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07-15-2009, 09:15 AM   #31
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QuoteOriginally posted by ftpaddict Quote
Couldn't agree more; though you may be surprised by what you can find out there.

I got me a stupid-cheap 8 GB Class 6 A-Data SD card, and typical write speeds are 10 MB/s or more; depending on the writer.

why stupid?

07-15-2009, 11:35 AM   #32
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Nice series.

What was your focus set to, AF-S, AF-C, or M?
07-15-2009, 12:14 PM   #33
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QuoteOriginally posted by Leaf Fan Quote
Nice series.

What was your focus set to, AF-S, AF-C, or M?

It was set to AF-S.. I was trying to determine the speed it could focus, as well as FPS testing.

I could have set with either 2 other options for better safer results, but that was not what I was looking for.


Cheers


Neil
07-15-2009, 01:49 PM   #34
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QuoteOriginally posted by Pentaxor Quote
why stupid?
Replace with "ridiculously".

07-15-2009, 03:22 PM   #35
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QuoteOriginally posted by ftpaddict Quote
Replace with "ridiculously".
that's better. I thought you hated it !

got a 2x16 gb turbo version of the A-DATA for an insanely cheap price as well.
07-15-2009, 06:36 PM   #36
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It's not Neil Put To Test.It's K7 fps Put To Test.Some of the replys have really gone off track from the speed of the K7,to picking on Neil's photographing techniques.STICK TO THE MAIN SUBJECT GUYS!As far as I can see,Neil's main subject,which is the boy on the scooter is well in focus.My fav of the pics would be the 5th one down.Keep up the good work Neil,and bring us somemore of the Action shots with the K7.

Last edited by Barnster; 07-15-2009 at 08:05 PM.
07-21-2009, 06:33 AM   #37
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It seems to me that if AF was set to AF-S, then this is not a test of the K-7's fast-focusing ability as the camera only focused for the first shot. The sequence worked out as well as it did because most of the motion is in the same plane relative to the camera, ie no forward-backward motion. Apparently the only thing tested was FPS and not AF speed.

CN
07-21-2009, 09:55 AM   #38
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Wow, with HD video and HDR mode the K-7 is great for action shots so it does look like a true upgrade from the K-20D.

07-21-2009, 10:34 AM   #39
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Nothing to do with the card

I set the camera to AF-S, SEL (centre). Using the same Kingston class 6 SDHC, when I point it at the light, it shoots at >4 fps (didn't count precisely, but it should be 5), but when I point it at something dark, it falls to 3 fps or sometimes less.
07-22-2009, 04:49 AM   #40
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QuoteOriginally posted by wolfier Quote
when I point it at something dark, it falls to 3 fps or sometimes less.
5.2fps means 192ms per image.
1/15s exposure would be 67ms.

192+67=259ms or 3.9fps.

We all have to learn that 5.2fps are a lot and it is really easy to slow it down for reasons which aren't camera-related.
07-22-2009, 05:42 AM   #41
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QuoteOriginally posted by wolfier Quote
I set the camera to AF-S, SEL (centre). Using the same Kingston class 6 SDHC, when I point it at the light, it shoots at >4 fps (didn't count precisely, but it should be 5), but when I point it at something dark, it falls to 3 fps or sometimes less.
Yes in low light, it's better to use Manual metering. I noticed a big difference in fps between AE modes and Manual exposure in low light.

The Kingston Class 6 SDHC is rather slow BTW. I received my Sandisk Extreme III 8Gb yesterday and I did make a quick test between the:
1) Sandisk Extreme III 4Gb 30Mb/s edition
2) Panasonic Gold class 6 4Gb
3) Sandisk Extreme III 8Gb 20Mb/s
4) Toshiba Class 4 4Gb
5) Kingston Class 6 8Gb

The first 3 gave roughly the same performance (a rough calculation put them at about 12-15Mb/s).
The last 2 had about the same performance too but were about two times slower. I had about the same kind of performane on the K20D. On the K-m it's less problematic because the buffer is very short and the files smaller.
07-24-2009, 09:24 AM   #42
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QuoteOriginally posted by falconeye Quote
5.2fps means 192ms per image.
1/15s exposure would be 67ms.

192+67=259ms or 3.9fps.

We all have to learn that 5.2fps are a lot and it is really easy to slow it down for reasons which aren't camera-related.
I wasn't paying attention to the shutter speed, it was just a quick test :P

What you point out seems to make a lot of sense, although it implies the 192ms to be a "fixed cost". I thought the 67ms would be included in the 192ms since the exposure time is within the time between mirror-up and mirror-down, so the FPS should only decrease to 3 fps or below if the shutter speed drops to 1/3 second.

I'll try again when I get home with a higher ISO or a -2 EC just to confirm. I'll keep every other variable constant.
07-24-2009, 09:27 AM   #43
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QuoteOriginally posted by ManuH Quote
Yes in low light, it's better to use Manual metering. I noticed a big difference in fps between AE modes and Manual exposure in low light.

The Kingston Class 6 SDHC is rather slow BTW. I received my Sandisk Extreme III 8Gb yesterday and I did make a quick test between the:
1) Sandisk Extreme III 4Gb 30Mb/s edition
2) Panasonic Gold class 6 4Gb
3) Sandisk Extreme III 8Gb 20Mb/s
4) Toshiba Class 4 4Gb
5) Kingston Class 6 8Gb

The first 3 gave roughly the same performance (a rough calculation put them at about 12-15Mb/s).
The last 2 had about the same performance too but were about two times slower. I had about the same kind of performane on the K20D. On the K-m it's less problematic because the buffer is very short and the files smaller.
This is interesting, although I seldom need anything more than 4 fps. I found the Kingston can take 5 fps photos, maybe I just didn't wait for the buffer to get full, but for short bursts, it seems good enough for me
07-24-2009, 09:44 AM   #44
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QuoteOriginally posted by wolfier Quote
This is interesting, although I seldom need anything more than 4 fps. I found the Kingston can take 5 fps photos, maybe I just didn't wait for the buffer to get full, but for short bursts, it seems good enough for me
Any card will take 5fps because we have a generous buffer on the K-7 (14 DNG at the minimum). The difference is the buffer flushing speed. It takes twice the time to write the buffer onto a Kingston Class 6 SD card than onto a Sandisk Extreme III. Not such a big deal when you don't do a lot of bursts but when you do the Kingston feels very sluggish.

I did my test like this: I took pictures (DNG) in burst mode (all settings manual to get the fastest fps) during 5 seconds continuously. I then look how many pictures were taken and how much time it took for the buffer to be completely cleared.

The Sandisk and the Panasonic did 17 shots and took 13 to 15s to flush the buffer. The Toshiba (class 4) and Kingston took 14 shots and flushed the buffer in 31s (Toshiba) and 35s (Kingston). Unfortunately I forgot to check the size of the DNG to calculate the writing speed in Mb/s.
07-24-2009, 01:47 PM   #45
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QuoteOriginally posted by wolfier Quote
I thought the 67ms would be included in the 192ms since the exposure time is within the time between mirror-up and mirror-down
The included time between mirror up and down is 6ms (corresponding to 1/180X flash snyc speed). This is the time the shutter's open slit needs to travel from one edge to the other. But the actual time between curtains is not included, of course.

(192-6)/2ms=93ms is the time which the mirror is moved in once.

Interestingly, the K-7 doesn't do faster bursts if the mirror stays open (like when started from live view). I believe, there is some dead time (i.e. time where mirror is down) where the sensor is read out. We know from live view bandwidth that a full sensor read out takes about 170ms.
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