Join Brian Bradley for an in-depth discussion in this video Overview of the Physical Camera controls, part of V-Ray 3.0 for 3ds Max Essential Training.
- In this video we're going to take a look at just a few of the many controls that are available on 3ds Max's new Physical Camera object. With the camera selected then let's come over to the modify tab in the command panel and take a look in the Physical Camera roll-out where we find plenty of options that can help us control sensor, lens, and shutter operations. Now, by default the sensor in our virtual camera will behave as per a full frame DSLR camera. Full frame being a term that describes a camera using a sensor size that is equivalent to a 35mm negative, so 36mm x 24mm.
Typically, in film photography and cinematography images taken using a bigger negative tend to produce better quality images than those generated from smaller negatives, and the same can also be said of cameras that use full frame digital sensors. In general, pictures taken on these are sharper, they pull out more fine detail in a shot, they tend to have smoother tones, and the wider range of tones they produce can help bring a greater sense of depth to an image. Now does the same hold true when we render with the full frame sensor option chosen on our 3ds Max Physical Camera? Do we get a better final image from it? Well in terms of finished image quality the answer unfortunately is no.
Image quality will still be controlled by the sampling settings that we chose in the various V-Ray tools that use them. What this option will have a big effect on however is both the framing and composition of our shots. You see, with the full frame option chosen the lens settings that we work with will be as specified. In other words, if we chose a 55mm lens then the framing, perspective, and compostion that we get from it will be that of a 55mm lens, which if you are somewhat unfamiliar with photography may seem like a bit of a silly statement.
The simple truth though is that the focal length measurements used on lenses are based on the 35mm standard. If we use a crop frame, or crop sensor camera though the sensor is actually cropping out the edges of the frame effectively increasing the focal length of our lens. The amount of difference in the field of your focal lens when using a crop sensor is measured by its multiplier. The reason and the need for us to be careful when making the choice of just which sensor or film size we're going to be rendering with, especially so if we're going to have to match our renders to already existing footage or lens focal lengths.
As focal length is the parameter on a camera that ultimately controls both the framing and feel of any shots that we take, we do need to understand that higher values, such as 125mm, put us in telephoto territory, with perspective in a shot becoming much flatter and distances between objects becoming that much harder to gauge correctly. Whereas going to lower focal lens of course, so values around 25mm or so, give us a wide angle effect with the camera's field of view now becoming much wider and so able to take in or capture a much broader view of the environment.
To add a photographic field to our work then we would want to use, as much as possible, focal lens that match those most commonly used by real world photographers and cinematographers. An alternative to using the focal length measurement would be to make the switch and instead frame our shots using the field of view, or FOV parameter, an option measured in degrees of rotation. These degrees essentially describe the angle being used to determine our frame, the left and right sides of an image.
Imagine your nose is the point of a triangle, the left side of the triangle is the left edge of your view and the right side is the right edge. The horizontal angle of view, a term completely interchangeable with field of view, is simply the angle of those edges as measured against a level horizon line. We also have here this very handy zoom control that can be used to give us a very quick zoom offset in our renders. And to use this we do need to be calcualting our framing using the focal length parameter.
If I go ahead then and punch in a zoom offset of two you can instantly see the effect we get in the view port. Now the brilliant thing here is that altering the zoom in this manner doesn't change any exposure levels or depth of field effects that may already be set up. One option here that we may not be too familiar with is the lens breathing control. Breathing, or lens breathing is a term used to refer to a sometimes seen phenomenon of a shift in the angle of view of a lens whenever its point of focus is changed.
This can tend to make focus adjustments in a series of shots a little bit undesirable as it does noticeably alter the compostion of framing of the image. This physically accurate behavior is modeled into our new camera and is enabled by default. If we would prefer to work with this disabled however all we have to do is set the lens breathing parameter to zero. Another nice set of controls here are the options available for setting the shutter type. These essentially give us the ability to chose the unit that we use to measure shutter behavior which ultimately of course will affect the way in which we calculate any motion blurring the scene.
The default of frames is of course a typically used shutter measurement in computer graphics, and if you have been a Mental Ray user, may well be an option that you are used to working with. Seconds, and even fractions of a second are more typically associated with stealth photography and so if that is a part of our skill set these may be options that we are more comfortable working with. Finally we have degrees, which are typically used in motion picture photography due to the circular nature of the shutters used in motion picture cameras.
Now of course, one of the big reasons for using a Physical Camera model in any rendering set up is to more accurately mimic the way in which the brightness of an image is calculated during the photographic process. In our next video then we will begin to take a look at how the exposure process is handled on the Physical Camera starting first of all with a very important primer on exposure values.
- Using the new UI elements, Quick Settings, and revamped Frame Buffer
- Understanding color mapping modes
- Adding V-Ray light types
- Working with the V-Ray Sun and Sky systems and dome light
- Using irradiance mapping and light cache
- Working with diffuse color maps
- Making reflective materials
- Creating a translucency effect
- Using the new SSS and skin shaders
- Ensuring quality with image sampling
- Working with the adaptive subdivision engine
- Controlling the physical camera
- Working with FX tools such as VRayFur and VRayMetaball
- Stereoscopic 3D rendering
- Using Render Mask