Introduction
The FE 28-70mm F2 GM is an unprecedented large aperture standard zoom lens for Sony Alpha full-frame E-mount mirrorless cameras.
The 21st G Master optic is comprised of 20 elements in 14 groups, including 3 super ED, 3 aspherical, 1 ED and 3 XA elements.
This weatherproof lens features a Nano AR Coating II, internal focusing, new 11-blade circular aperture unit, 86mm filters and a floating focus design.
Razer sharp even at f/2, this new model compares very similarly to prime lenses for sharpness.
It offers a 0.38m minimum focusing distance with 0.23x magnification throughout the entire zoom range.
It has 4 XD linear motors and supports focusing at 120fps for stills and 4K 120p video. It offers minimal focus breathing and supports breathing compensation.
The FE 28-70mm F2 GM weighs just 918g and measures 119.9mm x 87.8mm, versus 695g for the 24-70mm F2.8 GM II.
It has an aperture ring with engraved f-stops, an iris lock switch, aperture click switch, 2x focus hold buttons and a zoom smoothness switch with Smooth and Tight settings.
The Sony FE 28-70mm F2 GM lens is priced at £3200 / €3600 / $2899 in the UK, Europe and the US, respectively. It is made in Thailand.
Ease of Use
Weighing in at 918g / 32.4oz and measuring 14cm in length, the hybrid metal and plastic bodied Sony FE 28-70mm f/2 GM is very light and compact for a standard zoom lens that offers such a fast maximum aperture.
It proved to be a well balanced partner to the the flagship Alpha A1 II camera that we tested it with, as shown in the photos below.
It’s significantly heavier than all of its main rivals, though, which include amongst others the Sony FE 24-70mm F2.8 GM II (695g), Sony FE 24-105 f/4 G OSS (663g), and the Sigma 24-70mm F2.8 DG DN Art (830g).
This new lens does extend when zoomed from the minimum 28mm focal length to the 70mm focal length by almost 3cms.
The overall build quality is veery good, which is something of a relief given the high price-tag, with this very modern lens utilizing a hybrid metal and plastic construction.
This lens has a sealed dust and moisture resistant design utlising silicon seals around all the buttons and switches and a rubber gasket around the lens mount, which makes it well-suited to life in both the field and the studio.
There’s also a a fluorine coating on the front lens element to help repel water, oil, and any other contaminants, as well as making it easier to clean.
It has a metal lens mount and accepts 86mm filters via metal threads.
The Sony FE 28-70mm f/2 GM has two round Focus Hold Buttons for easier access when shooting in either a horizontal or vertical orientation.
By default they keep the lens locked to the current focusing distance, useful if you’re auto-focusing and don’t want the lens to try and find focus again. An alternative function can also be assigned to either of these buttons through the camera’s custom settings.
There is a generously sized, ridged focus ring at the end of the lens. Manual focusing is possible by using the dedicated AF/MF switch to toggle between AF and MF.
There are no hard stops at the ends of the range, making it harder to set focus at infinity. Polariser users should be pleased that the 86mm filter thread doesn’t rotate on focus.
The lens utilizes four XD Linear Motors for satisfyingly fast, smooth and precise auto-focusing, and it’s very quiet in operation making it well-suited to shooting video.
An internal focusing design ensures that the overall lens length remains constant during focusing.
When it comes to auto-focusing, this lens is a really quick performer, taking less than 0.10 seconds to lock onto the subject when mounted on the Sony Alpha A1 II that we tested it with.
We didn’t experience any “hunting” at all, either in good or bad light, with the lens accurately focusing virtually all of the time.
It’s also a very quiet performer, which makes this lens equally well-suited to both video recording and more candid stills shooting.
This lens has a dedicated aperture ring with 1/3EV stops ranging from F2 to F22. It can be switched between smooth and notched rotation using the dedicated Click On/Off switch on the bottom of the lens barrel.
Using the Iris Lock switch on the lens barrel, it can also be locked to either the Auto or F2-F22 settings to prevent accidental movement of the aperture ring.
The generously sized zoom ring sits in the middle of the aperture and focusing rings and rotates through approximately 80 degrees. It has four different focal length markings – 28, 35, 50 and 70 mm.
This lens has a switch for setting the torque of the zoom ring, with two options available, Tight and Smooth.
The former is useful for preventing zoom creep during transportation or for use on a tripod, whilst the latter is a more general-purpose setting that most people will use most of the time, either for stills or for slow zooming during movie recording.
This lens does not feature optical image stabilisation, so it relies on the camera body’s own built-in stabilisation, which is fine unless you’re an owner of an early Sony Alpha camera.
The Sony FE 28-70mm f/2 GM lens is commendably supplied with both a good quality soft case and plastic petal-shaped lens hood (ALC-SH182) which rotates through 90 degrees and which has a button to lock/unlock it.
The hood also has a filter window which allows for more convenient operation of circular polarizing and variable ND filters.
Focal Range
The 28mm focal length provides an angle of view of 75 degrees.
28mm
The 70mm focal length provides an angle of view of 34 degrees.
70mm
Chromatic Aberrations
Chromatic aberrations, typically seen as purple or blue fringes along contrasty edges, are not a problem for the Sony FE 28-70mm f/2 GM lens, even in areas of very high contrast.
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70mm
Vignetting
With the lens set to its maximum aperture of f/2, there is some light fall-off in the corners, requiring you to stop down by at least 3 f-stops to completely prevent it.
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70mm
Distortion
The Sony FE 28-70mm f/2 GM exhibits some barrel and pincushion distortion, as you can see in the photos below, which will you need to correct in post-processing.
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70mm
Sunstars and Flare
The Sony FE 28-70mm f/2 GM is capable of producing very nice sunstars when stopped-down to f/16 or f/22, as shown below, and the lens doesn’t exhibit very much flare even when shooting directly into the sun, provided that you have the supplied lens hood fitted.
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70mm
Macro
The Sony FE 28-70mm f/2 GM offers very good close-up performance for a standard zoom lens, with a close focus point of 38cm / 1.25ft from the sensor plane and a maximum magnification of 0.23x throughout the zoom range.
Bokeh
Bokeh is a word used for the out-of-focus areas of a photograph, and is usually described in qualitative terms, such as smooth / creamy / harsh etc.
Sony have paid close attention to this aspect of lens use, employing a 11-segment diaphragm with rounded blades for more pleasing bokeh.
In our view, their efforts have been very successful for a standard zoom lens – see the examples below to judge for yourself.
Sharpness
In order to show you how sharp the Sony FE 28-70mm f/2 GM lens is, we are providing 100% crops on the following pages.
Credit : Source Post