Tamron 28-75mm f/2.8 Review

Tamron 28-75mm f/2.8  Real world images

Tamron 28-75mm f/2.8 lens review:

The Tamron 28-75 f/2.8 generated a lot of excitement from me and others when it was announced. 2.8 zoom lenses are quintessential lenses for many professionals and enthusiasts. The only standard native normal view 2.8 zoom for Sony was the very heavy and expensive Sony 24-70 f/2.8 GM lens. The weight and price of the GM lens are major factors for many photographers.

Meanwhile, Tamron has been hitting home runs making high level enthusiast lenses for DSLRs. I personally love their 45/1.8 and 85/1.8. Every lens is a matter of differing compromises. To make a lightweight and affordable 2.8 standard zoom, Tamron would have to make compromises. But I was hopeful they would make the right compromises to deliver a very desirable lens. Let’s see how they did…

Body and Handling

The Tamron 28-75mm F/2.8 is pictured above beside the Sony 24-105mm f/4.   The Tamron has a narrower barrel but is slightly longer.   When extended, the Sony 24-105 extends a bit longer.  The Tamron weighs less than the Sony 24-105mm F/4, 550 grams compared to 663 grams, an appreciable difference.

The build quality overall rates as “ok.”  It is more of a consumer lens than a professional lens.  It feels sturdy but the the hood is small and flimsy.   There are no buttons or switches, autofocus/manual focus must be set in the camera body.  No focus hold button, which is a great place to assign eye-AF on Sony bodies.

Autofocus is exceptionally silent and relatively fast in my experience.  There are reports of focus issues but I had no problems with my copy.  Tamron has promised to address the issues with a firmware update.  Yes, there was an occasional focus miss but that’s the case with any lens.  Unfortunately, Sony’s AF-C isn’t always quite as precise and accurate as advertised.

The Tamron 28-75 f/2.8 lacks any lens stabilization but Sony’s IBIS provides some level of stabilization.  IBIS works better on the wide end than on the telephoto end.   I found at the wide 28mm end, I could rely on the IBIS system of the Sony A7riii to get consistently sharp images at 1/10.   At the telephoto end of 75mm, I wasn’t comfortable going much slower than 1/40 to 1/50.  Your results will vary based on your hand holding technique.

Image Quality

The point of a 2.8 zoom is hopefully to get near-prime type image quality with the convenience of a zoom.   There will always be some trade offs, even with a lens like the $2200 Sony 24-70 f/2.8 GM, but let’s see the level of trade offs with the Tamron 28-75mm F/2.8.

Vignetting

At 28mm above, vignetting is very severe wide open and isn’t totally gone even at f5.6. Eventually Lightroom will have a lens profile that will correct it, but that will result in more corner noise.  If you’re stopping down to F8 for a landscape, the vignette won’t bother you but will be a factor at wider apertures.  It’s a similar story at the telephone end of 75mm:

Let’s do a side by side comparison at the wide end with the Sony 24-105 f/4 which is also known for severe vignette at the wide end, so let’s compare boy around 28mm and f4:

By the time you get around the 28mm mark, the vignette on the 24-105 f/4 isn’t horrible, just still a tiny bit in the extreme corner.  The Tamron 28-75 f/2.8 is actually a bit worse.

Flare – Chromatic Aberration/Purple Fringing

Mostly good news here.   The lens isn’t flare-free at smaller apertures, but it’s not an ugly pervasive flare and good contrast is maintained.  I don’t see much purple fringing in high contrast areas, though it appears the Tamron 28-75mm f/2.8 bakes CA correction into even RAW files.   But at least it works.

Bokeh

Some will use the telephone end of the Tamron 28-75mm f/2.8 for portraits and narrow DOF.  So it’s worth taking a look at the bokeh.

The bokeh is a bit on the busy side and you can get very clear onion ring effect.   On the positive side, the bokeh is well rounded.   I don’t expect great bokeh from zoom lenses.  Thus, if you want spectacular bokeh, this lens wouldn’t be your first choice.  But it’s not horrible.

Close Focus:

A short minimum focus distances opens up some semi-macro shooting nicely with the Tamron 28-75 f/2.8.  At the 28mm end, you can get a 1:3 magnification and 1:4 at the 75mm end.

Sharpness

Considering the price and size of the Tamron 28-75mm f/2.8, a significant question is whether it is better than the Sony 24-70 f/4 and the Sony 24-105 f/4 (review here).  At f2.8, the Tamron lens has a one stop aperture advantage which is very valuable, if it can produce good results at F2.8 and great results at F4.

Starting with center crops at 28mm (click for large):

28mm at the aps-c border:

And 28mm in the extreme corners:

Another series from closer focus:

Centers at 28mm:

Borders at 28mm:

And the extreme corners:

At 28mm, the Tamron 28-75mm f/2.8 secures a passing grade overall.  Center sharpness is quite good at all apertures.   The border is acceptable wide open at 2.8, but becomes visibly sharper at f4 and really reaches great sharpness at f5.6.  The corners are a bit disappointing as they are severely affected by distortion and vignette in addition to poor sharpness.  At 2.8, the corners can only be described as ugly.  Corners improve progressively with stopping down, but don’t become acceptable until f5.6 and don’t really become tack sharp until f8.  At closer focus distances, the Tamron 28-75mm f/2.8 performs a bit better than from more distance.

Look at 50mm tests:

The borders:

50mm corners:

Closer focus, centers at  50mm:

50mm borders:

And extreme corners at 50mm:

50mm seems to be the strong point for the the Tamron 28-75 g/2.8.   The center and border are acceptably sharp wide open, just sharpening up a bit more at F4.  Meanwhile, the corner starts to look pretty good at F4.

Turning to 75mm, center crops:

75mm border crops:

Finally, 75mm extreme corner crops:

The closer focus series, 75mm center:

75mm borders:

And finally, 75mm extreme corners:

 

At the telephoto end, you can get away with shooting wide open but the corners will be a bit ugly.  At f4, you get acceptable results over most of the frame but you must stop down to F5.6 to get a tack sharp result across the entire frame.

Sharpness Comparison to the Sony 24-105 f/4

I keep returning to this comparison because I believe many Sony shooters will be choosing between these two lenses.   Where one lens is a bit smaller, cheaper and with larger aperture, the other lens has a superior build quality and more convenient range.   But how do they compare in sharpness?  In theory, when comparing at F4, the Tamron should have an advantage since it gets the benefit of stopping down while the Sony is wide open.   Let’s compare borders and corners at F4, side by side:

At 28mm, I give the advantage to the Sony 24-105 f/4.  At the borders of the frame, sharpness is about equal but the Sony 24-105 f/4 is just slightly sharper in the corner.

 

The situation reverses at 50mm.  When shooting at F4, the Tamron 28-75mm f/2.8 has a noticeable advantage at the border and corner.   The Sony 24-105 f/4 is just slightly soft while the Tamron is tack sharp.

We again see the corner problems of the Tamron 28-75 f/4 at the telephoto 75mm, end.  At the borders, the Tamron is noticeably sharper than the Sony.  But in the corner, the Sony 24-105 f/4 puts up a surprisingly good performance while the Tamron is quite soft, despite the benefit of stopping down.

My full Sony 24-105 f/4 review here.

Overall:

The Tamron 28-75mm f/2.8 is a light weight and affordable lens capable of producing sharp images.  It benefits from low purple fringing, a useful short minimum focus distance and large 2.8 aperture.   Focus is extremely silent.  Unfortunately, there were may compromises to keep the size and price down.  A wide end of 28mm isn’t wide enough for this to be a full time walk-around lens, especially if you shoot landscapes.   Vignetting is significant.  Corner softness is quite poor.

For enthusiasts and casual shooters looking for more than the kit lens for Sony full frame, the two best choices are the $1300 Sony 24-105 f/4 (now in stock at Amazon ) or the Tamron 28-75mm f/2.8.  

Overall, I would rate the Sony 24-105 f/4 as the better lens.   It has better build quality, optical stabilization, more useful focal range, and better corner sharpness.  While the Sony 24-105 f/4 also suffers from severe vignette issues, the worst is at 24mm.  In the 28mm to 75mm range, the Tamron is even worse.    But there are still plenty of reasons to prefer the Tamron 28-75mm f/2.8:

• 100 grams lighter than the Sony 24-105 f/4
• $500 cheaper than the Sony 24-105 f/4
• At comparable apertures, the Tamron may be slightly sharper in the center and borders
• All the benefits of 2.8 aperture

The 2.8 aperture is really the big selling point.  If I wanted a general walk-around lens for good light, I’ll take the Sony 24-105 f/4.   But if I’m shooting a lot of events or other indoor low light situations, then the 2.8 aperture becomes very valuable and it would be my preferred lens.   If you don’t care about weight or price of course, go with the Sony 24-70 f/2.8 GM.

Rating (1-10):  Score: 6.5

(About my scoring:  9-10 is a superb lens which could have a place in the bag of almost every photographer.   6-8:  recommended with caveats.   3-5:  A compromised lens that may still be suitable for some shooters and situations.  1-2:  Just stick to your phone camera)

If you purchase the Tamron 28-75mm f/2.8, it uses 67mm filter and my recommended filter is below:

Recommended UV filter – B+W 67mm filter