Low Power Mode
Low Power Mode (LPM) allows you to do more energy-efficient shooting, by powering on only part of the controller each time a photo is triggered. This helps you to conserve power.
By way of example, a scenario where you might use LPM is at a significant mid-project event like a concrete pour, where you will shoot frequently to capture all the activity.
LPM is ideal for shooting at fast intervals (e.g. every 20 seconds), while connecting and uploading photos less frequently (e.g. every 30 minutes).
Note that the photoSentinel Tempo has high power efficiency and fast charging, so in most cases, you will only need to use LPM with Tempo where there is limited sunlight available or for overnight sessions.
This article is specifically about using LPM on the photoSentinel Tempo. To learn how to use LPM on a Mach II unit, go here.
Using Low Power Mode incorrectly can result in missed photos, so it’s recommended to read through this article in full before using it.
Using LPM also requires knowledge of how Scheduling works; we recommend you read our knowledge base article on Scheduling before reading this article.
If you’re unsure if you should use Low Power Mode, contact our Support team to discuss your project.
In order to use LPM, your system must meet the following technical requirements:
- Your Tempo must be fitted with a remote shutter release cable (distinct from the USB cable). This is not available on some DSLR models, such as the Nikon D3400 and D3500.
- Your Tempo should ideally be on the latest firmware version. If your system is on an older firmware version, or to check if it is up-to-date, refer to the Firmware Update Knowledge Base article.
Limitations of LPM
The primary use of LPM is to frequently shoot and save photos to the SD card with minimal power use, to capture high-activity.
To achieve this power efficiency, LPM limits some of the other normal functionality, as follows:
- The fastest shooting frequency we recommend is every ten seconds; faster speeds are possible but reliability below 10 seconds will be determined by the camera model, exposure, and remaining SD storage capacity.
- The fastest upload frequency we recommend is every five minutes; reliability or power consumption issues may result with faster frequency.
- The speed at which photo files are transferred (uploaded to the cloud and/or copied to the external drive) varies and is determined by:
- The photo file handling will occur every interval you set when you create a LPM session.
- Your Photo File Handling section settings for file types to transfer on your installation’s Config page.
- Your number of Upload sessions (if uploading to the cloud).
- Camera model, photo file size, power availability, and network strength (for uploads).
- If you are running LPM for a day or longer on solar power, it is recommended you upload photo files in regular intervals during sunlight hours where your system can get steady power, in order to best manage your power for the next day of shooting.
- If you need to use LPM without uploading photos, we recommended you calculate you have enough space on the SD card to store a full day’s worth of shooting. Reduced capture frequency or photo quality may be necessary depending on SD card size.
- Uploading RAW images during LPM is power-intensive, so it is not recommended in environments where you are only receiving partial sunlight (such as winter).
- It is recommended you check on your system’s power levels now and then if doing heavy shooting and/or uploading during LPM.
Use these recommended settings for LPM:
- Set up a Capture session as normal with your desired parameters
- Set your photo file handling will occur every interval to every thirty minutes.
- If you want to upload photos during the session, we recommend setting Upload sessions to occur every thirty minutes.
- Choose the Upload as many photos as possible option.
- Your Upload session time block should run for two hours longer than your Capture session time block to ensure all photos get uploaded. This will also ensure photos get deleted off the SD card to prevent it from filling up.
- Set up a Check-in session that takes place every 30 minutes.
- In your Config page’s Photo File Handling section, we recommend you:
- Set Files to upload to cloud to JPEG only, as this will help you manage your data and power better; we recommend you upload RAW only if it’s needed for your project. RAW upload is not recommended in low-sunlight/winter environments.
- Set Files to transfer to SSD to JPEG + RAW. This will allow you to collect both off the local SSD storage during your next site visit.
- Activate Start deleting old photos from the external drive, when its free space drops below 2%
- Activate Start deleting old photos from the SD card, when its free space drops below 64 MB
- Select Save file handling settings
- If you doing extended LPM shooting using LPM in a low-sunlight/winter environment, then we recommend using a 12V car battery with the External Battery Box to bolster your power reserve. If you’re unsure if you should use the External Battery Box, contact our Support team to discuss your project.
SD Card Management During Low-Power Mode
The standard workflow for a Tempo is that it will not delete a photo from the SD card until it confirms the photo has been processed according to the parameters set by:
- The Photo File Handling section on the Config page in Control Hub (how are photos processed)
- The photo file handling will occur every interval in a LPM Capture session (when are photos processed)
If it cannot confirm the photo has been processed, it will leave the photo on the SD card as a precautionary measure to ensure it isn’t lost. A SD card near capacity may cause performance issues, and once the SD card is completely full, the system will cease to take photos.
You can prevent your SD card from filling up by using the Start deleting old photos from the SD card, when its free space drops below 64 MB function in Photo File Handling settings as previously mentioned.
You can also format the SD card anytime to clear its image by using the On next connection, delete all photos from camera CF/SD card function in Config, under Advanced Settings.
Note that with both functions, there is no way to recover photos deleted from the SD card.
If you notice on the Status page that the space remaining on the SD card is not going down at the end of each day, double check your Photo File Handling settings that all images are being processed, and thus will be deleted.