Why do I need to check back focus on a lens if I move it from one camera to another?

Maintaining correct adjustment of the back focus, you are correcting for any discrepancies in the calibrated distance between the rear element of the lens and the camera’s sensor to assure that your zoom lenses function optimally and retain focus accuracy during filming. Cameras—even those from the same manufacturer—often have subtle differences in the manufacturing, assembly, or configuration that may require the camera-to-camera adjustment. Confirming all your lenses and camera accessories work as expected should be part of your pre-production preparations. These adjustments are crucial for optimization of the performance characteristics of the lens and we recommend readjustment whenever the lens conditions change (like changing cameras).

Why is there no back focus on a prime lens?

There is a need for back focus adjustments on single focal length, or “Prime,” lenses. Unlike with zoom lenses with multiple focal lengths in a single lens, adjusting the back focus on your prime lenses allows a cinematographer to control the focusing characteristics and accuracy of every lens on that camera.

Why is Back Focus labeled on some lenses as “FB”?

Some manufacturers often refer to Back Focus by using the engineering term 'flange back distance” to define the distance between the mounting flange of the lens and the film/sensor plane of the camera. “Back focus” is defined as the distance from the rear element to the focal plane or camera sensor; “flange back” or “flange focal distance” is defined the distance between the flange of the lens mount and the camera sensor. User access to many of these types of settings have been limited since the early days of broadcasting, to keep them in the hands of the engineers. But as more and more uses for broadcast style cameras became commonplace, access to some of these adjustments became more available to the average user. Back focus adjustments were a regular part of your camera setup when three-chip CCD cameras were more commonly used by broadcaster crews.

When will Fujinon cine lenses have auto focus?

Auto focus is used to quickly capture imagery with precise focus. Broadcast and still lenses have enjoyed auto focusing systems for some time; however, the design and use of cinema lenses have not included auto focus. Creatively, the first camera assistant (focus puller) wants full control of where focus is set within in a shot because the choice of where and when to focus is part of the creativity of filmmaking, Currently, there are cine-style auto focusing systems that utilize an externally mounted range finder that works in direct concert with the Focus, Iris, Zoom motors (FIZ) systems. They are available from a wide variety of manufacturers.

Can I switch Premista lenses back into Super 35 image circle format?

The image area on Fujinon Premista lenses was optimally designed for use on Full Frame or Large Format cinema camera systems. However, if you choose to use your Premista on a camera with the smaller Super 35/APS-C sized digital sensor, your lens will function exactly the same but magnify the image by approximately 1.4x. Your Premista will retain the clarity and sharpness you are accustomed to, albeit with a slightly longer effective focal length than you are accustomed to associating with when using a large format sensor.

Can I add a Cabrio drive to Premista LF lenses?

No, the Cabrio drive mechanism is not compatible with Premista lenses. It will not physically fit; however, Chrosziel’s Servo Drive Unit for Fujinon Premista is fully compatible with and completely interchangeable between all Premista lens models. A variety of third parties, such as Duclos Lenses, offer a lens motor mount/bracket designed specifically for Premista lenses.

Do Cabrio lenses need external power to work?

Yes. Fujinon’s Cabrio series zoom lenses are designed to draw power (and provide lens data) directly to the camera via the PL Mount. Most cameras provide that lens power via the PL mount; however, some early Blackmagic cameras and some third-party PL mounts for RED cameras do not provide that power directly, requiring an external 20-Pin connection cable to deliver data and supply power between the camera and lens.

Can I use the Cabrio zooms on my EF/E/RF/LPL mount camera?

With limitations, yes. PL Mount Cabrio zoom lenses are compatible with a wide range of mounting systems found on still, video and film cameras due to the standardization of the PL mount. While your Cabrio lens is capable of working with a wide variety of lens mounts, many of those mount styles are designed for imaging systems that use Full Frame or larger sensors rather than the Super 35/APS-C sensor size Fujinon’s Cabrio lenses were designed for.

What is the maximum coverage of Cabrio lenses? Do they cover full frame?

Fujinon’s Cabrio zoom lenses are designed to cover the film and television industry’s standard Super 35 or APS-C digital format camera sensors, which are all roughly 15.44mm x 27.45mm with an image circle of approximately 31.5mm in diameter. Full Frame 35mm utilizes the 36mm x 24mm that requires 43mm or greater image circle to fully illuminate the image sensor. That limitation is also why Fujinon Premista lenses, designed for Large Format camera systems, produce an even larger, 46mm size image circle to cover not just full frame cameras, but the larger sensor formats found in the Panavision DXL2, Sony Venice, and RED VV format camera systems.

What are the main differences between V1 and V2 of Cabrio 19-90mm?

While both Versions of 19-90 have a 114mm outside front barrel diameter, V2 has a 111mm filter thread and V1 has a 112.5mm filter thread, resulting in a doubling of the housing thickness. This change was made due to the thinner front ring being more prone to damage. New version front barrels for V1 Cabrios are available from Fujifilm Optical Devices service centers at a charge. The serial number on V1 is also located on the front rings whereas the serial number on V2 is located on the zoom ring. When looking at the factory model number of Cabrio 19-90, V2 includes a "B" at the end (ZK4.7x19-SAFB). In terms of optics, lens performance is in many ways a matter of personal subjectivity. Some optical adjustments were made to improve Cabrio 19-90 V2; however, the differences in optical performance between the two versions can be difficult to perceive when looking at real-world moving pictures, as compared to high-end lens bench/test equipment.

What are the main differences between V1 and V2 of Cabrio 85-300mm?

While both Versions of 85-300mm have a 114mm outside front barrel diameter, V2 has a 111mm filter thread and V1 has a 112.5mm filter thread, resulting in a doubling of the housing thickness. This change was made due to the thinner front ring being more prone to damage. New version front barrels for V1 Cabrios are available from Fujifilm Optical Devices service centers at a charge. The serial number on V1 is also located on the front rings whereas the serial number on V2 is located on the zoom ring. When looking at the factory model number of Cabrio 85-300, V2 includes a "B" at the end (ZK3.5x85-SAFB). In terms of optics, lens performance on Cabrio 85-300 V2 was unchanged.

What makes a 2/3" lens 4K?

For a 2/3” lens to be considered “4K,” the lens needs to have more than double the resolving power of an HDTV lens. Broadcast lenses with a resolving power in excess of 100 LPmm (individual lines per millimeter) were considered sharp enough for HDTV production, whereas for your 4K deliverable, that same lens now requires a resolving power in excess of 200 LPmm just to be considered a 4K lens.

I don't care about 4K/8K, I want 1080P HDR. Will a modern 2/3" lens give me better HDR?

Higher quality, sharper lenses will always make your High Dynamic Range content look better, with the understanding that so much of the HDR workflow is dependent on the image processing pipeline for each camera type. Lenses designed for 4K and 8K filmmaking are extremely well suited for today’s large format and high resolution sensors, but have an even greater benefit when used for HDR filmmaking. These lenses offer more flare resistance due to the newer designs and latest optical coatings, giving you a dramatic reduction of unwanted reflections, and higher local contrast with an increased level of detail for your production. The acquisition of HDR compatible content needs to meet a wide range of requirements that include the camera recording at 10bit or greater color depth recorded in the Rec2020 (preferred) or P3 (acceptable) color spaces prior to it being processed to be considered High Dynamic Range (HDR) content suitable for broadcast. Many older broadcast/live event workflows may need to have their early HDTV infrastructure updated to properly address various HDR workflow concerns and constraints.

Can I use my old Canon remotes on my new Fujinon 2/3" lens?

Remote controls designed for a specific broadcast box or field lens are not usually compatible with lenses from different manufacturers. Control cabling varies widely in the broadcast realm, and your new Fujinon lens may have greater functionality or offer expanded data output that may not translate over an aged camera connection. We recommend that any existing camera and lens cabling should be thoroughly tested for compatibility and consistency when adding new equipment to your production workflow.

Can I use my old 2/3" lenses on Super 35 cameras?

Yes, many types of B4 to PL mount expanders are available on the market. Typically, there will be between 1 and 1½ stops less light with any lens expander when changing the image circle of your lens. Remember, too, that it expands not only the image size but also enhances any chromatic aberrations, which may not be suitable for the visual look of your production.

What is the difference between 2/3" and Super 35 focal lengths relative to angle of view?

Looking at the relative size of each sensor, a 2/3” sensor is about 8.8mm x 6.6 mm, while the size of a S35 sensor is roughly 24mm x 13mm, on average. That means the field of view of a 50mm lens would appear roughly 2.5 times wider on the S35 camera than it would on the 2/3” camera. By using a mount adapter that matches your sensor size, you will keep the same angle of view.

What is the difference between 2/3" and Full Frame relative to angle of view?

Looking at the relative size of each sensor is a good comparison of how your lenses will look. A 2/3” sensor is about 8.8mm x 6.6mm, or about ¼ of the size of the 36mm x 24mm 35mm Full Frame sensor. That would make the corresponding field of view for a Full Frame lens appear to have its focal length magnified 4X when used on a 2/3” broadcast camera.

Why shouldn’t I use my old HD lenses on the new 4K HDR cameras?

While your existing lenses may have been great for use in HD, they do not have the necessary sharpness or contrast that 4K and HDR workflows need. The higher resolution and increased dynamic range required to deliver content as 4K HDR can expose issues with older lens coatings, misalignment, as well as spherical and chromatic aberrations that went unseen at the lower resolution. Modern cine-style lenses offer cinematographers tools designed specifically for the ultra-high resolution and extended dynamic range requirements, maintaining a level of contrast and sharpness in your images that would not be possible with your older lenses.

Can I get servo lens control on an MK Micro Four Thirds lens?

In response to the increasingly popular pairing of the Fujinon MK series lenses with Micro 4/3 cameras, Chrosziel developed a Fujinon certified Servo controller specifically for the MK series lenses.

Which Fujinon lenses are weather-proof?

Fujinon lens are well protected against dust and dirt, and are sealed to limit the intrusion of a little bit of rain, making them quite weather-resistant. Our lens seals and weatherproofing are designed to protect your optics against the day-today maintenance issues and minor incidents that can and will happen during production. Fujinon’s latest lens accessories have additional weatherproofing for increased security against the elements.

Why do cine lenses have "T" stops and Broadcast lenses have "F" stops?

While F-stops and T-stops both define the amount of light that is passing through a lens, F-stops are determined by dividing the focal length of a lens by the diameter of the aperture opening, while T-stops are determined by an actual measurement of the transmissive characteristics of each lens. Even though F-stops are technically an approximation of exposure, digital sensors and internal exposure tools have refined the level of accuracy to be within the exposure tolerance of a camera sensor. T-stops start with the F-stop calculation and additionally include any customization or modifications done to cine-style lenses. This includes using coated or uncoated elements, modification to the internal design, customized iris, internal filtering, lens adapters, or expanders that are to be used with the lens. T-stops are a carryover from the earliest parts of the film era, while the usage of the term F-stop became more popular with the advent of portable light meters in the early 1950s and internal metering in still cameras in the early 1960s.

Should I be using shims on my PL Mount lens?

We recommend any repairs or modifications be done by a qualified lens technician. He or she will be able to tell you if your lens needs to be modified with shims to maintain focusing accuracy or if it is a de-lamination of elements, internal damage, or even fungus interfering with the quality or limiting the functionally of your lens. It should be noted that a simple back focus adjustment will solve many issues where shims would normally be installed. This will save you time and money.

Does B4 to PL connection cause light loss?

Yes, any time you add additional glass elements in the image pathway, those adapters will diminish the light transmission characteristics of your lens. Typically, there will be between 2 and 2½ stops less light with any lens expander, just the same as when you use the telephoto setting on your lens to increase your focal length.

Is there a conversion factor to determine my field of view if I put a B4 lens on my Super 35 camera via an adapter?

There should not be. Most B4 to PL mount adapters are designed to expand the image from the standard 2/3” broadcast CCDs to the larger Super 35/APS-C sensor size without additional magnification.

Is there stabilization on cinema lenses?

Cinema lenses do not traditionally have any stabilization properties built into them. Image stabilization in lenses was developed to enhance the capabilities needed by still photographers when operating at lower light levels. Utilizing a moving lens element electronically compensates for minor camera movement or shake while shooting static subjects. Internal optical lens stabilization does not dampen camera movement in the same manner as a gimbal-mounted camera would. Cinematographers using internal lens or camera image stabilization risk degrading the image quality of video content if not used sparingly on a shot-by-shot basis.

Why does the 2x extender on my broadcast lens reduce the light by 2 stops when I go to 2x?

Any time you add additional glass elements in the image pathway, those adapters will diminish the light transmission characteristics of your lens. Remember that F-stops are determined by dividing the focal length of your lens by the diameter of the aperture opening. Adding a teleconverter to your lens reduces the amount of light hitting the sensor by the factor of magnification, so a 2x conversion will reduce the light falling on the sensor by two stops.

Why is it difficult to put different format lenses on various cameras?

There are a number of factors to consider here. Lenses today can be limited by a camera manufacturer’s proprietary auto focusing and stabilization technologies if they weren’t designed to interconnect with tools outside that manufacturer’s eco-system The simpler the lens design, the easier it is to translate to different camera systems. The best example is the PL Mount; it is used across the widest variety of camera systems, and while it was originally designed for ARRI 16mm and 35mm film cameras, it is now used universally across cine-style digital cameras.

What is the difference between Super 35 and Full Frame relative to angle of view?

A typical S35 camera sensor is roughly 24mm x 13mm while the standard size for Full Frame cameras is considered to be 36mm x 24mm. That makes the crop factor .8x when using the same focal length lens on a larger camera sensor. This is roughly the same size differential for digital still cameras when switching between APS-C and Full Frame camera sensors.

Will Fujinon ever make MK Lenses for EF or PL mount cameras?

We see your comments, messages and forum discussions asking for EF-mount or PL-mount MK lenses, and we hear you. The reason this is not a possibility with the current product is because MK lenses are designed for cameras with a short flange distance, so while you could design a mount adapter to physically mount it, it won’t focus to the sensor. MK lenses are designed for mirrorless cameras. That’s why they can make them small and light. If they worked on EF or PL, they would be a totally differently design—bigger and heavier, like the PL-mount Cabrios.