Mastering The Art Of Focusing Your Red Camera

Focusing a RED camera is a complex process that requires an understanding of the camera's system and the lens's technical specifications. The RED camera's autofocus feature is not a replacement for the skill and expertise of a camera assistant. The autofocus feature works through a complex computational calculation that depends on the camera's system and the lens exchanging information. The RED camera has two autofocus modes: knowing and guessing. In the knowing mode, the camera can make accurate corrections as it knows which lens motor position corresponds to a given distance. In the guessing mode, the autofocus hunts more, adjusting the servo until the image is in focus.

Using the RED Focus operation guide

The REDFOCUS Operation Guide provides instructions on how to set up and use the REDFOCUS to properly adjust the camera sensor for optimal image quality.

Compatibility

The RED Focus is compatible with the following cameras equipped with a PL mount:

• WEAPON
• SCARLET-W
• EPIC
• SCARLET
• REDONE

It is important to note that REDFOCUS is not compatible with the REDMOTIONMOUNT.

Autofocus

The RED camera has autofocus capabilities, but it is not a perfect system and may require some manual adjustments. The autofocus feature works by detecting the edges with the highest contrast in the scene and highlighting them in a bright colour, usually red.

Manual Focus

When using manual focus, the RED camera will allow you to adjust the size and position of the AF point. The AF mode can be set to either full-time Continuous or Single shot. In Single shot mode, the camera will focus on the selected point and then stop focusing.

Focus Pulls

The RED camera also allows for nice focus pulls, where the AF doesn't snap on but slows down as it nears the focus point, creating a more natural-looking focus pull.

Limitations

While the RED camera's autofocus system is useful, it may not be as precise as those found in other camera systems, such as Canon Dual Pixel AF or Sony's hybrid systems. Additionally, the speed of the AF cannot be adjusted, and it may occasionally miss the focus point or struggle to refocus when you try to change the subject.

The RED Focus operation guide provides essential instructions for setting up and using the REDFOCUS feature on compatible RED cameras. While the autofocus system has its limitations, it can still be a useful tool, especially for those new to autofocus or those working in a cinematic context where reshoots are more feasible.

Adjusting the camera sensor for optimal image quality

Sensor Calibration

Also known as black shading, sensor calibration is a process that optimizes image quality by ensuring consistent pixel sensitivity across the sensor. Calibration generates a map based on system and environment settings, resulting in a uniform noise profile without falloffs. It's important to calibrate the sensor after significant temperature or exposure time changes or if the CAL: T/E indicator shows issues.

Sensor Size

The size of the camera sensor plays a crucial role in image quality. Larger sensors offer a more extensive light-gathering area, improving low-light performance and dynamic range. The crop factor, which describes the sensor's coverage relative to a reference sensor, also influences image characteristics like depth of field and angle of view. A higher crop factor can provide more reach but may require a longer focal length or increased distance from the subject.

Camera Settings

Certain camera settings can significantly impact image quality. Shooting in RAW format provides greater flexibility in post-processing. Using Lossless Compressed RAW, if available, reduces file size without compromising quality. Disabling noise reduction features like Active D-Lighting, HDR, and lens corrections is recommended when shooting in RAW as they don't improve image quality. Adjusting the ISO is crucial—lower ISO values generally produce cleaner images with less noise, but higher ISO may be necessary in low-light conditions to maintain adequate shutter speeds.

Understanding the autofocus system

RED cameras are mostly used in high-end film productions, but the company has recently expanded its market to include lower-budget documentary and indie filmmakers. The RED KOMODO 6K camera, for example, is expected to cost around $5,000. This camera is RED's first to have autofocus, a feature that is untested for the brand.

RED recommends using autofocus modes only as focus-assist tools. Autofocus modes are available in the Mode drop-down menu when a lens mount and lens are attached. However, performance may vary from lens to lens, and for optimal focus accuracy, RED recommends using manual focus.

There are four autofocus modes available: Single, Continuous, Touch Track, and Rack. Single mode is optimised for rapid focus even in low-contrast conditions, while Continuous mode attempts to keep objects in the target in focus and works best with good lighting and contrast. Touch Track dynamically updates a positionable AF point using the touchscreen, and Rack enables rack focus.

Phase detection autofocus (PDAF) is a focusing assist tool that works by splitting light into two different angles. When the operator triggers autofocus, the motor aligns those two angles to the same position, and as a result, the image is in phase (in focus). PDAF is generally better, faster, and more accurate for video than another form of autofocus called contrast detection, which can be found on Panasonic cameras. However, contrast detection can focus on any part of the image, not just where the focusing points exist on the sensor.

RED's autofocus system is not meant to be a replacement for the skill and instinct of a camera assistant.

Using focus peaking

Focus Peaking is a manual focus assistant found in all of today's mirrorless cameras. It can speed up your manual focusing and help you focus more accurately, but it can also be a nuisance if used at the wrong time.

Focus Peaking works by outlining the edges that are in focus. The camera looks for "sharp" edges by analyzing contrast. When there is a hard edge, which will only happen when something is in focus, there will be high contrast. When the camera sees enough contrast, it will overlay a colour on top of the edge.

The stronger the contrast, the bolder the lines are going to be. You will slowly refine the manual focus until the lines are boldest over your subject.

Cameras typically offer a selection of colours for you to choose from, such as red, blue, white, green, and yellow. You can also set a peaking sensitivity, with most cameras offering two levels: High and Low. Low gives you absolute precision, only highlighting the sharpest areas of the photo. High will highlight more and show more "in-focus" areas.

Focus Peaking is particularly useful when you want to get rapid focus at moderate to deep depths of field, when there are a lot of fine details, to quickly find Hyperfocal Distance without using a focus magnification on the horizon, and in low light when your eyes can't make out the edge contrast on their own.

However, you should turn it off when you have an extremely shallow depth of field where you need absolute precision, as the highlights can obscure too much. You should also turn it off when it distracts from your composition.

To set up Focus Peaking, consider the following:

• How will you enable/disable Focus Peaking? It's beneficial to be able to do this with just a couple of easy button pushes, such as programming a button to quickly change Manual Focus Assist modes/Focus Peaking or programming it into some kind of Quick Menu.
• Which colours should you use for Focus Peaking? While this isn't a one-size-fits-all solution, you'll probably find at least one colour that works for most things. Red tends to offer the best contrast and is the easiest to see in most situations.
• Which Peaking Sensitivity Should You Choose? As mentioned above, the sensitivity determines how much is highlighted.

Finally, Focus Peaking does take some practice to become proficient at it, so experiment with different colours and sensitivity levels to find what works best for you.

Working with cinema lenses

Cinema lenses are designed specifically for motion picture production, offering superior image quality and precise control over focus and depth of field. They are an essential tool for filmmakers and video producers, providing calibrated focus and iris rings, consistent T-stop ratings, and a wide range of focal lengths. When working with cinema lenses, there are several key aspects to consider:

Understanding Cinema Lens Characteristics:

Cinema lenses differ from regular camera lenses in their construction and features. They typically have a longer focus throw, allowing for more precise focusing. They also feature a de-clicked aperture, enabling smoother transitions between different aperture settings. Additionally, cinema lenses are usually more robust and heavier, reducing camera shake and resulting in smoother shots.

Selecting the Right Cinema Lenses:

When choosing cinema lenses, it's important to consider factors such as image quality, build quality, colour reproduction, and compatibility with your camera system. Some popular options include the Irix Cinema lenses, which offer sharp images, excellent build quality, and accurate colour reproduction. The Zeiss CP.3 line is another well-regarded option, known for its exceptional optics and ergonomics. Other alternatives include the Fujinon 18-55mm cine zoom lens and the Sigma 18-35mm f/1.8 zoom lens.

Adapting Lenses to RED Cameras:

RED cameras are designed with modularity in mind, accommodating most camera lenses through interchangeable lens mounts. When working with RED cameras, ensure that you have the correct lens mount for the lenses you plan to use. Additionally, RED provides standard Canon RF-EF adapters and Canon RF-EF "speedbooster" adapters that can be used with various lenses, although some lenses may exhibit sharpness and chromatic aberration issues with the "speedbooster" adapter.

Lens Maintenance and Accessories:

To ensure optimal performance and longevity of your cinema lenses, proper maintenance is essential. This may include tasks such as cleaning, calibration, and storage. Additionally, there are various lens accessories available, such as lens filters, lens hoods, and lens support systems, that can enhance your cinematography experience and improve your image quality.

Practising with Cinema Lenses:

Familiarise yourself with the unique characteristics of cinema lenses by practising focusing, zooming, and aperture adjustments. Experiment with different focal lengths and shooting scenarios to develop a feel for the lenses and improve your technical skills. Practising with cinema lenses will help you master the art of cinematography and achieve the desired visual outcomes for your projects.

Frequently asked questions