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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 6:40 am 
Viceroy

Joined: Wed Oct 22, 2008 7:41 pm
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There's no good reason for the card speed to be an issue at all.

They simply need to have a few GB of super-fast internal memory to serve as a cache when a card is inserted. I'd gladly settle with some 64GB of internal memory and never buy a memory card - but they would hate it, they want to sell those pesky cards.


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 11:20 am 
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Maybe it’s to do with current camera design, I think they use very high speed memory in the buffer alright, but I think it’s also volatile, if a camera is turned off or the battery goes flat anything in the memory buffer is likely lost for good if it hasn’t been transferred to a flash card yet. :shock:
Greg


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 2:25 pm 
Viceroy

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Greg, they could just use a wide parallel interface and write very fast into the same kind of flash memory as found in the cards and/or in SSD drives. And the fastest SSD drives do many hundreds MBps.


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 4:24 pm 
Imperial Ambassador

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Lets think about the new A77. We know it's 24mp. I know when I shoot jpg and RAW on my A900 my jpg's are about 8mb in size and the raws are about 32mb. So, 32mb + 8 is 40mb. If you wanted to do at 3 shot per shutter bust with the a77's estimated 10 fps, then that's 30 fp/s * 40mb = 1.2 gb/s. That's alot with even with today's fastest memory cards.....

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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 4:52 pm 
Viceroy

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1.2GBps is 9.6Gbps, which is about twice the speed of USB3.0 that is a serial interface, and there's also the SATAIII. So having 9.6Gbps over a parallel interface is no strain at all. Just make the datapath wider.

And once again, we really need some large fast internal memory bank.


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 5:04 pm 
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I am surprised that modern DSLRs have no internal non-volatile memory. An old Canon P&S I had contained about 8 megs, enough for a few of it's shots. It wouldn't be a bad idea to do that on today's modern cameras.

As to write speeds: memory keeps getting faster, and smaller, and cheaper all at the same time. They could do it if they wanted to!

Dusty

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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 5:33 pm 
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Well you can have your internal flash memory, but I prefer replaceable memory cards and a fast volatile buffer. If you have internal flash memory in the camera it will get full at some stage no matter how big it is, especially with an unnecessary 24MP on APS-C and the camera is useless until it's purged and reformatted, (the bigger it is the more time consuming this would be), with a flash card you just swap out the full one and off you go again.
Greg


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jun 30, 2011 6:11 pm 
Viceroy

Joined: Wed Oct 22, 2008 7:41 pm
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Greg,

Just like I said, card's in - it's cache (like L2/3 cache), card's out - it's storage. Simple to do, but eats into mem card sales.

But now it becomes close to impossible to keep up with data volumes/speeds while using the traditional card interfaces.

So...?


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Thu Jul 28, 2011 5:29 pm 
Viceroy

Joined: Mon Aug 18, 2008 11:20 pm
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Perhaps there are no implications relating to the rumoured $999 price for the A77 as Sonyalpharumors are now advising a SR5 price of $1299 here
http://www.sonyalpharumors.com/sr5-excl ... 50mm-lens/
As a "bonus" Sony apparently are giving you a good reason to retire your much used CF cards before they expire as the CF slot has been dropped from the A77. In any event AF is immensely fast and with 12 fps that will be the fastest show on earth. I wonder what is going on in the CAN/NIK design brains if this is true. 24MP, 12fps and ultra fast AF. Too good to be true??????


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Fri Jul 29, 2011 7:45 am 
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alphaomega wrote:
24MP, 12fps and ultra fast AF. Too good to be true??????

Hard drive sellers rejoice!

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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Fri Jul 29, 2011 8:50 am 
Viceroy

Joined: Wed Oct 22, 2008 7:41 pm
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KevinBarrett wrote:
Hard drive sellers rejoice!

Hardly so.

As the pixel count goes up, the difference between the adjacent pixels' data is going down. It means that both the lossless RAW compression and the lossy JPEGs need less per pixel data to store.
Hence we get at the saturation in the per-shot compressed data volumes. We are already there, almost or mostly.

What we really need is the ability to crunch those wittily compressed data volumes. Means faster multicore processors and lots of RAM.


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Fri Jul 29, 2011 5:44 pm 
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Well looking at the new so called information they're now saying the price is $1300 body only. CF wise this could be a sticky point to some I've no problems with SD it's common and useful in many devices some do like CF though esp higher end bodies. I think Memory stick should be dropped (really it's clearly lost and badly to SD) and dual SD card slots in place.

As for the 24mp it's a bit like CPU speed there comes a point where it's not overly obvious in real world use. Reading DK's article the point is not about "it's going to trash IQ" the point is it's unnecessary for the vast majority of users. I do hope the industry moves beyond resolution as a judge of IQ there is so much more to it than that.


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Sat Jul 30, 2011 10:37 am 
Viceroy

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There is a problem with the SD interface, the same problem as with with the other 4-bit interfaces, like the MS.

The problem is absolutely fundamental. Simple physics dictate that an interface working at its top possible speed consumes a lot of energy simply to keep its impedance active rather than reactive which would cause signal ringing.
Then for the same data throughput a 4-bit interface would need to dissipate four times more energy than a 16-bit interface simply because the power losses go as frequency squared.
So a CF, being a 16-bit design, has an inherent four-times speed advantage at a given power consumption limit.

You need not blindly trust me over that. You may just connect some a700/850/900 by its USB2.0 link to a computer and watch how fast that 1-bit serial interface drains the cam's battery. That happens because they are high-end cams, and so the interface is operated at the max speed possible due to performance priority in design.
You can imagine what would happen with USB3.0 that's an order of magnitude faster yet...


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Sat Jul 30, 2011 11:04 am 
Emperor of a Minor Galaxy
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It's less about what it technically right/better and more about what is popular. Quirks aside SD dominates the market for removable media it's so common now any device that supports a memory card will pretty much use SD.

I'm ok with CF though and you are right it's faster and has some advantages. The only downside is the pins though I have not had major problems I've trashed a few card readers. But the cards are robust much more so than other ones such as SD. Leaving that aside Sony have had no choice but to integrate SD into their camera products.
For once it might be an idea for the company to accept the most logical path for end users. And offering SD and CF would make a lot more sense than blindly clinging to a memory card format that simply has not taken off. Either that of I'll stick to my dual SD slots ;-)


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 Post subject: Re: Implications of a $999 body only price point for A77
Unread postPosted: Sat Jul 30, 2011 11:18 am 
Viceroy

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Barry, but like I said above, the card speed is no issue at all if there's a fast non-volatile cache mem inside the cam. We don't even need super-duper lightning-fast SD cards for the cam to shoot and store as fast as needed.


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