Lytro LYTRO ILLUM | SHOOTING REPORT
With the "light field technology," the LYTRO ILLUM changes focus, depth of field, and depth of field even after shooting. And, it has become easier to get the camera in Japan. I can imagine many photographers are raising their eyebrows at this revolutionary feature and I couldn't understand how it is possible. Anyway, seeing is believing. I will show sample shots first and explain the mechanism later.
( Photo / Text : 4beats )
- INSTRUCTIONS -
- When the data is downloaded, it will play a movie of shifting focus and perspective.
- When it finished playing, move the pointer on the image. And, you can see the perspective shifting.
You will notice the shifting better if you pay attention to how the subjects in front and back overlap. This perspective shift mode continues until you click again. - Click on the point where you want to focus. You will notice the focus shifts every time you click.
- If you want to shift perspective again, drag the pointer until the perspective starts shifting.
Once it does, you can unclick and the perspective shift mode continues until you reclick. - If things don't work well, click the play button or the reload button on the bottom center to reload the image.
With the dedicated software, you can write regular image files. Of course, you can also adjust parameters such as brightness or color temperature just like ordinary developing software.
I'm still new to this camera, but I'll do my best to explain the mechanism.
There is a layer in front of the CMOS sensor. The layer is called micro lens alley and special micro lenses are arranged on the layer. The micro lenses can detect the direction of travelling light. The size of a micro lens allay is about some pixels on the sensor. And this micro lens allay:
- allows each pixel to detect the direction of light
- groups pixels on the sensors by each micro lens.
This mechanism is analogous to a pinhole camera. Imagine a large hole on a thin wall. Say, if you're trying to look what is beyond the wall though the hole. If you want to look to the left, you look from the right. And, the reverse is also true. This means eye position changes the direction of vision. Now, what if you use a sensor instead of an eyeball? Or, what if you use a pinhole digital camera? Here, each pixel has own direction of vision. The LYTRO ILLUM realized this mechanism with the combination of the micro lens alley and the sensors grouped by the micro lenses.
Let me put it another way. Think about a stereo camera. Because it has two lenses with a separate image sensor (or film frame) for each lens, it has parallax (difference in viewpoint between right and left eyes when viewed with one eye). If you imagine many stereo cameras or many lenses and sensors lined up and down or sideways, you can better understand the structure of the LYTRO ILLUM. The parallax of a stereo camera expands sideways, but the LYTRO ILLUM expands up and down, too. And, this is why it can change perspective.
Now, why can it change focus afterwards? When something is focused, the light received from the subject is captured as a point on the sensor. Conversely, when something is defocused, it's not captured as a point but as a surface on the sensor. Normally, it was impossible to reproduce a point from a surface after shooting. Why? Look at the sample shot above. The lights from the coffee cup in the front and the dish in the back are defocused and create a surface together. Originally, the lights are coming from different directions. But, once they overlapped, there's no way to distinguish their direction of light afterwards. Also, there's no way to reproduce the thickness of the coffee cup or the pattern on the dish once they were shot defocused. Now, what about the LYTRO? Even though the light is defocused and surfaced, it knows the directions of the lights coming to and it can discriminate the bokeh of the coffee cup and the fish. And, it does calculations to gather the lights coming from the same direction into a point.
I hope you got it...
Aperture: top image F2 / bottom image F11
The two images are written from the same original image file using different aperture values. Of course, this was done after shooting. That's right. You can control depth of field after shooting.
This maverick can become a part of the new age
Even though it's a fixed-lens camera, it looks like a mirrorless camera. Operation is done with minimum number of buttons and the touch panel rear LCD screen. You can autofocus and manual focus, and the rear LCD also allows touch focusing on the liveview. Because of the camera's mechanism, the aperture is fixed at wide open and you set exposure by shutter speed and ISO sensitivity. Even though it can focus afterwards, there's a limitation in the depth of field. So, it may require some practice to check the focus indicator while looking at the actual image and decide where to focus. Maybe, it will be faster if you follow the old rule (focus a little toward foreground from the center of the focused range) and play the image to check.
Because of the nature of mechanism, it has smaller number of pixels and it can't be helped. But, if the sensor technology advances and the demand for light field technology grows, the number of pixels will increase. The theory was existent since quite long time ago, but the camera was only recently produced and it still appears to be quite a maverick. But, remember the dawning of digital cameras. They used floppy disks and their maximum output size was at the level of analogue televisions. So, there's a high possibility that this camera becomes a part of the new age. 20 years from now, this camera may become a legend and I want to be one of the people who had enjoyed the process.
( 2014.12.10 )