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ruby_barbs
21st January 2010, 06:44 PM
Hi,

I am using an Olympus E-420 camera with 40-50 mm and 14-42mm lenses.It is a 10 MP camera.

Few days back, I noticed that when I shoot in RAW, and open the files in any photo editor, it shows megapixels as 1.92 MP. If I shoot in Jpg with large format, it is coming to 9.9 mps. The file size for both are almost same( 8-9 MB).

Even with RAW+ jpg format, RAW files are of only 1.92 mega pixels. Why is this so?

Is there any setting that I have messed up?

Why am I not getting 10 MP resolution with RAW files?

Please help.Any pointers will be appreciated.



Thank you,

Ruby.

snaarman
21st January 2010, 07:01 PM
Hmm. Odd that.

You usually need to use special measures or plugins and the like to import a raw file into an image editor.

However: I know that each Raw file also includes a low resolution jpeg intended for viewing purposes. I wonder if you have managed to open that instead of the raw data.


Pete

Ian
22nd January 2010, 08:39 AM
What software are you using to open the RAW files? I sounds to me like the software is only displaying an embedded JPEG thumbnail in the original RAW file.

Ian

OlyPaul
22nd January 2010, 09:38 AM
The embeded jpeg in e-420 raw file is 1600px x 1200px, now even at the highest quality jpeg setting it would only result in a less than 1mb file size,

This leads me to belive that your editor/veiwer is converting the raw file to jpeg on the fly. .knowing the software you are using would be a help.

Ian
22nd January 2010, 01:22 PM
The embeded jpeg in e-420 raw file is 1600px x 1200px, now even at the highest quality jpeg setting it would only result in a less than 1mb file size,

This leads me to belive that your editor/veiwer is converting the raw file to jpeg on the fly. .knowing the software you are using would be a help.

1600x1200 will be computed as 1.92MP as the OP reported, so I don't think there is any conversion going on, just the extraction of the embedded JPEG.

Ian

OlyPaul
22nd January 2010, 01:39 PM
1600x1200 will be computed as 1.92MP as the OP reported, so I don't think there is any conversion going on, just the extraction of the embedded JPEG.

Ian


True Ian if it showing the uncompressed size. :)

Just for general info the embedded preveiw of the E-620 and E-30 ORFS are much larger at 3200px X 2400px. :)

Ian
22nd January 2010, 01:43 PM
True Ian if it showing the uncompressed size. :)

Sorry for any confusion Paul, it's mega pixels (not bytes), which is regardless of compression :)

Ian

ruby_barbs
22nd January 2010, 05:12 PM
Thank you Snaarman, Ian and Paul , for your responses.

I guess I was seeing the embedded and scaled down image , as you people suggested.
I was opening them in photoshop and Irfanview.
When I opened in Olympus master and converted to jpg, it is showing as 9.98 MP :-) ( could not find where to see the MPs for the RAW File in Olympus master)

Thank you again for the help.

Cheers,
Ruby.

toady
11th March 2011, 02:32 PM
Hi,

I am using an Olympus E-420 camera with 40-50 mm and 14-42mm lenses.It is a 10 MP camera.

Few days back, I noticed that when I shoot in RAW, and open the files in any photo editor, it shows megapixels as 1.92 MP. If I shoot in Jpg with large format, it is coming to 9.9 mps. The file size for both are almost same( 8-9 MB).

Even with RAW+ jpg format, RAW files are of only 1.92 mega pixels. Why is this so?

Is there any setting that I have messed up?

Why am I not getting 10 MP resolution with RAW files?

Please help.Any pointers will be appreciated.



Thank you,

Ruby.

Mp isnt the same as file size
depends on how much light to dark ratio there is
my recent RAW are coming around 6-8 mega pixels with not much pp done
i have gotten up to 13-15 with loads of pp

check the picture size you are getting
and if you do want good jpegs set the menu for superfine large

Ian
11th March 2011, 02:38 PM
Mp isnt the same as file size
depends on how much light to dark ratio there is
my recent RAW are coming around 6-8 mega pixels with not much pp done
i have gotten up to 13-15 with loads of pp

check the picture size you are getting
and if you do want good jpegs set the menu for superfine large

No that doesn't make sense.

MP = mega pixels, or the number of image pixels

MB = megabytes, or the quantity of bytes in the file

Unless you crop or resize the image the number of pixels in an image file remains constant.

In uncompressed form the number of bytes in a 24-bit RGB image (8-bits per byte and 3 bytes in all, so 3x8=24) the number of bytes is 3x the number of pixels and then divided by a million (or 1024x1024).

JPEG, though, is compressed, so the number of bytes can vary significantly, even though the number of pixels stays the same.

With a 10MP camera the maximum possible file size is 30MB (3x10MP). With JPEG compression the file is normally well below 10MB, but if - as Toady suggests - you post process, you can increase the file size because compression is less effective. This can be because of increasing sharpness and even adding noise, which is a technique for adding depth to some types of image. The noisier the image the less it can be compressed.

Ian

toady
12th March 2011, 04:59 PM
No that doesn't make sense.

MP = mega pixels, or the number of image pixels

MB = megabytes, or the quantity of bytes in the file

Unless you crop or resize the image the number of pixels in an image file remains constant.

In uncompressed form the number of bytes in a 24-bit RGB image (8-bits per byte and 3 bytes in all, so 3x8=24) the number of bytes is 3x the number of pixels and then divided by a million (or 1024x1024).

JPEG, though, is compressed, so the number of bytes can vary significantly, even though the number of pixels stays the same.

With a 10MP camera the maximum possible file size is 30MB (3x10MP). With JPEG compression the file is normally well below 10MB, but if - as Toady suggests - you post process, you can increase the file size because compression is less effective. This can be because of increasing sharpness and even adding noise, which is a technique for adding depth to some types of image. The noisier the image the less it can be compressed.

Ian

thanks ian
my ignorance not having used raw a lot or even knowing the information
i checked my raw files and they are indeed 10.1 Mb
the corresponding processed tif is 33.6
and the final jpeg..13.7

this is all new to me
cheers
geof