Jeff Newcomer has been a physician practicing in New Hampshire and Vermont for over 30 years. Over that time, as a member of the Conservation Commission in his home of Chesterfield New Hampshire, he has used his photography to promote the protection and appreciation of the town's wild lands. In recent years he has been transitioning his focus from medicine to photography, writing and teaching. Jeff enjoys photographing throughout New England, but has concentrated on the Monadnock Region and southern Vermont and has had a long term artistic relationship with Mount Monadnock. He is a featured artist in a number of local galleries and his work is often seen in regional print, web publications and in business installations throughout the country. For years Jeff has published a calendar celebrating the beauty of The New England country-side in all seasons. All of the proceeds from his New England Reflections Calendar have gone to support the Pulmonary Rehabilitation Program at the Cheshire Medical Center.
Jeff has a strong commitment to sharing his excitement about the special beauty of our region and publishes a weekly blog about photography in New England.
The bad news is that every photographic lens induces some degree of distortion
to the image that it sends to the sensor.Some lenses cause more warping than others, but the amount and type of
distortion is dependent on the focal length and the proximity of the
Types of Distortion
There are two types of distortion.Wide angle lenses can cause the appearance of swelling out from the
middle of the image, called Barrel Distortion.This warping is often associated vignetting, a darkening at the corners.
Conversely, looking at more distant
subjects with a telephoto lens can result in an inward bending of lines on the
edges, called pincushion distortion.
The good new is that tools in
both Lightroom and Photoshop can correct much of these problems and most of the
adjustments are essentially automatic.In Lightroom the magic all happens with the Lens Correction Tool.
The Curved Door
Recently, I was shooting along the waterfront in Rockport Massachusetts. I
was especially attracted by the interesting detail in many of the Lobster shacks;
colorful buoys, ropes and weathered doors.I loved my angle on this shack, but I noticed that by using a 67mm focal
length the lines of the distant door showed considerable pin cushioning.The result was some post-processing correction
and an excuse for another blog article
Lightroom’s Lens Correction Panel
Recent versions of Lightroom have a few nifty tools for correcting Lens
distortion in the “Lens Corrections Panel”.In Lightroom CC Classic, the first choice is between “Profile” and “Manual”.In most cases you will not need to venture into
the Manual options.
The first option under “Profile” is to remove Chromatic Aberration.I discussed the cause and treatment of Chromatic Aberration in an article six years
ago. Since then the causes have not
changed, but many new lenses have become better at reducing the problem and the
software has made its correction easier.Just click on the button and most of the color banding will disappear. To
fine tune the results you may need to dive into the Manual Options, but that
will a subject for a future article.
I love automatic stuff.Adobe has
assembled a large and expanding data base on the characteristics of most of the
lenses that are available on the market and many legacy lenses that you may
still be using.This means that it is
very likely that Lightroom can identify the lens in your metadata and automatically
make the necessary adjustments to compensate for the distortion and vignetting.Click “Enable Profile Corrections” and
chances are your; Make, Model and Profile will pop up and the image distortion
will be corrected. If the meta data does
not contain the lens information, then you can look for it in the Lens Profile
drop-downs.If you can’t find your lens,
most likely because it is new, you can wait for the next update which always
includes a bunch of new profiles.When
all “automatic stuff” fails you can drop down to the “Amount” sliders and adjust
both Distortion and Vignetting manually.
The automatic profile adjustment made a marked improvement in the pin cushioning
of the door, but it wasn’t quite perfect. The door edge still had a definite curve.I went to the Distortion slider and found
that a full +200 correction led to a better result.For Lightroom and Photoshop automatic
adjustments can work great, particularly for lens profiles, but sometimes they
are just a good place to start.
A wide-angle close-up of a plain brick wall gives a nice view of Barrel Distortion
and for this I must thank the imposing façade of Dick’s Sporting Goods in Keene
New Hampshire.A straight-on view with
my 16mm lens clearly shows barrel distortion and edge vignetting.In this case the built-in Profile Correction nicely
fixes the problems without any need for further adjustments.
Often lens distortions are not immediately obvious until they are
corrected.It is always helpful to
compare a corrected image with the original, especially when using telephoto or
wide-angle shots and it is nice that the process is so quick and easy. My original shot of a Maple trunk in my yard
looks reasonable, but when compared to the corrected version it is easy to see the
bloated barreling in the center of the image.
The Lens Correction in Lightroom is one of the program’s simplest and
most magical tools.It is a worthy stop
every time you travel through the Develop Module’s workflow.
Jeff Newcomer, NEPG