Manfrotto 468 MG ballhead
The Manfrotto 468 MG ballhead is available from Manfrotto with no less than six different types of clamp and plates, plus a 1/4"-20 screw attachment. It is the top model in Manfrotto's line of ballheads according to the Manfrotto web site, and has been available for at least a decade.
For the past couple of decades, it has been clear that the Arca system of clamps and plates, now available from many different brands (although with varying degrees of compatibility), is the most common. Almost all high-quality tripod heads on the market have been equipped with Arca-compatible clamps - that is, with the exception of Manfrotto, which until recently continued to ignore the obvious and to use a broad variety of proprietary, mutually incompatible clamps and plates (at least seven or eight types simultaneously marketed).
A new addition to the Manfrotto clamp types is called Q6 Top Lock, and is said to be Arca-compatible. I have not tested its compatibility, but based on illustrations I can tell that the bottom screws used in Arca plates to prevent the plate from sliding out of the clamp when the latter is unlocked probably would not stop the plate from sliding out of the Manfrotto Q6 clamp. The proprietary safety mechanism of the Q6 clamp might be able to retain some Arca plates, but probably not all. Because of these differences, this solution should probably be described as only partly compatible with Arca plates. The 486 MG is available also with a Q6 clamp.
Manfrotto is a very well known Italian maker of tripods, tripod heads and other photographic fixtures. Manfrotto has decades of experience in heavy-duty fixtures for theatrical lighting and studio photography. As a whole, Manfrotto products are not especially renown for fine machining and precision mechanics, but rather for long-term reliability and for not skimping on the amount of metal used in its robust die-castings. Its tripod heads, in particular, tend to feel heavier than the competition's, and are usually finished in a robust coarse-textured black enamel rather than the black anodizing prevalent today. Some of the technical solutions used in past Manfrotto products have been criticized as having coarse mechanical tolerances and being literally painful to operate, and some users have likened them to Soviet-manufactured industrial goods. Some of the simpler Manfrotto items are abundantly copied by Chinese factories and sold mainly on eBay.
Gitzo (probably the most popular brand of tripods among nature and landscape photographers) and Bogen (distributors of tripods and fixtures) are owned by Manfrotto. Since 2005, Gitzo tripods are entirely produced in the Manfrotto factories in Italy. In turn, Manfrotto is owned by the UK-based Vitec Group, which owns other well-known brands of photographic products, including Kata and National Geographic (camera bags), Sachtler and Avenger (tripods and fixtures), Lastolite and Colorama (studio equipment). Many products are made by the factories of one of the Vitec Group companies and branded with the name of another of these companies.
The 468 MG
I owned and used up to four Manfrotto 468 MG ballheads for about ten years (on different tripods and fixtures), and sold the last ones only recently. Since I switched to Arca-compatible clamps and plates for all my equipment, I gradually replaced all other types of clamps. The clamp shown in Figure 1 is not from Manfrotto but a no-brand from China. The original clamp was a Manfrotto RC0, which is a hexagonal, rather large clamp-and-plate system. The model number in this case is 468 (the type of head), MG (magnesium alloy casing) RC0 (type of clamp and plate).
Casing, ball and associated controls
There are no bubble levels on the base or casing of this ballhead. Some of the Manfrotto clamps mounted on models of this ballhead, however, do have bubble levels.
The bottom of the ball (Figure 1, bottom left) has a hole closed with a plastic plug. This is meant to prevent dirt from entering the ball and subsequently fouling the internal mechanisms in the casing. However, there is enough space around the edges of the plug to allow sand grains to became lodged here and subsequently move into the mechanisms. The neck of the ball is apparently attached to the ball with a screw tightened from the interior of the ball, through the hole at the bottom of the ball.
The diameter of the ball is one of the main criteria to rate professional or semi-professional ballheads. Professional models start at about 30 mm and reach 70 mm. It is unusual to see models with balls larger than about 45 mm in actual use in the field.
According to the Manfrotto web site, the 468 MG uses "a 5cm PTFE coated aluminum ball" (e.g., see http://www.manfrotto.com/468mg-hydrostatic-ball-head). This diameter is repeatedly quoted in reviews and descriptions on the Internet. Unfortunately, it is wrong by a substantial margin. The ball has a diameter of 34.5 mm, or 3.45 cm (Figure 2). The ball diameter can be measured across the two U-shaped drop slots on opposite sides of the casing. This is a very large difference. A few mm of difference in the diameter of the ball have a large impact on the smooth-sliding and load-carrying capability of a ballhead, and here we are talking about a difference of over 15 mm, or 45% of the diameter. For instance, Sunwayfoto rates its 52 mm ballheads for 50% higher loads than its 44 mm ballheads, and the difference in this case is only 8 mm, or 18% of the diameter.
A side-by-side comparison with a Sunwayfoto ballhead that uses a 52 mm ball (Figure 3) also shows that the Manfrotto 468 MG cannot possibly have a 50 mm ball (Figure 3).
The casing is made from die-cast and subsequently machined magnesium alloy, which is slightly lighter and stiffer than aluminium alloy. The ball is made from aluminium alloy and, according to Manfrotto, coated with PTFE, also known as Teflon. This coating is not easily visible (I only seem to see the slightly rough texture of the metal) and, if present, must be very thin. I don't know whether the gray color has anything to do with the coating described by the manufacturer, but this gray color is also present on the panning base, ball neck and clamp attachments surface. Perhaps Manfrotto sprays these balls with a teflon-based lubricant after finishing them? This hardly qualifies as "PTFE coated".
There is indeed a thin layer of oil coating the ball. This is probably a necessity, since the metal ball rotates in direct contact with the metal casing, without the Teflon or Nylon bushings usually seen in high-quality ballheads. The locking mechanism that presses on the bottom of the ball also appears to be metal. The metal-against-metal contact ensures a very stiff locking, but potentially subjects the ball to wear of its coating or surface finish. However, in several years of moderate use, I must say that my specimens do not display any visible wear. The oil may cause dirt to stick to the ball when used in the field, especially in windy weather.
The ball is unusually deeply seated within the casing. A couple of millimeters more and it would have been fully protected against accidental impacts against flat surfaces. As it is, it projects more than 1 mm above the casing (Figure 4), and can be damaged if the head/tripod is dropped or knocked against a hard object while the clamp is turned to the side. It is better sheltered than in most other professional/semiprofessional ballheads, but with more attention to design detail it could have been even better protected.
A design compromise must be made between this protection and the allowed range of tilting when not using the drop slots. In this model, maximum tilting is less than 25°, compared to 45°-50° in other ballhead brands (Figure 5). By designing a flaring top opening of the casing, instead of a right-angle inner lip, the maximum angle of tilting could have been significantly higher without compromising on anything else. As it is, the MG 468 is neither optimized for protection of the ball, nor for an enhanced amount of tilt.
Two U-shaped drop slots on opposite sides of the casing allow a camera to point straight up or straight down. In fact, the slots allow slightly more than 90° of tilting. The drop slots could have been placed a more useful 90° from each other, instead of 180° - yet another example of missed design opportunities. The neck of the ball is long enough to avoid collision between the casing and even a large clamp and attached equipment. There is no plastic sleeve around the neck to pad it against direct contact with the casing.
The ball freely rotates about the axis of its neck, and this allows panning even when the panning base is locked, or tilting when the neck sits at the bottom of a drop slot. There is no provision to lock the ball about a horizontal axis, thus turning the ballhead into the equivalent of a pan-tilt 2-axis head without sideways tilt. This capability is natively available in one or two models of ballheads, while others achieve this capability by adding an external accessory that prevents sideways tilting.
The large majority of professional ballheads have balls precision-machined so that they are slightly aspherical, or egg-shaped (by a few tens of µm). In this way, friction increases together with the amount of tilt, and this prevents a camera or lens attached to the head from "flopping over" when the ballhead is unlocked. The Manfrotto 468 MG, instead, has a perfectly spherical ball, and no protection against flopping over. Among the top professional ballheads for each brand tested by DPreview (which in their 2014 review did not include Manfrotto models), the Novoflex displayed the same characteristic.
The ball locking mechanism is hydrostatic, and allows the ball to be solidly locked by applying a minimal torque to the large, rubber-coated knob. This knob needs to be turned only a fraction of a turn. I did not disassemble the head to study this mechanism, but it may be similar to the hydrostatic lock used in a series of small arms made by Manfrotto. The ball locks without any detectable shift in its position.
A smaller friction adjustment knob is coaxial with the locking knob and has built-in click-stops to avoid accidental loosening. As discussed above, friction is constant and does not increase with the angle of tilting. The friction adjustment knob rotates with the locking knob, and the latter must be held still while adjusting the friction. Unlike most other professional ballheads, this model does not require a coin or special screwdriver to adjust the friction.
The way friction adjustment controls work varies among brands and models of ballheads. In this model, the friction adjustment is completely independent of the ball locking mechanism. Friction is adjusted only by rotating the friction adjustment control, regardless of the position of the ball locking mechanism.
Relatively wide gaps (about 2 mm) exist between the ball surface and the casing at the bottom of the drop slots (Figure 6). One can glimpse the ball locking mechanism through these gaps. Dirt and sand can easily enter here and foul the internal workings. I do not know how easy it would be to disassemble the head to clean it out. This is a common drawback in ballheads (but technical solutions to mitigate this problem do exist).
The tripod attachment surface has a wavy surface that reminds me of "Russian mountains" amusement-park rides (top of Figure 1, bottom right). The depressions are supposed to catch the tips of screws tightened from the bottom of the tripod platform, thus preventing the head from accidentally unscrewing. Most current tripods lack these screws. Depending on the number and placement of these screws, it is entirely possible that none of the screws is on the right side of a "Russian mountain" to prevent a partial unscrewing of the head (it has happened to me with other Manfrotto heads). Sunwayfoto, for example, has a better solution in some of its leveling heads, which use oblique locking screws pointing also inwards rather than just upwards. The rotation of an unscrewing head automatically tightens these oblique locking screws.
The lever that locks the rotation of the panning base is a simple screw that presses with its end directly on the side of the panning base. The panning base becomes slightly indented whenever the lever is tightly locked, and in the long run this may cause the formation of "detents" at specific positions, which limit the reliability of this control. A rubber O-ring provides some dampening of the lever movement. The lever unscrews completely in a few turns (i.e., it is not a captive screw) and can potentially drop off during transportation and use in the field. The O-ring helps to lessen this risk, but is not a foolproof solution.
Size, weight, load capability and handling
Total height of the head is about 102 mm, not including the thickness of the clamp. Total weight with this clamp is 627 g. Other brands offer models that use substantially larger balls, but weigh just a little more than this (except the Really Right Stuff and Feisol top models, which weigh substantially more, but the Feisol uses a 70 mm ball).
The 468 MG is a conventional ballhead design. Other brands offer models of the same basic design, as well as low-profile models of substantially lower height, which are regarded as significantly more stable besides being advantageous in special conditions, like shooting from ground level (Figure 3, right). Manfrotto offers no low-profile models.
Virtually all brands specify a maximum load for their ballhead models, but there is no general agreement on what this rating actually means (e.g., what means holding a weight vertically above the head for one brand may mean maximum off-axis load for another, or mechanical failure for a third). For what is worth, Manfrotto specifies 16 kg for this model, which is lower than larger models from other brands but seems reasonable for the actual ball diameter.
With a relatively lightweight camera, it is easy to set friction to a point where it is not too tight to prevent the camera from being reoriented, but tight enough to eliminate the risk of flopping over. This avoids having to unlock and re-lock the head between shots, and makes operation much faster.
In practical use, I found it difficult to use this head with 300 mm and longer lenses on APS-C cameras. The ball movements are not smooth enough for this focal length, and the ball tends to slip-and-stick if friction is increased. With shorter and lighter lenses, this ballhead performs very well, although never as smoothly as the top models from Markins, Sunwayfoto or other well-known brands. The 468 MG is, nonetheless, not a hobby product but an eminently usable, durable and reliable ballhead in an intermediate class between hobby and top-of-the-line professional products.
The casing is finished in black paint with a coarse texture, apparently very resistant to wear, used on most Manfrotto products. Mold lines of the casing are still evident through the paint (Figure 4).
Virtually all professional ballheads from other brands are CNC-machined from solid metal blocks, rather than die-cast. Die-casting is cheaper when used for large production runs spanning many years without any changes or updates, but the molds are expensive to retool. CNC-machining, on the other hand, easily allows the production of small runs and prototypes, and their modification when testing or user feedback reveal shortcomings. In simple terms, the difference is that die-casting is a 19th and early 20th century technology, while CNC-machining is a late 20th and 21st century technology. Even in China, the best brands of tripods and tripod heads routinely use CNC machining today, while Manfrotto still clings to outdated industrial processes that are way past their prime. As a result, it cannot afford to tweak a product to correct small design oversights once its assembly line is started, and is much slower in introducing new models. There is certainly a lesson for Manfrotto to learn here, but it might already be too late.
The Manfrotto 468 MG ballhead is solidly built, durable and locks very stiffly with minimal torque of the locking knob. However, it tends to slip-and-stick with long lenses. The diameter of the ball is 34.5 mm, not 50 mm as declared by Manfrotto, which partly explains the limitations of this model. Its manufacturing processes are not modern and its design lacks attention to small details that are commonplace in other brands.