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Canon A510 question about file type & sise

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March 13, 2005 7:58:03 AM

Archived from groups: rec.photo.digital (More info?)

I just purchased a new Canon A510 & really love it.
However, I'm a little confused about file type & size.

Questions:

Is there a way to copy the "RAW" file images from the
A510 to my PC hard drive? I use XP Pro to simply "copy" the
JPG images to a folder via a USB cable while running Windows
Explorer. I do not use any Canon, etc. software.
I have no problem copying over the A510 JPG images to my hard drive
and viewing the JPG images on my PC.

This is a 3.2MP camera. I want to shoot "every" photo at
MAXIMUM quality. Therefore, I set the A510 to 2048x1536
and Superfine - which seems to be the maximum setting possible.
I make this assumption because it creates the largest file size of
all possible settings. I shot ~300 photos in a number
of different locations, lighting, etc. I "assumed" that the camera
would generate ~3MP image file sizes. It does not. The JPG
image sizes ranged from 1010KB to 2705KB. QUESTION:
How do I set this camera to get a 3MP image each & every
shot? Are the RAW images in the camera, or does it do the
JPEG conversion "on-the-fly" , thereby not preserve the
original raw data?

I did a little test.
I shot three photos under the same conditions.
Photo #1 was 2048x1536 Superfine = 1419BK JPG file
Photo #2 was 2048x1536 Fine = 879BK JPG file
Photo #3 was 2048x1536 Normal = 401BK JPG file

After blowing-up and comparing the above three JPG images,
I really can't see "any" difference in image quality.
They all look the same to me.

Here is my conclusion per the above.
To get the BEST quality photos: Set my Canon A510 to
2048x1536 Superfine and live with the fact that the
A510 converts the raw image data to a JPG file of
varying sizes. Given the settings of 2048x1536 Superfine,
there is nothing else I can do to cause this A510 to
generate an image of more pixels, or a larger JPG
image file. I'm going to get what I get, and I can't save raw
image files to my hard drive.

THANKS,
Gene
March 13, 2005 7:58:04 AM

Archived from groups: rec.photo.digital (More info?)

I don't think you can get RAW files from that camera. It would be a
specific mode if available.

3MP means 3 million pixels, not the file size.
2048x1536 = 3,145,728 pixels.

The file size varies according to the amount of detail in the image,
even for uncompressed images. A piture of tree branches will be larger
than a picture of a blank sky.

You should be able to tell the difference in the different settings,
jpeg compression simplifies in squares so you can see a larger grid
(artifacts) plus posterization in skys due to reducing the number of
colors in a gradual gradation. Try zooming in a ridiculous amount like
400% or more in the lower quality jpegs. Try saving an image at a
ridiculously low quality jpeg setting to get a feel for what jpeg
compression looks like if you don't know that will help.

The high quality jpegs from my D70 are very hard to see any squareish
artifacts until you zoom wayy the hell in. It's equivalent to about 95%
quality & I'm sure your camera is similar. My Olympus C3030 with 3MP
typically produced about 700K files so yours is less compression than
that at 1,400K for the same number of pixels.

RAW files would only be a significant benefit if you planned to do post
processing stretching the exposure & contrast but if you got the
exposure correct, the jpegs are indeed virtually indistinguishable from
anything a RAW file could create. Very subtle differences in the more
careful on-computer processing compared to the speed optimized in-camera
processing but no big deal. I made hundreds of lovely 8x10 prints from
my 3MP 700K images & I'm sure you will also have a lot of fun with this!



Gene wrote:

> I just purchased a new Canon A510 & really love it.
> However, I'm a little confused about file type & size.
>
> Questions:
>
> Is there a way to copy the "RAW" file images from the
> A510 to my PC hard drive? I use XP Pro to simply "copy" the
> JPG images to a folder via a USB cable while running Windows
> Explorer. I do not use any Canon, etc. software.
> I have no problem copying over the A510 JPG images to my hard drive
> and viewing the JPG images on my PC.
>
> This is a 3.2MP camera. I want to shoot "every" photo at
> MAXIMUM quality. Therefore, I set the A510 to 2048x1536
> and Superfine - which seems to be the maximum setting possible.
> I make this assumption because it creates the largest file size of
> all possible settings. I shot ~300 photos in a number
> of different locations, lighting, etc. I "assumed" that the camera
> would generate ~3MP image file sizes. It does not. The JPG
> image sizes ranged from 1010KB to 2705KB. QUESTION:
> How do I set this camera to get a 3MP image each & every
> shot? Are the RAW images in the camera, or does it do the
> JPEG conversion "on-the-fly" , thereby not preserve the
> original raw data?
>
> I did a little test.
> I shot three photos under the same conditions.
> Photo #1 was 2048x1536 Superfine = 1419BK JPG file
> Photo #2 was 2048x1536 Fine = 879BK JPG file
> Photo #3 was 2048x1536 Normal = 401BK JPG file
>
> After blowing-up and comparing the above three JPG images,
> I really can't see "any" difference in image quality.
> They all look the same to me.
>
> Here is my conclusion per the above.
> To get the BEST quality photos: Set my Canon A510 to
> 2048x1536 Superfine and live with the fact that the
> A510 converts the raw image data to a JPG file of
> varying sizes. Given the settings of 2048x1536 Superfine,
> there is nothing else I can do to cause this A510 to
> generate an image of more pixels, or a larger JPG
> image file. I'm going to get what I get, and I can't save raw
> image files to my hard drive.
>
> THANKS,
> Gene
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Anonymous
March 13, 2005 7:58:04 AM

Archived from groups: rec.photo.digital (More info?)

Don't know much about your camera and RAW images, but regardless of your
camera, every JPG image will be a different size based on the image and
colors in it. Take a shot of something with lots of colors and detail, and
then take a picture of a clear blue sky, or a white sheet of paper. The
shot with one color in the entire image will be quite small, as there isn't
much data to record.

During the compression process the data is basically "make every pixel blue"
for the sky, or "make every pixel white" for the sheet of paper. Put a
couple of marks on the sheet of paper and the jpg image size will go up a
bit.


"Gene" <genes@thegateway.net> wrote in message
news:vLPYd.205$3c2.22482@monger.newsread.com...
>I just purchased a new Canon A510 & really love it.
> However, I'm a little confused about file type & size.
>
> Questions:
>
> Is there a way to copy the "RAW" file images from the
> A510 to my PC hard drive? I use XP Pro to simply "copy" the
> JPG images to a folder via a USB cable while running Windows
> Explorer. I do not use any Canon, etc. software.
> I have no problem copying over the A510 JPG images to my hard drive
> and viewing the JPG images on my PC.
>
> This is a 3.2MP camera. I want to shoot "every" photo at
> MAXIMUM quality. Therefore, I set the A510 to 2048x1536
> and Superfine - which seems to be the maximum setting possible.
> I make this assumption because it creates the largest file size of
> all possible settings. I shot ~300 photos in a number
> of different locations, lighting, etc. I "assumed" that the camera
> would generate ~3MP image file sizes. It does not. The JPG
> image sizes ranged from 1010KB to 2705KB. QUESTION:
> How do I set this camera to get a 3MP image each & every
> shot? Are the RAW images in the camera, or does it do the
> JPEG conversion "on-the-fly" , thereby not preserve the
> original raw data?
>
> I did a little test.
> I shot three photos under the same conditions.
> Photo #1 was 2048x1536 Superfine = 1419BK JPG file
> Photo #2 was 2048x1536 Fine = 879BK JPG file
> Photo #3 was 2048x1536 Normal = 401BK JPG file
>
> After blowing-up and comparing the above three JPG images,
> I really can't see "any" difference in image quality.
> They all look the same to me.
>
> Here is my conclusion per the above.
> To get the BEST quality photos: Set my Canon A510 to
> 2048x1536 Superfine and live with the fact that the
> A510 converts the raw image data to a JPG file of
> varying sizes. Given the settings of 2048x1536 Superfine,
> there is nothing else I can do to cause this A510 to
> generate an image of more pixels, or a larger JPG
> image file. I'm going to get what I get, and I can't save raw
> image files to my hard drive.
>
> THANKS,
> Gene
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
>
Related resources
Anonymous
March 13, 2005 12:17:15 PM

Archived from groups: rec.photo.digital (More info?)

Gene wrote:

> I just purchased a new Canon A510 & really love it.
> However, I'm a little confused about file type & size.
>
> Questions:
>
> Is there a way to copy the "RAW" file images from the
> A510 to my PC hard drive? I use XP Pro to simply "copy" the
> JPG images to a folder via a USB cable while running Windows

The A510 does not save in RAW format. JPEG is all you get.

> I shot ~300 photos in a number
> of different locations, lighting, etc. I "assumed" that the camera
> would generate ~3MP image file sizes. It does not.

The fact that the prefix 'Mega' is used tends to confuse
people. Mega is the designator for 1 million and nothing
more. You can't directly equate pixels to bytes without
knowing something about the bytes.

A byte is a unit of storage. In the case of your camera,
a single byte doesn't contain enough data to represent the
information in a single pixel. In order to store all the
information in one pixel, it takes 3 bytes.

So.. the sensor on your 3 Mp camera captures 9 megabytes of
information each time you take a picture. (3MP x 3 bytes)

If your camera could record as uncompressed TIFF, then the
files would be a bit over 9 Mb each.

> I did a little test.
> I shot three photos under the same conditions.
> Photo #1 was 2048x1536 Superfine = 1419BK JPG file
> Photo #2 was 2048x1536 Fine = 879BK JPG file
> Photo #3 was 2048x1536 Normal = 401BK JPG file

Here's where the confusion lies. JPEG uses a compression
scheme so the saved file is *much* smaller than the original
image. You can vary this compression.. Your camera's
Superfine has the least compression and Normal has the
most. The whole purpose of compressing the data is to
save memory card space.

The compression is lossy. Some color information is
discarded during the compression. You don't lose any pixels,
but you do lose subtle color differences. As you've noticed,
at the compression levels your camera uses, you can't readily
see the difference so they truly are 'subtle' losses.
This is why JPEG works and why it's so popular.

You'll also notice that the file sizes vary even if you
take them all in Superfine. A shot of the blue sky alone
will be MUCH smaller than a shot with lots of detail
like branches and leaves on a tree. This is because the
solid blue of the sky is easier to compress than the high
detail in leaves and branches.

Note that you can apply a lot more compression than your
camera does to obtain even smaller file sizes, but the data
loss will become apparent. You'll see banding in large areas
of solid color and you'll see smudges (called artifacts) in
areas of bright/dark transition.

> Here is my conclusion per the above.
> To get the BEST quality photos: Set my Canon A510 to
> 2048x1536 Superfine and live with the fact that the
> A510 converts the raw image data to a JPG file of
> varying sizes. Given the settings of 2048x1536 Superfine,
> there is nothing else I can do to cause this A510 to
> generate an image of more pixels, or a larger JPG
> image file. I'm going to get what I get, and I can't save raw
> image files to my hard drive.

That's correct :-)

Your camera captures 9 Megabytes when you shoot. Depending
on the level of compression you choose, this 9 Megabytes is
'shrunk' down to around 1.5MB in Superfine or around 5Kb in
Normal.

It's hard to tell by looking at the image when it's the same
size as your monitor, but the Normal compression level isn't
as good as Superfine. There is less color information in the
Normal file, so you should use Superfine all the time.

A Superfine image is approx 1.5 Mb on disk, but it does 'inflate'
back to 9 Megabytes when gets uncompressed as it's loaded into your
computer's memory.

Note that if you save the image back to disk, the 9 Megabytes
will be compressed again. The compression this time depends on
your editing software. The image could be larger or smaller
depending on the software settings.

If you choose 'save as' an uncompressed TIFF, then the image
won't be shrunk when it's saved back to disk and you will
have a file that's around 9 Megapixels.
Anonymous
March 13, 2005 12:21:20 PM

Archived from groups: rec.photo.digital (More info?)

"Gene" <genes@thegateway.net> writes:

> Now that I have a better understanding of the A510 design, I will
> probably buy the A530 (replacement for the ~5MP Canon A95)
> when it ships. We plan to use a HDTV to display the image slide shows,
> so I "suspect" that a ~5MP camera will produce a much better image -
> but I have not researched what JPG file size will display best on
> a large HDTV.

I suspect you'll be surprised. Isn't the *top* "HD" TV resolution
something like 1920x768? That's just 1.5 megapixels!
--
David Dyer-Bennet, <mailto:D d-b@dd-b.net>, <http://www.dd-b.net/dd-b/&gt;
RKBA: <http://noguns-nomoney.com/&gt; <http://www.dd-b.net/carry/&gt;
Pics: <http://dd-b.lighthunters.net/&gt; <http://www.dd-b.net/dd-b/SnapshotAlbum/&gt;
Dragaera/Steven Brust: <http://dragaera.info/&gt;
March 13, 2005 6:00:56 PM

Archived from groups: rec.photo.digital (More info?)

Thanks, Paul.

I was hoping that there was a way to capture a raw file
that had "one" byte per pixel :-)

I waited for two years to buy a new camera, nothing
looked good until now. This little 3.2MP Canon A510 is
awesome. The more I play with it, the more I like it.
It's a replacement for the Canon A75.

Now that I have a better understanding of the A510 design, I will
probably buy the A530 (replacement for the ~5MP Canon A95)
when it ships. We plan to use a HDTV to display the image slide shows,
so I "suspect" that a ~5MP camera will produce a much better image -
but I have not researched what JPG file size will display best on
a large HDTV.

Gene





"paul" <paul@not.net> wrote in message
news:D KCdnUaqWrr7S67fRVn-qQ@speakeasy.net...
>I don't think you can get RAW files from that camera. It would be a
>specific mode if available.
>
> 3MP means 3 million pixels, not the file size.
> 2048x1536 = 3,145,728 pixels.
>
> The file size varies according to the amount of detail in the image, even
> for uncompressed images. A piture of tree branches will be larger than a
> picture of a blank sky.
>
> You should be able to tell the difference in the different settings, jpeg
> compression simplifies in squares so you can see a larger grid (artifacts)
> plus posterization in skys due to reducing the number of colors in a
> gradual gradation. Try zooming in a ridiculous amount like 400% or more in
> the lower quality jpegs. Try saving an image at a ridiculously low quality
> jpeg setting to get a feel for what jpeg compression looks like if you
> don't know that will help.
>
> The high quality jpegs from my D70 are very hard to see any squareish
> artifacts until you zoom wayy the hell in. It's equivalent to about 95%
> quality & I'm sure your camera is similar. My Olympus C3030 with 3MP
> typically produced about 700K files so yours is less compression than that
> at 1,400K for the same number of pixels.
>
> RAW files would only be a significant benefit if you planned to do post
> processing stretching the exposure & contrast but if you got the exposure
> correct, the jpegs are indeed virtually indistinguishable from anything a
> RAW file could create. Very subtle differences in the more careful
> on-computer processing compared to the speed optimized in-camera
> processing but no big deal. I made hundreds of lovely 8x10 prints from my
> 3MP 700K images & I'm sure you will also have a lot of fun with this!
>
>
>
> Gene wrote:
>
>> I just purchased a new Canon A510 & really love it.
>> However, I'm a little confused about file type & size.
>>
>> Questions:
>>
>> Is there a way to copy the "RAW" file images from the
>> A510 to my PC hard drive? I use XP Pro to simply "copy" the
>> JPG images to a folder via a USB cable while running Windows
>> Explorer. I do not use any Canon, etc. software.
>> I have no problem copying over the A510 JPG images to my hard drive
>> and viewing the JPG images on my PC.
>>
>> This is a 3.2MP camera. I want to shoot "every" photo at
>> MAXIMUM quality. Therefore, I set the A510 to 2048x1536
>> and Superfine - which seems to be the maximum setting possible.
>> I make this assumption because it creates the largest file size of
>> all possible settings. I shot ~300 photos in a number
>> of different locations, lighting, etc. I "assumed" that the camera
>> would generate ~3MP image file sizes. It does not. The JPG
>> image sizes ranged from 1010KB to 2705KB. QUESTION:
>> How do I set this camera to get a 3MP image each & every
>> shot? Are the RAW images in the camera, or does it do the
>> JPEG conversion "on-the-fly" , thereby not preserve the
>> original raw data?
>>
>> I did a little test.
>> I shot three photos under the same conditions.
>> Photo #1 was 2048x1536 Superfine = 1419BK JPG file
>> Photo #2 was 2048x1536 Fine = 879BK JPG file
>> Photo #3 was 2048x1536 Normal = 401BK JPG file
>>
>> After blowing-up and comparing the above three JPG images,
>> I really can't see "any" difference in image quality.
>> They all look the same to me.
>>
>> Here is my conclusion per the above.
>> To get the BEST quality photos: Set my Canon A510 to
>> 2048x1536 Superfine and live with the fact that the
>> A510 converts the raw image data to a JPG file of
>> varying sizes. Given the settings of 2048x1536 Superfine,
>> there is nothing else I can do to cause this A510 to
>> generate an image of more pixels, or a larger JPG
>> image file. I'm going to get what I get, and I can't save raw
>> image files to my hard drive.
>>
>> THANKS,
>> Gene
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
March 13, 2005 6:08:55 PM

Archived from groups: rec.photo.digital (More info?)

Thanks, Sheldon.

I'm getting a better grasp of all the features of this little Canon
A510 3.2MP camera. It's incredible how many scene modes,
and manual settings available! It's going to take months to try all
of them out ... and I thought my old Canon SLR 35mm stuff was
complicated:-)

When the ~ 5MP A530 comes out, I will upgrade to it.

Gene




"Sheldon" <sheldon@XXXXXXXXsopris.net> wrote in message
news:JpSdncdUk5hARq7fRVn-iw@comcast.com...
> Don't know much about your camera and RAW images, but regardless of your
> camera, every JPG image will be a different size based on the image and
> colors in it. Take a shot of something with lots of colors and detail,
> and then take a picture of a clear blue sky, or a white sheet of paper.
> The shot with one color in the entire image will be quite small, as there
> isn't much data to record.
>
> During the compression process the data is basically "make every pixel
> blue" for the sky, or "make every pixel white" for the sheet of paper.
> Put a couple of marks on the sheet of paper and the jpg image size will go
> up a bit.
>
>
> "Gene" <genes@thegateway.net> wrote in message
> news:vLPYd.205$3c2.22482@monger.newsread.com...
>>I just purchased a new Canon A510 & really love it.
>> However, I'm a little confused about file type & size.
>>
>> Questions:
>>
>> Is there a way to copy the "RAW" file images from the
>> A510 to my PC hard drive? I use XP Pro to simply "copy" the
>> JPG images to a folder via a USB cable while running Windows
>> Explorer. I do not use any Canon, etc. software.
>> I have no problem copying over the A510 JPG images to my hard drive
>> and viewing the JPG images on my PC.
>>
>> This is a 3.2MP camera. I want to shoot "every" photo at
>> MAXIMUM quality. Therefore, I set the A510 to 2048x1536
>> and Superfine - which seems to be the maximum setting possible.
>> I make this assumption because it creates the largest file size of
>> all possible settings. I shot ~300 photos in a number
>> of different locations, lighting, etc. I "assumed" that the camera
>> would generate ~3MP image file sizes. It does not. The JPG
>> image sizes ranged from 1010KB to 2705KB. QUESTION:
>> How do I set this camera to get a 3MP image each & every
>> shot? Are the RAW images in the camera, or does it do the
>> JPEG conversion "on-the-fly" , thereby not preserve the
>> original raw data?
>>
>> I did a little test.
>> I shot three photos under the same conditions.
>> Photo #1 was 2048x1536 Superfine = 1419BK JPG file
>> Photo #2 was 2048x1536 Fine = 879BK JPG file
>> Photo #3 was 2048x1536 Normal = 401BK JPG file
>>
>> After blowing-up and comparing the above three JPG images,
>> I really can't see "any" difference in image quality.
>> They all look the same to me.
>>
>> Here is my conclusion per the above.
>> To get the BEST quality photos: Set my Canon A510 to
>> 2048x1536 Superfine and live with the fact that the
>> A510 converts the raw image data to a JPG file of
>> varying sizes. Given the settings of 2048x1536 Superfine,
>> there is nothing else I can do to cause this A510 to
>> generate an image of more pixels, or a larger JPG
>> image file. I'm going to get what I get, and I can't save raw
>> image files to my hard drive.
>>
>> THANKS,
>> Gene
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
Anonymous
March 16, 2005 3:39:29 PM

Archived from groups: rec.photo.digital (More info?)

....
> I was hoping that there was a way to capture a raw file
> that had "one" byte per pixel :-)

You'd get one byte per pixel if you camera only recorded 8 bits per sensor.
Higher end cameras often record 12 bits or 16 bits per pixel. On the other
hand, perhaps you are thinking of an uncompressed format like TIFF which
typically gives 3 bytes per pixel (one byte R, G, and B). The obviouse draw
back is that at 3 bytes per pixel, each image would occupy 9.6 MB. Not
only does that eat up memory space quickly, but it takes a lot longer to
write a 9.6MB file to the memory card, versus a 1.4MB file.

>
> I waited for two years to buy a new camera, nothing
> looked good until now. This little 3.2MP Canon A510 is
> awesome. The more I play with it, the more I like it.
> It's a replacement for the Canon A75.
>
> Now that I have a better understanding of the A510 design, I will
> probably buy the A530 (replacement for the ~5MP Canon A95)
> when it ships. We plan to use a HDTV to display the image slide shows,
> so I "suspect" that a ~5MP camera will produce a much better image -
> but I have not researched what JPG file size will display best on
> a large HDTV.
>
> Gene
....

Gene, you might want to think about this a little more. HDTV resolution
is at best something like 1920 x 1080 (and most display far less than
that).
1920 x 1080 pixels is .... ta da! about 2 MP. Why would you "suspect" that
a 5MP cameral image would look better than a 3.2 MP camera image?
I'm not saying that there won't be differences, but they will be rather
subtle
to most people's eyes. The one place where the extra resolution pays off
is that you will have to crop your 4:3 original to get a 16:9 final output.
5MP will give more lea-way for cropping.

Lastly, please let go of the "JPG file size" concerns you seem to have.
Since
JPG is a lossy, compressed file format, the size of the file is only a crude
indicator of the resolution/detail/etc of the image. Resolution matters.
Amount
of information lost due to compression matters. When you set your camera
to its highest resolutiona and least compression, you are getting the best
images the camera can produce. So, at least you've done that right. }:) 

Another thing to keep in mind, the linear resolution of the image increases
with the square root of the image size. If you double the resolution, say
from
3MP to 6MP, the linear resolution has only increased by a factor of 1.41.
My guess is that ordinary observers don't really notice much until the
resolution
doubles. (Certainly, expert or trained observers will see considerably
smaller
increases.) So, if you really want to notice a difference, upgrage from
your
3.2MP camera to a 12MP camera. On the other hand, what's the point if
your planned diplay mechanism is 2MP or less? (Yes, there is some
advantage to essentially oversampling your picture, but is it worth the
prices
you'll pay?)


--
Dan (Woj...) [dmaster](no space)[at](no space)[lucent](no space)[dot](no
space)[com]
===============================
"I want to feel sunlight on my face
I see the dust cloud disappear
Without a trace
I want to take shelter from the poison rain
Where the streets have no name"
!