Ultracker Aleta S2C is a 360 camera that can capture 12K (66-megapixel) 360 photos and shoot 360 video in 4K. With one of the highest photo resolutions on the market, it is emerging as the virtual tour camera of choice, and it is now available in the US. I’ve been using Aleta S2C since August 2018 and here are is a detailed hands-on review, with full-resolution sample photos. June 13, 2019 update: major firmware update adds 7 new features
Table of Contents:
Summary and Review
Specifications and features (updated June 13, 2019)
– Street View compatibility
– Time lapse mode
How to shoot and stitch on Aleta
– WDR sample photos
– HDR sample photo (firmware 1.03.37)
– Firmware 1.04
How to update the firmware
Summary; Price and availability
June 13, 2019 update: major firmware update adds 7 new features
December 28, 2018 update: Street View compatibility + improved stitching.
October 31, 2018 update: new samples with improved stitching
August 31, 2018 update: availability, how to shoot, new samples.
June 18, 2018: New sample photos from prototype.
May 15, 2018: features updated, price and availability updated
Executive Summary and Review, Tutorial, Comparisons, and Sample
Here is a review, tutorial and comparison of the Ultracker Aleta S2C.
There are many 360 cameras on the market, and they’re leapfrogging each other with video resolution. But most 360 cameras have a photo resolution of only around 16mp and very few have a resolution higher than 32mp. Seeking to fill the need for high resolution photo, Ultracker’s Aleta S2 is a new 360 camera that captures 12K (66 megapixel) 360 photos. There will be two versions of the Aleta S2: S2C (Light) and S2 Pro (Professional), which differ in video quality. The S2C is now available, while the S2 Pro is still being developed.
Here is a product video:
June 2019 update
Aleta S2C has undergone many changes, most recently in June 2019 with firmware 1.06 and app 1.02, which added 7 new features:
1. revamped UI: the UI has been revamped with new animated exposure settings (see below)
2. improved auto white balance
3. intelligent auto HDR: the Aleta can now automatically choose the number of exposures and exposure interval to optimize the dynamic range of the HDR photo (see below).
4. HDR deghosting: automatically remove ghosting or doubled images from subjects that move during the HDR photo (see below).
5. object removal: automatically removes the photographer or moving objects from the photo (see below)
6. hot pixel mapping (“defective pixel removal”): automatically maps out hot or dead pixels for long exposures, e.g. astrophotography (see below)
7. long exposure bracketing: the auto exposure bracketing mode can now use long exposures for low light conditions.
Ultracker also offered a new discount code for 360 Rumors readers.
Ultracker Aleta S2 and S2C Specifications and Features
Here are their specfications. Note: Aleta S2 and S2C specifications are the same, except for the video framerate at 4K.
|five 2.6mm fisheye lenses (four horizontal + 1 zenith)
|Field of view
|five 14mp CMOS sensors
|11520 x 5760 (66mp)
|3840 x 1920 @ 30fps (S2 model)
3840 x 1920 @ 10fps (S2C model)
3072 x 1536 @ 24fps
1920 x 960 @ 30fps
|7680 x 3840 @ 2fps
5760 x 2880 @ 3fps
|HDMI, Wi-Fi, RTMP, RTSP
|Line in, Microphone input
|9-axis IMU (gyroscope, accelerometer, e-compass)
|Wi-Fi 802.11 b/g/n
|18650 Li-ion battery (2600 mAh) x 2
|-10C to 40C (14F to 104F)
|0 to 90%
|103mm diameter x 158mm height
One of the key features of Ultracker is its in-camera optical flow stitching. For users who prefer to stitch with their own software, it is also possible to save the photo as five unstitched photos.
Aleta also features WDR, an HDR mode that blends and stitches two exposures automatically, and HDR mode (which is actually an exposure bracketing mode). The in-camera stitching and HDR mode will be particularly useful and convenient for virtual tour photographers.
Intelligent HDR exposure setting (added June 12, 2019)
With Firmware 1.06 or higher, the Aleta can analyze the dynamic range of the scene and automatically choose the number of shots (3, 5, or 7 shots) and exposure intervals (from 0.5EV to 2.5EV) to maximize dynamic range.
HDR deghosting (added June 12, 2019)
Firmware 1.06 added a new feature to automatically remove ghosting in HDR images. Ghosting occurs in HDR when an object moves in between the multiple exposures of an HDR photo. With this feature, the ghosting effect can automatically be corrected.
Street View compatibility
As of firmware 1.03.37, the Google Street View app can now control the Aleta S2C and wirelessly import its photos with GPS metadata. The only current limitation is that in HDR mode, Street View keeps crashing. Hopefully, Ultracker will fix this issue. Firmware 1.03.37 also improved the stitching quality (see below).
Time lapse mode
In addition to photos, Aleta S2C also has a time lapse mode. Here is a sample shot by Ultracker:
Object removal (added June 12, 2019)
Firmware 1.06 and app 1.2 added a new object removal feature, which removes any moving subjects in the photo. This can be used to remove the user from the photo automatically. The user simply has to keep moving while the photo is being taken in Object Removal mode. This feature appears as a new exposure mode (you’ll need to swipe to see it). Here is a demo.
Hot pixel mapping (added June 12, 2019)
One of the new features in firmware 1.06 is the option for hot pixel mapping (“remove defective pixel”). This feature can help improve image quality for long exposures, especially for astrophotography, by mapping out hot pixels.
How to shoot and stitch with Aleta S2C (updated April 26, 2019)
Shooting with the Aleta is easy. You can either shoot with the on-camera controls, or the app. The on-camera control is limited to a shutter (although it can use a self-timer). Startup takes a while on the prototype (around 30 seconds, including the time to read the Micro SD card). However, there is a standby mode that can allow it to resume shooting in a couple of seconds.
To change settings, you need to use the app. You can download the app on the iTunes app store or Google Play Store. Once the app is installed, you can connect the camera to the app using your phone’s Wi-Fi. The password will be shown on the LCD display of the camera. By default, it is 88888888 (eight 8’s). I recommend turning on the camera (waiting for it to complete its startup), launching the app and then tapping on the app’s Wi-Fi icon on the upper right side. In most cases, the app will connect to the camera automatically. In my experience, this connection method is more reliable than using the phone’s Wi-Fi settings to connect to the camera.
Aleta S2 stitches photos automatically in-camera, in 360 equirectangular format, saved into the Micro SD card. You don’t need to do anything. However, it also has the option to save a photo as five unstitched photos, for stitching with 3rd party stitching software (this is called “Raw mode” even though the photos are JPG not Raw).
Aleta S2C has noticeable fan noise and the battery life seems quite short. On the other hand, it uses inexpensive Type 18650 batteries which are readily available for low cost at many electronics stores.
The Aleta S2C’s standard photo mode has limited dynamic range and excessively high contrast, but it has three waysto increase dynamic range: WDR mode, HDR mode, and auto exposure bracketing. WDR mode can be used for both photos and videos. The user can adjust the intensity of the WDR effect. From the app’s main screen, tap on the three dots on the bottom left corner, tap on the WDR icon, and adjust the slider. You’ll be able to preview the effect in realtime. WDR will not result in ghosting and can be used for day or night photos.
HDR mode is a true in-camera HDR mode for photos. It can take 3, 5, or 7 shots and fuse them in-camera. To use this feature, switch to photo mode on the left side of the screen and choose Day or Night (it doesn’t work for Sports or Manual), then make sure HDR is selected. To adjust the settings, tap on the three dots on the bottom left corner and tap on the gear icon to bring up the Settings. In the Settings screen, scroll down and tap HDR Mode. There are three presets, and a manual option:
Weak: 3 shots, 1.5EV exposure intervals, HDR effect 60
Medium: 5 shots, 1EV exposure intervals, HDR effect 80
Strong: 7 shots, 1EV exposure intervals, HDR effect 60
Manual: user selects number of shots, the exposure interval, and the intensity of the HDR effect.
Finally, auto exposure bracket takes a bracket of 3, 5, or 7 shots, with constant ISO and of course aperture. Each exposure is stitched identically to the other two exposures, making it easy to fuse them in an HDR program such as Photomatix. See below for samples. To use AEB mode, tap on the exposure mode and tap on the right arrow to bring up additional exposure modes, one of which is AEB Org mode.
To change the settings on AEB mode, tap on the 3 dots on the bottom left, tap on the gear icon to bring up the settings screen, and scroll down and tap on AEB mode. The settings for AEB are similar to those of HDR mode except there are no presets.
Aleta S2C retains the most recent settings for exposure mode and self-timer. For example, you can set the self-timer to 10 seconds, and the exposure mode to HDR, and Aleta S2C will retain those settings even if it is powered off. It is therefore possible to shoot a virtual tour without using your phone, although I recommend using a phone to check your composition.
Aleta S2C Sample Photos and Photo Quality (updated January 11, 2019)
Aleta S2C’s strength is its excellent detail, which is made possible because each of its five lenses uses the full sensor, unlike most 360 cameras that fit a circular fisheye into rectangular or square sensor, and thus are unable to use a significant portion of the sensor. By using the full sensor, the Aleta maximizes the detail from each of its sensors.
Although Aleta S2C has a fifth lens that faces the zenith, its stitching is on the whole less smooth than some professional 360 cameras such as the Insta360 Pro. This is because each component image from the Aleta S2C has very little overlap with the other images, and therefore it is much more difficult to get smooth stitching. However, Ultracker has been working hard on improving its stitching with every update. The latest update (Firmware 1.04 released January 11, 2019) improves the stitching noticeably, as seen below.
Another issue with Aleta S2C is that its slowest shutter speed is not very slow (up to 4 seconds, as of firmware 1.03.37), which forces it to use higher ISOs in low light. This is partly mitigated by a night WDR mode (see below), which can increase the dynamic range of high ISO shots. However, a future update will extend the shutter speed limit significantly.
Aleta can also be vulnerable to flare under some circumstances, and there is some visible chromatic aberration.
WDR Sample Photos
In August 2018, Ultracker added a WDR (wide dynamic range) mode. Although WDR and HDR both increase the dynamic range, WDR is different from HDR in that WDR uses only a single photo, whereas HDR uses multiple exposures. WDR takes two exposures and fuses them into a single photo. Here is a cropped photo showing the dramatic difference with and without WDR:
There is also a separate Night WDR mode for low light:
Although the WDR mode does increase the dynamic range significantly, the result appears to too artificial in my opinion. Rather, to get the best quality from the Aleta S2C, it is necessary to use the HDR mode (see below).
Aleta S2C AEB mode (formerly HDR mode)
Aleta S2C’s HDR mode is actually an exposure bracketing mode. It takes three exposures at -2EV, 0EV and +3EV. The three exposures are stitched identically and saved into one folder.
Stitching in small spaces is generally more challenging for many 360 cameras.
The stitching in the nadir has been improved. Until now, there had been a tendency for the nadir to appear distorted. The new firmware corrects the distortion:
Note that the toilet bowl in the issue has a slight stitching error, but that is because it was closer to the camera than the minimum stitching distance of around 3 feet.
I also noticed the LED banding is gone, but I don’t know if it just so happened to be the right shutter speed to avoid banding, or if there was some other change that somehow avoids LED banding altogether:
How to update the firmware
Updating the firmware on the Aleta S2C is simple.
- First ensure that the battery is charged, or use the AC adapter to plug the Aleta S2C to a power outlet.
- Copy the firmware zip file to the root directory of a Micro SD card. Do not unzip the file, and ensure that there are no other zip files in the Micro SD card.
- Insert the Micro SD into the Aleta S2C and power it on. After the startup sequence wait around 15 seconds. You’ll see that the LED display will turn upside down and state, “Firmware updating.” Allow the firmware to finish updating. The camera will reboot automatically.
SUMMARY; PRICE and AVAILABILITY (updated: January 11, 2019)
Ultracker Aleta S2C has excellent resolution and detail. When used in exposure bracketing mode (“HDR” mode) with a good third party HDR software, Aleta S2C can produce very good images that are better than any other 360 camera for $1200 or less, as of December 2018. Indeed, I found it has more detail than even the Insta360 Pro or Insta360 Pro 2 (see this virtual tour camera buying guide and comparison). At the same time, Aleta has a very fast workflow thanks to its in-camera stitching. Its bracketed “HDR” photos can also be easily batch processed in Photomatix HDR.
The Aleta S2C does have several downsides to be aware of. Its stitching is seldom perfect, and you can often see some warping somewhere in the photo. You also need to mindful of its minimum stitching distance, which is around 3 feet. There is also noticeable chromatic aberration and flare. White balance is usually inaccurate, and unfortunately it doesn’t have a true Raw DNG mode. Finally, it is not very good for low light due to the limited shutter speed (4 secs.).
In summary, I would recommend Aleta S2C for photographers who want to be able to take high resolution photos quickly, and are either able to tolerate some imperfections in stitching, or are willing to repair those imperfections in post processing. The standard photo mode has very limited dynamic range and the WDR mode has unnatural tone mapping therefore good third-party HDR software is practically a necessity for the Aleta. The HDR software I’ve been using is Photomatix Pro, which is available for 15% discount using this link and the discount code 360rumors.
Where to buy; Discount
As of January 2019, the price of the Aleta S2C is around $1210 on Amazon with Free Prime shipping. However, for a limited time, you can get a 20% discount using the code VWSSRELS . Thank you very much for supporting 360 Rumors at no additional cost to you so I can do more tests and reviews. Ultracker’s official website is here.