Pentax K100DS Memory Card Compatibility

The Pentax K100DS can use SD memory cards. 32GB is the largest capacity SD card that can be used in the K100DS.
SD memory cards labeled as SDUC or SDXC are not going to function in the K100DS. These cards are easy to avoid as they are 64GB or larger in size.
The SDHC format was announced in 2006. All 32GB cards that are currently being produced will have almost identical performance. You cannot go wrong buying the cheapest class 10 name brand card. At the time of writing this, the PNY Elite 32GB SD memory card has the best price.Recommended K100DS SD Cards
Here are several options to choose between that are compatible in the K100DS. With all of the cards below, you will not have to be worried about sluggish capabilities or card glitches.

- Sequential read speed of up to 100MB/s
- Class 10, U1 rating delivers speed and performance for full HD photography and HD videography.
- V10 video speed rating to capture uninterrupted HD video at 1920x1080 format
- Compatible with point & shoot cameras, DSLR cameras, standard & advanced HD-enabled video cameras, and more
- Reliable & Durable: Magnet Proof, Shock Proof, Temperature Proof, Waterproof

- Quick transfer read speeds up to 90MB/s.
- Write speeds are not capable of recording 4k video.
- Class 10 rating for Full HD video (1080p).
- Waterproof, temperature proof, X-ray Proof, magnet-Proof, and shockproof.

- UHS Speed Class 1 (U1) supports Full HD video and burst shots. 130MB/s transfer speeds1 let you upload footage to your PC in an instant.
- Built to survive tough conditions and heavy usage, whether you’re at home, outside, or on the go. Backed by 10-year limited warranty.
- Highly durable with comprehensive 7-proof protection.
- Backed by a 10 year warranty.
Best SD Cards
SanDisk, PNY, Samsung, and Lexar both produce premium quality memory cards. Low-priced no-name brand names need to be avoided.
Cut-rate cards are much more likely to encounter file corruption, meaning that you might lose all of your images contained on the card. The decrease in the level of quality is not worth the negligible savings.
In a situation where you want to save some money, purchase a card with a reduced capacity. They probably will be a tad lower in price and you won’t have to be anxious about the SD card losing your shots.
Be aware that, SD card problems are infrequent. Just two cards have become corrupted out of the loads I have acquired over time. Both of the memory cards were previously owned house cards that were bundled along with the purchase of pre-owned digital point & shoots.
Pentax K100DS SD Card Compatibility
Currently, 4 separate technical specs of Secure Digital (SD) memory cards exist. The Pentax K100DS uses SD memory cards. Every new memory card technical spec raises the max storage capacity and read/write speeds when compared to the previous spec.
Secure Digital memory card readers are backward compatible. A card reader built into a digital camera that can use SDXC cards will also be able to use SDHC and SD memory cards.
The Pentax K100DS’s card reader is only compatible with the initial two SD card specs. SDUC or SDXC SD cards are not going to be compatible.
- Secure Digital (SD) - These memory cards have a maximum capacity of 2GB and are compatible with the K100DS.
- Secure Digital High Capacity (SDHC) - The capacity of these memory cards range from 4GB to 32GB and are also compatible with the K100DS.
- Secure Digital eXtended Capacity (SDXC) - The capacity of these memory cards range from 64GB to 2TiB.
- Secure Digital Ultra Capacity (SDUC) - The capacity of these memory cards range from 4TiB to 128TiB.
Pentax K100DS Memory Card Full Error

Trying to use a memory card that has a storage capacity of 64GB or larger in the K100DS will cause the camera to show an error.
Get an SD memory card with a storage capacity of 32GB or smaller to prevent the problem.
If you attempting to use a memory card that is 32GB or a smaller capacity, and it is not working, try to format the SD memory card while it is in the camera.
Speed, Class, & Capacity
SD Card Image Capacity
Here is an estimation of how many large JPEGs you can expect to save on an SD memory card.
- 4GB - 1920 images
- 8GB - 3840 images
- 16GB - 7680 images
- 32GB - 15360 images
Memory Card Speed
Speed ratings for SD memory cards are determined by the sequential read and write speeds. The speed of the memory card is important when many pictures need to be written to the memory card.
SD Card Speed Class Rating

The Class speed rating of an SD card is based on the sustained write speed of the SD memory card. A Class speed rating of 2 means that the SD memory card can maintain a write speed of at minimum 2MB per second.
- Class 2 - 2MB/s
- Class 4 - 4MB/s
- Class 6 - 6MB/s
- Class 8 - 8MB/s
- Class 10 - 10MB/s
The top rating a memory card can have is Class 10. There are memory cards that are significantly faster than 10MB/s. Those memory cards use other technologies, such as UHS (Ultra Highspeed Bus), which have a different rating criteria.
Sustained write speeds of 2MB, 4MB, 6MB, or 8MB per second means the card has a speed class of 2, 4, 6, or 8. Cards that have write speeds of 10MB/s or faster are rated as Class 10.
Conclusion
Buy an SD memory card for the Pentax K100DS based on price. An expensive card isn’t going to improve performance. As long as it is a speed class 10 card, you will be fine. My recommendation is the PNY Elite 32GB SD memory card.