Quality

Testing: Longitudinal Chromatic Aberration and focus shift

Lenses with focal ratios of f2.8 or larger are often prone to longitudinal color aberrations (loCA, a.k.a. “axial color” or “Bokeh CA”). These normally show up as magenta coloration in the foreground and greenish hues in the background and are not easily corrected in post-processing. The Sony FE 35mm f1.4 ZA shows the effect pretty prominently. The following 100% crops show the foreground on the left and the background on the right with the first crop at f1.4, second at f2.0, third at f2.8:

 Longitudinal Chromatic Aberration (loCA)

Above: Sony FE 35mm f1.4 ZA at f1.4, f2.0, f2.8; 100% crops

You can see the coloration around the foreground or background branches in the following example:

Above: Sony FE 35mm f1.4 ZA at f1.4; 100% crop; click image for 4k version, here for large original

The test also revealed that there is no focus shift to speak of.

The Sigma 40mm f1.4 Art has very little loCA (see here) while the Sony FE 35mm f2.8 ZA is also not the best regarding loCA considering that it has a focal ratio of only f2.8 (see here, crops are f2.8 and f4.0).

Sharpness and contrast

Let’s have a look at the theoretical performance of the Sony FE 35mm f1.4 ZA first and compare it to some alternatives:

Above: MTF Sony FE 35mm f2.8 ZA (left), Sony FE 35mm f1.4 ZA (right)

Above: MTF Sigma 40mm f1.4 Art (left), Sigma 35mm f1.4 Art (right)

The MTF charts of the Zeiss (designed) lenses from Sony show the contrast wide open at 10 (red), 20 (green) and 40 line-pairs per mm (purple). The computed MTF chart of the Sigma Art lenses shows contrast at 10 lp/mm (red) and 30 lp/mm (green) at f1.4 without influence of diffraction. Higher values are better (more contrast) and the closer the solid and dotted lines are together the less astigmatism (= resolution depends on the orientation of the test-pattern) the lens has. The x-axis displays the distance from the optical axis (=center of the sensor) in mm. I’ll show you the real-life performance at 4 mm (center), 13 mm (APS-C-corner), and 20 mm (FF-corner) on a 42MP Sony A7R II body for the Sony lenses.

From the charts the Sigma 40mm f1.4 Art looks clearly better than every other lens in this comparison and both the Sony 35mm f2.8 ZA and the Sigma 35mm f1.4 art have steep drops in contrast towards the corners. But other than that the different methodologies and the different focal ratios used in these charts makes it hard to compare the lenses. So let’s see how these lenses perform in my sharpness test based on Siemens-stars. Processing was done in Lightroom 8/CRAW 11 from RAW to Adobe Color profile with the built-in lens profile applied. Noise-reduction is set to 0, sharpening to 50/0.5/36/10, with no extra tone, color, or saturation adjustment. White-balance was adjusted to a neutral white and I did some exposure compensation to make the brightness of all crops match. So you will not see light fall-off in the corners.

The following 100% crops show the Sony FE 35mm f1.4 ZA from f1.4 down to f11 compared to the Sony 35mm f2.8 ZA (both shot on a 42MP Sony A7R II)  plus the Sigma 40mm f1.4 Art (shot on a 46MP Nikon Z7 with FTZ-adapter) and the Sigma 35mm f1.4 Art shot on a 36MP Nikon D800. Linear resolution of the Z7 sensor is only 4% higher than from the Sony A7R II and of the D800 sensor 7% lower which should not make a distinct difference in this comparison. The Sigma 35mm f1.4 Art had no lens profiles applied but I increased sharpening to 70/0.5/36/10 to counteract the slightly softening effect of the AA-filter in the D800.

Sony FE 35mm f1.4 ZA; 100% crop from center, APS-C-corner, FF-corner

Above: Sony FE 35mm f1.4 ZA at f1.4

Above: Sigma 40mm f1.4 Art on a 46MP Nikon Z7 at f1.4; also available at f2.0, f2.8, f4.0, f5.6, f8.0, f11

Above: Sigma 35mm f1.4 Art on a 36MP Nikon D800 at f1.4

In this comparison at f1.4 the Sony FE 35mm f1.4 ZA is very sharp in the center but its corners look mushy in comparison to the excellent Sigma 40mm f1.4 Art. Even the older Sigma 35mm f1.4 Art manages to produce sharper FF-corners.

Now let’s see how the Sony FE 35mm f1.4 ZA develops when stopped down further and compare it to the Sony FE 35mm f2.8 ZA at f2.8:

Above: Sony FE 35mm f1.4 ZA at f2.0

Above: Sony FE 35mm f1.4 ZA at f2.8

Above: Sony FE 35mm f2.8 ZA at f2.8; also available at f4.0, f5.6, f8.0, f11

At f2.8 the Sony FE 35mm f2.8 ZA produces a slightly better APS-C-corner than the Sony FE 35mm f1.4 ZA.

Above: Sony FE 35mm f1.4 ZA at f4.0

Above: Sony FE 35mm f1.4 ZA at f5.6

Above: Sony FE 35mm f1.4 ZA at f8.0

Above: Sony FE 35mm f1.4 ZA at f11

Stopping the Sony FE 35mm f1.4 ZA further down reduces the softness at the APS-C-corner considerably at f5.6 and of the FF-corner at f8.0. Overall the comparison shows that the Sony FE 35mm f1.4 ZA is not one of the sharpest lenses: It cannot compete with the newest Sigma 40mm f1.4 Art and even the older Sigma 35mm f1.4 Art produces the better full-frame corners.

Performance at long distances

The Siemens-star test-targets are shot at a distance of 45x focal length (i.e. at around 1.6m). But as performance of lenses also depends on the shooting distance I did another series of test-shots of a city around 1 km away. Processing was done in Lightroom 8/CRAW 11 from RAW to Adobe Color profile with the lens-profile  automatically applied. Noise-reduction is set to 0, sharpening to 50/0.5/36/10, with no extra tone, color, or saturation adjustment. I used autofocus at the largest aperture and did not change focus for other apertures.

The main image shows the complete scene wide open to give you an impression of the angle of view and to judge vignetting. You can access the respective shots up to f11 via the links beneath the main image. Following the main image are 100% crops from the Sony FE 35mm f1.4 ZA from f1.4 down to f11 compared to the Sony 35mm f2.8 ZA (both shot on a 42MP Sony A7R II)  plus the Sigma 40mm f1.4 Art (shot on a 46MP Nikon Z7 with FTZ-adapter). All lenses were shot on the same day only minutes apart. The small differences in linear resolution between the Nikon and the Sony camera should not cause a visible difference in sharpness.

You can click on each image to access the large original. Please respect our copyright and only use those images for personal use.

Above: Sony FE 35mm f1.4 ZA at f1.4; click image for 4k version, also available as large original at f1.4, f1.6, f1.7, f2.0, f2.8, f4.0, f5.6, f8.0, f11

Above: Sony FE 35mm f1.4 ZA at f1.4; 100% crop from center, APS-C-corner, FF-corner

Above: Sigma 40mm f1.4 Art on a 46MP Nikon Z7 at f1.4; 100% crop from center, APS-C-corner, FF-corner; available as large original at f1.4, f2.0, f2.8, f4.0, f5.6, f8.0, f11

Wide open The Sony 35mm f1.4 ZA produces a very sharp center although it suffers a little from magenta halos that reduces edge contrast a bit. Its APS-C-corner is less well defined than from the Sigma Art as field curvature bends the focal plane towards the camera (see the sharp looking branch in the foreground of the middle crop). In the FF-corner the Sigma Art has a clear lead.

Let’s see how the Sony FE 35mm f1.4 ZA develops when stopped down further and compare it to the Sony FE 35mm f2.8 ZA at f2.8:

Above: Sony FE 35mm f1.4 ZA at f2.0; 100% crop from center, APS-C-corner, FF-corner

Above: Sony FE 35mm f1.4 ZA at f2.8; 100% crop from center, APS-C-corner, FF-corner

Above: Sony FE 35mm f2.8 ZA at f2.8; 100% crop from center, APS-C-corner, FF-corner; available as large original at f2.8, f4.0, f5.6, f8.0, f11

At f2.8 the Sony FE 35mm f1.4 ZA has sharpened up quite nicely. The Sony FE 35mm f2.8 ZA trails behind the other lenses in this comparison with a generally softer rendering. I also had to take the other diagonal of the image in this comparison, as the little lens was quite decentered.

Above: Sony FE 35mm f1.4 ZA at f4.0; 100% crop from center, APS-C-corner, FF-corner

Above:Sony FE 35mm f1.4 ZA at f5.6; 100% crop from center, APS-C-corner, FF-corner

Above: Sony FE 35mm f1.4 ZA at f8.0; 100% crop from center, APS-C-corner, FF-corner

Above: Sony FE 35mm f1.4 ZA at f11; 100% crop from center, APS-C-corner, FF-corner

At f5.6 the Sony FE 35mm f1.4 ZA reaches its peak performance across the full-frame sensor.

Rendering of point-light sources at night-shots

Night-shots pose a different challenge for lenses as the contrast is even higher than under bright sun and point-light sources can reveal some weaknesses such as coma, haloing and color-aberrations that do not show up as prominently in other test-shots. The 100% crops below the main image show the effect of coma in the FF-corner of the Sony FE 35mm f1.4 ZA, Sigma 40mm f1.4 Art, and the Sony 35mm f2.8 ZA at various apertures:

Above: Sony FE 35mm f1.4 ZA at f1.4; click image for 4k version, also available as large original at f1.4, f1.6, f1.7, f2.0, f2.8, f4.0, f5.6, f8.0

Above: Sony FE 35mm f1.4 ZA; 100% crops from the FF-corner at f1.4 (left), f2.0 (middle), f2.8 (right)

Above: Sigma 40mm f1.4 Art on a 46MP Nikon Z7; 100% crops from the FF-corner at f1.4 (left), f2.0 (middle), f2.8 (right)

Above: Sony FE 35mm f2.8 ZA; 100% crops from the FF-corner at f2.8 (middle), f4.0 (right)

The Sony FE 35mm f1.4 ZA (at f1.4) shows some coma deforming point-light sources into birdlike apparitions. The Sigma Art produces almost no coma wide open while the Sony 35mm f2.8 ranks last – although it has the slowest focal ratio.

Rendering of out-of-focus point-light sources

This test is for the rendering of point-light sources in an out-of-focus background. The circle of confusion that is produced by this test is pretty indicative of Bokeh performance (in the background) and light fall-off. Ideally the out-of-focus image of the point-light is evenly lit and perfectly circular, with no “onion-rings”, and without coloration. Large aperture lenses normally produce an effect known as “cat’s eye” the further away from the optical axis the point-light is projected. This is due to optical vignetting in the lens barrel when light enters the lens from an angle.

Above: Sony FE 35mm f1.4 ZA at f1.4; click image for 4k version; also available as large original at f1.4, f2.0, f2.8, f4.0, f5.6, f8.0

Above: Sony FE 35mm f1.4 ZA at f1.4; 46% crops from center, APS-C-corner, FF-corner

Above: Sigma 40mm f1.4 Art on a 46MP Nikon Z7 at f1.4; 44% crops from center, APS-C-corner, FF-corner; also available as large original at f1.4, f2.0, f2.8, f4.0, f5.6, f8.0

Above: Sony 35mm f2.8 ZA at f2.8; 46% crops from center, APS-C-corner, FF-corner; also available as large original at f2.8, f4.0, f5.6, f8.0

Of the three lenses in this comparison the Sigma clearly produces the nicest, smoothest Bokeh balls with no onion rings and only a little outlining that shows no coloration from loCA. Both Sony ZA lenses show visible onion-rings and the Sony FE 35mm f2.8 ZA also has some outlining. Compression of the Bokeh balls is visible in the APS-C-corner already with all lenses producing the typical cat’s eye. Due to its f2.8 focal ratio the Sony FE 35mm f2.8 ZA has 50% smaller Bokeh balls in the center compared to its f1.4 sibling .

Let’s see how this analysis of out-of-focus point-light sources translates into Bokeh-performance shooting a book-shelf.

Above: Sony FE 35mm f1.4 ZA at f1.4; click image for 4k version, also available as large original at f1.4, f2.0, f2.8, f4.0, f5.6, f8.0

Above: Sony 35mm f1.4 ZA at f1.4; 46% crops from foreground, middle-ground, background

Above: Sigma 40mm f1.4 Art on a 46MP Nikon Z7 at f1.4; 44% crops from foreground, middle-ground, background; also available as large original at f1.4, f2.0, f2.8, f4.0, f5.6, f8.0

Above: Sony 35mm f2.8 ZA at f2.8; 46% crops from foreground, middle-ground, background; also available as large original at f2.8, f4.0, f5.6, f8.0

From the comparison above it is clear that the large focal ratio (potentially) produces the better Bokeh: The Sigma Art leads in this comparison followed closely by the Sony FE 35mm f1.4 ZA which is a little harsher in the middle-ground and background. Last comes the Sony 35mm f2.8 ZA which simply cannot compete with the other lenses in this comparison.

Close-up performance

The Sony FE 35mm f1.4 ZA goes down to 1:5.3 magnification which is better than the Sony FE 35mm f2.8 ZA. And its performance is quite usable once you stop down to f2.8 or beyond. The following image was shot at 1:5.5 magnification where the area of sharp focus is just 132 x 198mm. The crops shown below are (from left to right) from 2mm, 9mm, and 18mm off the center of the sensor respectively:

Above: Sony FE 35mm f1.4 ZA at f1.4, 1:5.5 magnification; 100% crops

Above: Sony FE 35mm f1.4 ZA at f2.8, 1:5.5 magnification; 100% crops

Above: Sony FE 35mm f1.4 ZA at f5.6, 1:5.5 magnification; 100% crops

Btw.: At these distances the lens develops pretty strong pincushion distortions.

Flare, ghosting, and sun-stars

Catching a strong light-source shining directly into the lens is always a risky business: it could produce strange colorful ghost-images or reduce contrast considerably through flare and glare. The appearance of flare and ghosting depends on factors like the aperture and the angle of the light hitting the lens. So to judge the proclivity of the Sony FE 35mm f1.4 ZA for these artifacts I went through a series of well calculated shots against a strong light source to provoke glare and ghosting.

The Sony FE 35mm f1.4 ZA shows a little flare and ghosting. The following image at f11 is one of the most obvious examples:

Above: Flare and ghosting. Strong light hitting the Sony FE 35mm f1.4 ZA at f11; click image for 4k version

The little square inset in the upper left of the image shows the respective area with an exposure compensation of +3 EV to make it easier to see which levels of black the lens renders at that point. It shows that the Sony FE 35mm f1.4 ZA renders a very deep black against contra light. But when the light-source is just outside the corner there is a very obvious resulting streak. Fortunately this only happens in a very small area around the corners:

Above: Flare and ghosting. Strong light hitting the Sony FE 35mm f1.4 ZA at f11; click image for 4k version

All-in-all the Sony FE 35mm f1.4 ZA let’s you shoot confidently under adverse contra-light situations as long as you avoid strong light-sources just outside the corners.

The sunstar in the image above does not look to well defined but when shooting smaller light-sources the lens produces better sunstars at f5.6 already although they are not too pronounced:

Above: Sunstars from the Sony FE 35mm f1.4 ZA at f5.6 (left) and f8.0 (right), 100% crops

Next check out my sample images!