Pentax K-S2 Review
Thanks to its built-in Wi-Fi, the Pentax K-S2 can be controlled wirelessly using a smartphone or tablet. Remote image capture, live view, and image downloading is facilitated by the native Ricoh Image Sync app available for Android and iOS.
In addition, the K-S2 has an NFC (Near Field Communications) transmitter that makes it easier to use the Image Sync app if you have an NFC-enabled device. NFC allows you to download Image Sync, obtain the Wi-Fi password, and initiate tethering simply by placing your smartphone/tablet against the side of the camera. You never need to type in a password, select a wireless network, or even open the app, as NFC will take care of it for you. But if your device does not have NFC, you can of course accomplish everything the old-fashioned way without any loss of functionality.
Image Sync Logo
Overall, the K-S2's native wireless functionality is an evolution of the O-FC1 FluCard wireless card that was designed for use with the Pentax K-3, 645Z, and K-S1. The one key difference is that at this time, the K-S2 does not offer an interface for tethering using a PC, but instead uses a native app.
On this page, we evaluate version 1.03 of the Image Sync app (current as of June, 2015). We expect newer versions with fixes and enhancements to be released periodically.
The video below demonstrates the Image Sync app running on Android. It shows most key features but does not go in to as much detail as the text guide that follows.
Walkthrough: Establishing the Connection
Let us begin with a step-by-step guide of how to connect the K-S2 to your device. Fortunately, this process is both easy and intuitive; you hardly even need to look at manual.
1. Turn on the K-S2's wireless
Press and hold the Wi-Fi button on your K-S2 for two seconds to enable its wireless functionality. This can also be done via the third tab of the setup menu. You will hear a beep and see a confirmation message on the LCD screen if using the former.
Note that once the Wi-Fi is enabled, you will see a greyed-out icon in live view and on the status screen. This simply means that the camera is awaiting a connection.
2. Turn on your device's Wi-Fi
Make sure that your smartphone or tablet's Wi-Fi is on. If your device has NFC, be sure to enable it as well.
3. Download and install the Image Sync app
NFC: Hold your device against the side of the camera for a few seconds. The Google Play / App Store should open automatically. Next, simply press the button to download and install the app.
No NFC: Open Google Play or the Apple App Store on your device. Search for "Ricoh Image Sync" and install it.
(This step only needs to be performed the very first time you use the K-S2's wireless)
4. Open Image Sync
NFC: Once again, hold your device against the side of the camera for a few seconds. The app should automatically open.
No NFC: Locate the Image Sync app on your device and open it.
5. Connect to the K-S2's Wi-Fi
Image Sync Default Screen
NFC: Make sure the screen above is shown. If it is not, tap the wireless symbol in the upper-right corner of the app (shown in the following section).
Then, simply hold your device against the side of the camera for a few seconds. The camera will transmit the wireless SSID and password to your device, and the connection will automatically be established.
No NFC: Open the third tab of the setup section of the K-S2's main menu. Select "Wi-Fi" then "Communication Info" to view the wireless password.
K-S2 Setup Menu
Then, in the Image Sync app, press the "choose network" button, connect to the Pentax network, and type in the password. If the screen above is not shown, tap the wireless symbol in the upper-right corner of the app. If you still cannot connect, exit the app, connect to the K-S2's wireless network using your device's native Wi-Fi menu, then re-enter the app. You may need to tap the "start application w/o a connection" button, as this actually tells the app that you manually established the connection.
If all went well, you should now be connected to the camera and you will be able to make full use of its wireless capabilities. In the future, to reconnect to the camera simply repeat steps 4 and 5. For NFC-enabled devices, this essentially entails only two easy taps!
Note that the camera's wireless password cannot be chosen by the user.
The Image Sync app features three main screens: a gallery of photos stored on the device, a gallery of photos on the camera (also known as Image View), and the Remote Capture interface. In this section, we will cover the capabilities of each screen in detail. You can cycle between the different screens using the buttons at the bottom of the app.
This screen simply displays all the photos found on the camera's SD card in a grid of thumbnails. It includes both JPEG and RAW files and does not categorize photos by folder.
The thumbnails load very quickly and as you scroll down the page, more will load automatically.
Image View Screen
You can tap on any thumbnail to view a slightly larger version along with basic metadata (shutter speed, aperture, ISO, date, exposure compensation, and GPS coordinates).
On this page, you can pinch-zoom to further enlarge the image, though the magnification is very limited (no more than 2x) and insufficient to evaluate the sharpness of the image at the pixel level.
Single Image Zoom
Another function of the Image View screen is to facilitate file transfers. Tapping on the leftmost icon at the top of the screen will allow you to mass-select files. Tap and hold for two seconds to bring up a context menu and then tap on the icon on the right side to start transferring the selected files.
It is not possible to delete files from the camera via the context menu, as the corresponding icon is permanently greyed out. Similarly, the Facebook sharing icon is greyed out as it seems that this feature has not yet been implemented (as of v1.03 of the app).
File Transfer Context Menu
The number of remaining transfers will then be shown in the upper-left corner of the screen. Note that this requires the latest version of the Image Sync app (1.03, released on May 11, 2015).
File Transfer in Progress
Apart from the number of files left to go, there is no progress bar or time remaining display for the transfer to complete. The process can be time-consuming as the original JPEG or RAW files do get copied to your device.
The leftmost tab shows photos that have been transferred to your device. They can be enlarged just like in Image View, and they can also be deleted via the context menu.
Gallery with Context Menu Shown
Via the leftmost icon at the top of the screen, the Gallery can also be used to browse photos from the native gallery app on your device. No other functionality is available beyond this.
Remote Capture Screen with Live View
The Remote Capture screen allows you to wirelessly capture photos, see what the camera sees, and change key shooting settings. You can adjust the white balance, shutter speed, aperture, exposure compensation, and ISO; some of these will be unavailable depending on your shooting mode.
From a user's perspective, the interface is a little basic, but it gets the job done.
Changing the Aperture
If the camera is set to autofocus, you can also tap anywhere on the live view image to focus on that spot. It is not possible to magnify the image or focus manually.
Other controls on the page include the green button, which resets the exposure to settings recommended by the camera, and the live view button, which allows you to disable live view and capture photos without it.
Finally, there are indicators throughout this screen to show the shooting mode, metering mode, battery level, file format, and remaining frame count. You can also tap to enlarge the latest photo captured in the upper-right corner. There is currently no way for that photo to be automatically downloaded to your device, however; it has to be done manually every time.
Image Sync Settings (with typo!)
Two additional settings can be changed via the cog icon: the file format, and the type of autofocus. Rather than touching to focus, you can have the camera focus on the selected area at the time of image capture.
Remote capture cannot be used unless the camera is set to the single frame drive mode. If a different drive mode is selected, you will receive an indication in the app advising you to swap modes.
After prolonged wireless use, the K-S2's grip does warm up slightly. Fortunately, the heat dissipates quickly once the Wi-Fi is disabled, and the grip never gets hot enough to cause damage or discomfort to your skin.
The range of the K-S2's Wi-Fi transmitter is quite good; its signal strength is much greater than that of the FluCard. In direct line of sight, with a Samsung Galaxy smartphone we were able to use it reliably at a range of up to 20 meters, or more than twice that of the FluCard. At a range of up to 10 meters, performance remains consistent even with obstacles such as (non-brick) walls and doors. We were even able to get good results being one floor above the camera in an office building. Metal doors and brick walls, however, proved to be a show-stopper.
Note that in practice, your results may vary depending on the placement of the camera, your device, and any obstructions or interference.
Stability and Power Use
Overall we found the K-S2's wireless connection to be highly stable. Normally, the camera will only automatically disconnect from your device if it remains idle beyond the auto-off time configured in the setup menu. If you accidentally close Image Sync while in use, you can reconnect quickly and easily after re-opening the app.
Unlike the FluCard, the K-S2's Wi-Fi does not disable the controls on the camera, which is highly convenient. You can still capture photos using the shutter release button while Image Sync is connected. If you change settings on the camera (i.e. the AF mode) while viewing live view remotely, however, you will need to exit out of live view and turn it back on for the settings to take effect.
When the camera's battery voltage is low, it may occasionally freeze up due to the Wi-Fi's added power drain. This only happened to us once during testing; such freeze ups are normal and will not damage the camera. A simple battery pull will get things back to normal.
Across a series of nine measurements, with a strong wireless signal, we measured the average live view latency to be 329ms, or about a third of a second. The latency ranged between 242ms and 399ms. This is comparable to the performance of other Wi-Fi enabled cameras we have tested in the past, and it's perfectly fine for casual use, but even this small degree of latency make it difficult to shoot action using the image sync app.
Wireless latency test showing 342ms delay
The live view display does freeze momentarily when you tap to focus in remote capture mode, a characteristic that the K-S2 shares with the FluCard.
File Transfer Speed
Generally speaking, the K-S2's wireless file transfer speed is quite slow. It takes about 10 seconds to transfer a JPEG and 30 seconds to transfer a RAW, which can get frustrating when combined with a lack of a progress bar. The implementation is not nearly as user-friendly or speedy as that of the Ricoh Theta app we reviewed earlier this year.
Community-Developed PC Tethering App
Forum member czielke has developed an impressive Windows application that mimics the functionality of Image Sync and essentially enables Wi-Fi tethering with the K-S2 and a PC. Since this is community-developed software, however, it is not officially supported and it might have some quirks. It supports file transfers and remote capture.
Overall we are very happy with the native wireless tethering in the Pentax K-S2. Unlike certain other cameras, it's easy to connect to the K-S2 and take advantage of the full functionality of Image Sync. The camera's wireless range has also proved to be much larger that that of the previous-generation wireless SD cards, which makes the tethering more useful in practice. The Remote Capture screen lets the user focus, see what the camera sees, and change basic shooting settings.
While the implementation isn't perfect due to a rudimentary interface, 300 milliseconds of latency, and slow file transfers, Remote Capture gets the job done and opens up new possibilities with the Pentax K-S2. One big improvement made to the K-S2 is that the on-camera controls can be used even when the camera is in Wi-Fi mode.
We remain hopeful that an official client app compatible with PCs will be released for future Wi-Fi enable Pentax models. Support for Lightroom integration and better documentation of the K-S2's wireless features would be icing on the cake, as would support for more drive modes, live view magnification, and automatic transfer of images captured remotely.