What happened to the FA 21 Limited?

Started 3 months ago | Discussions thread
James O'Neill Veteran Member • Posts: 5,728
Re: What happened to the FA 21 Limited?

Breakfastographer 2 wrote:

And for the record, in case it matters: XQD does 125 to 500 MB/s. Using your ballpark figure of 33MB times 12fps, we get 400MB/s, which means XQD could in theory give unlimited raw bursts on the K-3 III, while UHS-II at full speed comes close enough that you should be able to maintain around 8fps (to account for margins of variation).

The potential silver lining is that if your card writing speed matches or exceeds your data capture rate, you don't need much buffer.

<<See below>>

For a fully optimised camera with similar characteristics as the K-3 III even 200MB of RAM would seem slight overkill - rather than 1GB as it currently needs.

So in my mind, eliminating the buffer should be an engineering priority.

It's a house of cards, of course, in the sense that when the user inserts a slow card, everything falls apart. That's the nice thing about using a completely new card standard like XQD - it's got an added up front cost to the user, but at least you know they'll be using a fast card because no slow and/or "legacy" cards exist.

Yes, you keep a buffer for slow cards, but it can be quite small, and a new standard gives you a minimum speed.

You've got input of 26 Mpixels per frame at 12 fps which transforms into 33MB per file at which needs 400MBytes per sec to write 12fps.

But in between you need something which can process 300MPixels per sec. There's an easy test - if save small, ** or * JPEG so the file sizes are ~1MB what happens to the shooting speed.  My guess is the frame rate is much the same, because the prime is the bottleneck (the accelerator makes it less of one).

I wonder what you could get if you wrote DNG files WITH NO PREVIEW,

I think reception of a stellar camera that requires a new card would have been better than of a camera that provides only moderate performance, but with all sorts of cards.

For every machine gunner who thanks you for allowing bursts of 720 frames in a minute (before changing card and/or battery)  there is at least one customer who hates having to use different cards which cost 10 times as much, new readers etc.

When SD became the norm I went to "single use" because the cards are so cheap.  My back up of last resort is the card I shot on. Today a 128GB Kingston costs £17 and Amazon want £178 for a120GB Sony XQD. Just having to buy two cards (one spare / for when the other fills up) adds 20% to the cost of the K3-iii

That's not to say everything is perfect, even shooting at my 1 frame per 2-3 seconds the K1 can be saving files 30-40 seconds after I have finished shooting, either the Prime chip or the SD interface is slow. But I don't think I've ever found the limits of the K1 (or K5) buffer.

 James O'Neill's gear list:James O'Neill's gear list
Pentax K-5 IIs Pentax K-1 Pentax smc FA 50mm F1.4 Pentax smc DA 18-250mm F3.5-6.3 Pentax smc FA 43mm F1.9 Limited +3 more
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