask used with Gaussian Blur (from Capture NX2)
Personally, I don’t like to completely obliterate the background into a featureless single color. I like what I call a watercolor effect, where the background is blurred, but the environment still shows through a little bit. The beauty of the Gaussian blur is that you get to choose how much to use via the selected ‘radius’ and opacity.
Image editor masking tools allow both adding and erasing of the mask, so you needn’t be worried about being extra careful as you mask. Just erase your mistakes and try again. I’m a Capture NX2 holdout, but most image editors offer similar masking options.
The Gaussian blur technique is just one more option that’s available for use in your photography. I think that too often it’s an overlooked tool.
You might just find that you can salvage shots that you originally thought were worthless. And it’s not even that much extra effort.