Since its release in 2017, Sony 24-105mm f/4 lens has been a hit. It is the beginning of July 2018 now and the lens is still on preorder in all camera stores.Yes, small batches have been released and if you pre-order it is most probably that you will receive one soon, but it is not available for direct buy online.
While waiting for this lens to come, Tamron announced, and later released, a brand new 28-75mm full frame lens with constant f/2.8 aperture. It was probably released to compete with the Sony GM 24-70mm f/2.8, as many of the reviewers jumped to compare the two. Yes, both lenses have similar focal length, and both have constant f/2.8 aperture, but pricewise are very different. While the Sony GM 24-70 F/2.8 is almost $2,200, the Tamron 28-75mm f/2.8 is only $799.
Couple of weeks ago my Sony 24-105mm f/4 finally arrived. Because there were no signs that it can be delivered on time for the two upcoming events I had to shoot, I decided to rent the Tamron 28-75mm f/2.8 as well. At the end both lenses arrived on time, so I had the opportunity to shoot with both lenses at two weddings, and also use them for some casual family pictures.
Just a comparison
I want to make the note beforehand that this article is not meant to be a detailed, scientific comparison between the two lenses. It is more to share my personal experience with both in real life situations, as also to show some sharpness tests I did in home made setup.
Let me start with sharing my thoughts about the two lenses. Some people say that the Tamron looks “plasticky” but I am pretty happy with the build quality of the lens. To me the feel is more “velvety” than “plasticky”. The manual focus ring is extremely smooth. The lens is light, fast and reliable. I didn’t have any issues with it – in any light conditions. The EYE AF worked perfectly. The only “problem” I noticed was that when it acquires focus – it kind of hesitates for a split second. It’s more like trying to confirm focus than hesitation – similar to what the contrast detection is doing – going a bit back and forth to determine the best focus. The Sony 24-105mm did not do this. This happens very fast so it’s not a real problem – that’s why I put “problem” in quotation marks.
Among the Tamron’s advantages are the lightweight, the amazing center sharpness, the constant f/2.8 aperture, closer minimum focusing distance, the size, and the price. Sony responds with better zoom range, slightly better build quality, it has assignable button on the lens (which I use to activate Eye AF), and also has AF/M switch, it has Optical Steady Shot (OSS), it has better corner sharpness in most of the cases, and it is a native Sony lens.
I decided to shoot the first wedding primary with the Tamron, and the second primary with the Sony, so I get better idea how the two lenses will perform in various situations. I can tell – both lenses held up to my expectations. The obvious “achilles” heel of the Sony was the f/4 aperture, and for the Tamron this was the limited range, especially on the wide side.
Below you can find a quick comparison I did at home – may be not the perfect and 100% accurate, but it still shows quite well what you can expect from these two lenses. For these who want to watch it, I uploaded a video on YouTube. I will not compare the results here – you can see the pictures yourself, and also can watch the video, but what I’ve noticed is that in most of the cases the Tamron excels Sony in the center sharpness, and radically falls behind in corner sharpness with very few exclusions. I did not find this to be a disadvantage shooting the weddings, but for landscape I would definitely go for the Sony. Also, the difference in the center sharpness is not that big as it is in the corner sharpness. In all sample images the Sony lens is on the left and the Tamron is on the right side.
Comparison at 28mm:
Comparison at 50mm:
Comparison at 75mm:
I will add a separate shot of the top left corner at f/8 – just so you can see how much sharper the Sony is.
So you may ask which one of the two lenses I kept for myself (I rented the Tamron, but I was considering buying it when it’s in stock). Although I will definitely miss the 2.8 aperture and also the closer focusing distance of the Tamron, I found much more use of Sony’s advantages for me, which made me to keep the Sony. Yes, most of the time the Tamron was sharper in the center, but this is comparing the two at f/4 (the Tamron is already a full stop down). Sony has OSS, the assignable button, better corner sharpness, better range, etc. Put it on A7RIII and you end up with having 37-152mm lens in crop mode.