Secure Digital (SD) and SD High Capacity (SDHC) Cards

Wildlife Monitoring's free SD cards

In general we give you a free memory card with each camera purchsed. The cards we use are:

• Sandisk 2GB SD cards; and
• Sandisk 8GB SDHC Class 4 cards

We choose Sandisk because we have never had reliability or compatibility problems with these cards in any model of our cameras. At times we have had faults with other brands. Occasionally we may vary the brand without notice, for a brief period of time, but all our products are backed by our own warranty service.

SD card capacities

Card "capacity" refers to how much data it can store (how "big" it is).

• SD cards can store a maximum of 2GB of data
• SDHC cards can store a maximum of 32GB of data
  • SDHC cards come in sizes of 4GB, 8GB, 16GB and 32GB

The higher your card's capacity, the more photos and videos that can be stored. The exact number can't be calculated and depends on the camera model and lighting conditions. Cards over 32GB in size are referred to as SDXC but none of the available trail cameras use these.

How long before the card is full?

As an indication, we have captured hundreds of photos on a 2GB card using a Scout Guard SG550. How long the camera can last in the field before the card is full depends on how often the camera is triggered and how long the batteries last.

SD card speeds

Card "speed" refers to how quickly data can be written to and/or read from a card. Usually the speed of writing is slower than the speed of reading. The speed of writing is important for camera applications that require multiple photos in quick succession (usually with a fast trigger time) and for recording video.

SD card classes

The SD Association defines 4 speed class for SDHC cards:

Speed Class	Marks	Applications
Class 2		SD (standard definition) video recording
Classes 4 and 6		HD (high definition) to Full HD video recording
Class 10		Full HD recording and HD still consecutive recording

The free SDHC cards shipped with Wildlife Monitoring cameras are Sandisk 8GB SDHC Class 4 cards.

Class 4 cards are completely adequate for trail camera applications. In some specific applications using high-end trail cameras with fast trigger speeds and continuous, consecutive recording of high definition photos, a higher speed class may be warranted. We can supply these - please ask.

Larger capacity cards are also available at extra cost. Please ask.

SD card x-ratings

Many resellers use an x-rating when describing the speed of an SD card.

Example x-ratings include:

• 33x, 66x, 100x, 133x, etc

These ratings are based on the data transfer rate of a standard CD ROM, which is 1x, which is 1.2Mb / second (approximately 150k per second). Hence, 33x is 33 times faster than 1x.

But note - some manufacturers will use their minimum guaranteed write speed, but others will report the maximum. (The rate at which data is written to, or read from a card is not constant - it fluctuates during the writing/reading process). Still others will report on the read speed of the card, which is usually higher.

Therefore the x-rating is an unreliable way to compare 2 different SD cards unless you are sure the speed is measuring the same thing on each card. This is why Wildlife Monitoring advertises the class rating for the cards we supply, and the classes we have chosen are completely adequate for practically all trail camera applications.