In addition, Sigma recently began offering a bundle for their 150-600mm with a 1.4x teleconverter. Since I shoot mainly with a Nikon D750 full frame, the lens bundled with a 1.4x TC interested me very much. The 1.4x TC makes the 600mm, an 840mm on a full frame camera, so in theory this allows my full frame camera to shoot wildlife with nearly the same zoom factor as a crop sensor. (Nikon crop sensors are 1.5 and Canon, 1.6)
There are two things to consider when looking at a new lens:
- First is its ease of use
- Second is the quality of its optics.
In this article I’ll be applying both of these considerations as I review Sigma’s new bundle, and make comparisons between the Sigma and Tamron lenses. All images in this article were captured with the Sigma 150-600mm with the 1.4x TC.
The Tamron features a larger, thicker focusing ring than the Sigma, which makes it easier to manually focus the lens. As for the Sigma, it has an extra setting on the autofocus switch for manual override (MO) which combines autofocus with an option to manually focus. I did not notice any major difference in the focusing responsiveness between the two lenses. Both did a fair job when grabbing focus, though neither lens is going to focus as quickly as a much more costly 600mm prime lens. The minimum focusing distance on the Tamron is just slightly less than the Sigma – not a game changer, but nevertheless a plus for the Tamron.
Focus Limiter switch
While both lenses have a focus limiter switch, with settings between Full and 10m (Sigma) or 15m (Tamron) to infinity, the Sigma features a third option on the limiter switch for 10m to 2.8m. In my testing, this third option proved very useful and was easy to locate and use, in order to focus on closer objects much quicker.
A feature the Sigma lens offers that the Tamron does not is an extra customization switch, which provides for an optional USB docking station (purchased separately). This allows a photographer to create two customized setting for OS (Optical Stabilization), AF, and focus-distance limits, and can also be used to download firmware updates directly to the lens.
Both the Tamron and the Sigma have a locking switch to prevent zoom creep at 150mm. However, the Sigma can also lock at several other focal settings, and what is even better, a quick twist of the zoom ring will unlock the it, without having to fumble around to find the switch. (In some cases this might be the difference between capturing and missing a killer shot!)
I found that my Tamron lens crept more than the Sigma, but this could be caused by the fact that it is an older lens with more use. Still, the lock switch on the Sigma is a great feature, especially since one can “soft lock” at many focal lengths.
Both lenses have their own image stabilization systems: Tamron’s VC (Vibration Compensation) and Sigma’s OS (Optical Stabilization). The Tamron has a simple on and off for the VC, while the Sigma has two settings: #1 is the standard setting for normal lens movement, and setting #2 is used for hand-held panning on a vertical plane, which will correct for up and down movement in subjects, such as birds in flight.
The zoom ring on the Sigma turns counter clock-wise, which is no big deal for Canon shooters. But for Nikon users, this is opposite from the normal zoom rotation on most Nikon lenses. It’s not a big deal, but does take some getting used to.
Both lens come standard with a tripod collar, but the foot on the Sigma collar is much smaller than the Tamron’s. This is only a minor problem, but I found a solution for it. I added a 5 inch quick release plate to the foot, which makes a great handle to carry the Sigma lens, as well as a plate to connect to a tripod.
Here is where the comparison gets tougher, as both lenses are much sharper at the shorter focal lengths, and both are softer at the longer focal lengths. Both are sharper when stopped down to f/8 or f/9, than wide open. In my opinion, the difference in image quality between the two is negligible. There is no clear winner here, both having areas where they are slightly better than the other.
The addition of the 1.4x TC to the Sigma when stopped down, doesn’t seem to affect the image quality. The Sigma seems to have a clear advantage when it comes to chromatic aberration (CA), and even using the 1.4x TC there was noticeably less fringing in high contrast areas, when compared to the Tamron. Of course, CA is very easily corrected in Camera RAW or Lightroom when shooting in RAW.
The advantage for warranty goes to Tamron, which offers a 6 year one, compared to 4 years with the Sigma. Still, in my opinion, both lenses are well constructed, and I am not convinced how much of an advantage that is, as most warranty issues show up early on.
Adding the bundle of the 1.4x TC, and the 150-600mm Sigma can get your full frame camera back in the field when it comes to wildlife photography. While adding the teleconverter seems to slow the autofocus a bit, I shot with this bundle on both my crop sensor and full frame sensor cameras, and I believe the autofocus was more responsive on the full frame.
NOTE: Before purchasing the 1.4x TC, make sure the camera will autofocus at f/8. Many entry model DSLRs will not autofocus above f/5.6, so while this bundle may fit those cameras, manual focus will be necessary. Other models may only autofocus on the center focus point, and still others may have a limited number of focus points with the 1.4x TC.
Adding the 1.4x TC did seem to give a softer image when the lens was extended to 600mm (840mm), but if you stop down to f/10 to f/11 the images are nearly as sharp as at 600mm without the TC. Of course, stopping down means either using a slower shutter speed or a higher ISO, which may add some blur or noise to an image. I did find that the OS on the Sigma did a nice job of reducing camera shake, when hand holding at slower shutter speeds.
The rule of thumb when shooting with long focal lengths is to set the shutter speed equal to, or greater than the focal length, so remember that when by adding the 1.4x TC to a 600mm, one is now shooting at 840mm on a full frame, and 1260 mm on a crop sensor. For sharp images, a shutter speed over 1/1000th of a second is a must.
When carrying your camera with a large lens such as these 150-600mm lenses, it’s best to hold them by the lens rather than your camera. These lenses weigh much more than your camera and can put a lot of stress on the lens mount if carried by the camera. Likewise, when mounting on a tripod, always use the tripod collar to reduce stress on your camera’s lens mount (it is better balanced using the collar and won’t be front heavy).
Both the Tamron and Sigma lenses are well designed, and for the price range are great equipment investments. As mentioned earlier, I feel the image quality compared very closely. The Sigma does offer some useful extra features, out-weighing the issues of the smaller focusing ring and the counter-clockwise turning of the zoom ring for a Nikon shooter.
If you currently have a Tamron it may not be worth making a switch. But with the addition of the 1.4x TC, the Sigma bundle offers a great setup for full frame cameras, as well as crop sensors for some extra reach. So if you are looking for some extra reach (and we all are) the addition of the 1.4 TC to the Sigma may be a game changer. It was for me!
As a result of my review of the Sigma bundle for this article, I sold my Tamron 150-600mm, and purchased the Sigma 150-600mm bundled with the 1.4 TC, to extend the usage of my full frame Nikon D750, especially for photographing wildlife.