Seems to me that the 645D specs call for SDHC cards.

'course, I could be remembering it wrong.

[jogiba]

That's the problem, you say they "will be", but they are not available yet. Even when they are, they are still going to be class 10 at first as far as write speed. The fastest max speed write speed so far I've seen is 30mb/sec (not guaranteed, they only guarantee class 10, so 10mb/sec, any more is a bonus)

Panasonic's press release. Berlin, Germany (September 1, 2010)

"With the higher reading speed of up to 60MB/s, the 8GB and 16GB Memory Cards can transfer data to a PC more than two times faster than Panasonic's current Memory Cards.3 These also offer stable writing performance with Class 10 speed specification, ensuring highly-reliable 3D and full HD video recording."

There is a reason why pro DSLR's come with CF cards, because they need them. Pro level DSLR's will continue to come out with CF cards because as the megapixels go up so does the need for faster cards, and many of them need 2 slots to help keep up. CF isn't resting on it's laurels either. Faster cards continue to be released in that format.



When it comes to cost, the SD really isn't cheaper. Of course a card three times as fast will cost more, but compared to a CF with the same write speed and the price difference is negated.

SanDisk 16GB, Extreme 30mb/sec $109
SDSDX3016GA31 SanDisk 16GB, Extreme Secure Digital High Capacity (SDHC) Memory Card, Class 10

SanDisk 16GB Ultra 30mb/sec $65
SDCFH016GA11 SanDisk 16GB Ultra Compact Flash Memory Card with 30MB/SEC Speed

The CF card is cheaper by a large margin. So if cost is important one can just buy the slower card and even save some money. Where as if someone needs the buffer to clear quickly, with a SD card they are stuck with long buffer wait times. I for one would like to have the choice.

Like I said, SD is fine for an entry level soccer mom camera, but not for a flagship "semi pro" camera.

Get out of your CF cave and you will see SDHC/SDXC will be on 99% of DSLRs coming out with speeds up to 300mb/sec in 2011.



---------- Post added 11-20-10 at 05:55 PM ----------

Seems to me that the 645D specs call for SDHC cards.

'course, I could be remembering it wrong.

Dual slot SD/SDHC memory card
Dual slot SD/SDHC memory card support ensures fast and reliable storage for high resolution image files, simultaneously saving in multiple formats, assigning images to different cards based on their original format, or easily holding one memory card in reserve.


645D - Official PENTAX Imaging Web Site

[ManuH]

While it's true CF still has the edge for performance, it's clear that the trend is for SD. Already many mid-level models from Canon & Nikon switched to SD.

[dankoBanana]

I find the promise of a large and fast (300mb/s) SDXC card very exciting
we will be able to take even more pictures in a row with a k5

[zuiko]

Get out of your CF cave and you will see SDHC/SDXC will be on 99% of DSLRs coming out with speeds up to 300mb/sec in 2011.



---------- Post added 11-20-10 at 05:55 PM ----------


Dual slot SD/SDHC memory card
Dual slot SD/SDHC memory card support ensures fast and reliable storage for high resolution image files, simultaneously saving in multiple formats, assigning images to different cards based on their original format, or easily holding one memory card in reserve.


645D - Official PENTAX Imaging Web Site

It seems that with the new UHS-I (SD 3.0) standard, the speed is fast enough even compared with compact flash, the question now is: should UHS-I be considered a transitional standard between SDHC and SDXC, or it is simply another upgrade UNDER SDHC (like class 10+) standard thus supported by K5? This is important for some users as they need something to fulfill their demanding purposes before the price of SDXC eventually come down to the earth.

[tomkong]

I had a 16GB class 6 in the K7. Now in the K5 I'm using a Sandisk 16GB Extreme (class 10). I have tried and compared both cards in the K5. The class 6 cards seems to be sufficient for video. But somehow I have the feeling that with the Sandisk class 10 pictures are written a tick faster to the card. For the shooting performance it doesn't really matter.
Cheers