Guide to Film Lenses


By VMI Director and DP, Ian Jackson (assoc BSC)

There are two fundamental factors that impart a moving image with its character, the quality and size of the digital sensor and the lens used. Ten years ago it was the brand of film stock and the lens, or the type of recording tape and the lens.

The lens is the constant-no image, still or moving, has ever been shot without one and as we ease towards the end of the second decade of the new millennia, the range and choices of lenses available to professional film makers is vast with plenty of snake oil and pitfalls to catch out the uninformed. In the way that ‘unbleached muslin’ can become a thing after being used by one well known DP, then the same is also true of lens trends and may or may not necessarily be the best choice for your project.

[Pinhole cameras are an exception as one discerning reader reminded us but not very practical for mainstream production!. Ed]

This article will (hopefully) be a useful resource, explaining some of the most common terms, de-bugging some of the mechanical and optical principles and concluded by a comparison of the lenses VMI supply, the pros and cons along with a screen shot ‘shoot out’.

The range of lenses will always be increasing and so the comparison section will be revised as we add new stock.

This article is presented in three main sections. 

Part 1 explains all of the common terminology which filmmakers use freely and I felt would be useful to explain these fully.

Part 2 seeks to answer the question, “What Lens System to Use and Why”

Part 3 will describe particular sets of lenses from different manufacturers with their characteristics and some screen shots for comparison purposes.

Reproduced by kind permission from VMI. Read full article here on VMI website

Part 1: Fundamental Terms

Anamorphic 

Anamorphic

Anamorphic is the name of an optical process developed in the 1920s and taken from tank periscope technology. Anamorphic ‘squeeze’ uses one or a series of elements to gather in twice as much horizontal light onto the width of the film (sensor). This is known as 2:1 or 2x squeeze-please note not an Aspect Ratio number just the degree of squeeze.

The process was designed to fulfil the movie industries’ desire to present audiences with a spectacle and to get bums on seats by showing big widescreen films to fight off the emerging TV market. Anamorphic lenses were marginalised to some extent with the emergence of digital sensors until ARRI released the 4:3 sensor Alexa camera which had the correct sensor ratio to interface with the lenses. When used on a 4:3 (12:9) ratio sensor, the 2x squeezing of the horizontal information is therefore applying an actual ratio of 8:3 (24:9) when un-squeezed on projection, giving the full widescreen ratio ( when 8 is divided by 3 or 24 divided by 9) of 2.66:1.

The more familiar sounding ratios of 2.39:1 and 2.35:1 are basically derived from the days when magnetic tape was stripped down the side of print film for soundtrack and so the picture element was offset and reduced slightly to accommodate this.

Anamorphic image

There are two main optical characteristics that combine with the widescreen ratio to endow an anamorphic image with its creative attributes. Firstly because the ‘squeeze’ is twice the horizontal, it means that the image is twice as wide so to achieve a similar size shot on a spherical lens the anamorphic will need to be double the focal length- so a 50mm shot spherical will be matched in horizontal size by a 100mm anamorphic-with the consequence of half the depth of field and a flatter perspective.

The second attribute is again created by the squeeze process and concerns the unfocused light and flares. Because of the oval nature of the squeezing elements a point source highlight will be dragged and bent over the whole of the lens creating a streak effect which has become very fashionable, the degree to which is very much dependent on the lens range used and the intensity of the light source.

Aspect Ratio

Aspect ratio diagramAspect Ratio refers to the relationship between the horizontal and vertical size of an image but not the physical size as this can vary depending on the size of the sensor and the image circle of the lens. The most common ratio is 16:9 (1.78:1) but there are others including 18:9 (2:1) and 21.5:9 (2.39:1) which tend to be used for high end TV or film work.

 

Coating

Lens coating

Lens manufacturers have applied anti-reflective coatings to lens elements since the 1930s to improve the light transmission performance and increase contrast by reducing internal reflections.

Modern lenses have multi coated surfaces that can deal with specific wavelengths of light and allow them to pass through the lens and not be reflected away, which increases the light transmission performance.

A simple five element lens has therefore ten surfaces that would reflect light away and wash out the contrast if they were not coated and therefore reduce the effective maximum T stop due to internal light loss.

 

 

 

Depth of Field

Depth of field comparison

Depth of Field is the term used to describe the band of acceptable focus within an image. All lenses output circles of light and the circles reduce in diameter as we move closer to the point of focus until they become acceptably small enough to become ‘sharp’.

The degree as to how quickly the size of the circles increase to become ‘soft’ either side of ‘sharp’ is the measurement of the depth of field (DoF). Depth of Field is affected by the focal length of the lens and the setting of the iris.

Doubling the focal length will halve the DoF at a given distance as will moving the iris one stop more open. So it follows that the larger the sensor, the greater the focal length of lens needed to achieve a certain shot size and therefore the depth will be shallower, which explains the popularity of the Canon 5D camera.

As cameras increase in resolution and are able to actually record the output of high quality lenses it is certainly true to say that the perception of DoF and the lack of depth has increased because the bits that are sharp are very sharp but the fall off to soft occurs in a very small change of distance.

 

 

 

 

 

 

 

 

 

 

EF Mount

EF Mount refers to the lens mounting system developed by CanonEF Lens mount in 1987 to support newly auto focus cameras.

The ‘Electro Focus’ mount provides power to the internal motor in an EF lens to drive the focus ring. Since the advent of the 5D camera, EF lenses have grown in popularity to the point where other manufacturers such as Panasonic and ARRI offer EF options on their products.

The EF mount is not as mechanically robust as some of the other professional systems but its shallow flange depth allows for large sensor coverage. 

 

 

 

 

 

Element

Lens elementsSimply refers to the individual glass pieces that when combined in groups perform the various functions required in a lens.

 

 

 

 

E Mount

E MountA recently developed mounting system by Sony which allows for full frame coverage (A7s) or for Super 35 like the FS7. Usually supplied with an adapter to work with EF lenses although Fuji have recently released two small E mount zooms.

 

 

 

 

 

 

 

Focal Length

Focal length

Refers to the distance of the rear nodal point (ie light travelling in the same direction as when it hit the front of the lens) from the focal plane (the sensor) in millimetres when the focus point on a lens is set to infinity.

The lower the number the wider the lens’ field of view (FoV) so for example a 24mm lens provides a much wider picture than a 100mm lens and because it has to bend the light from a wider angle (and nearer the sensor) the perspective ‘throws’ the image to the distance and can start to look bendy as we feel the curve of the glass.

This is why longer mm lenses tend to be used on faces as the flatter perspective is cosmetically advantageous.

Bear in mind that the mm of a lens is a constant and that it is the size of the sensor that will vary the magnification, so a 25mm is always a 25mm and if you are used to Super 35mm aspect ratios then that is what you will get-a larger sensor will give a wider image for the same mm but it is still 25mm- a Cooke S7 lens is designed to cover Full Frame sensors but will be the same as a Cooke S4 on a Super 35mm size sensor.

The shallower DoF argument on bigger sensors comes from the need to be one lens tighter in order to achieve the same shot size as Super 35mm.

 

FocusFocus

Focus is the ability of the lens to move elements within it to affect the path of incoming light rays and converge them onto the sensor. That point of convergence is where the subject will be in focus on the sensor.

All professional lenses provide a scale in feet or metres on the focus ring and the adjustment of this ring alters the point of focus on the image by bending the rays of light to converge on the front of the sensor and the distance marking on the lens corresponds to the actual subject distance from the sensor.

 

  

Flange Focal Depth

Flange focal depth

Flange Focal Depth is the mechanical distance in mm between the lens mounting surface (flange) on a camera and the focus plane of its image sensor.

This distance is hypercritical and any variation in microns of distance can create issues with lens focus scaling as the convergence of light beams relies on this distance being an absolute.

Lenses can be altered to re-align to this distance by the addition or removal of micron sized ‘shims’ which then correct the accuracy of their focus scales. It is usually only fully professional camera systems that can provide this degree of accuracy-do not expect an A7s or 5D to be able to do this.

 

 

 

 

 

 

 

 

FlareFlare

Flare refers to light being scattered across an element or element’s surfaces and ‘degrading’ the image, usually as a result of a bright point source of light being in shot or near to the edge of frame, and in a position where light is more likely to become ‘trapped’ and bounce between element surfaces.

Traditionally thought of as undesirable and the reason that multi-coated lenses were built to supress such artefacts, flare and flaring has become a bit of a holy grail of modern lighting technique which has seen a resurgence in both anamorphic and ‘vintage’ lenses being used to enhance and magnify these imperfections for creative and narrative reasons.

 

Full frame_Super 35Full Frame

Full Frame is an expression to describe a sensor that is dimensionally derived from still camera proportions based on film ‘travelling’ sideways as opposed to Super 35mm movie film ‘travelling’ north to south.

The gauge of the film is (was) the same (35mm) but the orientation allowed for a bigger picture on the Full Frame then on the Super 35mm even if the aspect ratio was the same.

We can see Full Frame sensors appearing on fully professional cameras such as the Sony Venice now, however the 3:2 aspect ratio (1.5:1) usually associated with these sensors does not lend itself to widescreen acquisition and therefore some cropping will need to occur in order to produce a sensible, usable aspect ratio.

 

 

  

IrisIris

Iris is the mechanism by which the amount of light allowed to pass through the rear lens is controlled.

Usually consisting of a set of metal blades that converge in a uniform circular pattern that increasingly restrict the amount of light allowed to pass to the sensor as the iris is closed.

The pattern of the iris hole can contribute to the visual characteristics of the lens and can be from 3 to 12 blades in complexity, with the greater number of blades forming a more perfect circle.

The iris setting is either controlled manually by a ring on the rear of the lens or by an electronic interface with the menu on the camera depending on the system being used. The numeric scale on an iris ring refers to a mathematical measurement of light as a known quantity and aids accurate correct exposure within a combination of light intensity, the native sensitivity of the sensor (EI or ASA) and the shutter speed.

The numbers on an iris ring are based on the square root of 2 and are known as ‘stops’, each stop represents a halving or doubling of the amount of light intensity allowed to pass through the lens. It also has a direct relationship with Depth of Field which also halves or doubles at a given set focus distance when the iris is moved one stop.

Those familiar with numbers on an iris ring can see the progression as described below, given that the square root of 2 is 1.4 and each increase represents a halving of the light transmission;

1.4 x 1.4=2, 2 x 1.4=2.8, 2.8 x 1.4=4, 4 x 1.4=5.6, 5.6 x 1.4=8, 8 x 1.4=11 etc.

Therefore it is very much the case that the iris setting has as much creative influence as both focus and the focal length of a lens.

 

Macro lensMacro

Macro refers to a specific group of lenses that allow for extreme close ups of objects due to their ability to focus to a very small minimum distance to create large (macro) images of small objects.

It can be used to describe lenses that just have a close focus ability although in technical terms it refers to a lens that has the ability to deliver a reproduction ratio of 1:1 in that the actual size of the subject is the same size or less than that on the sensor.

Essentially this is producing an image of something that is larger than the real thing.  The image of a 20p piece was taken on a Tokina 100mm Macro lens

 

 

Lens MTFMTF

MTF is an acronym for Modulation Transfer Function which is a frightening term with a simple purpose.

The MTF of lens is simply a measurement its ability to pass detail and black/white contrast through itself.

A ‘4K’ lens must have the ability to pass through 4096 black/white repeating cycles per horizontal line otherwise it’s not a 4K picture arriving at your sensor.

As usual you pays your money you takes your choice but for example a Canon USM zoom on your 8K RED Helium is not giving you an 8K picture.

 

 

PL MountPL Mount

PL Mount is a professional lens mounting interface developed by Arri and is an acronym for ‘Postive Lock'.

This mounting mechanism is ubiquitous in professional camera and lens systems apart from the eponymous PV system from Panavision and replaced the Mitchell BNCR mount (Blimped Newsreel Camera Reflex) and Arri Bayonet systems.

The PL mount has to control the Flange Focal distance to exactly 52mm in order to maintain focus accuracy and has a four pronged interface with a keyway seating point for strong and solid mounting with a locking mechanism that ‘pulls’ the lens mount into position.

 

 

 

Prime lensPrime Lens

 

Prime lenses are individually created units with a specific, fixed focal length. They are usually used as a set ranging from wide focal lengths to telephoto.

The advantages are they are usually fairly lightweight, have very wide iris capability and have short minimum focus distances.

The only disadvantage is the need to change lens when needing a different focal length.

 

 

 

 

Lens speedSpeed

Essentially a colloquial/professional term for a lens’ ability to transmit large amounts of light when in open iris mode, thereby being very useful in low light, ambient or unobtrusive lighting conditions or when a very shallow depth of field is desirable.

A ‘Speedbooster’ adapter refers to an add on device that takes one lens system (usually EF) and adapts the Flange Focal distance to match another system (usually PL). The ‘speedboost’ refers to an EF system Full Frame image at a Flange Depth of 42mm being reduced in size to fit a PL Flange at 52mm onto a Super 35mm sensor where the ‘boost’ comes from the increase in light transmission as the image is shrunk from Full Frame to Super 35mm and gains 2/3 of a stop of light.

 

 

  

Tilt Shift lensShift & Tilt

Shift & Tilt lenses of a fixed focal length that have extra mechanical adjustments either built in or as a separate mounting frame. Essentially the lens to create two points of focus at different distances or to artificially shift focus to an unusual point thereby creating a ‘weirdness’ within the frame. 

The tilt movement can also compensate for the ‘perspective’ on wide lenses-to keep columns straight for example.

 

 

Spherical lensSpherical Lens

Basically a term to describe a non-anamorphic lens in that the image cast at the point of the sensor is a circle and the elements of the image that are sharp are just very small circles within the bigger one.

 

 

 

 

Super 35 filmSuper 35

Super 35 is a term used to describe the size of most digital movie camera sensors. There is some variation between manufacturers in terms of actual dimensions but essentially it refers back to the size of the film image rectangle available to use after the need to preserve a strip of film down one side for magnetic sound was removed.

The aspect ratios would remain the same but the exposed area and therefore the image quality increased as a larger piece of film was being used. In lens terms this meant that they had to be built with a bigger image diameter to cover the larger ‘sensor’ area and so many vintage lenses that are used today are most unlikely to have been built to cover Super 35mm size and will therefore vignette or will suffer a significant loss of quality at the edges of frame, particularly with an open iris so beware.

 

 

 

 

T stopT Stop

As we have seen earlier, ‘stop’ refers to one full notch on an iris ring and represents a halving or doubling of light transmission based on a mathematical progression and is calibrated from a lens’ greatest point of sensitivity which is represented by the ratio between the focal length and the diameter of the front element (entrance pupil) and is known as the ‘f-number’ and the iris progression as ‘f-stops’-a 50mm lens with a front element diameter of 25mm is an F2 lens on maximum open iris.

However this is a mathematical/ theoretical progression and does not build into the system any absorption of light by the elements of the lens as it passes through. A T-Stop is a calibration of the iris ring to match that of a particular lens and will represent the amount of light exiting the lens or being ‘transmitted’ by it, therefore the T stop is the ‘Transmission’ Stop.

In the case of some zoom lenses the F Stop may well be F2.8 but the absorption of light will lead to a maximum T Stop of T3.5 which will help avoid under exposure.

 

Uncoated lensUncoated Lenses

In the pursuit of flare and unusual lens characteristics there is one process that has proved to be very popular and has two distinct modes. Uncoated lenses are lenses that have had some coated surfaces removed or have been supplied with elements that have never been coated.

Lenses that have had front or rear or both coatings removed tend to sit in the vintage category and are fairly unique as each set will have had different treatments to remove the coatings and therefore will not necessarily match another set of the same base lenses.

The most popular uncoated lenses in this area are the Zeiss Super Speed T1.3 uncoated primes because despite not being manufactured for 30 years they were very common and lots of sets still exist so the one–way process of uncoating is not so cataclysmic if it does not work, but each set does display a variation in characteristics, meaning some sets are more popular than others.

Lens flareVMI also experimented and have created the only set of uncoated Zeiss ZF DSLR lenses which also flare very effectively and are a much more cost-effective way of achieving a similar effect.

The combination of uncoating with ‘fast’ lenses is popular as a wide aperture enhances the flare effects. Modern lens systems can be uncoated by the exchange of a coated element being replaced by an uncoated one supplied by the manufacturer from source so has never been coated. This method can provide stability of look across several different sets of lenses and in some cases allow for front or rear or both uncoated elements to be used, such as Cooke uncoated mini S4s.

The main creative reason for using uncoated lenses is to increase flare and create interesting anomalies with point sources, however there are certain situations where an uncoated lens will not perform well ( large, hot windows for example) so be aware to have sufficient coated lenses as well.

 

Vintage lensVintage Lenses

A term to politely describe lenses from previous decades that have seen a resurgence in popularity as a means of controlling the precision and clinical imaging of digital sensors.

As they tend to be from eras that still allowed lead to be used in the glass and therefore increased the refractive power, it meant that these lenses were fast but small physically and therefore easy to use and to have shallow depth of field. Sometimes the old housings have or will fail working with modern LCS devices and there is a thriving cottage industry that re-houses old lens packets or indeed even creates new elements with the same heritage characteristics of the originals.

Vintage lenses will be softer, less consistent between individual focal lengths and carry less contrast and some are downright crap. Use with caution and be wary of using in conjunction with Log recording colour spaces. Some Vintage glass packs are being re-housed into modern robust housings in order to provide the ‘look’ but mitigate the mechanical fragility of the originals.

 

 

Zoom lensZoom Lens

A complex lens that not only has focusing elements but travelling packs of elements that can magnify or reduce the image size by varying the virtual focal length and in the case of most professional lenses do this without variation of light transmission or variation in focus settings which is no mean feet (pun). This is why they are bloody expensive.  

Cheaper zooms designed for still work will not hold focus (parfocal) or consist iris and may well ‘breathe’ when the focus ring is moved (ie the image shifts a little bit as the elements move).

18-35mm zoom lensZoom lenses represent a great convenience in that under the right circumstances, they can avoid the need and time for any lens changes and therefore not miss any real time or one off events. However, the almost ubiquitous adoption of Super 35mm sensors in cameras over recent times has thrown up a clash between creativity, convenience and physics that is certainly polarised in the zoom lens world.

So until we discover a parallel universe with a different set of physical rules, the following statements will not vary.

If you want range and speed your zoom lens will be big and heavy.

If you want small and hand-holdable you will sacrifice range and/or speed.

If you want small with range and speed and hand-holdable you are not listening or you need to go back to B4 size sensor where the world of HJ lenses will welcome you back.

If you want to hold focus when you are zooming, then you should not expect to use a DSLR lens.

Part 2: What Lens System to Use and Why:

The above section attempted to explain some of the technical and practical attributes of lenses as individual factors. The final section will describe particular sets of lenses from different manufacturers with their characteristics and some screen shots for comparison purposes.

This section however will hopefully deal with the rather more woolly notion of what lens is suitable for a particular shot/project and why. It will be comforting to start with a massive cliché along the lines of ‘think of the above section as describing your palette/canvas/brushes’ etc as it is pretty much true and without a grasp of that knowledge yourself or not having a collaborator that does, you will potentially become unstuck. Nothing has ever been an image without being resolved by a lens including in our own heads so it is pretty much the fundamental path to anything with a picture. This is optics and mechanics bending bits of light into stories and information and transcending the sum of their physical parts. The 300,000 extras and all the logistics and organisation to get them there at the right time for the funeral scene in ‘Ghandi’ don’t exist without a bit of wide bendy glass in a bit of metal made by Panavision, nor does Neil Armstrong step on the moon or Bake Off have a nice cake…you get the picture (pun).

There are three factors to consider and all have been explained above as to what they ‘are’ but not what they ‘do’- Focal Length (Field of View), Depth of Field and Iris (stop), Prime or Zoom Lens.

Focal Length

Lens

Focal length and its association with Field of View (FoV) are akin to your canvas and set the groundwork for the other factors to build on. As we have seen, the smaller the focal length, the wider the image on the sensor and the wider the FoV. The FoV is the angle of which light can be gathered from left to right and top to bottom- but bear in mind all spherical lenses output a circle and it is the restriction on the vertical by the aspect ratio that usually makes the horizon the dominant axis and which is more obvious on wide shots.

Wide shots are geographical and environmentally explanatory, they are not analysers of emotion or content, they are observers and passively remote. A wide focal length lens tends to throw even near objects to the distance and therefore requires strong lines to shape a decent image. On wider lenses you may find that verticals near the edges of the picture start to bend as they ‘feel’ the curve of the lens and a way to solve this is to keep the camera level and move it up or down physically (ie not tilt) until your picture works.

If the wide lenses are scene setters then the mid-range focal length lenses become our story tellers. It is a truism that a 50mm lens on Super 35mm is an approximate two dimensional version of our own eyeballs Field of View and that is why it has been known as a ‘standard’ lens and a very popular focal length. At this point it is worth explaining that all lenses can only ‘see’ in varying degrees of a straight line and the longer the focal length the straighter and tighter that line is and therefore they can only observe what is placed within their FoV or only see something new by being ‘taken’ there by a movement.

35mm lens compared to 200mm lens

The mid-range lenses because of their FoV are able to gather information from the edge of a shot (a person, a movement) and use it to find the next important point and if necessary focus in on it using the reducing Depth of Field, This is the essence of visual story-telling, the lens can observe a scene yet isolate a small part using focus if needed, but it has to be guided-‘directed’ in fact to what is important.

The longer focal length lenses-100mm and up have a narrower FoV and exhibit some accumulative compression characteristics as the focal length increases. This compression manifests itself as reduction in the width/height of the background behind a subject and the ability to ‘punch’ through soft foreground artefacts so creating an isolation or observation of a subject surrounded by people or objects. This compression and narrow FoV mean that a subject can walk from distance towards camera for a significant amount of time before growing too big and so is a classic lens set up for a ‘walker-talker’ dialogue scene or a documentary explaining ‘piece to camera’.

Anamorphic frame

Anamorphic lenses display all the traits as per spherical lenses but with one significant difference in that the FoV is the same as for the relevant focal length except that the horizontal axis has twice the width squeezed in, so the compression of the background is effectively double that of the spherical equivalent- a 50mm anamorphic lens has the same FoV as a 25mm spherical lens (for a given aspect ratio) but still exhibits the visual compression or perspective flattening of a 50mm spherical lens.

An average project will use a range of lenses to cover all the above eventualities whilst some drama jobs will take every focal length (perhaps 16 lenses) in a particular range but share them across two camera platforms. The decision as to which range to use is dictated by cost, preference and suitability, usually in that order.

 

Depth of Field

Depth of Field is the measurement of the amount of stuff in focus surrounded by stuff that isn’t in focus and the further away in front and behind the subject, the softer the stuff gets as the circles of confusion (ovals in anamorphic) get bigger. So that’s the technical bit reprised and so what does DoF (we love an acronym) mean in the real world?

Depth of Field has two main controlling factors-focal length and iris setting.

The focal length will affect DoF as the longer the focal length the ‘shallower’ the DoF for a given same distance-BUT a subject at 5ft from camera on a 50mm will have the same approx. DoF (and subject size and iris setting) as a subject at 10ft from camera on a 100mm, the only difference will be the compression and softness of the background on the 100mm. Remember that DoF refers to the acceptably sharp band of focus, not the rate of descent into mushiness and this is where the creativity control lies.

 

Iris

Depth of field comparison

The iris setting has direct influence over the DoF and whilst it is used as an exposure tool, it can be used to control the DoF whilst other parameters (EI and ND filters mainly) are adjusted to compensate for correct exposure.

The wider the setting on the iris, the shallower the DoF the greater proportion of the image that will be soft or ‘unexplained’. The creative power of DoF is akin to that of lighting of which there is an old adage along the lines of ‘it’s not what you light, it’s what you don’t….

Our eye and brain combination means that we see things pretty much in focus all the time and therefore when we are presented with images that only have a tiny proportion of ‘in focus’ fragments, it points our attention to that spot and that spot only. This is the story telling aspect of a technical unavoidability and has been used to great effect on many a project.

For example, there is a an Amazon Prime show called ‘Mr Robot’ which uses shallow DoF to create an unease in the framing by placing the subjects very low in that frame which fashions a sense of underdogs fighting the ‘machine’- they are still the only focused ‘piece’ within the frame and so the audience is still drawn to them and their issues, if the DoF was greater then the framing would just look plain wrong and like a mistake.

 

 

 

 

Primes or Zooms?

Primes or zooms or a combination have both creative and operational factors for us to consider.

Prime Lenses

Prime lens set

Prime lenses are by definition individual focal lengths and therefore usually ship in a ‘standard’ range from reasonably wide to reasonably tight and about five lenses-typically 18,25,35,50,85mm. This set will cover most eventualities and will to the most part provide a kit of lenses that are similar weight, size and of a similar wide aperture because if you are working wide open on the iris you do not want to change lens to find that the new one is two stops less ‘fast’ and you have to re-light for exposure purposes.

A five way kit also means it can be shipped in one flight case for convenience of use and to have all the lenses to hand when shooting. Wider and tighter lenses such as 14 and 135mm will ship as individual items to complement the main set and because there is a convention to maintain size and weight for operational considerations, it is more likely that these lenses will sacrifice maximum aperture in order to achieve this-an average 14mm will be T3.5 minimum and a 135mm is usually T2.1.

A very notable exception to this is the new Sigma Cine EF mount 14mm which is T2 in a small housing and will no doubt make a hugeSigma 14mm EF prime lens impact in the Natural History world where low light and slow motion are common necessities. The main inconvenience of prime lenses is the need to change lens every time a new size is needed-sometimes the perception of this however is somewhat over stated however it is very much the case that if you are in a ‘one time only’ situation then prime lenses are not the way forward and another way should be used.

 

 

 

 

 

 

Zoom Lenses

Zoom lens

Zoom lenses as explained above have a third function which is the ability to manipulate the focal length and thereby alter the size/magnification of the shot on the fly without having to change lens.

A common misconception inherited from the seventies is that a zoom lens is used for adjusting in shot and negating the need for a dolly move. The zoom effect increases the focal length and therefore flattens the perspective and decreases the background DoF so creating a two dimensional ‘move’ which does not create the tension of a physical camera move where the foreground, background and focus shift according to the distance of the move. In reality zoom lenses these days tend to be used to adjust size between shots or gaps in events in order to achieve something new and editable.

The clever party trick of zooms of a certain standard is that they can maintain focus and iris continuity across the zooming range-this is no mean feat and comes at a price and weight point.

 

Canon zoom lens

The cheapest zooms used for filming purposes are the Canon EF mount USM range with the very familiar range of 16-35, 24-70 and 70-200mm, these lenses are in constant use but have the drawback of not holding focus or iris across the focal length range (apart from the 70-200mm which will hold focus because it is only a 2.8x range and at the telephoto end of focal lengths) but satisfy a need at a price point.

Think carefully on your zoom lens choice because short/lightweight lenses may be easy to hold but their limited range may not have ‘2 sizes’ within them so you may be changing lens and be better off on primes because of the potential for wider aperture.

For example Fuji released two dedicated Sony E Mount zooms, the 18-55mm and 50-135mm which on paper look to complement each other as there is a 50-55mm crossover and they are lightweight and fast for small zooms (T2.9), however if we consider that your first size of shot is maybe 24mm to get your wide angle and then you need to crack in to get a close up or detail on a one-time event, then your next size in will most likely need to be more than 55mm (more like 75-100mm) so you will have to change lens anyway.

So overall zoom choice is between range, weight and iris over ease of Fujinon 50-135mm zoom lenscarrying but with the operational caveats already stated. If this seems a bit bewildering and inconclusive that’s because it is but basically big range is the Angenieux 24-290mm and ease of use with least compromise is the Canon CN7 17-120mm.

 

 

Part 3: Lens Comparison

Please note that screen shots from specific lenses will be inserted in due course.

Angenieux

French manufacturer of zoom lenses since the 1950s and the most consistent choice for high end acquisition.

The Angenieux zooms have traditionally fallen into two categories- small and lightweight or large and heavy with a big range and good maximum aperture. Currently the 15-4028-76 and 45-120mm Optimos form the lightweight range and the 24-290mm Optimo (or 28-340mm) is the heavyweight with a 12x range.

 

There is also a mid-range Optimo, the 19.5-94mm which has a lot of character for a modern lens and a 25-250mm Optimo at a slightly more accessible price point. Recently Angenieux have started to produce lenses that have mechanical adaptability- be it either anamorphic to spherical or Super 35mm to Full Frame. The most accessible of these are the two new EZ zooms that are available at an aspirational price point in either Super 35mm or Full Frame coverage and in PL, EF or E Mount (15-40mm PL or 22-60mm FF and 30-90mm PL or 45-135mm FF).

 

ARRI

In conjunction with Zeiss and Fuji manufacture both Prime and Zoom lenses in PL Mount for high end use.

ARRI Master Primes: Are available as both spherical and anamorphic versions. These are the ultimate ‘clean’ ‘crisp’ and sharp modern lenses. They are ultra-fast at T1.3 have very little flare/aberration transmission and MTF way beyond 4K. Because they are so sharp and can be operated with a tiny DoF they are the best lenses to use for that ‘isolating’ effect. They are big and heavy for primes although are all the same size and weight for operational stability.

ARRI Ultra PrimesA replacement to the Zeiss SuperSpeeds when not using lead in glass became a thing. Ultra Primes are light and fast (T1.9) and will resolve to almost 4K and are a good work horse lens that keeps the footprint of a camera channel down to a reasonable size if space is an issue.

ARRI Alura ZoomsBuilt by Fuji and released to complement the Alexa, the Alura zooms have a range that is designed to tackle some of the issues of Super 35mm coverage. There is a small 15.5-45mm and 30-80mm for handheld, a medium 18-80mm for range and a 45-250mm for reach.

Canon

Several ranges of primes and zooms to suit all tastes and price points-mainly with EF mount which has become probably the most used lens mount system in the world.

USM Primes & Zooms: Good quality stills spec lenses and designed for Full Frame coverage for the 5D and other Full Frame sensor cameras. The lenses have autofocus and electronic coupled iris adjustment and the zooms have mechanical focal length adjustment. The autofocus function of theses lenses is now being exploited by cameras such as the Canon C200 which can achieve very consistent results and is a great improvement on large sensor focus issues.

CNE Primes: USM Primes in a posh housing with a nod to Zeiss Compact primes in terms of styling. Although a little ‘fussy’ in appearance these lenses are very popular especially in C300 or FS7 world where a degree of manual control is preferable but still with  a maximum iris of T1.5 across the core range with other lenses being markedly slower (the 14mm is T 3.1) but delivered at a low price point.

K35: Vintage PL Mount lenses from the 1980s where they were introduced as a competitor to Zeiss SuperSpeeds. Fast and small (T1.3), the K35s are a very popular vintage choice as they combine a heritage and shallow DoF look with relative optical and mechanical consistency as they are a fairly recent creation in terms of history.

CN and CNE ZoomsThe Canon CNE zooms are a partner to the CNE primes and are 15.5-47mm and 30-105mm at a constant wide iris of T2.8, they are relatively small and lightweight but with the usual compromise on range. There are two CN zooms that fill different requirements very well- the CN7 17-120mm cabriolet Zoom is the best compromise in terms of size, speed and range and partners very well with the ARRI Amira for the best current version of a documentary or ‘run and gun’ set up. The CN20 50-1000mm is specifically designed for outdoor long lens filming-it is slow, T5.6-T11 is the widest aperture depending on focal length, but with a great range ( and a 1.5x extender) and is relatively light at 6kg and so has become a constant on most natural history projects.

 

Celere

A range of fast (T1.5) and consistent size and weight primes by German manufacturer HIT.

These lenses are Mount agnostic (..thank you Sony) being PL EF or E Mount and are also Full Frame coverage up to RED VV in fact. These are serious Prime lenses with a look reminiscent of S4s but nearly a whole stop faster. They accommodate modern platforms such as Gimbals by being the same size and weight and should be a contender for any project regardless of budget.

Cooke

Several ranges of Prime lenses at different specification and price points. Cooke lenses have a specific artistic quality which has its technical roots in the multi coatings and the shape of the iris leaves as the stop shuts down. Cooke S4s are very much the ‘go to’ choice for most dramas and spherical films

 

Mini S4Small and light with a compact range from 14-135mm these are the ‘aspirational’ Cooke lenses as they are available at a price point, the compromise being that they are a stop slower than S4s but still carry the ‘Cooke look’. They are also available with uncoated front elements which because they are new elements that have never been coated, they have a consistency across the range which is difficult to achieve with vintage glass.

 

S4A large range of lenses consisting of 18 focal lengths between 12 and 300mm. There is a warmth and 3D quality to these lenses that very much lend themselves to narrative work-pretty much any drama will be using these as there is a perception that they are particularly kind to skin tones and take the ‘edge’ off the clinical nature of a digital sensor without opening the minefield of vintage lenses. These will also soon be available with uncoated front elements as per the Mini S4s.

 

S6The correct nomenclature for what are known colloquially as the Cooke Anamorphic Prime set. Ranging from 25-135mm, these are 2:1 squeeze modern lenses designed to work with 4:3 sensors in order to achieve the accurate aspect ratio of 2.66:1 (24:9). A remarkable set of lenses with huge amounts of character but within a modern, easy to use, housing. Disadvantages are the size and weight (particularly the close focus 65mm which is a big and heavy as some zooms) and the cost, although it is worth bearing in mind that from a rental perspective a set of S6s is comparable to that of a full set of S4s.

There is a new version of the S6 lenses arriving in 2018 which are the ‘SF-Special Flares which have much reduced coatings to increase light bounce and mimic a more vintage character.

 

S5: A fast range of lenses with a maximum aperture of T1.4. Not as popular as S4s for two main reasons- there is less range than with S4s and a majority of jobs will share a big set of lenses between two cameras and want lots of lenses, and if a project is looking to shoot at wide apertures, there is a school of thought that Master Primes are able to maintain contrast and detail to a greater extent than the S5s.

 

S7: A new set of lenses that will grow in range and are following the current trend of large sensor coverage. They can of course still be used on Super 35mm sensors where their focal lengths will provide familiar shot sizes.

 

Speed PanchrosAre available as original vintage glass cassettes re-housed in new mechanics. Some Panchro glass will be very old indeed and this is reflected in the inconsistency of the colour transmission as the coatings decay. Great care should be taken when using these lenses as they will not carry the contrast of modern lenses and log recording may well hide this milkiness until too late.  Cooke are now manufacturing a modern version of these lenses called the Panchro Classic which will carry as much of the character of the originals but in a consistent range which mechanical integrity.

 

Anamorphic Zooms: Designed to complement the S6 range of lenses the 35-140mm and 45-450mm Cooke zooms have the same characteristics as their Prime cousins and are an ideal B Camera solution. They are of course big and heavy but fast for anamorphic zooms and a superb bit of engineering.

Kowa

Vintage anamorphic lenses now available in two forms from manufacturer P&S Technik.

The P&S Technik Kowa Classics use the original glass but all the mechanicals including the cell packs are replaced in order to allow the lenses to cope with the rigours of modern LCS systems. The classics are a four lens set, 40-100mm and whilst they exhibit all the vintage character you would expect, they must be used at T4 or above otherwise they will appear to be very mushy. Due to the demand for the Kowa look (which frankly is the only vintage anamorphic type that still works), P&S are also making the ‘Evolution’ Kowas that will use new glass with as much of the old Kowa look as possible but with the advantages of consistency, the ability to work at wider apertures and the addition of extra focal lengths’ such as the 135mm.

Other re-housed (and original) versions of Kowa Anamorphics do exist but the P&S re-build is definitely the most robust to date. 

Sigma


The Sigma prime range consists of core focal lengths 20-85mm at T1.5 with a 14 and 135mm at T2 also available. VMI offer the full set of Sigma primes in PL and EF mount though Sigma also make an E mount version too. The Sigma film primes resolve Full Frame and S-35 format.

The Sigmas are solidly built and achieve T1.5 at Full Frame cover (20-80mm).  When used in EF mount, they need to be supported by 15mm bars as they would otherwise pull an EF mount out of true, though in PL mount this is not a consideration.

In our view, the Primes are worth serious consideration if using a PL or EF based camera set up as they are strong enough to cope with the physical demands of an LCS system. The mechanics and optical performance are excellent.

Sigma currently have 3 zooms in their product range.

There are 2 x Super-35 zooms:18-35mm and 50-100mm with the usual caveats to usability and these are fast zooms at T2 and hold focus across the zoom range.  VMI stock the EF versions and plan to stock the PL versions in 2018.

Sigma also unusually produce a full frame (FF) version in EF mount only which is 24-35mm and a surprisingly fast T2.2.  Although this only works over a limited range, it is the first of its kind and so is worth of a special mention and VMI stock this lens.

Veydra

The Veydra Cinema Mini range is purpose built for APS-C mirrorless sensor cameras such as the Sony A7s II as they are natively E Mount but will also fit the Sony FS7 without vignetting. They are based on Micro Four Thirds (MFT) glass packs but will cover Super 35mm sensors and consist of 19mm, 25mm, 35mm, 50mm, and 85mm. They are T2.2 apart from the 19mm which is T2.6

Zeiss

As well as manufacturing lenses for ARRI, Zeiss have their own branded ranges as well, the most popular being the Compact Primes, although they also make various types of lenses for stills cameras with various mounts that can also be used for video use.

The Zeiss Compact Primes are either PL or EF mount and offer Full Frame coverage and are all T2.1 apart from the 15mm and 18mm and 21mm. They are lightweight which makes them useful for gimbal and hand held work. Zeiss have released a High Speed version (which they call SuperSpeed) but with a limited range of 3 focal lengths of 35,50 and 85mm at T1.5, this does not represent a ‘set’ and you would be better off with the very comparable CNE primes from Canon.

Zeiss also released a CP.3 Compact Prime set in 2017 which offered smaller lens housings and improved mechanics but are optically the same as the original CP.2 sets.

 

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23 Feb 2018


By VMI
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