The camera object as some awesome settings to get just the right angle, focal length and depth of field, adding that nice blur and bokeh that everybody loves in photos. Today I wanted to focus on some ideas around the camera.
In an earlier article, we tackled the movement of the camera and viewport navigation. In this article, we continue with corresponding real world camera settings and continue with some special cases.
Here is the table of content if you will:
- Camera settings
- Viewport display helpers
- Isometric camera setup
- Turntable camera
- 360 degree camera
- Fisheye Lens
Blender camera settings
Blenders camera object is not that different from a regular camera. Since our built in render engines, Eevee and Cycles aim at physically correctness it is not very shocking that the camera should mimic the real world.
While the more camera specific settings live within the camera object, settings related to output lives within the render settings.
Here we can set the resolution and the aspect ratio. Leave the aspect ratio set to one and adjust the resolution for your needs. We can change the percentage value to render a smaller or larger version of the same view. This is useful primarily for creating preview renders quicker.
With resolution and aspect ratio out of the way, select the camera and move over to the object data tab for a quick rundown. We will look at the most useful settings and then dive into some special cases further down.
We will start with the first section called lens. Here we can set the type of camera we want. Perspective is your typical camera you have everywhere, from your webcam, to mobile phone and to your most high-end film camera.
The next type is orthographic. This type eliminates all perspective and lens distortion. We can use this head-on view for more technical applications. For instance, rendering a blueprint, or an isometric view that is common when making certain kinds of low poly art.
The third option is for extreme lens distortion instead. It’s called panoramic. This is for emulating a fisheye lens or a 360 degree camera. A common use case is VR.
We use the perspective type in most cases, so let’s stick with that for now.
Next is focal length. This is your typical camera zoom. For a DSLR camera, your typical kit lens would be something like 18-55mm zoom. If we know little about real world cameras, this may not make very much sense to us. How much zoom this really is depends on the size of the camera sensor. We can set the sensor size under the camera section. Sensor fit should be horizontal if you are trying to match a real world camera. Height will gray out and width will be the value to change to match a real world camera.
Two common terms in the DSLR world are a full frame sensor or a crop sensor. A crop is somewhere around 23mm and a full frame is around 35mm. But for your smartphone, the sensor could be somewhere along the line of 4.5mm. The focal length will have to vary between these sensors for a similar result.
So why do we care? There is a relationship between the sensor size and the focal length. Keep this in mind if you expect a certain look and you can’t get it with the focal length you try with. With a real camera, the sensor size cannot change. All we have to work with is the focal length. But in Blender, we have all the flexibility in the world. Just carving away or gluing on to our sensor with the help of a slider. That is the power of virtual.
In the camera section, we also have a whole range of presets. Click on the lines to the right from where it says camera. There are some common DSLR sizes, some phones and other devices. Keep in mind, those presets that have a fixed lens will not only adjust your sensor size but also the focal length value.
Let’s leave focal length and sensors for a while and move on to depth of field(DOF). Depth of field is really referring to the aperture of a real world camera but also the focus point.
In this section, we can set an object we will focus on. This could be an empty we can move around. The second option is to set a distance from the camera.
Next, the subsection aperture. F-stop is the standard measure used by photographers when talking about aperture. Aperture refers to how wide the hole is in the lens to let in light. The wider the hole, the smaller the f-stop number and the shallower area will be in focus.
In the real world, an aperture of 1.2 would be a wide open gap. But depending on the scale of your scene, you may have to go to the extreme sometimes to get the DOF you want. Don’t be afraid to try a number like 0.1 just to see how it looks.
One key difference between a real world camera and Blenders camera is that the aperture only controls the DOF and not how much light is coming in through the lens. We have no shutter speed. Shutter speed being the time the hole is open for our shot. Instead, we have light and exposure value to play with. We also don’t have an ISO value on the blender camera.
The last setting we will touch briefly upon before moving on is the clipping settings. We find these settings in the lens section. These settings will dictate where the camera view will start and where it will end. The camera will see nothing outside this range. Just make sure that your scene fits within the clipping start and end values so that nothing gets lost.
Viewport display helpers
We will now jump over to the viewport display section. This section will not give us any changes to the rendered result. Instead, it contains different guides to help us with composition and setting other values.
The size dictates how large the camera will appear in the viewport. The limits and Mist check boxes are more useful. Let’s start with Limits. When depth of field is set to a distance value, limits will show a cross where that distance is and gives us an exact focus location. It will also show the start and end of clipping.
The mist checkbox is a guide to help us tweak the mist pass for the compositor. We can use this to create depth maps or add compositing effects. To enable it, go to the view layer tab. In the passes section, check the mist checkbox. To adjust where the mist starts and end go to the world tab and find the mist section. The start and depth values will dictate the start of the mist and how far it progresses. This is where the mist checkbox comes in handy; we can see the beginning and end of the mist easily.
From this point, it is a matter of post processing to use the mist pass. Let’s move on to the composition guides subsection. When viewing through the camera, these check boxes will draw different lines across the camera view. This can help to frame our shot according to common composition rules, like the rule of thirds or the golden ratio. It can also help us find the middle of our shot easily.
Next we have the passepartout subsection. This controls the opacity outside the bounds of the camera while viewing through it.
Now we have some understanding of what settings we can tweak and control through the camera object itself. Let’s continue to some different camera setups useful for different projects.
Isometric camera setup
An isometric camera is orthographic and has a specific angle viewing down on the subject from top right in most cases. Giving an overview shot, usually of a small low poly world.
In the latest release of Blender 2.80, the isocam add-on is included by default. We will use it to quickly set up the camera.
Enable the add-on from the preferences under the blender menu. Find the add-ons section and type “isocam” it filters in the list as you type. Check the box next to it. Go to the 3D viewport and hit shift+a for the add menu. At the bottom, you will find “create isocam”. The TrueIsocam option should do the job for you. Position it in your scene, all parameters should be setup correctly.
As for the isometric camera setup, there is an add-on for creating turntable cameras in Blender. The name of the add-on is “Turnaround Camera” and bundles with Blender. Enable the add-on in your preferences.
We find the settings for the turnaround camera in the n-panel. Under the view tab. Here you will find shortcuts to the start and end frame values and the scenes camera object. You can set the rotation axis and change some options.
To use the add-on, set your camera to a starting position, select the object or group of objects to rotate around and hit the turnaround button at the top of the settings.
We are halfway there. Play the animation with space or shift+space depending on your settings. You notice that the camera speeds up and slows down as it circles around. This is because by default Blender interprets animation with an ease in/ease out bezier curve. We want a constant rotation and want to set the keyframes interpretation to linear.
To do this, select the empty object that the add-on created called “MCH_Rotation_target” This is the animated object. Open the graph edit and hit “A” to select all keyframes. Press “T” and chose linear. All keyframes now has a linear interpretation, and our camera will rotate at a constant speed.
360 degree camera
Let’s see how we can create 360 degree images or videos using the camera object. This is probably the easiest special case camera to set up. All you have to do is to select your camera and go to the camera object data settings. Then change the camera to panoramic and by default panorama type should be Equirectangular.
With the default settings, you have a 360 degree camera. With this camera you could render video for VR, or possibly your own hdri maps for lighting.
Note that at the time of this writing, the panoramic camera type does not work in Eevee.
Fisheye lens & mimicking a real world camera
If you know a thing or two about photography, you may think a fish-eye lens is configured using the normal perspective camera with a low focal length to distort the image. However, if you try this, you realize that there is no distortion happening. Instead, a fisheye lens is in the panoramic category and therefore also restricted to cycles only for now. Change type to panoramic and then change the panorama type to “Fisheye Equisolid”. Now “Lens” will be the focal length value and together with “field of view” these two settings can create a fisheye lens.
If you tested this out, you probably realize that the perspective type of camera has no distortion. So, if you want to make the blender camera look more like a real camera, you can use a fisheye Equisolid type. This will ensure that there is some distortion, just like a real camera. The lens value can only have values between 0,01 and 15.0 if you use the slider. But you can type in numbers up to 100.
Focal lengths of up to 100 is probably enough since the greater the focal length the smaller the distortion of the image, so for any higher focal length values you probably won’t notice the distortion anyway and are better off with a perspective camera.
If you have read all this way, you now have a good understanding of what the camera object in Blender is capable of. We looked at isometric setup, turntable animation, 360 camera, and more. You have also learned some differences from a real world camera. For instance, the lack of distortion in a perspective type camera and that the aperture of Blenders camera does not influence light.
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