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Sunday, November 07, 2010

Pentax DSLRs Require Fast Cards for A Bit Longer Video Recording!

Otherwise, it will end pre-maturely, within one minute! >:-(

I have a Sandisk Class 4 SDHC card in 8GB, which is normally used in my NEX. I record so many videos with my NEX without any problem and in any lengths, since I bought them back to July.

This weekend, I just swapped the Sandisk card into my K-x for use for some reasons. I was recording videos and suddenly found that the video recording always ended pre-maturely. When I reviewed back the video clips, I found that the recorded lengths of the videos were ranged from 53 to 56 seconds at most. Damn it!

So, this is what some people have been saying about the major problem of using Motion JPEG for video recording, which is without any video *motion* compression! As such, the bandwidth and requirement is just very high and it needs fast to very fast cards to be used in all those Pentax video-capable DSLRs so as to avoid buffer overflow. Otherwise, when the buffer is full, video recording will be stopped.

The worst is that after the video recording is stopped, it takes somehow a rather long time to complete the writing to the card after that. During which, only a sand-glass is displayed and the card access lamp lights up consistently.

On the other hand, I used to use another Class 6 8GB card in my K-x and I have never seen the same problem. So, my quick conclusion is that my K-x requires at least Class 6 cards in order to use the video feature. In contrast, the NEX, which has at least some kinds of video compressions, has no problem at all even with my that slower Sandisk card of Class 4 or maybe even Class 2 ones, I guess.

So, if you are going to use a K-5 for video recording, do buy only Class 10 cards and that is my humble advice! It is just because K-5 features 1920 x 1080(p or i?) Full HD video recording, but not only a 720p one which the K-x or the K-r has. As I said before, this must be a "ground-breaking" "innovation" by Pentax for being made the first video recording device on Earth which records in Full HD but without any option of video compression! :-o Frankly speaking, I do believe that the Pentax engineers had to resort to use a higher compression ratio in JPEG for video recording in order to lower the bandwidth, which is yet highly undesirable as the IQ of the still picture per frame of the video will suffer in the end!


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Comments (15)

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VladimirYo's avatar

VladimirYo · 749 weeks ago

What about next post will be? What happend... again, Rice?
The advantages of MotionJPEG are that you don't have to worry about compression artifacts which can happen in some situations and it is very easy to edit because all the frames are keyframes.

Pentax is not the first, Canon SX1 records 1920x1080p MotionJPEG (42.8 Mbps).
I really don't see the problem. How fast is a class 4 card, not very (specs say a minimum of 4MB per second, class 6 start at a minimum of 6 MB per second). I use the Sandisk Extreme III 20MB/s cards, and have no problems recording one clip until it's full. Also the quality is very nice, which I appreciate. Is the quality of the Nex lower or equal, or maybe higher than those of the K-x? If lower, have you tried lowering the quality on the K-x to see how it helps?

To me, this sounds like complaining that you need new stuff to work with new stuff, that you can't just buy a brand new camera, and the old cards aren't keeping up anymore, which makes no sense to me.
8 replies · active 748 weeks ago
This is not a "complaint", but a real experience and a true advice. For potential K-5 buyers, do buy the fastest card available instead of standard ones. Very possibly Class 6 will be not adequate, as it is just enough for the K-x, which features 720p HD video recording only.
Ok, I took it as a complaint, my bad :P

The K-x can also record in SD, 640x416.

I'll be buying the SanDisk Extreme III 30MB/s cards, but that's to make emptying the cards go faster :P Specially since I'll do more time lapse when I get my K-5.
Sandisk Extreme II is same in speed as the current generation of standard Ultra (rated Class 4) of Sandisk now. So, I think your upgrade is essential! :-)
I have the III now too, just the 20MB/s version, 10MB more per second will be nice when emptying big cards :)
Siang Boon's avatar

Siang Boon · 749 weeks ago

Agreed with Rice. It really took long time (more than 15sec) for the video to output if using normal SD card, I just witnessed this last week while the representative demo the video recording to me during the KLPF at Malaysia.
Michael A.'s avatar

Michael A. · 749 weeks ago

True and makes sense, C6 is the bottom now and C10 is a necessity. Less than that is just good for updating FirmWare... If shopping around, SDHC Transcend 16GB C10 is around $29.00
Transcend C10 card is slower than Toshiba C6 card according to the last test by the DC Watch (link provided above). So, there is risk! :-p
Michael A.'s avatar

Michael A. · 748 weeks ago

Will see this week when 2 Tr 8GB C10's & K-5 on the way start to "dance" :o)
Class 10 is now slowly becoming standard anyway, what I regard as worse than the speed requirement is the fact that AVCHD recording doesn`t seem to be available, so your fast and expensive card will be full sooner than you think... Then again, pro filmers will be getting a pro video cam anyway
bandymelis's avatar

bandymelis · 748 weeks ago

Voilà! I am happy both of my cards are Class 10. When (and if) I buy the K-5 to replace my K10D (actually, I would do it right now, if I had the money), those cards will be enough.
Michael A.'s avatar

Michael A. · 748 weeks ago

Transcend C10 8GB is fast enough for K-5 1920 x 1080 video...tested fine on 4+ min 1.6gb clip.
I am using a Panasonic class 4 SDHC 8GB but I was able to record 720P HD video for more than 4 mins long. I did notice that the temp warning appear after that.

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