The World’s Only Interchangeable
35mm Full-Frame Power Zoom
Sony FE PZ 28-135mm f/4 G OSS Lens
In my opinion the Sony PZ 28–135mm lens is the cine lens for Sony A7 series camera owners, and especially for owners of the 4K-capable A7s and the upcoming A7RII. We’ll look at what makes it tick, but first let’s make the letters in the lens’ official name comprehensible.
FE: Sony mirrorless full frame 35mm lens
PZ: power zoom
G: Sony’s top ranked lens line (after their Sony / Zeiss series)
OSS: Optically stabilized
What It Is And What it Isn’t
Like Canon and Panasonic, Sony stands astride the still photography, video, broadcast and film-making worlds with products for each market, and in some cases with cameras and lenses that cross-over between segments.
In recent years Sony has taken the stills industry by storm with their A7 series of full-frame mirrorless cameras, the A7, A7R, A7s, A7II, and due in August, 2015 the industry-challenging A7RII.
Sony PXW-FS7 4K XDCAM Super35 Camcorder
Though the FE mount is found on Sony’s A7 series stills cameras, this same FE lens mount is also used in a range of professional and prosumer video cameras, including the FS7. In fact the PZ 28-135mm was first introduced last year, and was first seen included with the Sony FS7, even though that camera is Super-35mm format, (a movie industry standard with roughly an APS-C sized sensor). The PZ lens though, was designed for the future, and provides for full-frame 35mm coverage.
Sony plans ahead, and while the PZ 28-135mm will work for stills and video on all A7 series cameras, it really will become the go-to lens for many people who will be using the A7RII camera for video applications. The A7RII looks to become a top-tier choice for not just stills photographers, with its 42 Megapixel sensor, 5 Axis Image stabilization and on-sensor phase detection autofocus, but also for video shooters and film makers. It is the least expensive full-frame ILC camera that can record 4K video in-camera to regular SD cards (though fast ones).
Hybrid Camera Limitations, and PZ Features
In prior articles on these pages we have discussed the problems associated with the use of hybrid stills / video cameras when shooting video. Fortunately, many of the commonly available lens features that film makers expect and require are found in the PZ 28-135mm. These include servo powered zoom, remote iris and focusing, de-clicked aperture stops, parfocal capability, lack of breathing, and focus end-stops.
Parfocal: Many if not most zoom lenses for stills cameras do not hold focus when zoomed. They are less expensive to build this way. Still photographers don’t really mind, or even care, because when autofocus is used the camera is constantly and almost instantly adjusting focus as the focal length is changed between shots.
But for cinematographers manual focus is used most of the time, and the norm is to go to maximum zoom, focus critically, and then zoom out to the required focal length for the shot. Of course if the lens is to be zoomed during the shot the shooter needs to be assured that focus will not shift.
Breathing is a change in focal length that takes place as the focus distance of a lens is changed. This is the corollary to what is wanted when a lens is parfocal. In other words a parfocal lens doesn’t change focus when it is zoomed, and a lens that does not “breath” is one that doesn’t change focal length when it is focused.
With stills shooting a small change in magnification when changing focal length can easily be adjusted by moving the camera slightly, or even zooming a tad. But in film production it is common to change the point of focus during a shot so as to draw attention to or away from someone or something. If a lens changes magnification while focus is being pulled it can be obvious on screen, and can detract from the shot.
Videographers and film makers pay large amounts of money for lenses that are parfocal and which have no or minimal breathing. My use and testing shows that the PZ 28-135 is indeed parfocal, and I also can see virtually no breathing, except maybe at the longest focal length where it is just visible.
This is remarkable performance for such a modestly priced cine lens, and I am unaware of any lens that can cover full-frame 35mm which has these characteristics.
The PZ 28-135mm is a constant aperture lens, holding f/4 as its maximum aperture from 28mm to 135mm. Again, in the stills world if a lens changes from f/4 to f/5.6 as it’s zoomed, well, so be it. But when shooting video a change in focal length which produces a change of aperture, and thus also a change in depth of field, is completely undesirable.
Another indication that this lens is designed for the serious cinematographer is that the index marks for aperture and focus are not on the top of the lens, but rather on the left side at about 45 degrees. This still allows them to be viewable by someone behind the camera, but also are easily seen by an assistant or focus-puller standing to the left of camera.
The aperture ring also has the ability to be set to one third click stops, or continuous. This will be appreciated by cinematographers who need to pull aperture during a shot and who therefore don’t want discrete click positions, either visually or audibly.
Though I have not done a rigorous measurement myself, I have read that the PZ actually has a T stop of about T4.2. A lens’ T stop is its true light transmission, rather than its theoretical aperture. This is important to professional cinematographers on a film set who are lighting a scene to within a quarter stop, usually using external metering. For the rest of us, it’s mostly academic.
Caps and Hoods
There’s good news and there’s bad news – as the saying goes. The good news is that the PZ comes with a decent rectangular lens shade that also has a large protective cap. The bad news is that Sony also ships the lens with a 95mm lens cap whose quality is slightly below that of the soft drink lids that you find at the concession stand in a movie theatre. Really! Literally. A total piece of crap.
I can only imagine that some bright spark in Sony’s marketing department saw that there was a large hood with fitted cap, and figured that since this is the way that the camera will likely be used, all they needed was something to protect the front lens surface during packaging and shipment.
Ahhh…NO! That’s not the real world Mr. unknown Sony employee. In the real world people work with matte boxes and filter holders; meaning that the provided shade isn’t always used, and when the lens is then placed in a case or bag the front glass needs to be protected. Also, with the supplied square shade attached the lens’ size is sometimes too large to fit in a designated space in a cut-foam case or soft pouch. So front element protection is a must.
Until Sony wakes and smells the coffee the solution is to go on E-Bay and find someone that sells 95mm snap-on lens caps. Its annoying to have to spend money on something that should be properly supplied by the manufacturer on any lens, let alone one that costs more than two and half thousand dollars.
Variable ND Filter
Unless you are using the PZ lens on a proper cine camera which has built-in ND filters, you’ll have to purchase a 95mm variable ND filter. B&H sells one from Bower for under $100. There is also a higher quality filter from B+W but it’s closer to $500 and so the choice comes down to that of ones budget.
Be aware though that this filter, and likely all variable NDs because of their need for a grippable variable ring, does not fit with the Sony lens shade attached. This could mean the need to use a bellows lens shade with rails and rods, or a French Flag.
The focus, zoom and aperture control each have large rubberized knurled rings. These are quite grip-able, and lend themselves to the use of external, manual “follow focus” knobs if desired.
Note that the zoom ring is servo controlled. The focus ring is fully manual only and non-servo. The aperture ring feel mechanical but in the A position can be controlled by the camera automatically or via one of the camera’s control wheels.
I should add at this point that the lens also has true hard stops at the infinity and close-focus positions.
The zoom has a Manual / Servo switch. In either case zoom is fly-by-wire, which means that even when you are manually turning the zoom ring you are driving the servo. The downside of this is that if you want to do a very fast zoom or focal length change, the servo prevents this. It has a top speed and simply won’t go any faster.
The upside is that the recessed servo zoom control on the lens works very well. The amount of pressure applied to the control will range the zoom speed from as fast as it gets down to quite slow, apparently with 8 distinct increments. Nicely implemented, though still photographers are not going to find much joy in this control. Cinematographers, much more so.
Because the zoom is servo controlled it can be remoted. The latest Sony A7 series cameras have a micro-USB port called a Multi/Micro USB Terminal, that is used for battery charging and also for transferring files, though since it’s only USB2 it’s fairly slow in this latter role.
But Sony has added extra pins, and with a Sony cable that has these connections a remote control cable can be attached allowing zooming as well as other functions.
But there’s a typical Sony-style gotcha. Amazingly, Sony does not sell a stand-alone remote zoom control device that uses this connector. They have cables for stills shutter release, but nothing for video start/stop, zooming or other controls.
Really! No joking. Nowhere in Sony vast catalog of accessories is there a zoom control for the Multi/Micro USB Terminal.
There are two solutions. The first, is that if you already have or want to purchase a LANC controller such as the Manfrotto RC Pan Bar EX Remote Control for LANC Cameras, you can do so by kludging together an adaptor cable using a Sony VMC-AVM1 A/V R Adapter Cable and a VariZoom Mini Audio/Video to LANC Converter Cable.
I have not tried this myself, but I have been told that it works.
Now, I have written that Sony does not make a stand-alone video remote controller. This is fact. But, if you buy a crappy little Sony Compact Remote Control Tripod VCTVPR1 for about $95, you will find that it comes with a very nice removable video remote controller that plugs directly into current A7 series cameras, and which allows camera on/off, video start/stop and zooming, including an ultra-low-speed zoom setting.
This controller can easily be velcro-attached to the pan handle of any video tripod. Oh yes; and once you have unplugged the remote you can throw away the tripod, or better yet give it to your 12 year-old nephew.
OK Sony… let’s get real. Does anyone in your marketing department know that there is no video remote for A7 cameras and the use of your exciting new PX 28-135mm lens? Does anyone within Sony know or care that your customers have to either kludge together an adaptor cable to use a third party device, or, buy your crappy little VPR1 tripod and then throw it or give it away, just to get the included remote? Humm. I thought not.
Sensibly, the PZ has a removable mounting foot. This losens to rotate, and can also be quickly removed. It also has mounting points for a provided neck strap. Due to the lens’ weight it is likely a good idea when carrying the camera / lens combo over ones shoulder to use this strap. It will eliminate the risk of stressing the camera or lens’ mounts unnecessarily.
A Mini-Cinema Lens
I purchased the Sony PZ 28–135mm lens for use with the upcoming Sony A7RII. I will be on a major photo expedition to Ethiopia later this year and want to shot documentary video in 4K as well as stills. I had planned on bringing a stills camera as well as a 4K video camera, but now with the A7RII and the PZ 28–135mm and I do both with one device.
Sure, there are other camera / lens combinations that will do the trick, but I own a good range of high quality Sony, Sony / Zeiss, and Zeiss lenses for the A7 series FE mount cameras, and being able to shoot 42MP stills and 4K video with the same device looks to be a no-brainer.
Since at the time of writing this – June, 2015 – I don’t currently have a 4K camera that will take the PZ lens I can’t really test or demonstrate image quality. I have other FE mount cameras, but HD video isn’t going to show what this combo can really do. But as soon as the A7RII ships in early August I’ll return with some test footage and a further experience report.
These are early days for me with this lens, and my experience so far would be just anecdotal. I like what I’m seeing, both in 24MP stills and HD video, but I want to reserve judgement for the time being.
But, the highly regarded cinematography web site RedShark News said the following about the PZ lens in their review of the Sony FS7 camera, with which the lens comes bundled…..
“The FS7’s 28-135mm F4 lens is the first high-performance S35mm-format zoom to be offered at such a breakthrough price of around $2500. In the past OEM kit lenses have been mediocre at best, as name-brand lens makers paste their names on poorly performing optics that serve mainly as placeholders to maintain a kit’s overall low price. Indeed, one of the first things camera buyers did after acquiring their new pride and joy was …… spend another $10K or more on a proper well-performing lens.
Integrating sculpted aspheric elements and unique low-dispersion glass the FS7 4K zoom represents a revolution in economical lens technology. Remarkably free of chromatic aberrations the lens compares favourably with much pricier hand-built optics; its relatively slow F4 maximum aperture posing less of a challenge these days for many shooters….
Sony’s sophisticated servo control of zoom and focus enables both a close focus capability and a constant F-stop throughout the zoom range, producing images remarkably free of chromatic aberrations – the main reason cheap lenses look cheap…..”
Again, please note that while the PZ 28–135mm lens is described as “S35mm-format” when used on the Sony FS7, it is an FE mount lens and thus indeed designed to cover full frame 35mm, such as with the A7, A7II, A7R, A7s and A7RII. But, when the A7RII is used for serious video it will likely be set to S-35mm, in which mode there is no line skipping or binning. This means that the PZ lens will lose some focal length at the wide end and also gain a bit at the long end.
A Word To Still Photographers
The PZ 28–135mm lens is not just for video; it is eminently usable for shooting stills. But, frankly, if you have no interest in shooting video I would suggest that because of its size, weight and cost, as well as video specific features, this is not a lens that stills-only photographers should make their first choice.
But of you are a photographer of any stripe who also shoots video, I strongly suggest that you explore what the PZ 28–135mm lens has to offer. It is one of the great bargains available today for someone looking for an quality yet affordable cine zoom lens to use on a Sony A7 series camera.