Tamron 24mm F2.8 Di III OSD Review

Introduction

Sony E-mount users are graced with many options for wide angle lenses. Offerings by Sony, of course, but also from third-party manufacturers such as Laowa, Sigma, and of course Tamron.

Tamron offers a trio of primes, ranging from 20mm to 35mm. We have already reviewed the wider 20mm option, and today we are taking a look at the lens sitting in the middle of the range, the Tamron 24mm F/2.8 Di III OSD M1:2 (Model F051). Like its siblings, the 24mm provides a fast F2.8 maximum aperture, 0.5x macro focusing, weather resistance and a light weight.

In this in-depth review, we will take a look at all the technical and artistic parameters which help to define a lens. Read on to find out everything there is to know about the Tamron 24mm F2.8!

Specifications

Lens Name	Tamron 24mm F/2.8 Di III OSD M1:2 (Model F051)
Optical formula	10 elements in 9 groups
Image circle	Full frame
Field of view diagonal	FF: 84° APS-C: 62°
Aperture range	F2.8/F22
Aperture blades	7, curved
Aperture ring	No
Max magnification	0.5x
Minimum focus distance	120mm
Internal focus	Yes
Filter thread diameter	67mm
Lens cap	Plastic, clip-on
Lens hood	Removable petal-shaped
Diameter x Length	73 x 64 mm (2.9 x 2.5 in)
Weight	215 g (7.6 oz)
Price (US MSRP)	$249

Construction and Handling

In this section, we take a look at the physical characteristics of the Tamron 24mm. Note that given the similarities, many aspects and comments will be identical to those from our Tamron 20mm review.

Front Element

The front of the lens is devoid of markings. The glass takes up a relatively small part of the total front surface.

The lens uses a large 67mm filter thread. This diameter is shared with its siblings the 20mm and 35mm, as well as most other FE-mount Tamron lenses.

The lens cap is plastic, and a bit thick.

Lens Body

The Tamron 24mm has a simple body with a minimum of features and controls. It is also extremely light weight.

The bottom of the body, near the camera mount, bears a silver ring. This nicely matches the dual-color of the Sony A7C. A discrete mark next to the silver ring helps to line up the lens for mounting. Above, the lens tapers out to a larger diameter.

Higher up are the only markings on the lens. At the center is the brand name, and to the right is the lens name. At the back are the certification markings and the “Designed in Japan” label. Next is the wide focus ring. As with other E-mount lenses, the 24mm uses focus by wire and, while it does offer manual focus override, this must be activated in a menu and cannot be used with continuous AF. There is no switch for manual focus on the lens.

The ring is ribbed and easy to find.

The lens does not extend when focusing.

Aperture

The Tamron 24mm uses 7 curved aperture blades.

Lens Mount

The lens mount is metal, and features a black o-ring to protect against water ingress. There is a rectangular cut-out on the back, to diminish stray reflections. To some extent, it serves a function akin to a lens hood.

Lens hood

The lens ships with a plastic lens hood, not too deep and easy to reverse for transport.

Mounted On Camera

The Tamron 24mm looks right at home on the Sony A7C, for which it is an excellent match.

Side by side

Here is the Tamron 24mm next to Sony’s FE 28-60mm and the Tamron 35mm, an identical twin. For size comparison, note the thicker lens caps on the Tamron lenses.

Focusing

As was the case with Tamron’s 20mm, focusing with the 24mm F2.8 is for the most part pleasant. The lens is not completely silent; it emits some clicking sounds when adjusting focus, especially for larger ranges variations. These will not be audible in most situations but will be noticeable for the photographer in silent environments.

Focusing can feel sluggish when the lens needs to rake through the whole range. Smaller adjustments, on the other hand, are almost instant. The 24mm keeps up flawlessly with subject tracking using AF-C. It supports every focusing mode available on the A7C.

There are no switches or dials on the lens, controls are all done via the camera, which makes using manual focus cumbersome at times. The focus ring is surprisingly well dampened and shouldn’t move accidentally. It also gives adequate feedback to the user, better than expected. On our test copy, there is a small backlash but no observable delay when focusing manually. The precision of the focus adjustments will be dictated by the speed of rotation of the focus ring. Tamron did a good job even though focus-by-wire is not as direct as mechanical focusing.

There were few occurrences of hunting during our tests, only with poorly delimited subjects in very low light. In that case, the lens sometimes appeared to hesitate before finally locking on the subject.

AF Speed

AF speed was tested with the A7C. The subject was a black cross on a white background, about 1.5 meters in front of the camera. We used the central focus point. Three measurements were averaged for each data point.

For reference, 5 EV corresponds roughly to a small room lit with a 60 W bulb, and a sunny day corresponds to 16 EV, and a moonlit night to -2 EV.

Usually, we test AF speed by moving from infinity to about 1.5m. In this case, in part because of the close focusing capabilities of the lens, its AF speed is quite different depending on the starting point.

The first takeaway from this chart is that there is a huge difference depending on the starting point. That is because the level of precision at closer distances is much higher, thanks to the lens’ close focus capabilities.

The Tamron 24mm F2.8 is never a speed demon. Even in the best conditions, it never gets much better than 0.5 seconds. At low light levels, it can take as much as one second for small adjustments, and more than 5 seconds for larger adjustments! his is in the same ballpark as the Tamron 20mm F2.8.

Do not expect lightning fast AF from this lens. The good news is that AF accuracy is high.

AF Tracking

AF tracking, or continuous AF, is a hallmark of Sony cameras. As such, it is important to evaluate whether or not the Tamron 20mm can keep up with fast movements of the subject.

In our experience, the lens performs very well in this regard, comparable to the Tamron 20mm. Once focus is locked, the camera keeps up with most subject movements. We almost never encountered occurrences when the camera would lose its focus lock once achieved. In this regard, the lens performs better than with single AF.

The following animation illustrates tracking performances with a subject approaching and the photographer rotating to follow. Only the four last images (on a series of 22) are slightly blurred. It is hard to fully blame the lens, as the photographer was moving also.

General Image Quality

Before diving into the technical aspects of this review, let’s have a look at the more subjective elements which can make or break an image.

Field of View

24mm is, by all accounts, a comfortable focal length. Much less extreme than 24mm or even 20mm, this lens offers a wide field of view without requiring the user to really think about composition challenges. Being narrower than its 20mm sibling, it does not offer as many possibilities but is still significantly wider than the ubiquitous 28mm of many zooms.

As for other wide angle lenses, 24mm is well suited for landscapes and cityscapes. The large maximum aperture means the lens can be used in low light. Interior architecture photography is possible but tight spaces will benefit from an even wider angle.

Many user swear by the 24mm focal length for vlogging. It gives a wide angle of view without creating too much unflattering perspective distortion.

The lens’s close focusing abilities offer even more versatility, and the narrower field of view (when compared with the 20mm) makes composition easier, preventing the inclusion of unwanted elements near the edges of the frame.

Having a dependable, wide angle lens capable of 1:2 magnification offers a wealth of possibilities.

Color and Contrast

It is obvious that the Tamron 24mm shares DNA with the company’s 20mm. Our observations for the latter also apply to the former. The 24mm produces rich colors, well saturated.

Starbursts

At F2.8, there isn’t much to mention. Closing the aperture to F8 shows visible starbursts, however they are divergent and not perfectly defined. F11 improves things further.

In short, the starbursts are present, generally pleasing, but not as good as some other lenses, even Tamron’s 20mm.

Metering and Exposure

We observed some overexposure occurrences with bright light sources in the frame, at the smallest apertures. Nothing problematic, but exposure readings changed versus wider apertures for a given scene.

Sharpness

Sharpness, or a lens’s ability to resolve small details, is far from the only important characteristic of a lens, but it is probably the one which many users look at first. Soft images distract the viewer and the sharpest point in an image draws the eye of the viewer.

There are several ways to measure resolution. Some are quantitative, such as the number of lines per millimeter that can be resolved, while others are comparative, such as using a standardized scene to pit lenses against one another. We will use the latter, and supplement it with real-life samples.

To evaluate sharpness, we use a standard test chart that can be used to compare lenses to one another. We place the camera and lenses at a distance of 100x the focal length, so that the chart occupies the same area on all test images. This results in distances of 2.4 m in the present case. The chart is positioned successively in the center, on the edge and corner off the frame, testing all apertures each time. Focus is repeated for each position to avoid field curvature contributions.

This test will not show how good a lens can be. Quite the contrary, it is a stress test to illustrate the limits of a lens’s capabilities.

Resolution is of course sensor-relevant. For this test we use the A7C camera’s 24 MP sensor.

Test results at 24mm

The following images illustrate the results at all apertures at 24mm.

In a few words, sharpness with the Tamron 24mm is excellent. This is one area where the lens excels.

In more details, center sharpness is quite good even wide open, but improves before reaching a maximum between F5.6 and F11.

Edges are never as good as the center, but never far behind either. There isn’t much difference between results at F2.8 and F8.

Corners lag a bit more, but the difference is minimal. Uniformity across the frame is impressive, and the lens can be reliably used at almost all apertures, with a subject positioned anywhere in the frame.

In all cases, F22 shows much softer results, and should be avoided except for the center which remains usable.

The images below show the amount of detail that the lens can capture in close focusing conditions. You can click images to see larger versions.

Summary

Tamron produced, with the 24mm F2.8, a lens capable of delivering high resolution figures. What is impressive is the uniformity across the frame, and the excellent results wide open. Using the sweet spot between F5.6/F8 will improve things, but only marginally.

Vignetting

Vignetting, or the darkening of corners at wider apertures, is both a defect and a feature, as it can be used creatively to put emphasis on subjects closer to the center, create a mood or a vintage look. It can also be corrected automatically by modern cameras so is less of a problem than in the past. That is only true for lenses with electronic contacts, including the Tamron 24mm.

The following chart illustrates the vignetting of the lens for full frame when left uncorrected.

Tamron 24mm vignetting — Vignetting of the Tamron 24mm

The 24mm’s designer visibly decided to rely on automated corrections for vignetting. The small size and large maximum aperture yields important vignetting at all apertures, never going much below 1.25 stops. Wide open, the effect is dramatic. We recommend using automatic correction profiles to avoid the problem.

The images below show the lens’s vignetting at varying apertures.

Bokeh

Bokeh is a Japanese term describing the quality of the background blur. It does not relate to the depth of field but to the areas in the image that are beyond the range that is expected to be in focus.

Bokeh is highly subjective. In general, a smooth bokeh with blurred shapes and contours is generally perceived as being of a higher quality. A shallow depth of field does not always equate a more pleasing bokeh.

To evaluate the characteristics of the background blur, we took pictures at varying apertures, using a scene with a lot of detail and bright highlights. The following images show the results.

Thanks to the F2.8 maximum aperture, depth of field can be made very shallow. However, the out-of-focus rendering is not ideal. It is busy, lacking the smooth transmissions we usually look for in those areas. There are visible shapes edges on the edges of objects.

Thankfully, the transition between in-focus and out-of-focus is gradual, as can be seen below.

Highlights are not distracting, though not perfectly round-shaped. They do have a uneven pattern, as can be seen on these crops from an image at F4.5.

Flare and Ghosting

Flare is a decrease in contrast caused by reflections on internal lens elements. Ghosting is the appearance of orb-shaped artifacts in an image containing a light source, caused by the same internal reflections. High-quality coatings reduce the importance of flare and ghosting in an image.

We test flare and ghosting by taking pictures of a bright light source positioned at the center and on an edge of the frame, at varying apertures.

Test results at 24mm

In the center, there is some flare around the light source at wider apertures, and a ghost a little below. It gets more visible as the aperture closes, and is joined by other ghosting patterns. At F16 and F22, flare gets out of hand with numerous steaks of colour between the starbursts rays.

With the light in the corner, ghosting gets more important. At all apertures, there is a streak of highly visible ghosts going from one corner to the other.

Management of flare and ghosting is not one of the Tamron 24mm’s strong suits, to say the least.

Chromatic aberration

Chromatic aberration (CA) occurs because different colours do not always have the same focal point. With modern lenses designs, which are better corrected than vintage designs, this is more likely to occur in out-of-focus areas. CA effects are more visible near fast transitions from bright to dark areas.

Most modern cameras have built-in tools to remove CA. Digital manipulations can have an impact on other aspects of an image, thus it is useful to know how a lens performs when those automatic corrections are disabled.

Our test sets up the camera at 45° and focuses on the center of the frame, with targets at the center, top and bottom. Images are captured at varying apertures.

Chromatic aberration with the Tamron 24mm

Chromatic aberration is handled very well by the Tamron 24mm. Wide open, there is some subtle (and hard to miss) CA at the top and bottom, in the out-of-focus areas. It is gone by F5.6.

These results are excellent, and automatic corrections will easily take care of what little CA there is.

Purple fringing

There were almost no occurrences of purple fringing in our tests with the Tamron 24mm. The image below shows the worst of what we observed.

Distortion

Distortion refers to a lens’s ability to represent straight lines as straight lines… Wide angle lenses frequently generate barrel distortion, while longer focal lengths are more likely to cause pincushion distortion.

The Tamron 24mm is an ultra wide lens and, as such, some barrel distortion is to be expected. On the other hand, the company prides itself for its designs with low distortion, even applying to the lens the “Zero-D” moniker.

We use a standard test pattern of straight lines and test at 24mm.

Tamron 24mm distortion — Distortion with the Tamron 24mm

The Tamron 24mm shows significant distortion when left uncorrected. We measured 2% of barrel distortion.

This is clearly an area where the designers decided to rely on automated corrections. Still, the 24mm is much better than the Tamron’s 20mm, but worse than the best, such as Laowa’s 15mm F2.

Sample images

Here is a gallery of samples images captured with the Tamron 24mm. You can click on individual images for a larger view.

Conclusion

There are a few questions to answer when evaluating the Tamron 24mm. The first is how good it is in its own right. The second is how does it compare with the company’s 20mm?

The second question can be answered easily, and the results are a bit surprising. The 24mm is, quite simply, not as good as the 20mm. The wider lens edges out slightly for sharpness (although the two are close), does much better for flare, offers smoother bokeh and produces better starbursts. The 24mm does better for distortion.

In itself, however, the 24mm is a pretty good lens.

Build quality is good. The 24mm offers basic features, with no controls or switches, but it is well assembled, very light, and is even weather resistant.

Optical performances are, for the most part, excellent. In particular, sharpness is a strong aspect, with high resolution and impressive uniformity across the frame. The lens performs well even wide open.

Distortion is not impressive, reaching 2%. Automatic corrections should be used by default.

Chromatic aberration is almost entirely absent. Likewise, purple fringing is hard to spot.

Bokeh and out-of-focus rendering is acceptable, with gradual transitions. However, highlights can show distinctive textures, and the blur can get busy around sharper edges.

Flare and ghosting are definitely a weak point. The effect is always present and can get very distracting, at all apertures.

Starbursts are pleasing, but rays tend to diverge instead of tapering. The lens is still above average in this regard.

Vignetting is another weak point. Easy to correct in post-processing, it is still strong and will manifest at all apertures. Luckily it can (and should) be compensated automatically.

Autofocus is acceptable, and probably better than the lens’ reputation, but nothing unique either. Small adjustments are fast, but raking through the range takes a ludicrous amount of time in low light. In good conditions, it is adequate but not particularly fast. The lens also emits a clicking noise, which will probably be audible in videos if using the camera’s microphone.

In summary, the Tamron 24mm F2.8 is a very good lens taken by itself, but its weak points make it hard to recommend over the 20mm. People who are bothered by distortion or who are more comfortable with a narrower focal length will be served by the Tamron 24mm. Others will probably get a better lens with the 20mm, especially considering that they are of the same size, similar weight, and close in price.