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Articles Table of Contents   Page 1: Keep and Use Classic Lenses For an Unusual Look Page 2: Shoot One and Only One Subject Page 3: Shoot One Lens, and Not a Zoom Page 4: Choosing a Lens by Focal Length Page 5: Fast Lenses—Shutter Speeds / Background Blur (Bokeh) Page 6: Shoot a Fast Lens at Dusk or Dawn Page 7: Blur Can Be Beautiful Page 8: Making Sharp Photos Handheld Page 9: Shoot Another Format (Size or Aspect Ratio) Page 10: Use Manual Exposure for Perfect Results Page 11: White Balance Tools Page 12: Understand Perspective and Size Variance Page 13: Look For Natural Patterns Page 14: Depth of Field Is Oh-So-Shallow Page 15: Depth of Field—How Far To Stop Down Page 16: Depth of Field and Megapixels Page 17: Never Go Traveling Without a Backup Camera Page 18: Don’t Assume a New Lens is Good! Page 19: Infinity Focus Requires Care! Page 20: How to Carry Large and Heavy Lenses Page 21: Shooting Tip: Use Mirror Lockup Page 22: Shooting Tip: Aurora Borealis Page 23: Shooting Tip: Grizzly Bear vs Black Bear Scat Page 24: A brief glossary of photographic terms

Don’t Assume a New Lens is Good!

It’s a brand-new lens, right out of the box. It should be perfect optically. If only real life worked that way! It does not.

When buying a new lens, resign yourself to the tedium of verifying that it’s not a bad sample. Do it right away, so you can return or exchange it.

Periodically check your important lenses; they can go out of whack for no apparent reason (this happened 3 times with my Nikon 17-35). Nearly always, the factory service can fix the problem, but why start with a bummer? Of course, buying used entails additional risks of abuse by the previous owner.

The best way to verify performance is to shoot two samples of the same lens and/or shoot against a reference lens of the same focal length, keeping everything locked down, exchanging only the lens; this rules out everything but focus error (assuming you’ve done everything else right).

Digital sensors, which are perfectly flat and also very high resolution, mercilessly show anything less than perfect optical alignment. A mosaic like the one seen above (actual pixels crop) makes a perfect target for spotting such problems. Be sure to focus perfectly, and align the camera to the subject squarely, and be aware of both horizontal and vertical. However, tilting the camera up is OK, so long as you look for symmetry, and have reasonable depth of field. Choose a target that allows near-infinity focus to make the job easier.

In my personal experience, somewhere between 20-30% of lenses are optically “off” in some way or another right out of the box. I’m referring to both Canon and Nikon based on experience with 40-50 lenses. While I don’t write up every bad experience, you can read about several experiences in Brand-new Blur. Some problems are really awful; others are more subtle.

Zoom lenses and shorter focal length lenses seem to be the worst offenders; I've had no problems with high-end telephoto lenses. Finally, do not forget the lens mount itself.