NP Hound

New to posting, but I’ve been reading on here for awhile. I have a weird situation, and I am at a loss. My wife has a Canon SL2 with a Tamron 16-300, and all of the sudden, she is getting green and red edges. She switched to a Canon 18-135, and all is well. I even let her use my Tamron 16-300, and the problem returned. She loaded her photos on the computer, opened them with Corel Paintshop, and the green and red edges were gone. Any thoughts or advice would be greatly appreciated.

halraiser

Do you get the same effect when you use that camera? If so, it is likely a camera issue. If not, she must be doing something different, maybe even slight movement of the camera when she snaps the shutter.

rehess Loc: South Bend, Indiana, USA

Where do you see the edges? On the camera screen? On a computer screen? {your description isn't very clear to me}

NP Hound

By edges, is am referring to the edges of objects, (trees and bridges). I did not use her camera, but I did use her lens on my 80D with no issues.

DeanS Loc: Capital City area of North Carolina

I have this set-up as well and get that result when shooting at the wider end. When I zoom out abit, the prob disappears. I also have several ef L lens and the 18-55 kit lens. Only have the prob with the Tammy shooting near the wide end. Spoke with a dealer and didn’t get a clear answer. So now when I shoot that particular combo, I just zoom out a few mm and hope for a good result.

NP Hound

Thanks for the info DeanS. We did a little experiment, and found that it does it from 16-20mm. Anything above that, turns out fine. She will have to be careful when shooting wide angle, or just use my 18-135. Thanks again.

DeanS Loc: Capital City area of North Carolina

Glad it works for you.

Apaflo Loc: Anchorage, Alaska

Now you know why expensive lenses are expensive. And why lenses with very wide zoom ranges should probably just be avoided.

brucewells Loc: Central Kentucky

DeanS Loc: Capital City area of North Carolina

I have lens that span the quality/cost spectrum from moderate to expensive. First time I have encountered this prob.

Apaflo Loc: Anchorage, Alaska

Maybe the first time with this specific problem, but not with the generic facts that 1) inexpensive lenses are not as good as expensive lenses in multiple ways, and 2) 20x zoom ranges have more compromises than zooms with a 10x range, which are worse than lenses with a 5x zoom range.

High quality zooms just don't have greater than a 5x zoom range and only a very few exceed 3x.

Whether that level of quality is important to any given photographer or not depends on both the photographer and the type of work.

DeanS Loc: Capital City area of North Carolina

No argument here on your points. Just a simple fact: good stuff, in general, tends to be more expensive than “cheap” stuff.

E.L.. Shapiro Loc: Ottawa, Ontario Canada

Your lens is suffering from a classic case of COLOR FRINGING which is indicative of CHROMATIC ABERRATION.

Optical aberrations, simply stated, are certain shortcomings or irregularities in lenses which can cause various distortions, performance deficiencies or impairments. Technically speaking, all lenses have some of them in various degrees. In the better and usually more costly models, theses aberrations are minimized oftentime to the extent where they become insignificant and have no noticeable effect for most general photographic intents and purposes. Some older formulas have more aberrations than the more contemporary models which benefit from the latest advancements in optical engineering, designs and manufacturing methodologies.

Chromatic aberration is defined as a problem that occurs when a lens is unable to bring all wavelengths of color to the same focal plane and/or when wavelength of color are focused on different positions on the focal plane.

Theses aberrations are not manufacturing defects or quality control glitches, per se. The are just intrinsic in the design or formula of any particular model. They are less likely to be remarkably present in prime lenses and more likely to occur in zoom types. Higher quality, top-of-the line lenses with their accompanying higher prices will usually have less aberrations than the lower priced economy models.

As with many kinds of equipment choices there is alway the matter of compromise. Zoom lenses offer a great deal of convenience where as primes, with their fixed focal lengths, usually provide higher quality- all other things being equal. The visual affects of theses irregularities are more pronounced at certain apertures and/or focal length settings and can be somewhat diminished or even negated at others .I have seen some lenses where the aberrations were more pronounced at wider openings and tended to lessen mid range and then, due to diffraction, other issues appeared or kicked in at yet smaller f/stops. In some lenses the various aberrations can augment each other and kinda "conspire" against you. It' best to chen out the specifications and do some serious testing before making a significant purchase. For this reason, I lie to deal with a local supplier raher thatna big-box or mail-order stores. Sometimes it costs me a few more points but at the end of the day, its better economy. I have avoided ending up with disappointing lenses and the time wasted in returning or exchanging them and have been able to zeroin on better equipment through testing.

For my commercial work, I have a few zooms for jobs where they are kinda indispensable for shooting speed- they are very costly, however, I prefer to use primes on multiple bodies when practical.

There are other aberrations as well that can degrade lens performance such as astigmatism whereby both horizontal and vertical lines can not be focused on the same plane. Then there is Coma, Field, Curvature and Geometrical Distortion. Some aberrations are termed zonal in that the "live" on certain areas of the lens and only show up on corresponding zones on the projected image. Aberrations that are on the edges or periphery of the lens will not register on the film or sensor when the aperture is stopped down Certain specially designed soft focus portrait lenses incorporate deliberately placed aberrations at the edges so that they produce soft images quality when thee aperture are wide open and become sharper as they are stopped down.

In certain kinds of work, I suppose we can "live with" some of theses issues, such as the the fringing, but they can become very problematic in more critical or precise work especially at greater degrees of image enlargement where many of theses manifestations will become more prevalent in the image. Sometimes it is possible to work around some of theses issues in zoom lenses by understanding which focal length settings and apertures are least affected.

The harsh reality is "better glass costs more cash".

I hope this helps.

rehess Loc: South Bend, Indiana, USA

I encounter fringing the most with long old lenses, like AdaptAll and Takumar lenses.

LoneRangeFinder Loc: Left field

It would really help if you would post an example....