P25: Faster Capture with Faster CPU?

Questions, comments and suggestions regarding Phase One P+ series and P series digital camera backs.

P25: Faster Capture with Faster CPU?

Postby Mark 3 » Mon May 09, 2005 6:06 pm

PhaseOne:

If I'm shooting tethered to, say, a 867mghz Powerbook G4, is the capture rate affected in any way by the speed of the CPU, or even the hard drive?

Would the P25 \"recycle\" faster if I was shooting tethered to a G5DP2.7gig, over this G4 867?

Does the speed of the host computer affect the performance of the P25?

To take it further, if so, would the speed of the internal hard drive help the capture rate? Would it be better to be shooting to a 7200rpm drive, over, say a 5400?

To take it even further, would the capture rate increase if I set the P25 to IIQSmall, instead of the seemingly default IIQLarge? I did a random test, this weekend, and didn't see any compromise in image integrity with the P25 set to SMALL.

http://marktucker.com/temp/compression.jpg

If you think the image would be degraded, how would it show up? As noise? As artifacting?
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Postby damienlovegrove » Mon May 09, 2005 6:29 pm

Hi Mark,

I use a 1.25 Ghz Powerbook 15\" and I found a faster capture process when I added an external 250Gb hard drive with a 7200rpm spindle speed running from the Firewire 2 port. Before that I always had a bit of a bottleneck at the 4 or 5 capture point. I have always used the RAWs option and not noticed any artifacts.

I hope this helps. Damien.
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Postby FlemmingHandberg » Tue May 17, 2005 3:26 pm

Capture Speed is depending of a number of things:

1. First of all the camera body - some have a fast internal bus others have a slow one - (and the manual eg. Hasselblad 501 have none :) )
2. Your host computer - Internal amount of RAM - 1-2 GB is preferred.
2b. A fast disk is preferred (eg. a 7200 rpm is prefered over a 5400 rpm)
2c. Frequency of the processor and processer type - Try is on a dual G5 and you will never use your power book any more :?

So basically there is not an easy answer to your question, but the first couple of things i would change was processor speed and amount of RAM.

IIQ Small vs. IIQ Large is not that different to each other - but is depending on the host computer as well. and you you are looking for a real \"fast\" capture - shoot on card and forget tethered....
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Postby Mark 3 » Tue May 17, 2005 4:02 pm

Thank you for your response, Mr. Handberg.

1. Could the P25 ever be converted to Firewire 800, to increase the transfer rate?

2. Do you think the use of Sandisk Extreme III might increase the write speed, to CF, even further?

3. How does the \"internal bus speed\" of the H1 compare to the Contax 645 AF?

----

My very informal, unscientific tests today:

P25 on H1
Tethered: Mac 17\" 1.3gigPB with 10.3.9 w/1gig RAM
CaptureOne 3.7 Final
IIQ-Large Setting
Buffer set to 10
Shooting to Desktop (Internal drive)
H1 Motor set to Continuous; Finger on button
One minute period = 12 Frames

---------

P25 on H1
Tethered: Mac 17\" 1.3gigPB with 10.3.9 w/1gig RAM
CaptureOne 3.7 Final
IIQ-Large Setting
Buffer set to 10
Shooting to Desktop (Internal drive)
H1 Motor set to Single; Shoot only when hear CameraReady sound
One minute period = 12 Frames

---------

P25 on H1
Shooting to Lexar 2gig 80x SecondGeneration
IIQ-Large Setting
H1 Motor set to Single; Shoot only when hear CameraReady sound
One minute period = 27 Frames

---------

P25 on H1
Shooting to Lexar 2gig 80x SecondGeneration
IIQ-Small Setting **
H1 Motor set to Single; Shoot only when hear CameraReady sound
One minute period = 30 Frames

---------

P25 on H1
Tethered: Mac G52gigiDP with 10.3.9 w/4.5gig RAM
CaptureOne 3.7 Final
IIQ-Large Setting
Buffer set to 10
Shooting to Desktop (Internal drive)
H1 Motor set to Single; Shoot only when hear CameraReady sound
One minute period = 27 Frames

---------

P25 on H1
Tethered: Mac G52gigiDP with 10.3.9 w/4.5gig RAM
CaptureOne 3.7 Final
IIQ-Small Setting
Buffer set to 10
Shooting to Desktop (Internal drive)
H1 Motor set to Continuous; Finger on there, nonstop
One minute period = 24 Frames

---------

P25 on H1
Tethered: Mac 12\" 867megahertz PB with 10.4.1 Tiger, w/1gig RAM
CaptureOne 3.7 Final
IIQ-Small Setting
Buffer set to 10
Shooting to Desktop (Internal drive)
H1 Motor set to Continuous; Finger on button
One minute period = 10 Frames

---------


- http://www.marktucker.com
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Postby FlemmingHandberg » Tue May 17, 2005 6:47 pm

Yes you pretty much proved it your self... CF cards is faster than shooting tethered. And the faster CF card you can get the faster the write speed is. Usually i guess you will never shoot continously but if you do eg. an Extreem III card is better, but the first approx. 300 MB of data is stored in the buffer of the back and is wrote to the card at the same time as you continue to shoot... In an everyday scenario i doubt that you will improve a lot, but is speed important to you i would go for it and squeeze 1-2 captures more out of the back.

Currently we do not have any official plans with firewire 800 however you can use firewire 800 today, but that will not give you any improvement in performance.

If you really are looking into high speed tethered capture use a Hasselblad V-series on Windows :oops: and P20 (because the filesize is smaller on P20 compared to P25) then i would guess you could reach between 40 and 45 per minute.
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Postby Ashley11 » Tue Jun 21, 2005 10:57 pm

Hi Mark,
Just got two new SanDisk Extreme III, 1gig cards, so decided to test them out against the SanDisk Ultra II, 1gig card, that came with the back.

Results:

P25 on Hasselblad 555ELD
Shooting to SanDisk Extreme III, 1gig
IIQ-Large Setting
Finger on the button.
30 second period = 18 Frames


Slows down slightly after about 21 / 22 frames.
Same results over a 30 second period using IIQ-Small Setting.

P25 on Hasselblad 555ELD
Shooting to SanDisk Ultra II, 1gig
IIQ-Large Setting
Finger on the button.
30 second period = 17 Frames

Frame one seems slow but after that it rattles away.
Took longer for the red light to go out on the back but otherwise, not a lot in it.

Cheers
Ashley
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