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02-13-2014, 07:19 AM   #286
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QuoteOriginally posted by Digitalis Quote
I don't think SD cards are quite up to those kind of transfer rates, XQD and SSD cards can do it. Also the image processor used in Pentax DSLR cameras will be taxed considerably with live 4K video - unless they incorporate more than one of them in the image processing pipeline, if that is the case expect battery life and sensor heating to also be issues. In most MF backs the sensor is passively cooled with heat sinks and in some cases actively cooled with a fan. The weather sealed construction of the 645D makes this rather problematic. Pentax possibly could use a small heatpipe or perhaps a peltier effect cooler to shunt heat away from the sensor and dump it into the chassis - but thermoeletric cooling will also chew up energy and in the end it is only moving the problem, not eradicating it.
As, I understand - there is a basic architectural difference between Canon, Nikon and Pentax in terms of the image processing hardware. Canon's image processing chip allows for multiple parallel processing paths, while Nikon/Pentax's do not. Both Canon and Pentax use variations of the Fujitsu Milbeaut, while Canon uses a version of Texas Instruments OMAP. Unlike Fujitsu Milbeaut, Digic (Texas Instruments OMAP.) supports multi-processor configurations and can also execute external programs. The ability to support and execute external programs enables the Canon's ability to have third party capabilities like CHDK.




Last edited by interested_observer; 02-13-2014 at 07:25 AM.
02-13-2014, 07:34 AM   #287
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QuoteOriginally posted by Digitalis Quote
I don't think SD cards are quite up to those kind of transfer rates, XQD and SSD cards can do it. Also the image processor used in Pentax DSLR cameras will be taxed considerably with live 4K video - unless they incorporate more than one of them in the image processing pipeline, if that is the case expect battery life and sensor heating to also be issues. In most MF backs the sensor is passively cooled with heat sinks and in some cases actively cooled with a fan. The weather sealed construction of the 645D makes this rather problematic. Pentax possibly could use a small heatpipe or perhaps a peltier effect cooler to shunt heat away from the sensor and dump it into the chassis - but thermoeletric cooling will also chew up energy and in the end it is only moving the problem, not eradicating it.
The new UHS-II SDXC cards for 4K video do up to 312MB/s.
http://www./2014/02/12/sandisks-new-extreme-pro-sd-uhs-ii-cards-are-worlds-fastest-sd-cards/

02-13-2014, 07:39 AM   #288
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QuoteOriginally posted by jogiba Quote
wow that is fast....

SanDisk Extreme PRO SDHC/SDXC UHS-II Memory Card

But not yet in the specs off the Pentax camera's I guess. I don't think that PRIME III nor the electronic lay-out in the K-3 is up for this work yet.

02-13-2014, 08:37 AM   #289
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But the 645D is not supporting UHS-II, only UHS-I (so it appears from the images).

02-13-2014, 08:58 AM   #290
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Even with 64 GB, how quickly will that card fill up?

Better have dual or quad card and make them hot swappable.
02-13-2014, 09:08 AM   #291
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QuoteOriginally posted by RonHendriks1966 Quote
But not yet in the specs off the Pentax camera's I guess. I don't think that PRIME III nor the electronic lay-out in the K-3 is up for this work yet.
Not even close...it only can do 45MB/sec internally :-P
02-13-2014, 09:09 AM   #292
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Well with the K-3 you can record 25 minutes off FullHD 60i and that is about 22 Mb/s.

So when the BlackMagic is to compare with (in output, different sensor) Blackmagic Production Camera 4K available now for $3000: Digital Photography Review then you have lots off cards needing in your pocket. So maybe for ProRes 2.5k is already the max. At a max that already (200Mb/s) that would mean 42 minutes on a card off 64GB.

---------- Post added 13-02-14 at 17:10 ----------

QuoteOriginally posted by kenyee Quote
Not even close...it only can do 45MB/sec internally :-P
I know Imeasured that myself, but no idea where thew bottleneck is. It could be processor or something in the pipeline. But for video that is already plenty to make excellent footage.
02-13-2014, 09:11 AM   #293
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Are there any cine lenses for 645 format out there?

02-13-2014, 09:11 AM   #294
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doesn't matter as much about the card write speed, there's two ways around that..
1) have it record to memory card in 1080 p, BUT have 4k hdmi out so film makers can record to external recorders
or
2) have a HUGE internal buffer or ssd drive.

The 645d would have a lot of extra space inside to accommodate an extra battery and an ssd drive...
02-13-2014, 09:39 AM   #295
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QuoteOriginally posted by mikemike Quote
Even with 64 GB, how quickly will that card fill up?

Better have dual or quad card and make them hot swappable.
Get a 256GB SDXC card.

Lexar 256GB SDXC Memory Card Professional Class LSD256CTBNA600
02-13-2014, 09:47 AM   #296
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Damn! The mic/speaker holes always pointed towards video, but I'm still having trouble believing it! There is definitely tape in that image, covering up whatever symbol applies to the Play button. Also, the AF point selection dial is unlabeled...seems strange that they would move that function elsewhere. Who knows. Ricoh sure knows how to string us along!

Edit...

Now I see that AF point selection is performed a la the K-3--press the button with the 4 arrows on it, then use the 4-way controller. So that could free up the old AF point dial for a stills/video switch. Still leaves the mystery of the taped-off label...
02-13-2014, 10:37 AM   #297
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The sensor plane on this is really far foward compared to pentax's normal APS-C cameras. Was the original 645D that way too?
02-13-2014, 11:07 AM   #298
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QuoteOriginally posted by mikemike Quote
The sensor plane on this is really far foward compared to pentax's normal APS-C cameras. Was the original 645D that way too?
Yes. A cutaway view reveals a lot of empty space in there. A result of keeping the form factor of the old 645 with its film inserts.
02-13-2014, 12:48 PM   #299
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QuoteOriginally posted by filoxophy Quote
Yes. A cutaway view reveals a lot of empty space in there. A result of keeping the form factor of the old 645 with its film inserts.
No, there is not so much empty space in 645D behind the sensor. I don`t know about 645d II, but taking into account that 645DII has articulated screen, there is less space behind the sensor than in 645D.


Last edited by Roberts; 02-13-2014 at 01:02 PM.
02-13-2014, 03:53 PM   #300
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A mirrorless MF camera with the right flange distance could allow FF lenses to be used in Crop Mode for a FF experience and this would allow a transition to MF, over time, for people with legacy glass. If it's good enough for Sony and Leica to develop adapters then I don't see why Pentax should limit themselves.
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