Buffer question.

[lejazzcat]

Hi
Just reading through the manual (RTFM) and noticed that the buffer table on p62(72of 218) "choosing a shooting mode" shows the buffer can hold more L size images than M size in a burst/continuous mode - why is that?
the S has the most , which stands to reason ...

and yet the file sizes are larger for L than M .

TIA

[Greg B]

Firstly, good work for reading the manual.

Secondly, this is a strange thing. Even more strangely, the number of Medium size shots the buffer can hold is 7 for Basic, Normal and Fine, even though the number of Small and Large shots vary between the three.

Thirdly, Thom Hogan in his book confirms that this odd situation is correct, but unfortunately doesn't say why.

[stubbsy]

Firstly, good work for reading the manual.

Secondly, this is a strange thing. Even more strangely, the number of Medium size shots the buffer can hold is 7 for Basic, Normal and Fine, even though the number of Small and Large shots vary between the three.

Thirdly, Thom Hogan in his book confirms that this odd situation is correct, but unfortunately doesn't say why.

Or the manual is wrong & Thom just lifted it from the manual

[Greg B]

I can understand the manual being wrong, but not Thom!!!

(He does actually note that "This is correct")

[lejazzcat]

Firstly, good work for reading the manual.

Secondly, this is a strange thing. Even more strangely, the number of Medium size shots the buffer can hold is 7 for Basic, Normal and Fine, even though the number of Small and Large shots vary between the three.

Thirdly, Thom Hogan in his book confirms that this odd situation is correct, but unfortunately doesn't say why.

Quite right , youd think the resolution would affect the buffer capacity.
I wonder if its the same with the other models - D1/D2(...xyz)?

[digitor]

Hi
Just reading through the manual (RTFM) and noticed that the buffer table on p62(72of 218) "choosing a shooting mode" shows the buffer can hold more L size images than M size in a burst/continuous mode - why is that?
the S has the most , which stands to reason ...

and yet the file sizes are larger for L than M .

TIA

I noticed this when I first got the camera - the only thing I can think of is that it's to do with the way the processor uses buffer space for temp. files when changing the resolution.

Cheers

[radar]

Hi,

The camera-indicated buffer size at NORMAL compression is 12 frames at large JPG, drops to 7 images when set to JPG medium (2,240 x 1,448 pixels) and goes up to 27 images when set to JPG small (1,504 x 1,000 pixels). It is more at SMALL and less at FINE compression settings. This makes sense: it takes more internal memory for the algorithms to process the more complex non-integer size transform for the medium size, and it must take much fewer resources to scale the image by exactly one-half for the smallest size. Of course since the camera writes pretty fast you may not fill up the buffer at all and can shoot continuously at some settings.

That is Ken Rockwell's explanation. I was thinking about something along those lines, ie one format needs more processing then the other so it is a processing speed issue not a buffer size issue, but he is better at putting it to words. This is the page he talks about it.

http://www.kenrockwell.com/nikon/d70.htm

HTH,

Radar.

[Glen]

Greg B, I obviously haven't told you about the email Thom sent me in which he insists a foot is 28cm and a foot varies between 11-13 inches. Knowing your penchant for maths and accuracy, if you would have received it I am sure it would be the start of many missives from you. He didn't stand corrected when I did correct him.

[lejazzcat]

Hi,

The camera-indicated buffer size at NORMAL compression is 12 frames at large JPG, drops to 7 images when set to JPG medium (2,240 x 1,448 pixels) and goes up to 27 images when set to JPG small (1,504 x 1,000 pixels). It is more at SMALL and less at FINE compression settings. This makes sense: it takes more internal memory for the algorithms to process the more complex non-integer size transform for the medium size, and it must take much fewer resources to scale the image by exactly one-half for the smallest size. Of course since the camera writes pretty fast you may not fill up the buffer at all and can shoot continuously at some settings.

That is Ken Rockwell's explanation. I was thinking about something along those lines, ie one format needs more processing then the other so it is a processing speed issue not a buffer size issue, but he is better at putting it to words. This is the page he talks about it.

http://www.kenrockwell.com/nikon/d70.htm

HTH,

Radar.

ty Radar.
Interesting explaination and link.
The only thing is that S is more than twice as fast as L !
If the algorithmic processing/compression was the culprit that forced M to be so slow, then ide expect S to still be less than twice the buffer capacity of L.
IMO, theres something else going on. It has me baffled ...

Are all of the nikon DSLR's similarily affected ? D2X owners?

( 100 ! )

[Greg B]

Greg B, I obviously haven't told you about the email Thom sent me in which he insists a foot is 28cm and a foot varies between 11-13 inches. Knowing your penchant for maths and accuracy, if you would have received it I am sure it would be the start of many missives from you. He didn't stand corrected when I did correct him.

Glen, I do recall that now you mention it. Very strange behaviour from the Thomster. It does throw the veil of uncertainty over the entire Thom experience.

And yes, I would have engaged Thom in an exchange on that issue. There are people who will not admit when they are wrong, foolish people in my view (and I am always right about these things ), and I am much more concerned about people who can't accept correction than I am about those who make more errors but are happy to learn.

Anyhoo, now I'm confused.

But it seems that Kenny Rockwell is onto it too, and Kenny is never wrong.

[Glen]

Greg, like you I am happy to stand corrected. What was even funnier about my exchanges with Thom was I was correcting an error on his website where he chides Nikon for being wrong, when in fact they are right! (they are a metric country after all). That error is there to this day in his 12-24 review. Personally, if I had described black as white on my website and someone had pointed out my mistake, I would change it immediately and thank the person.

[Onyx]

Glen - he's probably got a complex. It's a loss cause... (BTW, hi Thom if you're reading this).

This camera buffer issue I thought I had covered in the Camera FAQ (which I haven't updated in yonks). Maybe I didn't. Anyways, it's an anomaly of the D70 (no other Nikon cameras) - the other was the NEF remaining shots counter which was corrected in firmware version 2. The D70s' manual seems to have figures which indicate this anomaly has been carried over to the newer model - so the explainations of camera's processing requirements of medium size images and the buffer's use as essentially "RAM" could be accurate.