2.8 Understanding How the Camera Manages Buffered Images
When images are buffered in the camera’s internal memory
The camera’s internal memory is divided between the number of triggers that are configured. For example, if 5 triggers are set, each trigger can use 1/5 of the camera’s internal memory, and if 3 triggers are set, each trigger can use 1/3 of the camera’s internal memory, etc. See 14.3 Internal Memory Capacity for Buffered Images for information about the camera’s internal memory capacity.
For example, when buffering JPEG images at 320 × 240 resolution and standard quality:
BB-HCM511/BB-HCM531 only
Number of triggers
1
2
3
4
5
Maximum number of JPEG images that can be buffered by each trigger (approximate)
970
480
320
240
190
BB-HCM515 only
Number of triggers
1
2
3
4
5
Maximum number of JPEG images that can be buffered by each trigger (approximate)
350
170
115
85
70
When you change settings for a trigger, all images buffered in the internal memory for the selected trigger are deleted. Additionally, images buffered for other triggers may also be deleted. When configuring a trigger to buffer or transfer images, it is important to understand how the camera manages buffered images.
All images for the selected trigger are deleted when:
You change the settings for a trigger (image buffer frequency, transfer method, transfer settings, etc.)
You click [Delete Buffered Images] on the trigger page
All images for all triggers are deleted when:
You disable or enable a trigger (see 2.3 Disabling and Enabling a Trigger)
You restart the camera (see 9.4 Restarting the Camera)
You update the camera’s firmware (see 9.5 Updating the Camera’s Firmware and Updating a camera’s firmware)
You reset the camera to its default settings (see 9.8 Resetting the Camera)
You change the date and time setting (see 5.3 Setting the Date and Time)
When selecting [No Transfer, Memory Overwrite] for buffering JPEG images using alarm or motion detection triggers
If you want to configure the camera to buffer pre-trigger and post-trigger images, please note the following recommended settings when selecting [No Transfer, Memory Overwrite] for buffering JPEG images using alarm or motion detection triggers.
When buffering JPEG images at 320 × 240 resolution and standard quality:
BB-HCM511/BB-HCM531 only
Number of triggers
1
2
3
4
5
Maximum number of JPEG images that can be buffered by each trigger (approximate) (“A”)
970
480
320
240
190
Recommended maximum number of pre-trigger images (“B”)
300
160
100
80
60
Recommended maximum number of post-trigger images (when the number of pre-trigger images shown above is set) (“C”)
370
160
120
80
70
Approximate number of images buffered when using the above settings (“D”)
670
320
220
160
130
BB-HCM515 only
Number of triggers
1
2
3
4
5
Maximum number of JPEG images that can be buffered by each trigger (approximate) (“A”)
350
170
115
85
70
Recommended maximum number of pre-trigger images (“B”)
100
50
30
20
20
Recommended maximum number of post-trigger images (when the number of pre-trigger images shown above is set) (“C”)
150
70
50
40
30
Approximate number of images buffered when using the above settings (“D”)
250
120
80
60
50
Note
As a general guideline, the recommended maximum number of pre-trigger images is about 1/3 of the maximum number of images that can be buffered by the trigger.
(“B” equals or is less than “A”×1/3, as shown above).
As a general guideline, the number of post-trigger images should not exceed the total number of images that can be buffered by the trigger minus 2 times the number of pre-trigger images.
(“C” equals or is less than “A”-(2דB”), as shown above).
Note that when using the above settings, the actual number of images buffered (“D”) is less than the maximum number of images that can be buffered by the trigger (“A”).
If the value set for post-trigger images is set too high, pre-trigger images may be overwritten.
If the value set for pre-trigger images is set too high, images may not be buffered as expected.
When images are buffered to an SD memory card
SD memory card is divided between the number of triggers that are configured. For example, if 5 triggers are set, each trigger can use 1/5 of SD memory card, and if 3 triggers are set, each trigger can use 1/3 of SD memory card, etc. See 14.4 SD Memory Card Capacity for Buffered Images for information about an SD memory capacity.
All images for the selected trigger are deleted when:
You click [Delete Buffered Images] on the trigger page
You change the image format (JPEG or MPEG-4) setting on the trigger page
All images for all triggers are deleted when:
You format the SD memory card (see 8.2 Formatting an SD Memory Card)
You disable or enable a trigger (see 2.3 Disabling and Enabling a Trigger)