RICOH THETA X Development Story ー Image Processing and Electronics l RICOH360 Blog

RICOH THETA X is equipped with a large touch screen. It is aimed for ease of use, but also supports up to approximately 60 megapixels for still images and 5.7K/30fps for video. For the first time, THETA X also offers dynamic stitching and zenith correction when shooting video. And there were many other challenges in developing and designing THETA X.

We interviewed members of the image processing and optoelectronics development team to learn more about the challenges they faced and what they focused on!

THETA X Image Processing and Optical Design

What were your overall aims in the development of THETA X?

Hojo (Development Leader): In order for THETA X to be used by a wide range of customers in business and other situations, we have greatly improved THETA’s ease of use, while also aiming to improve its basic performance as a camera. Also, like THETA V and Z1, THETA X is equipped with an Android-based OS, but we wanted to make it more expandable with plug-ins than ever before.

Daisuke Hojo (Development Leader)

What are the features of the THETA X sensor?

Hojo (Development Leader): THETA X uses a new image sensor with a resolution of 48 megapixels despite its 1/2.0-inch size. Each pixel is further divided into four smaller pixels in a special structure called quad bayer coding, which allows switching between modes that prioritize high resolution and those that prioritize low noise, depending on the scene. This is why THETA X offers two resolution settings, 5.5K and 11K.

THETA X 11K

Photo by Sam Rohn

While 11K offers high resolution, the pixel pitch of the image sensor is narrower, which tends to increase image noise depending on the shooting settings. For this reason, we recommend shooting in HDR mode or NR mode while THETA is fixed on a tripod in order to minimize noise. On the other hand, 5.5K has a wide pixel pitch, allowing shooting in a wide range of scenes, including hand-held shooting and shooting in dark places, in the same way as with previous THETAs. The default setting is 5.5K, but it can be easily switched to 11K on the touch screen.

Yuji Toriumi (Optics):

Besides resolution, are there any other features regarding the optics?

Toriumi (Optics): We have improved chromatic aberration over previous models such as THETA V. There are two types of chromatic aberration: vertical chromatic aberration, which affects focus shift, and horizontal chromatic aberration, which affects magnification shift. With THETA X we’ve managed to suppress both. In particular, vertical chromatic aberration is relatively difficult to eliminate with image processing compared to purple fringing, which tends to occur in THETA V and other models, but we have been able to reduce both types of aberration.

Left：THETA V 、Right：THETA X

The color tones of HDR, often used in real estate, also look more natural with THETA X.

Sensyu (Image Quality): Right. For example, under light sources with low color temperature such as light bulbs, THETA V, Z1, and SC2 were basically tuned to preserve the color tones of the light source.

THETA X 11K HDR

Photo by Sam Rohn

However, many customers who use THETA for business requested that THETA correct the color cast from various light sources. So, we have modified THETA X’s image processing to apply color correction.

Left：Masato Sensyu (Image Quality)

THETA X Video Design

For the first time, THETA X supports “Dynamic Stitching,” a process that joins videos together into a 360° view in real time while shooting. A lot of users tell us that it makes shooting video much easier.

Hojo (Development Leader): THETA X supports 5.7K (5760*2880px) 30FPS and 8K (7680*3840px) 10FPS recording*. For the first time in the THETA series, dynamic stitching and zenith correction are performed during video recording, eliminating the need for manual conversion to 360° video, allowing the user to use the 360° video immediately after it’s shot.

*8K/10fps will be supported by updating to the latest firmware soon.

THETA X 5.7K/30fps

Shot by Sam Rohn

THETA V, SC2, and Z1 differ from X as they require static stitching when done within THETA during video recording.

With static stitching, two images are stitched together at a predetermined distance, regardless of the distance from THETA to the subject, which can cause the same subject to appear twice in the image or missing subjects at the image seam. Dynamic stitching, on the other hand, detects the subject and changes the position of the two images according to the distance between them, producing less noticeable joints.

What made you decide to try Dynamic Stitching for video with THETA X?

Hojo (Development Leader): With conventional THETAs, 360° video requires a conversion process that involves stitching and zenith correction using the THETA app on a smartphone or PC. This time-consuming conversion process was one of the difficulties in handling 360° video, so we took on the challenge of developing dynamic stitching so that more customers can easily capture 360° video in the same way they capture 360° still images.

Were there any challenges in developing this feature?

Yoshida (Video): We started our preliminary studies not knowing if we could technically achieve true dynamic stitching and zenith correction in real time. Dynamic stitching, in particular, is computationally intensive, so existing models were not able to support real-time video, and at first we did not have the technical confidence that we would be able to achieve this. We also had the goal of supporting 4K/60fps video. We reviewed the processing flow and maximized the hardware’s potential to clear each issue one by one, and managed to achieve our goals.

THETA X 11K HDR

Photo by Sam Rohn

THETA X achieves real-time dynamic stitching and zenith correction directly in the unit without the need of any external device, so users can immediately view the video. We hope that many people will give 360° video a shot as well.

THETA X Electrical Design

THETA X is the first in the series with a replaceable battery. Did you encounter any difficulties in design and development?

Okuma (Electrical): Actually, it was more difficult to deal with the mechanism of making THETA X function while powered via USB and the battery removed than with the fact that we had to support battery replacement.

THETA X can be powered by an AC adapter*, allowing it to shoot for extended periods without a battery inserted. Since THETA is primarily designed to have a battery in it, ensuring stable operation even without a battery was a major engineering challenge.

*AC adapter K-AC166J (sold separately)

Center: Takafumi Okuma (Electrical)

Has there ever been a need for THETA to operate with the battery removed?

Okuma (Electrical): Rather than the need to operate THETA X with no battery, we have heard of the need to turn THETA on and off in conjunction with the on-site power supply in business situations.

For example, there are situations where THETA is installed at a site where people are not allowed to enter. In such cases, THETA needs to be operated remotely. Now it’s possible to utilize THETA in such special environments.

Are there any other aspects of THETA X that you were particular about in its design and development?

Okuma (Electrical): One of my joys was that we were able to make THETA X work with a USB HUB. This made it possible to run THETA X for long periods of time while supplying power via USB. It still needs plug-ins for that, but we hope that users also utilize the feature.

THETA X’s battery is the same DB-110 as the RICOH GR series, right?

Okuma (Electrical): To maintain the small size of the THETA X body, we use the same DB-110 battery as the GR series. THETA V and Z1 also use the same battery inside, though it is not replaceable. However, THETA X has a large touch screen, which consumes a lot of power, so we will continue to improve power consumption through firmware updates and other measures.

Expectations for THETA X

Okuma (Electrical): Since THETA X has a touch screen the UI changed dramatically, allowing for improved customizability, including ease of plug-in development. We hope that users will explore various ways to utilize THETA X.

Sensyu(Image Quality): THETA X is easier to use than ever before for shooting still and moving images with improved operability and image quality. Although we had some difficulties in developing it, I think it is a good model in that it is easy to shoot and view images. We hope that many people will try it.

Toriumi (Optics): THETA X is much easier to operate than previous models as there’s no need to use a smartphone with it. So, we hope you enjoy many kinds of shooting with THETA X.

Hojo (Development Leader): Since the release of THETA X, it has often been compared to Z1, mainly in terms of still image quality. But from an engineer’s perspective, X is the evolution of V. We have not only improved the performance of the still and video functions, as I mentioned earlier, but we have also eliminated many frustrations at the same time, such as adding built-in GPS, a replaceable battery, and an SD card slot, as well as many other things that previous THETA models couldn’t do.

Personally I am looking forward to seeing how the touch screen will be appreciated by users and plugin developers, as it has made it very easy to use plug-ins which were rather limited in THETA V and Z1.