Archive | September 2016

Sony a6300 and Techart LM-EA7 II

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Sony a6300 with Leica 35/1.4 Summilux-M ASPH and LM-EA7 II

Sony a6300: love to hate you

There may not be any point, six months after the fact, to writing anything about the Sony a6300 compact camera. Well, maybe there is. Sony APS-C cameras are something that Fuji fans love to hate. And what’s not to hate from their perspective? Sony doesn’t make cameras that look like old rangefinders or SLRs, Sony lords it over Fuji with sensors that are slightly ahead (Fujifilm buys sensors from Sony, so it is not going to get the pathbreaking product immediately), Sony lenses are supposed to be terrible, and despite all this, Sony still outsells Fuji by an order of magnitude. How could this be?

— Sony strengths relative to Fuji in the mirrorless arena

The two possible answers are video and AF performance. Video on the a6300 is nothing short of phenomenal: 4K, 120fps HD, and just about every type of video gamma geekery that you could want. The Multi-Interface Shoe allows for some interesting snap-on microphone options, including XLR and wireless. The worst thing anyone has said about the a6300’s video is that it has rolling shutter problems, and the answer to that is really, so what? It’s an artifact of any mirrorless camera when used for video. And since Fuji sources its sensors from Sony, you’re not going to do any better. In fact, no one outside the Fujisphere considers Fuji’s video in any way significant.

The focusing speed and accuracy a NEX/Alpha has always been somewhat incredible. Even back to the old NEX-5, Sony could make lenses that silently and smoothly achieve focus on faces. The a6300 with its kit lens posts some insanely fast times, and Sony’s claims about continuous focus tracking are largely true, at least as far as this author has been able to reproduce the right photographic, ahem, “needs.” In fast action, a camera with poor lenses but a responsive system does much better than a more ponderous camera/lens combination that misses the forest for the trees.

One thing that is clear from the dpreview.com tests is that with whatever mystery lenses the site used to test the X-Pro2 and A6300,* there is almost zero difference in image quality, anywhere on the frame.

*Never disclosing the lenses used is dpreview’s second-biggest failing. The first is retconning itself into the time before the internet and digital cameras existed. Sorry. That was a mistake. The first is allowing itself to be bought by Amazon. Then the second is retconning. Then the third is mystery lenses (apologies to Steve Martin).

— Handling

The A6300 is fairly easy to handle. The grip section of the camera is substantial, and in general, it is easy to operate. No one, though, understands what the second command dial is doing on the top deck. It’s not comfortable to use with the camera at your eye. Controls are snappy and solid, as is the general build.

— Viewing

The A6300 has the latest OLED high-density electronic viewfinder that features a 2-axis level (pitch and roll) and more information display possibilities than you want to admit you want. Battery life is helpfully provided by percentage (and if there is one nice thing about Sony batteries, they are good communicators. Shooting does not black out in continuous mode. The EVF senses heat (infrared radiation); hence, its eye sensor does not react to glass-lensed glasses or sunglasses. If you don’t like the EVF, there is a big LCD on the back. Knock yourself out.

— Shooting

This is mostly unchanged since the a6000. The big thing is silent shooting, which uses a front and back electronic curtain (you can also choose electronic front or mechanical front). Silent shooting has two failure modes: first, in any situation with fast-moving objects, the progressive read of the sensor will cause typical “rolling shutter” artifacts. Second, dimmed LED lights (dimmed at the wall switch) flicker, even at full brightness, and can cause light banding in the finished frame (rolling shadow).

— Legacy lenses

One big note is that it is not particularly easy to engage viewfinder magnification on a shot-to-shot basis. You either have to learn to live with focus peaking or slow way down if you want to focus older SLR lenses, for example.

— Accessories and cutting corners

If you are accustomed to older NEX cameras, you will marvel at how Sony expects you to charge this camera with a USB connection to something else. The better solution is the Sony BC-TRW, which is a microscopic dual-voltage charger. It actually has four charging indicators (1-3 and off – meaning “fully charged.”). But yes, you still get a useless camera strap in the box.

 

An exit from the closed system

The problem with APS-C camera systems, whether Sony or Fuji makes them, is that they are closed, highly proprietary systems. You can’t stick a Fujinon on a Sony; you can’t get a Sony Zeiss lens onto an X-Pro2. Change systems? Get ready to pay the price when you sell your old system’s lenses.

There are two tired retorts:

  1. But the system has all the lenses you’ll ever need.
  2. Why don’t you just mount legacy lenses on an adapter?

The first argument is disposed of easily: what if you don’t like the one lens with your preferred angle of view and preferred maximum aperture? What if you don’t want to shell out for new lenses? What if you need the money for booze?

The second fails due to the kludge factor. Yes, it’s possible to mount other lenses on these bodies for use with cheap Chinese adapters and your old lenses. It’s also generally miserable. Both Fuji and Sony allow focus magnification, but Sony makes it difficult to use when a non-Sony lens is mounted. Both makes have focus peaking, but that’s not as definitive as you think. And although Fuji offers a phase-detect driven split-image manual focusing function, it’s not that much fun and not that fast to use.

The “out” provided by Sony was to enable phase-detect autofocus with third-party lenses. This enabled things like the TechArt LM-EA7 II adapter, which in theory allows the autofocusing of any M mount lens (or lens that can be adapted to M, provided it physically fits the adapter). If this works, it would be a game-changer, since it would bypass the usual foibles of adapted lenses (focus difficulty and inaccuracy of focus peaking being two big ones). Is this true?

The good, the bad, and the ugly with the LM-EA7 II

The adapter comes in a nice, foam-padded box and includes a NEX/E-mount body cap and rear lens cap. This is a nice touch, since people who bought the a6300 with a kit lens will have neither.

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50mm f/1.5 ZM C-Sonnar with LM-EA7 II

The good news is that with the sweet spot for Leica lenses: 35-50, the LM-EA7 works like a charm. The noise is a faint whirring, and the Sony phase-detect system fairly effortlessly computes and reaches the focus point (provided, of course, that your lens would ordinarily need 4.5mm or less of travel between infinity and minimum focusing distance).

Some observations:

  1. Focusing is through the lens, at shooting aperture. ***This forces the camera to automatically adjust for focus shift on fast lenses, again making the a6300 more accurate and repeatable than a Leica M body, which can only have accurate focus at one aperture.
  2. The camera plus adapter can focus on an off-center subject using (for example) wide AF. Face recognition works with this adapter, even though the adapter supports phase-detect only. ***This is significant because it means that the a6300 can more accurately focus fast Leica lenses on off-center subjects than a Leica body can.
  3. The camera plus adapter rarely misses, even off-center. In fact, the focus with things like the 50/1.5 ZM Sonnar (the modern version) is better than can be achieved with a rangefinder (naturally, due to focus shift).
  4. The adapter is serviceable with 75mm and longer lenses, provided that you pre-focus to somewhere at least near the expected focus point.
  5. The adapter, by virtue of its inbuilt extension, gives you slightly closer close focus with 35mm and shorter lenses.
  6. There is little or no color shift with adapted wides. Depends on the lens, but even the ZM Biogon 4.5 seemed to do ok.
  7. Flash works with the adapted lenses.
  8. The multi-shot vibration-reduction mode works (JPG only).
  9. The weight limit for the objective assembly (lens plus any adapters to M mount) is 750g. This is well beyond what you need for almost any Leica-mount lens and covers most DSLR prime lenses (if you go lens – to M adapter – to LM EA7 – to camera.
  10. The artistic effects, such as “Sad Clown with Single Tear Airbrushed onto Sweatshirt” still work with adapted lenses.

Now, what’s the catch? Well, there are seven.

  1. PDAF does not work for video, and the adapter does not do contrast-detect.
  2. Due to some clear limits in the Sony PDAF software (which is probably set up to look for big focusing changes), wide lenses (≤21mm) and lenses with maximum apertures of f/4 or smaller do not focus well. Granted, why do you need AF with these lenses?
  3. The motor part of the adapter hangs below the camera, making it hard to set the camera down. This is not entirely negative because it also makes a nice grip.
  4. Not all SLR mount to M mount adapters work. In general, you have to use the Leicaist versions because they taper enough to miss the motor unit. Konica AR is one of the couple that work with the adapter, and even then, it’s just the typical Chinese adapter with a relief milled into it to clear the autofocus adapter.
  5. Taking the camera’s aperture setting off f/2 or 2/8 tends to cause overexposure.
  6. The system for selecting and recording lens-specific metadata is confusing, pointless, and possibly both. Your best word may be to record everything as 15mm.
  7. It does take a toll on your battery.

Tips and tricks

  1. Disengaging AF. For some reason, there is a lot of internet kvetching about how it is difficult to disengage AF. This is probably based on old firmware that requires you to use Aperture Priority and turn to a small f/stop. It is actually very easy to disengage the AF temporarily. If you press and hold AE/AF-L on the a6300, the adapter will park at its “infinity” setting, the focus peaking will come on, and you can then focus manually. When you let go of the AE/AF-L button, the adapter goes back to normal AF operation (make sure the lens is set to infinity before you do this!).
  2. Quickly overriding face-detect or wide area AF. If you have the camera set to wide AF, and you press the center of the back wheel, it will go into spot AF, center area only. It will also automatically focus in that zone. There are many possible green boxes, so it’s not like spot AF – but it suffices in most situations where you need an arbitrary focus point.
  3. Minimum focusing distance. With a travel of 4.5mm, and the lens set to infinity, the adapter does not have extension enough to reach minimum focusing distance with any lens over 50mm. The slight exception appears to be some zooms, since their designs often obviate a direct relationship between focal length and extension while focusing. Minimum focusing distance, though, is all in your mind with the A6300, whose narrower angle of view causes you to back up to get the same field as with an FX/35mm camera.
  4. Prefocusing longer lenses. With long lenses the quickest and easiest way to get to a range where you can achieve focus is to press AE/AF-L (which parks the lens), turn focus peaking on, and focus to a point where focus is just behind the intended subject. Once you are there, let go of the AE/AF-L button to reactivate AF. Because you focused behind the subject, and because the adapter extends (thereby moving the focus point closer to the camera), you have now put your lens exactly in the right place. Needless to say, the longer the lens, the less frontward subject movement this technique will tolerate.
  5. Marking your close-focus point with long lenses. If you habitually shoot at 1-1.5m, find the right “parked” focus distance (see above) and then mark it on the focusing ring with a dot of colored paint.

Compatibility

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Konica 57mm f/1.2 Hexanon AR, shot by the Konica 35-70 f/3.5-4.5 Zoom Hexanon AR ($50), the “plastic fantastic” in its quasi macro mode, on the LM-EA7II.

Yes. In general the performance of this adapter depends on two major variables: lens weight and maximum aperture.  The former degrades focusing speed; the latter, certainty of locked focus. As noted above, Hexanons were tested due to the availability of an ulterior SLR adapter (plus I had a bunch sitting around).

  1. 35mm f/1.4 Summilux-ASPH M (pre FLE)
  2. 40mm f/2 M-Rokkor
  3. 50mm f/1.1 MS-Sonnetar
  4. 50mm f/1.5 ZM C-Sonnar
  5. 50mm f/1.5 Jena Sonnar (prewar)
  6. 50mm f/2.0  M-Hexanon
  7. 50mm f/2.4L Hexanon
  8. 50mm f/2.8 Jena Sonnar (with Amedeo dual-mount Contact to Leica adapter)
  9. 50mm f/2 Jena Sonnar collapsible prewar
  10. 50mm f/2 Carl Zeiss (Opton) Sonnar, postwar
  11. 75mm f/1.4 Summilux-M (prefocus)
  12. 90mm f/2.8 M-Hexanon (prefocus)
  13. 10.5cm f/2.5 PC Nikkor (LTM)
  14. 40mm f/2 Hexanon (AR) (Konica mount via Leicaist adapter)
  15. 57mm f/1.2 Hexanon AR
  16. 35-70mm f/3.5-4.5 Zoom-Hexanon AR
  17. 85mm f/1.8 Hexanon AR

Kinda. For wide-angle, medium aperture lenses the adapter does not do so well because Sony’s phase-detect AF isn’t set up to split hairs.

  1. 24mm f/2.8 Hexanon AR

No? Here, the details are too small and/or the depth of field too much to get an easy lock (or sometimes, any lock) with the A6300 [edit note: this appears to be due to the camera’s having difficulty in deciding where the focus point should be – and even in its “spot” modes, the a6300 is picking a focus point]. The behavior on these is more deliberate focusing, almost as if the camera had switched into contrast-detect].

  1. 18mm f/4 ZM Distagon [too wide, too small an aperture]
  2. 21mm f/4.5 ZM Biogon [too wide, too small an aperture]
  3. 21-35mm f/3.4-4.0 M-Hexanon Dual [too wide, too small an aperture]
  4. 50mm f/1.5 Carl Zeiss (Opton) Sonnar [aberrations that Sony AF can’t understand?]

Conclusion

The Sony A6300 is a pretty formidable camera for video and not a slouch for stills provided either that your style does not exact ultra high performance from kit lenses or provided that you are willing to invest in better Sony or Sony/Zeiss glass.

The LM-EA7II may never be good for sports or high-intensity moving work, but it provides some fun with old lenses, or as much of it as you can take! It’s actually a bit irritating that I did not have an A7-series camera on hand to try it.

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Zoom lenses: good vs. not good vs. both

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This simple feeling… is beyond V’ger’s comprehension. No meaning… no hope… and, Jim, no answers. It’s asking questions: ‘Is my kit zoom lens good enough?’

In reality, we actually know little about zoom lenses except that the best ones (from a numerical standpoint) are very large, heavy, and expensive. Once you move into the enthusiast and kit versions, the question of whether or not they are good (or, more to the point, useful) is complex, subjective, and somehow optimistic.

General limitations

The struggle of zoom lenses, since basically forever, is designing a multifocal, focus-maintaining lens that is at least as good as any lens of the focal lengths covered, without being massively heavy or unimaginably expensive. This struggle is driven by four conditions of design, manufacturing, physics, and software.

  1. Design. Fixed focal length lenses have an inherent advantage because they are always going deliver high performance at low prices. Such lenses require computations at one focal length, have fewer parts, need less assembly labor, and require less glass. A zoom has to be good at a theoretically unlimited number of focal lengths between two extremes and has to maintain focus as it focal length changes.
  2. Manufacturing. The difference between a good lens and a great lens can be 0.01mm. Zoom lenses have numerous glass and precision molded plastic elements that have to work in formation at an infinite number of focal lengths between two extremes (say 14mm and 24mm). It is more difficult to make larger-diameter glass elements with great precision, and the more mechanical linkages exist in a lens (for example, ones that maintain focus through focal length changes), the more tolerances add up. Sometimes low moving mass and “slop” is built in to make lenses focus faster.
  3. Physics. More glass means more flare and dispersion, and zoom lenses have tons of glass. Flare can be mostly tamed via muticoating, but even so, dispersion adds up with the element counts. A 13-element lens with modern multicoating (losing ~1% per air-glass surface) can have a total loss of 25% of all the light coming into it.
  4. Software. This enters the picture in two ways: focus correction and image correction. On DSLRs and some mirrorless cameras, the AF Fine Tune function helps correct focus errors that occur with particular lenses and phase-detect autofocus. The difficulty with zooms is that the nature of focusing errors can change with each focal length, and dialing in a correction for one focal length for a lens can greatly improve images there but degrade images shot at other focal lengths. The second limitation arises in software correction of lens aberrations (distortion, vignetting/falloff, and sharpness). One cheat (or innovation, depending on how you look at it) is to let the camera make corrections that the lens design itself does not permit. This provides more freedom to design smaller, lighter, and cheaper lenses. But you can’t really reconstruct data that isn’t there – or bend it infinitely.

Why many enthusiasts have been suspicious of zooms

It mainly seems to be a thing with people 40 years old and up, who remember the bad old days. As to the history, in the 1970s, optical correction was not what it is today, and zooms got a really bad rap because things like the 43–86mm Nikkor were convenient but not optical superstars. The original zooms were two-touch, which allowed the easy setting of focal length and focus with two separate rings. If a lens mostly held focus as you changed focal length, it was a true “zoom;” if not, it was a varifocal (Nikon is, and long has been, an offender in calling varifocal lenses “zooms”). Zooms of that era were difficult to design, and it was a time where lens design was transitioning to more computerized methods. They worked for a lot of purposes, but given the natural male inclination to over-spec and compete with equipment, they were not taken very seriously.

In the late 1970s, manufacturers went to one-touch, where you could adjust focus and focal length with the same grip. The temptation was to conclude that you could just re-zoom, re-compose, and fire away, but the reality was that focus drift followed focal length changes, and if you didn’t bother to refocus, you could get slightly soft pictures. One-touch zooms also suffered from zoom creep: eventually, as the lens loosened up, pointing the camera up or down would cause the zoom mechanism (governed by front-back movement of the ring) to move on its own. This too, did not help perceptions, though there are some very good zooms of the 1970s and 1980s, including some third-party offerings like the Vivitar Series 1.

SLR manufacturers rediscovered the two-touch in the 1990s, when it became an advantageous design for autofocus lenses (an AF motor could turn a focusing ring but not also a zoom ring). And that is when they all backslid into selling varifocal lenses as “zooms;” the assumption being that the camera’s AF would correct the focus anyway. Although questionable from a marketing standpoint, autofocus helped assure that the new “zooms” would  be

The rise and fall of zooms (1999-2005)

If zooms had a heyday, it was from the late 1990s to the mid-2000s. Several things came together to make this happen:

  • Vis-a-vis prime lenses, zooms were more heavily telecentric than prime lenses. In simple terms, their design created the straight-on light rays that digital sensors like.
  • Advances in lens coating took away some of the performance penalties of using a large number of lens elements for image correction.
  • Prime lenses were getting little in the way of updates. This meant that the best ones were standing still, and others did not work as well as zooms with digital. Consider that it took Nikon 50 years to update the formula of its 50/1.4.

The prototypical lens of this era was the AF-s 17-35mm f/2.8 Nikkor, which was designed for the D1 cameras but was usable with contemporary film cameras too. This lens outperformed most primes within its focal length range, was solid, fast-focusing, and very  popular.

But just as every pendulum swings, the 2010s to the present are where the optical (but not necessarily total) performance level of cheap zooms took a little bit of a dive.

  • In a market with softening demand, maintaining competitive MSRPs for entry-level cameras and lenses required simpler and cheaper designs.
  • The processing power of digital cameras increased to the point where it became possible to correct for distortion, light falloff, and sharpness in-camera.
  • Increased emphasis on video, especially from mirrorless, demanded lenses that could focus quietly and continuously, driving toward lower moving mass.
  • The move by the market toward camera phones meant that the “burden” associated with separate cameras had to be minimized.

In other words, the ethic was (and is) using technology to make cheaper, lighter, and easier-to-make lenses acceptable, not so much to make good lenses better.

At the high-end of the lens lines, updated primes also began to exert pressure on the more expensive zoom lenses, especially where trends push toward small and light.

What is the quick and dirty way to identify “good” zooms?

When shopping for a zoom lens with high potential, this is the general hierarchy to predict (with some but not total certainty), where a lens fits on the performance curve.

— By effective aperture

  • Constant f/2.8 aperture – this generally means a pro-level lens. It also means big, heavy, and expensive.
  • Constant f/4 aperture – this is the high-end amateur or lower-end pro zoom. It takes a lot of engineering to keep the aperture constant on a zoom, and this type of lens generally has the best balance of performance, weight, and cost. Canon and Nikon both make this style of lens. These are not cheap, but they are much easier to live with than monster pro zooms.
  • Variable f/2.8-4  or 3.5-4.5 (1 stop aperture shift) – this lens type of lens generally has been optimized for compactness over speed. F/2.8 is really a bragging right; it’s only half a stop faster than f/3.5.
  • Variable f/3.5-5.6 (or f/6.8) (1.5+ stops) – when a manufacturer lets the maximum aperture float this much, it is generally an indicator that you should not be expecting world-beating performance. But you will get a lens that will do well in most circumstances and not break your back or budget in the process. These are actually the lenses that are fun to shoot with.

— By zoom range

This may sound deceptively simple, and maybe it oversimplifies, but it is a fairly good bet that where a modern lens has a zoom range of greater than 2.5-3x from short to long, it is is probably a “convenience” zoom rather than one oriented toward absolute performance.

Can “not-good” be good?

Yes. Despite having performance a notch or two below pro lenses, kit zooms can be quite good within some limits. First, in an era where photos are overwhelmingly likely to be shared on social media, and not printed, kit zooms are actually complete overkill. In fact, anything beyond an 8mp iPhone 6 might be complete overkill – the same way that a lot of expensive pro equipment in the 1970s was used by amateurs to generate 3.5×5 inch prints.

Second, even if you print, you only need about 6mp of real-world performance out of a lens to print a nice 8×10, which again is bigger than most prints made today. “Real world performance” means type of system resolution that DxOMark measures (lens performance plus body performance, moderated through focus accuracy). That might be a 12mp body and a midrange lens.

Third, you will still get really good results – though optimum performance may be ~3 f/stops from wide-open (f/8 vs. f/3.5 maximum) as opposed to (f/4 vs. 2.8 maximum). There is an old adage, “f/8 and be there,” but in reality, once a lens is stopped down even to f/6.3 (let alone 8), even a plastic meniscus lens will have performance approaching an expensive coated lens. Like vampire tears, the pro-lens advantage evaporates in bright sunlight.

Finally, especially for mirrorless cameras, some lenses have video performance that vastly outweighs whatever perceived deficiencies they have for other purposes. For example, you might conclude that the 16-50mm f/3.5-5.6 power zoom lens that comes with a Sony a6300 is terrible. It’s not terrible for still pictures (in no small part because it is one of the fastest-focusing lenses ever invented), but it really shines in video, where it can silently and reliably track moving subjects without introducing noise. And it’s also tiny.

Conclusion

To wrap up: the performance, utility, and fun factor of zoom lenses is actually pretty subjective. Try as many as you can. Pick the one that you like the best, so long as it does what you need it to do.