Field Test :: Sony 70-200mm f/4 G OSS

An Overview of This Review

For this blog, I will discuss my thoughts about the Sony 70-200mm f/4 G OSS. This review will be just my opinion coming from 40 years experience of testing various glass/camera combinations. My camera for all of my tests is the Sony a7R. And yes, it is now a permanent part of my landscape bag! I am not comparing the Nikon 70-200mm because I do not own it.

The obvious reason I’d like for the Sony 70-200mm to pass my stringent tests, is that it is lightweight and is made specifically for the alpha series cameras.

Both lenses (Canon and Sony) have performed admirably in lab tests conducted by DxOMark Labs. In fact, in an overall rating, the Sony 70-200mm f/4 was actually rated slightly better than my current Canon 70-200mmL f/2.8 Series II lens. I will be reviewing the Sony 24-70mm f/4 in my next blog.

But these are lab numbers. What about real world situations – yes, actual location shoots?

Where I Conducted My Tests

My wife Beri and I decided to take the short drive to Elkhorn Slough National Estuarine Research Reserve in nearby Moss Landing, California (now that’s a mouthful)! Our goal was to photograph late-afternoon light, then finish on nearby Moss Landing State Beach for a sunset shoot.

One of my first images was captured (above) on a trail that leads through an oak tree tunnel. If I would have been shooting with my Canon 5DMKIII, I would have not even considered photographing this scene in this contrasty of light. But I’ve been so impressed with the Sony a7R’s ability to capture a wide latitude of contrast that I applied what is now becoming a standard exposure formula: overexpose the brightest part of the scene by +1 stop, and fire away! Because I am shooting in RAW mode exclusively, I can easily recover that +1 stop (I’m even starting to go as high as +1 1/2 stops – yes – I’m pushing the hell out of the Sony sensor with great results)!

This technique allows me an additional +1 to 1.5 stops exposure in the shadows. I push open the shadows +100 in Lightroom 5 and open them more with a bump in the 3/4 shadow portion using Lightroom 5’s Curve tool. It consistently works and the shadows open with little to no noise! With this technique in mind, I have no problem photographing contrasty scenes. As you can see, the Sony 70-200mm was up for the task – even at an extreme aperture of f/22.

During the first month of working with the Sony a7R, I used a Metabones IV adapter and my Canon Series II glass. The adapter worked flawlessly and will remain in my bag for my other Canon lenses. Zeiss is in the process of building 15 new lenses for the a7R over the next year!

My Studio Tests

So let’s start this test from the beginning. Before venturing outside, I setup a mini studio and tested extensively inside. The below setup was lit by one Elinchrome 600 WS RX light bounced into a white umbrella.

NOTE: If you are shooting studio lighting conditions, you must disable your Display Setting Effect: Under the Gear icon > #2 > Live View Display > Setting Effect > Off. There is also no hard wire sync port on the a7R, thus you must use a remote trigger mounted on your hot shoe. I used (2) Pocket Wizard MultiMax Transceivers.

As you can see, the Sony 70-200mm is every bit as sharp as the Canon 70-200mm. I’ve always felt that my Canon was one of my sharper lenses in my bag, so I was excited to see that the Sony matched up quite well. If anything, to my eyes, I see just a tad bit more color contrast/saturation with the Sony 70-200mm f/4 lens. Both lenses are extremely sharp. OK – now it is time to zoom!

Besides the slight perspective/crop difference (shot at 200mm), I again see just a bit more color contrast/saturation with the Sony. Also, both lenses are tack sharp from edge to edge!

I went on to perform this test at all aperture settings and the sharpness is there throughout (too many images to post here so you’ll have to take my word on this one).

Something I am noticing from comparing both lenses is that there may be a slightly less depth-of-field at comparable apertures with the Sony lens. I can’t confirm this fact definitively without lab equipment (which I do not own), but I wonder if it has something to do with the thin lens flange of the the a7R? We are talking “very slight,” but if any of you have experienced this, let me know. I’d love to run this by a Sony engineer. In the real world, I don’t think I’d even notice the difference.

What About Bokeh?

One of the complaints I had read about this lens was that the bokeh was not good. As a landscape photographer this did not bother me, but I nonetheless decided to check it out for myself.

Once again, I think the criticism is unwarranted. I should note that I recently updated my Sony a7R firmware and now have version 1.02 installed. There was a tweak made for this particular lens with this current firmware version.

NOTE: Version 1.10 was released for the a7 and a7R 10/30/14:

Improvements over version 1.02:

Improves the power-on time after downloading the Smart Remote Control application of the PlayMemories Camera Apps™.

If you are building a mirrorless system, be aware that there are electronics in not only the camera, but the new lenses as well. Keep updated with the latest firmware as it may affect how the lens and camera interact.

One can see bokeh even from a small aperture of f/16 when shooting at extreme telephoto. You can see the sharp plane of focus on the beach shrub from shooting at 200mm.

How Sharp is This Lens?

On the other end of the spectrum, let’s take a look at edge sharpness. Here is an image of an old barn captured in late-afternoon light:

What blows me away is how much detail and sharpness is captured by this lens and contained in the Sony file. Here is an extreme crop of the above image:

Lens Design and Build

The design and build of the lens screams professional across the board.

For optical quality, the lens features numerous specialized elements, including Super ED and Advanced aspherical elements. These elements reduce the impact of aberrations and distortion for high resolution imaging.

The lens is also benefited by the use of Nano AR coatings that reduce the effects of flaring. It even has dust- and moisture-resistant construction for use in less than ideal weather conditions.

During automatic shooting, the 70-200mm lens uses a Dual Linear Motor Autofocus System to achieve quick, precise focus and has focus hold and limiter options for improving performance in certain situations.

There is also Optical SteadyShot image stabilization for maintaining sharpness at long focal lengths or long shutter speeds. Additionally, there is a removable tripod collar and a lens hood.

Focus hold button and focus range limiter allow you to hold focus by holding a button and adjust the range that the lens will focus between, limiting the amount of hunting the lens will do Panning mode adjusts the lens to account for horizontal movement while shooting Aspherical lenses reduce distortion and spherical aberrations that occur in large aperture lenses Super Nano AR coating limits glare and flaring, producing an image with good contrast and sharpness Low-dispersion glass elements, or ED and Super ED, reduces chromatic aberrations, producing a high contrast image with minimal fringing Rounded 9-blade aperture produces pleasing out-of-focus areas similar to when the lens is wide open even when closed down 2 stops Aperture range from f/4 to f/22 Uses screw-on filters 72mm in diameter Minimum focus distance of 39.3″ with a maximum magnification of 0.13x





What About Auto-Focusing?

The Sony a7R autofocus is “contrast” only, while the Sony a7 is “contrast and phase detection.” In short, don’t expect great autofocus from the a7R (hopefully this will be rectified in future versions of this camera). It’s tough to achieve great autofocus in low light, non-contrasty scenes with the a7R. In bright sunshine it works great (remember, it is looking for contrasty edges to focus).

I actually have turned my autofocus off in my a7R for two reasons: a.) Manual Focus Assist is awesome and lets me see precise focus, and b.) Focus Peaking is on all the time to help me easily calculate my depth-of-field. NOTE: for Manual Focus Assist to work, place your A/M switch on your lens to the Manual position.

If you are new to the world of mirrorless cameras, then let me explain. Manual Focus Assist allows me to zoom in on a very small area of my frame – all the way to the edges, to allow me to focus precisely. Moreover, because mirrorless lenses do not allow for the “old-fashioned” depth-of-field preview button (I could never see what was going on anyway), Sony has added a feature called “Focus Peaking.” Once you have chosen a color (I use red), it will place a red line along an edge that is in focus, allowing you to see where your depth-of-field begins and ends – a very useful feature especially when shooting in low light on the fringes of the day.

What About Manual Focusing?

With most DSLR lenses (at least the ones that I have owned) the focus ring is mechanically attached to the inside of the lens. Thus, when you would turn the lens’s focus ring, it would move the lenses inside along a track. With these new mirrorless lenses, the focus is achieved electronically by a method known as “focus-by-wire.” This means the lens must be receiving power from the camera. If you are using extension tubes, they must have electrical connections.

Focus-by-wire is named after “fly-by-wire,” which is a system used in modern airliners where the flaps are connected by sensors, which in turn activate servos to move the wings. In these new mirrorless lenses, the focus ring has sensors that activate the autofocus motors in the lens. In reality, you won’t notice much difference, but you may notice a slight lag. I don’t experience a lag with the Sony 70-200mm, but I do notice that it takes more of a turn of the focus ring to move the same amount of focus in my DSLR lenses. I’ll soon adapt, but it is noticeable and at first I did not know why this was happening.

My Conclusion

If you are seriously considering converting to a mirrorless system, then you NEED this lens in your bag – along with the Sony a7R, a7, and/or a 7s. Let’s face it folks, mirrorless cameras and lenses are here to stay. Believe me, you will not regret purchasing this system, and your back will thank you for the dramatic reduction in weight!

COMING NEXT: My Review of the Zeiss 24-70mm f/4 ZA OSS lens. Please check back!



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