877-865-7002
Today’s Deal Zone Items... Handpicked deals...
$4499 $2999
SAVE $1500

$799 $499
SAVE $300

$100 $100
SAVE $click

$2198 $1798
SAVE $400

$130 $100
SAVE $30

$3498 $2998
SAVE $500

$2999 $1699
SAVE $1300

$2397 $2197
SAVE $200

$1697 $1297
SAVE $400

$2998 $2898
SAVE $100

$2198 $1798
SAVE $400

$190 $161
SAVE $28

$580 $410
SAVE $170

$2997 $2697
SAVE $300

$1799 $1599
SAVE $200

$2198 $1998
SAVE $200

Upgrade the memory of your 2018 Mac mini up to 64GB
OWC

Best Deals of the Year!


Promo code BFCM2021 good thru Nov 29
Check for new deals daily!

Don’t Assume a New Lens is Good!

2010-01-10 - Send Feedback
Related: howto

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.

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).

Performance should be symmetric about the center eg left/right, top/bottom

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.


Save the tax, we pay you back, instantly!

diglloyd Inc. | FTC Disclosure | PRIVACY POLICY | Trademarks | Terms of Use
Contact | About Lloyd Chambers | Consulting | Photo Tours
RSS Feeds | Twitter
Copyright © 2021 diglloyd Inc, all rights reserved.