Purpose of the article is to point out long standing discussions and controversies around the Zeiss 16-70mm zoom and compare it to the Sony 18-135mm lens which is far more recent release from Sony and believed to be all around well praised lens.
- Zeiss 16-70mm F4 (released on August 27, 2013)
- Sony E 18-135mm F3.5-5.6 (released in January, 2018)
The Sony APS-C sensor cameras such as A6000 all the way to A6500s have a limited options when it comes to zoom lenses and the entire range from Sony comes down to 4 lenses which has their own strengths and weaknesses.
- Sony E PZ 18-105mm F4 G OSS
- Sony E 18-135mm F3.5-5.6 OSS (more recent release than other two)
- Zeiss 16-70mm F4 OSS
- Latest Sony E 16-55mm f2.8
I ignored the Sony 18-105mm G from comparing as it has known issue with high distortion and a considerably bigger lens for APSC mount, also it is a power zoom for videographers than people who wants to take photos and need smaller zoom for portability to go with their crop sensor bodies. I have also seen many comparisons between 18-105 vs 18-135 so it is not difficult to figure out which is best out of the two image quality and sharpness wise.
On the other hand, It is too early to say how good the latest 16-55mm f2.8 is as it was released few days ago and haven’t seen any in-dept reviews yet. I also don’t find the ~$2000 (AUD) price tag is reasonable for the lens unless you are a professional and need weather sealing and additiona custom button is a requirement.
Hence the research to weigh options such as the 18-135 vs 16-70mm as they both cover a versitile zoom range at a similar price range (Zeiss is around $200 expensive).
Why a comparision?
Reason 1: Zeiss 16-70mm F4 is a controversial lens mainly due to the blue “Zeiss” label and the price tag it comes with. Many people who bought it has been getting decentered lenses with QC issues or generally softer edges.
Reason 2: So many online forum discussions by people who either has the zeiss or wants to buy the lens asking recommendations. Mostly the answer has been hold off from owners who got bad copies.
Some online forum threads comparing the two
Reason 3: Zeiss vs the Sony price gap is getting lower. Zeiss lens price has come down to around $980-$1200 range here in Australia. Therefore I believe both lenses should be considered as great general purpose zooms.
Reason 4: purchased both lenses recently within a month or so, and decided to keep only one, sell the other and figure out which is the best lens overall IQ wise.
This wasn’t a perfect scientific test, but I tried to keep the parameters between lens tests fair and accurate as possible to derive unbiased results.
There are number of ways to test the IQ of a lens but for this particular exercise, I choose to shoot indoors on a solid tripod at a fixed target.
The target is from B&H lens test document which is http://static.bhphotovideo.com/explora/explora/sites/default/files/bandh-test-target.jpg
I only managed to print the lens test chart in A4 size due to the home printer limitation so printed 4 copies of that and made a bigger rectangular chart by connecting copied using tape and stuck it to the wall in a somewhat equally lit room.
Focus mode: Manual
White balance: Fixed to indoor flurocent
Distance from the target: Fixed (~60cm away)
I kept the above settings fixed between lenses, but when taking photos I only changed the aperature to take test shots. I went from F4, F5.6 and F8 as those are the most common aperture values I would shoot with the zeiss. For the Sony went from F3.5, F4 and F5.6 and F8.
I purchased both lenses recently within a month or so and did test for decentering issues. I didn’t find any obvious issues with the Zeiss, however the Sony 18-135 was very slightly soft on the left side, but I believe this is within the acceptable threshold.
If you see issues with any of the lenses that I didn’t, feel free to leave a comment and point that out.
The results between two lenses are shown below at different aperture values. Some tests had to be done at different aperture values due to their max aperture values in each lens.
NB: Right click, and open URL in a new tab or click on “Download” to get the full 24MP image to view at 100%.
Test 1: at shortest focal lengths Sony 18mm f3.5 vs Zeiss 16mm f4
Test 2: at shortest focal lengths Sony 18mm f5.6 vs Zeiss 16mm f5.6
Test 3: at shortest focal lengths Sony 18mm f8 vs Zeiss 16mm f8
Test 4: at ~24mm Sony f4 vs Zeiss f4
Test 5: at ~24mm Sony f5.6 vs Zeiss f5.6
Test 5: at ~24mm Sony f8 vs Zeiss f8
Test 5: at ~35mm Sony f4.5 vs Zeiss f4
Test 6: at ~35mm Sony f5.6 vs Zeiss f5.6
Test 7: at ~35mm Sony f8 vs Zeiss f8
Test 7: at ~50mm Sony f5.6 vs Zeiss f4
Test 8: at ~50mm Sony f5.6 vs Zeiss f5.6
Test 9: at ~50mm Sony f8 vs Zeiss f8
Test 10: at ~70mm Sony f5.6 vs Zeiss f4
Test 11: at ~70mm Sony f5.6 vs Zeiss f5.6
Test 12: at ~70mm Sony f8 vs Zeiss f8
- The obvious point from the above tests is that both lenses is that they are both sharp at centre even wide open.
- Both lenses become outstandingly sharp corner to corner when you step down. Specially f8, given this is a common aperture for landscape photos both lenses can be recommended for landscapes.
- Zeiss performs better at corners at larger apertures (f4) than the Sony from my observations. 18-135’s sharpness falls apart quickly when diverges from the centre.
- Zeiss’s weakness becomes apparent at 70mm, as far as I can observe, this is the weakest focal length of the Zeiss lens, sharpness and contrast is slightly lower.
- Around 35mm both lenses perform equally well.
Following the tests, I decided to keep the Zeiss due to it’s overall performance below 70mm and constant f4 aperture as well as the smaller size compared to the 18-135. In these tests I didn’t pay any attention to AF performance or OSS.