Tamron SP 70-300mm f/4-5.6 Di VC USD : Review

Introduction

This is a review of the Tamron SP 70-300mm f/4-5.6 Di VC USD telephoto lens for the Nikon mount. The test was once again made using a D700 full-frame DSLR. This is a well-built lens, very solid without any wobbling parts, and competes directly with the Nikkor AF-S 70-300mm f/4.5-5.6 VR lens which has been very successful among amateurs and enthusiasts. Here’s how the D700 combines with the Tamron lens:

This has been a very welcome addition to the market, because the Nikkor had been alone price-wise, and third-party options were not up to the standards. Fortunately, the Tamron is a very viable alternative and it even has some characteristics that surpass its direct rival, as we will see. The Tamron belongs to the SP (Super Performance) line, the same line that has, among others, the highly praised 17-50mm f/2.8 (DX) and 28-75mm f/2.8 (FX) lenses. This 70-300mm is the first Tamron lens having the new USD (Ultrasonic Silent Drive) auto-focus motor for fast and silent focusing, and also the first including their innovative optical stabilizer mechanism, VC (Vibration Compensation). Indeed, the lens is very silent and rather quick focusing, but may hunt at times in areas with low contrast, the same happening in low light situations, otherwise the lens focuses quickly. The lens also has special glass elements, LD (Low Dispersion) and XLD (Extra Low Dispersion), which are employed to take care of chromatic aberrations. One thing that’s always good to have is IF (Internal Focusing) and this lens got it, and because of that the front element never rotates when focusing, therefore using a polarizer is no problem.
At a retail price of €389 right now, at a first sight and looking at the specifications, the lens seems to have a great price/perfomance ratio, but that’s the thing we’ll find out later in this review. On the D300 I had before, this lens was stellar for the price, having very good sharpness corner to corner at every aperture and only with a slight drop at 300mm, being a terrific combination for quick operation speed and optical performance in all focal lengths for users who don’t normally shoot in low light situations.

Technical Specifications

Focal length 70 – 300mm
Maximum aperture f/4 – f/5.6
Minimum aperture f/32 – f/45
Field of vision 34 – 8 degrees (on FX)
Weight 765 g
Dimensions 144 x 80mm (194 x 80mm extended)
Optical construction 17 elements in 12 groups (1 LD element, 1 XLD element)
Aperture blades 9
Filter diameter 62mm
Minimal focus distance 144cm (125cm from the front element)
Hood HA005, petal-shaped
Mount Nikon F

Mechanical Characteristics

Zoom ring Plastic with rubber finish
Focus ring Plastic with rubber finish, no infinity stop
Focus throw 160 degrees
Focus motor Ultrasonic Silent Drive, allows full-time manual focus override
Optical stabilizer Vibration Compensation, up to 4 stops capability
Front element rotation while zooming No
Front element rotation while focusing No
Internal focusing Yes
Lens extension while focusing No
Lens extension while zooming Yes, up to 51mm

Handling

The Tamron is a big fat lens and even with the D700 is a little front-heavy, but not overly so. Playing with the zoom ring feels like plastic against plastic, but nevertheless it’s not only smooth enough for quick operation, but also acceptable enough for the times when you need precise framing. Some people complain that the zoom ring is a little stuck on their copy, but that might be true when the lens is brand new; I don’t remember mine having a stuck zoom ring. The focus ring feel is similar, but since it’s lighter it’s easier to turn around.
The lens allows full-time manual focusing without the need to turn the lens or camera to manual focus. Common with other built-in auto-focus motor lenses, the focus ring never stops rotating and is capable to focus past infinity. The Tamron focuses as near as 144cm from the focus plane (125cm from the front element) at 300mm, resulting in a maximum magnification ratio of 1:4, which is less magnification than the previous Tamron 70-300mm was capable of (1:2).
The lens has a long petal-shaped hood and the caps are of good quality. The front cap is similar to Nikon’s, allowing you to take it off and put it on without the need to take the hood off. The lens has a metal mount, which is a must-have for such weight, but doesn’t have a tripod collar, so be sure to have the camera well attached to the tripod socket when using the combo for long exposures.

Resolution

For the resolution test I shot the 5 Euro bill in the studio. Focus whas achieved using Live View to avoid auto-focus imprecisions and to compensate for an hypothetical field curvature.
The first column shows a crop of the image center, the corner crop is on the second column and the third column shows a crop of the extreme corner. Each row represents an aperture setting, from maximum to f/22 in full stops. Here are the results:

70mm

At 70mm the center resolution is already excellent right from f/4 and only deteriorates at f/22 due to diffraction. The corner resolution is on a very good level until f/11 and drops noticeably at f/16. The borders are on a much lower level; by f/4 the sharpness is only acceptable and improves slightly at f/5.6, but reaches a good level from f/8 to f/11 before dropping again at smaller apertures. All in all, a very good performance at this focal length (not that, from now on, if you’re considering using this lens on DX, use the first and second columns only as reference, since the second column shows crops of the same area as the extreme corners on DX).
Moving on to other focus lengths now…

100mm

At 100mm the resolution at the center and corners is excellent already wide-open and only drops by f/22. The extreme corners are good wide-open at reach very good figures by f/5.6 and the resolution drops a bit at f/16. From 100mm to 135mm seems to be the lens’ sweet spot.

200mm

At 200mm the center resolution is always on an excellent level but the corners start to show some limitations. Wide-open and until f/8 the resolution figures are only on an acceptable level and the extreme corners follow closely. At f/11 there’s a sudden increase in quality in the entire frame and that continues at f/16. By f/22 the resolution drops a little but not by much as in previous focal lengths.

300mm

At 300mm, resolution drops noticeably in the entire frame but remains good to very good at the center. On the downside, the corners are never on the same level, and for good edge-to-edge sharpness one has to stop down to f/16 or even f/22. This is not noticeable in the real world, trust me, because at 300mm you tend to put the subject at the center anyway.

Overall, the Tamron shows a strong performance, producing sharp and contrasty images at all focal lengths, and its strongest selling point is the resolution and contrast at 300mm. This is much better than the Sigma 70-300mm f/4-5.6 APO Macro I had before and better than its direct rival, the Nikkor AF-S 70-300mm f/4.5-5.6 G ED VR I had played with.

The only thing that changed my opinion about the Tamron now, compared to the performance delivered with my previous D300, is the noticeable variation in exposure. It is very visible, at all focal lengths, that the lens underexposes a lot at the maximum aperture and less so stopped down, exposes well at f/8 and overexposes at f/11, before underexposing again by f/16. The weird thing is that it wasn’t noticeable at all with the D300, when only I had some minor overexposures in bright sunny days which were corrected simply dialing to -0.3 or -0.7 EV, independently of the aperture I was using. Now I can’t say that my lens doesn’t underexpose or overexposes, but instead a combination of the two that is dependent on the aperture. I can’t really say if this is because of heavy vignetting, but if so it affects the entire pictures and not only the borders, but also there’s a bit of overexposure at f/11 that is visible in the camera histogram. This will be more visibly explained below in the vignetting test.

Distortion

For the distortion test I shot a brick wall, again:

70mm

135mm

300mm

The lens distortion is practically absent at 70mm but starts producing a certain amount of pincushion at 135mm which stays constant until 300mm. On the field this is practically invisible and can be easily corrected in post-processing if needed.

Vignetting

In this test I shot a white wall at home using tungsten white balance and setting exposure manually. The exposures were judged by the camera histogram and are considered to be spot on when it’s centered.

70mm

At 70mm, vignetting is strong wide-open and less so at f/5.6, before improving considerably at f/8. At smaller apertures it disappears completely.

135mm

At 135mm, the same behaviour happens exactly as before.

300mm

At 300mm, only the widest aperture is affected by vignetting but in a very strong way. At other apertures there isn’t any noticeable light losses towards the edges.
As said above, the lens is affected by exposure differences that affect the entire image, as opposed by vignetting which only affects the borders of an image by any degree. I also could not find an explanation for the overexposure seen at f/11 from 70mm to 135mm. This is the first time I had a problem like this one and I’m not sure if the problem is related to this particular copy or any other sample. There are many people who complained about their copy producing under- or overexposed pictures, but mine gives exposures that were unpredictable at first, but can be corrected dialing exposure compensation accordingly depending on the aperture used. This phenomenon is more visible in Matrix metering mode and less so in Center-Weighted mode. I found no differences between aperture and shutter priority, or manual exposure modes. I will try to repeat the test if I have the chance of getting another copy.

Chromatic aberrations

For this test I shot a car roof from above, on a very sunny day early in the afternoon.

70mm

300mm

The Tamron employs low dispersion glass elements to reduce chromatic aberrations and it’s clearly visible that the lens performs as advertised. Aberrations are negligible at almost every aperture, except at its maximum where minor vestiges can be found on extremely high contrast situations, but only at the widest focal length. That’s a very good performance for a lens in this price point.

Coma

Coma is an important requirement in astrophotography and usually affects the corners of most lenses. Lenses that are affected by coma produce comas (hence the name) instead of bright light points in dark backgrounds. One way to test coma is using a LED source of light at home in a dark room.
I put the light source at the center (first column), corner and extreme corner of the frame (second and third columns, respectively), at maximum aperture and stopped down.

70mm

300mm

The lens isn’t much affected by coma and the only distortions visible are in the halos around the center, where they stretch the more the points are closed to the borders, but the points themselves remain perfectly circular. This is not uncommon for lenses with such moderate maximum apertures.

Flare

I shot a building in construction in front of me, with the sun sneaking from a window, to see if I could see any flare vestiges. I started to shoot directly against the sun, then placed the sun at the corner and finally made some shots with the sun just outside the frame.

Shot directly against the sun.
Shot with the sun placed at one corner of the frame.
Shot with the sun just outside the frame.

The images are not much affected in all situations, which shows that the lens has good resistance to flare keeping contrast on a high level. The worst case is when the sun is placed at one corner, where the multiple internal reflections of light may be noticeable in the opposite corner.

Bokeh

Thanks to the 9 aperture blades, we can expect circular out of focus highlights from this lens. I took a defocused picture at the widest aperture of the city lights and got crops of the center, corner and extreme corners. The test was repeated for the subsequent two stops.

70mm

300mm

The bokeh from this lens is perfectly circular at the center and suffers from the cats eye distortion due to vignetting in the corners and more so in the extremes. The out of focus highlights are rather nervous on the inside at 70mm but get perfectly smooth at 300mm, and the edges aren’t much accentuated, resulting in smooth transitions and backgrounds that are soft and not distracting at the longest focal length. All in all, the lens has good bokeh characteristics which are amongst the best in its class, especially when we take the moderate apertures involved into account.

Macro/Close-up

The Tamron was capable to focus as close as 144 centimeters from the sensor plane, which means 125 centimeters from the front element, resulting in a maximum magnification raio of only 1:4 at 300mm. I shot an 1 Euro coin and this is what to expect at the minimum focus distance:

70mm

300mm

Image stabilization

This lens introduced Tamron’s new image stabilization technology, VC (Vibration Compensation), to compensate for unwanted small movements, and it’s advertised as giving an advantage of 4 stops. This means that at 300mm, one can shoot with speeds as slow as 1/20 seconds.
To test it, I shot the back of a street lamp from my window. The first column shows crops of the subject shot with VC off, and the second column shows them with VC on for comparison. Here are the results at 300mm:

It shows to me clearly that the VC works as advertised, resulting in sharp images at 1/20 seconds. Of course, one has to build some technique to hold the camera and lens steady, so that the benefits of this technology can be applied. The image taken at 1/20 is a little softer but due to diffraction (an aperture of f/32 was used).
Contrary to Nikon’s VR mechanism where 2 axis (up and down) are used, VC used 3 axis: up, down and yaw (up-left, down-right) to compensate for diagonal shakes. One more difference to VR is that VC appears to work with full power right from the moment you press the shutter button halfway, and stays there moments after the picture is taken. VR works with less power and only commutes to full power when you press the shutter button down to take the picture. This is the reason why the images in the viewfinder are almost static with VC, when compared to what is visible with VR. This doesn’t mean that VR is much worse, because it’s not, but I found VC to give me more keepers. And it works as advertised, which is amazing.

Summary

Build quality 7 Mostly high quality plastic but all parts are tight together
Handling 7 Nice feel overall with silent and fast AF in most situations, the zoom ring could be damped for smoother operation
Resolution 7 Very good center sharpness, good corners and acceptable extreme corners in most apertures, amongst the best in class
Distortion 9 A little pincushion distortion but not noticeable in everyday shots
Vignetting 8 Strong at biggest apertures, negligible afterwards (not considering the variations in exposure)
Chromatic aberrations 9 Rarely visible, if any only at 70mm at the widest apertures
Coma 9 Not perfect, but the lens almost doesn’t have issues here
Flare 8 May produce some flare in harsh conditions, but contrast stays always on a high level
Bokeh 7 Circular but very nervous with accentuated edges at 70mm, but gets pleasantly smooth at 300mm
Overall 79% Very good lens on DX and FX, a valuable lens if you need stabilization and can’t afford any of the 70-200mm offerings

Samples

Here are some samples of pictures I made with this lens. Settings: native JPEG, picture control set to Landscape mode, no post-processing applied except reducing to 600 pixel width.

300mm, f/5.6, 1/125s, ISO 200
300mm, f/11, 1/160s, ISO 200
70mm, f/4.0, 1/1600s, ISO 200
70mm, f/4.0, 1/2000s, ISO 200, -0.7 EV
270mm, f/5.6, 1/1250s, ISO 200
70mm, f/11, 1/320s, ISO 200
100mm, f/4.2, 1/1250s, ISO 200
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