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10-27-2010, 07:34 PM   #1
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I have a question?

I have a question to anybody who cares to answer! Here goes:

Is the memory Buffer on a DSLR Software related?

The reason for my asking is because I am interested in the K-5, and according to the Manual for JPEGS is 30 Frames, which is probably more then enough for most things, and I have recently started shooting Raw. So with this Camera, I CANNOT SEE MYSELF USING RAW under such conditions as Sports on the K-5, maybe Wildlife or something like that I could see using Raw

The Things I would use K-5 for are Wildlife, Car Racing at local Dirt Track, Portraits, Macro's or Closeups, and maybe Night time Shooting (Stars, the Moon and such).
Anybody, Please help!

10-27-2010, 09:04 PM   #2
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Yes. And no.

EDIT: yes, the buffer is controlled by software. But, it is also hardware. There's a chip of flash memory on the motherboard that stores photos while waiting to be written to the card.

If you need to shoot a burst of more than 30 frames, you should work on your previsualization I'd think. VERY FEW circumstances in which I can imagine needing a buffer of larger than 30 frames.

It's like the old saying, a million monkeys pounding away at a typewriter will eventually produce a Shakespeare.

EDIT2: Also, in the future, try to make your post titles a bit more descriptive.
10-27-2010, 11:03 PM   #3
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No, not software related.

Compressed images (jpg) are smaller than raw images (raw) and therefore it fits more jpgs in the buffer than raws.
10-27-2010, 11:58 PM   #4
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QuoteOriginally posted by sterretje Quote
No, not software related.

Compressed images (jpg) are smaller than raw images (raw) and therefore it fits more jpgs in the buffer than raws.
QuoteOriginally posted by brofkand Quote
Yes. And no.

EDIT: yes, the buffer is controlled by software. But, it is also hardware. There's a chip of flash memory on the motherboard that stores photos while waiting to be written to the card.

If you need to shoot a burst of more than 30 frames, you should work on your previsualization I'd think. VERY FEW circumstances in which I can imagine needing a buffer of larger than 30 frames.

It's like the old saying, a million monkeys pounding away at a typewriter will eventually produce a Shakespeare.

EDIT2: Also, in the future, try to make your post titles a bit more descriptive.
Man this is confusing, you say it is Software base, the one below you says it is not.
Folks let's get our facts straight please

10-28-2010, 12:14 AM   #5
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QuoteOriginally posted by Pentax Lover Quote
Man this is confusing, you say it is Software base, the one below you says it is not.
Folks let's get our facts straight please
That is because It's a strange question. The camera is a computer, is it software related?
Naturally there is hardware limits and of course there is software running that uses the hardware.
10-28-2010, 12:56 AM   #6
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QuoteOriginally posted by Gimbal Quote
That is because It's a strange question. The camera is a computer, is it software related?
Naturally there is hardware limits and of course there is software running that uses the hardware.
Exactly. It's not software related because the size of the buffer (in terms of megabytes or gigabytes or whatever) is a finite limit; a hardware problem.

However, the software could certainly do a better job of optimizing itself to the hardware limitations in place.

Thus, it is a hardware AND a software problem. Both, and at the same time one or the other.
10-28-2010, 01:40 AM   #7
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In my point of view...buffering is a hardware related.

However, the total buffering capacities written within the manual is the average throughput tested by the manufacturer (Pentax in this case).
EDIT: the actual frame burst maybe different from the manual.

Also, as Sterretje said, JPEG (compressed) images are smaller in size compared to RAW, around a quarter of RAW file size. If you are willing to do panning shots, try to minimize the "bottleneck" of the file transfer by buying fast SDHC cards. Thus, the file transfer rates (the progress of saving RAW files you took) from buffer memory in your camera to the cards can be done faster.

The software (or I'd prefer to call it firmware) only has minimum impact on doing continuous shooting, because the job is just to tell the camera where to store the buffer and when to store to the card.

Hope this will help. Correct me if im wrong :-) cheers...
10-28-2010, 01:43 AM   #8
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QuoteOriginally posted by Pentax Lover Quote
I have a question to anybody who cares to answer! Here goes:

Is the memory Buffer on a DSLR Software related?
Buffer, being a physical memory is pure hardware. The way DSLR manages its buffer is mostly software.

10-28-2010, 02:05 AM   #9
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QuoteOriginally posted by brofkand Quote
However, the software could certainly do a better job of optimizing itself to the hardware limitations in place.
Mind to elaborate ?
10-28-2010, 02:10 AM   #10
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QuoteOriginally posted by Pentax Lover Quote
I have a question to anybody who cares to answer! Here goes:

Is the memory Buffer on a DSLR Software related?

The reason for my asking is because I am interested in the K-5, and according to the Manual for JPEGS is 30 Frames, which is probably more then enough for most things, and I have recently started shooting Raw. So with this Camera, I CANNOT SEE MYSELF USING RAW under such conditions as Sports on the K-5, maybe Wildlife or something like that I could see using Raw

The Things I would use K-5 for are Wildlife, Car Racing at local Dirt Track, Portraits, Macro's or Closeups, and maybe Night time Shooting (Stars, the Moon and such).
Anybody, Please help!
With questions like this. why worry about RAW in the first place? From reading your other posts I can see that you do have a slight issue putting down a coherent story and there might be multiple reasons for that, some not under your control. Let me try to help:

You pose multiple questions here actually:
1. Is a memory buffer software? (on ANY piece of equipment)
2. Can you fit as many RAWs as JPEGs into a memory buffer of a given size?
3. Is shooting RAW more suited to situations that require multiple frames shot in quick succession?

Answers:
1. A memory buffer is a piece of hardware with read/write access controlled by software. The hardware defines how much space there is so how many files of a given size can be stored. The software defines how quickly the files can be written or read back.
The camera will not be ready for the next shot until the sensor-data of the previous shot have been written to the buffer. More hardware (=memory space) means therefore you can fit more images into the buffer and better software(=read/write speed & control) means an image is written to the buffer faster, releasing the camera for the next shot.
2. A RAW file generally has a larger size than a JPEG (although I have seen cases, with lots of noise, where the opposite was true) so you can fit less images on your memory card as you can see by the available images count on the camera. The exact same thing applies to the buffer as it is made out of similar memory chips as the card you stick into your camera.
Do note that JPEG image size fluctuates with content and an image of a uniform blue wall will be tiny while an image containing many shapes & colors & structures will be huge.
With today's pixelcounts of 14MP+ however, differences should not be huge. Most of my camera JPEGs are 7-10 Mb, PEFs are 11-16Mb.
3. As shown above, access to the (hardware) buffer is controlled by software and RAW files will on the whole be larger than JPEGs. It therefore follows that not only will more JPEGs fit inside the buffer, they will also be written and read more quickly because there are less bits&bytes to store, resulting in a faster release of the camera for the next shot.
Although both buffer hardware (memory chip access speeds) and software (memory controller logic) improve continuously, the curve is flattening out and each successive improvement is less impressive in absolute terms.

Wrapping up: if you are really after pure, blistering speed, there are camera's with dual buffers and multiple controllers that do an awesome job but none of these specialized cameras come cheap. If you are varying your shooting techniques on the basis of the subject matter, JPEG will allow you to fire off more shots in a given minute.

The big question is: once you are in that league of keeping your finger down for 30 shots in a row, do you really care that much for quality issues anymore as it seems more about getting the shot? So why do RAW in that case to begin with. Read up on RAW and what you'd need/want it for and decide for yourself.

[EDIT] Reread and found this shocking error in my text: "not only will more RAWs fit inside the buffer". I obviously meant JPEGs so I corrected the mistake. Apologies to all.

Last edited by newmikey; 10-28-2010 at 02:28 AM.
10-28-2010, 02:34 AM   #11
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Oh my! No sooner had I written my reply or this dpreview post hit my frontal lobe. I think it provides more specific illustration to what I said above:

Dale108 wrote:

One of the only issues I had with the K5 specs is the size of the RAW buffer during continuous shooting compared to the K5. I picked up a K5 this afternoon and in one quick test was only able to shoot 5-6 RAW files before the buffer filled up. This was done under less than ideal conditions indoors. I will continue testing but hopefully i can get better performance as I like to shoot RAW even for wildlife. I may end up keeping the K7 as a backup body as this is somewhat of a disappointment. Overall, the body is exactly the same as the K7 so neat that way. All that was required when taken out of the box was to put in the spare K7 battery, attach the straps and then setup the user menu. Piece of cake. A quick shot at ISO 25600 looked quite good, at least on camera LCD.

10-28-2010, 02:51 AM   #12
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QuoteOriginally posted by sterretje Quote
Mind to elaborate ?
It's like with any piece of electronics. Say the buffer is 1GB and the card can write at 6MB/s.

At 5fps with RAW, you're using roughly 100MB of your buffer each second (assuming a 20MB RAW file, which is big for a K-7 but I don't know what a K-5's raw file sizes are like). The card wrote 6 of that, so you're left with 94MB in your buffer.

After another second, you've shot another 5 shots, 100MB, with 188MB in your buffer.

And so on and so on until your buffer is full.

Assuming the buffer in the K-5 is 1GB (I think that's a reasonable assumption based on the prices of flash memory these days), there's no reason why you shouldn't be able to shoot many more frames than the 5-6 newmikey is quoting before your buffer fills.
10-28-2010, 03:03 AM   #13
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QuoteOriginally posted by brofkand Quote
Assuming the buffer in the K-5 is 1GB (I think that's a reasonable assumption based on the prices of flash memory these days)
I would see that proven please - seems highly unlikely, ridiculous actually as 1GB equals a whopping 100-125 jpegs rather than the 30 quoted.

QuoteQuote:
there's no reason why you shouldn't be able to shoot many more frames than the 5-6 newmikey is quoting before your buffer fills.
You have not held a K-5 therefore YOU do not know why there would be "no reason". Neither do I. I merely quoted someone who used a K-5 in exactly that way and lets us know about his experience.

He has actually pushed the shutter on a K-5 in RAW mode and held it down, we don't and we haven't so I am unsure why you would answer like you did.

Your math is way off because while the buffer is filling up from the sensor side, it is at the same time emptying to the camera's SHDC drive.
10-28-2010, 03:29 AM   #14
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For what it's worth, the K5 will shoot 8 continuous raw frame before pausing at ISO levels from 800-5000. At ISO 6400 to 51200, the K5 will shoot 4 continuous raw frame before pausing. There is something going on internally at ISO 6400 and above which cuts the number of raw files that can be continuously shot in half.
10-28-2010, 03:43 AM   #15
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QuoteOriginally posted by dgaies Quote
For what it's worth, the K5 will shoot 8 continuous raw frame before pausing at ISO levels from 800-5000. At ISO 6400 to 51200, the K5 will shoot 4 continuous raw frame before pausing. There is something going on internally at ISO 6400 and above which cuts the number of raw files that can be continuously shot in half.
Thanks! That's conclusive info that will help the OP much more, I'm sure. Do you think the explanation is because of the buffer model? (see buffer explanations here)

Chances are that from ISO6400 and upward, some heavy(ier) NR is applied on the data in the buffer, before it is sent on its way to the memory card. If the K-5's buffer logic is setup this way:

that would explain the slowdown. TANSTAAFL, I suppose. The laws of physics are not bendable, not even for Pentax
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