7hi is actually SLOWER than 7i

Started Sep 25, 2002 | Discussions
Bill E. Regular Member • Posts: 202
7hi is actually SLOWER than 7i

I just tested how long it took my new 7hi to save a RAW file, using the procedure spelled out in Bryan Biggers's site:

http://webpages.charter.net/bbiggers/DCExperiments/html/dimage_flash_card_speeds.html

With the Ridata 512MB card ("20x"), it took about 16 seconds. According to Bryan's list, the same kind of card in a 7i performs the save operation in only about 10 seconds.

I also tested a Delkin 256MB, which also took 16s compared to 11s with the 7i on the list.

My guess for why the 7hi is slower is that it allows you to start taking additional pictures immediately after you snap the RAW shot. So the processor is partially occupied with running the LCD and being ready to record. Therefore, it gives fewer cycles to the transfer process. If anyone has any other possible explanations, I'd be interested!

This is not a complaint about the 7hi. In terms of functionality, the slow saving by the 7hi is really preferable to the faster save by the 7i, because you can be taking pictures while the save is in progress.

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Bill

José B
José B Forum Pro • Posts: 20,168
Re: 7hi is actually SLOWER than 7i

Bill,

Have you tried how long it took you between shots to shoot in Extra Fine mode? Thanks.

Jose

Bill E. wrote:

I just tested how long it took my new 7hi to save a RAW file, using
the procedure spelled out in Bryan Biggers's site:

http://webpages.charter.net/bbiggers/DCExperiments/html/dimage_flash_card_speeds.html

With the Ridata 512MB card ("20x"), it took about 16 seconds.
According to Bryan's list, the same kind of card in a 7i performs
the save operation in only about 10 seconds.

I also tested a Delkin 256MB, which also took 16s compared to 11s
with the 7i on the list.

My guess for why the 7hi is slower is that it allows you to start
taking additional pictures immediately after you snap the RAW shot.
So the processor is partially occupied with running the LCD and
being ready to record. Therefore, it gives fewer cycles to the
transfer process. If anyone has any other possible explanations,
I'd be interested!

This is not a complaint about the 7hi. In terms of functionality,
the slow saving by the 7hi is really preferable to the faster save
by the 7i, because you can be taking pictures while the save is in
progress.

 José B's gear list:José B's gear list
Sony a6600 Sigma 35mm F1.4 DG HSM Art Carl Zeiss Touit 1.8/32 Carl Zeiss Touit 2.8/12 Sony FE 55mm F1.8 +15 more
OP Bill E. Regular Member • Posts: 202
Re: 7hi is actually SLOWER than 7i

José B wrote:

Have you tried how long it took you between shots to shoot in Extra
Fine mode? Thanks.

There is really no time lag between shots in Extra Fine mode until the buffer is filled up. If you shoot continuously at 3 fps, the buffer fills up after 10 extra fine frames. However, you can still shoot again after about one second because enough of the buffer has been cleared to allow it to accept another image.

-- hide signature --

Bill

William West Senior Member • Posts: 1,237
Re: 7hi is actually SLOWER than 7i

Maybe, a better test for RAW is to take 6 consecutive
RAW images (without flash) and record the time when
you pressed the shutter release for the first image, and
record the time when the camera has finished writing all
images from the buffer to the compact flash card.

Then, you could average the time for each picture, and
see if it comes closer to 10-12 seconds.

William

*TOM* Regular Member • Posts: 143
what time did you measure?

Bill E. wrote:

I just tested how long it took my new 7hi to save a RAW file, using
the procedure spelled out in Bryan Biggers's site:

http://webpages.charter.net/bbiggers/DCExperiments/html/dimage_flash_card_speeds.html

With the Ridata 512MB card ("20x"), it took about 16 seconds.
According to Bryan's list, the same kind of card in a 7i performs
the save operation in only about 10 seconds.

I also tested a Delkin 256MB, which also took 16s compared to 11s
with the 7i on the list.

...
When did you begin counting the time?
Right after the shutter sound or when the CF LED turned on?
As I remenber the times in Bryans list are only the LED-ON time.
I timed my CF card in my D7 by taking a raw image:

16s total (4s after the shutter sound the LED turns on + 12s while the LED is on).

Tom

Bryan Biggers Veteran Member • Posts: 3,588
Re: what time did you measure?

Yes, that is right, just measure the time that the Red LED is on. Hmmm. ithere should not be a 4 second delay until it starts to write unless maybe you have instant playback turned on and set at 2 seconds? Anyway, it does not really matter how long the D7hi takes to save the file, because it can buffer several RAW shots ahead, and the D7i can't do that. As for speed, what Bill mentions with Fine mode sounds like the speed of the D7i, shoot fast for a number of shots, then it slows down to about one shot per second (depends on your card speed), except of course that the D7hi can maintain the 2-3 fps mode for 10 shots and the D7i can only take 4 shots before you slow down to 1 shot per second.

Bryan

TOM wrote:

Bill E. wrote:

I just tested how long it took my new 7hi to save a RAW file, using
the procedure spelled out in Bryan Biggers's site:

http://webpages.charter.net/bbiggers/DCExperiments/html/dimage_flash_card_speeds.html

With the Ridata 512MB card ("20x"), it took about 16 seconds.
According to Bryan's list, the same kind of card in a 7i performs
the save operation in only about 10 seconds.

I also tested a Delkin 256MB, which also took 16s compared to 11s
with the 7i on the list.

...
When did you begin counting the time?
Right after the shutter sound or when the CF LED turned on?
As I remenber the times in Bryans list are only the LED-ON time.
I timed my CF card in my D7 by taking a raw image:
16s total (4s after the shutter sound the LED turns on + 12s while
the LED is on).

Tom

 Bryan Biggers's gear list:Bryan Biggers's gear list
Panasonic Lumix DMC-LX7 Olympus PEN E-P3 Olympus OM-D E-M5 Olympus PEN E-PM2 Olympus E-M5 III
*TOM* Regular Member • Posts: 143
Re: what time did you measure?

Bryan Biggers wrote:

Hmmm. ithere should not be a 4 second delay until it starts to
write unless maybe you have instant playback turned on and set at 2
seconds

Yes, I think instant playback was on.
I'll try it again with instant playback turned off.

Bill: What did YOU measure?

Tom

OP Bill E. Regular Member • Posts: 202
Re: what time did you measure?

Instand playback was off, and I measured only the time the red light was on.

TOM wrote:

Bryan Biggers wrote:

Hmmm. ithere should not be a 4 second delay until it starts to
write unless maybe you have instant playback turned on and set at 2
seconds

Yes, I think instant playback was on.
I'll try it again with instant playback turned off.

Bill: What did YOU measure?

Tom

OP Bill E. Regular Member • Posts: 202
Re: 7hi is actually SLOWER than 7i

Great idea! I just tried that, and the camera recorded 5 RAW images at its "Hi" speed of 3 fps. The red light was on for a total of 71 seconds. So it was averaging about 14 seconds to store each image.

However, for all but 10 of those 71 seconds, the camera was available for picture taking. So we can guess that it was saving at its slow rate for 61 seconds and a faster rate for 10 seconds. Algebraically, it's

10 a + 61 b = 5

where a and b are the fast and slow rates in frames per second. We already know that b is 1/16 frames per second from my first experiment. So if we solve for a we get 0.119 frames per second -- or 8.5 seconds per frame. That's compared to 10 seconds per frame for the 7i. So I guess the 7hi is a bit faster after all. -- Bill

William West wrote:

Maybe, a better test for RAW is to take 6 consecutive
RAW images (without flash) and record the time when
you pressed the shutter release for the first image, and
record the time when the camera has finished writing all
images from the buffer to the compact flash card.

Then, you could average the time for each picture, and
see if it comes closer to 10-12 seconds.

William

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