At the wide end of the focal length range, the Sigma is sharper with a wide open aperture. The Tamron is 1/3 stop wider at some of the comparison focal lengths (200mm and 400mm) and to be fair, I am comparing those focal lengths at the widest equal aperture. At 200mm, these two lenses are very similar in sharpness wide open. At 300mm, I'll give the Sigma a slight advantage and at 400mm through 500mm, the slight advantage swings to the Tamron, though the Sigma's corners are better at 500mm. At 600mm, the Tamron has a very slight center-of-the-frame advantage and the Sigma has a larger corner-of-the-frame advantage.
Stopping down to f/8 reduces most of the sharpness advantages one lens has over the other. The Sigma has sharper corners at 150mm and 500mm, but the Tamron has sharper corners at 400mm. The Sigma is noticeably sharper at 600mm, especially in the mid and peripheral portions of the image circle.
The Tamron has slightly stronger pincushion distortion and has more noticeable CA. The Sigma has more vignetting with a wide open aperture, averaging roughly .5 stops of stronger corner shading over most of the focal length range except at the 600mm end where the the difference is only about .2 stops. Stopped down to f/8, the vignetting difference at the long end remains small, but the Tamron holds an edge in the wide end corners. Corner shading differences at f/11 are not going to be noticeable except perhaps in 300mm corners.
This image quality comparison does not place either lens with a clear lead and either lens can be justified, perhaps with decision emphasis being placed on the focal length expected to be most-valued. Here is a list showing additional differences between the Tamron and Sigma Contemporary versions of the 150-600mm lenses:
I found the Tamron's autofocus to be more consistently accurate at the wide end, but the Sigma's was more accurate at the long end.
The Tamron is modestly less expensive.
The Sigma has an optional dock, with various advantages including custom switch programing, AFMA, firmware update capability, and much more.
The Sigma is extender compatible.
The Sigma's OS system offers mode 2 and I found the Sigma's stabilization more effective at the long end of the focal length range.
The Sigma's zoom rotation direction is the same as Canon's; the Tamron's zoom rotates in the opposite (Nikon standard) direction.
The Tamron has slightly wider (1/3 stop) apertures over some of the focal length range.
The Sigma's focus ring has modestly more rotation (150° vs. 120°).
The Tamron has a smoother, larger, easier-to-use manual focus ring.
The Sigma has a smoother diameter.
The Tamron has lower profile switches.
The Sigma better-facilitates push-pull use.
The Sigma has a multi-position focal length lock while the Tamron only locks at 150mm.
The Tamron weighs slightly more, but has a 2x heavier tripod ring, allowing it to weigh slightly less with that ring removed.
The Sigma has a replacement ring for the removed tripod ring.
The Tamron's hood is larger.
The Tamron focuses slightly closer, but shares the Sigma's 0.20x maximum magnification spec.
The Tamron's warranty is 6 years vs. the Sigma's 4 year warranty (in the USA).
Which lens is better?
I don't think that there is a right or wrong answer here, but I lean slightly toward the Sigma, partially because these lenses are going to most frequently be bought for and used at the 600mm focal length and, at least at f/8, the Sigma holds the optical advantage at 600mm.
YouTube channel Sky Arts runs a regular segment called "The Unspoken Truth" where British celebrities provide their candid opinions on various topics. In this episode, the celebrities answer the question, "Is photography an art?"
If you take pride in what you do while holding a camera, these opinions may leave you shaking your head.
However, the video got me thinking. Anyone with a DLSR can set their camera into "P" mode and take a technically correct, eye-pleasing image with even a modest amount of creativity and luck thrown in. No, it's not going to happen every time, but it's much easier to take a good picture (even via inexperienced luck) than it is to create a comparably captivating oil painting from an equally inexperienced artist.
In the example above, technology has made the job of creating a decent image much easier; using "P" mode might be akin to using a paint-by-numbers canvas, thereby making "art" easier to create. There's nothing wrong with that, but it has led to a devaluation of photography as an artistic endeavor.
I think a photographer's work transcends into the art realm when they consistently produce images that captivate and intrigue those who gaze upon their work. That audience could number in the hundreds or it could simply be the sum of a photographer's close friends and family.
But at the end of the day, does it matter whether or not photography is considered an art in general? I don't think it does. What matters is the fulfillment a photographer experiences while creating his or her images. Whether it's an art form or simply snapshots is irrelevant as long as the camera fills a positive role in the photographer's life. [Sean]
What do you think about photography as an art form?
Join our friends at CreativeLive for Portrait Startup with Sue Bryce - a free, live online class that will teach you essential elements for building a successful portrait photography studio.
During this two-day class, Sue will detail the nine areas of mastery required to build a sophisticated, profitable portrait business. You'll meet several photographers who will share their own unique story of following Sue's business model and what worked (or didn't) for them.
Don't miss this chance to watch one of Sue's inspirational, action-packed classes. Tune in live on June 17 and 18 at 9 AM Pacific.
A rhododendron just outside of my studio was calling me. It was in full bloom and looking beautiful in the wooded landscape. With an already overwhelming to-do list, my mind said "No time!"
As you may have guessed, "No time!" was the wrong answer. About 6 hours later I walked by the window again and the flowers were completely wilted. The warm sun had finished them off with amazing speed. It will be at least another year until that opportunity returns, and more likely, it will be many years until the equal opportunity arrives as this shrub is seldom as beautiful as it was in the morning.
No, your computer/phone/tablet isn't having trouble loading the image. Instead of a beautiful flowering rhododendron image leading this post, the image is blank. Blank represents what you might get if you do not take your photo opportunities when they present themselves. Don't wait!
MELVILLE N.Y., June 05, 2015 - Canon U.S.A., Inc., a leader in digital imaging solutions, today announced the Company will provide onsite service support to help professional photographers and broadcasters capture the iconic moments of Copa America Chile 2015. Canon's professional onsite service support will include simple equipment repair, clean and check service and equipment loans to outfit professionals with the proper gear to capture the excitement on the field. Service and support will be available in the media centers in each of the nine stadia hosting matches in the tournament.
"Canon is thrilled to join the Latin America community once again in supporting the Copa America soccer tournament," said Kenji Kobayashi, senior vice president, Canon U.S.A. Latin America Group. "This tournament is an excellent opportunity for Canon to strengthen our bond with our Latin American consumer and business markets. We are proud to provide onsite service and support to assist imaging professionals in sharing the action of the games with devoted fans across the world."
The international soccer tournament will take place in Chile from June 11- July 4, 2015 in eight cities, with 12 countries participating, including Argentina, Bolivia, Brazil, Chile, Colombia, Ecuador, Jamaica, Mexico, Paraguay, Peru, Uruguay and Venezuela.
SIRUI W Series Waterproof tripods expand the capabilities of outdoor photographers and videographers like no other tripod. While most tripods warn against use in or near water and sand, the W Series welcomes it!
The SIRUI designed WPS Waterproof Sealing System has a series of waterproof rings that prevent water from seeping into the tripod leg tubes and locks and causing damage.
The SIRUI designed waterproof leg locks incorporate waterproof and leak-proof materials used in the automotive industry. The rubber locking components firmly grasp the legs without any gap when they are tightly locked - preventing water, dust or small particles from entering the legs or the locking system. This waterproof (not just water resistant) system lets you safely shoot in extreme environmental conditions (also ideal for use with spotting scopes and binoculars).
Equally impressive is SIRUI’s ability to extend and contract the legs as smoothly as their standard models. And with ½ twist leg locks, setup and break down is fast and easy.
Using the highest quality materials and precisely manufactured leg tubes lets SIRUI achieve uncompromising stability. The SIRUI W-2204 extends up to an impressive 70.9 in. (1800 mm) - vital when shooting in deeper water or to keep your equipment away from splashes and salt spray - while folding down to only 20.5 in. (520 mm). It weighs just 3.7 lb (1.7 kg.), but, holds up to 39.7 lb. (18 kg).
The redesigned Leg Angle Locks make adjustments faster and easier than ever before. Push the lock and it stays open until you select the desired position. Extremely convenient with wet or gloved hands! The slip-resistant rubber feet can be replaced with stainless steel spikes (included) for added grip and stability.
The SIRUI W Series tripod’s unique leg mechanism lets you invert the legs 180° - for compact storage and easy transport. And the split center column makes changing from standard center column to short center column fast and easy.
One of the legs can be converted into a waterproof monopod! Ideal when a tripod is not allowed or when you’re shooting in tight spaces. Attach the center column to increase the height of the monopod.
SIRUI W Series Waterproof tripods are available in economical Aluminum Alloy or Lightweight 10-Layer 100% Carbon Fiber legs.
Waterproof leg design - SIRUI designed waterproof ring system prevents water from seeping into the
pod legs and causing damage. Not just water resistant - actually waterproof!!
Ergonomic Leg Angle Locks make adjustments fast and easy. Extremely convenient with wet or gloved hands!
For speed and convenience, each leg has an automatic leg angle lock mechanism.
Tripod leg converts into waterproof monopod. Center column can be attached for increased height.
The center column can be detached and inverted for low angle or macro shooting.
Legs fold up 180° for extra compactness.
Three leg angle positions for uneven terrain.
Bubble level for fast horizontal alignment
Slip-resistant rubber feet can be replaced with stainless steel spikes (included).
Hook on bottom of the center column can hold a weight bag for added stability