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12-08-2008, 06:17 PM   #1
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Possibly Silly question about shooting JPEG

Since getting my K10d I have always shot raw. Recently I've found that I can get great jpegs for the occasions where im just shooting around for fun.. however, ive noticed that even though the setting in Camera are on "10mp" and 3 star, the jpegs that are being written to my memory card are about 2-3 mp in size.

At first I thought this might be compression due to picassa downloader, however I tried just putting the memory card in a card reader and looking at the file in the card and it was the same size..

Am I wrong to expect the files to be around 9 - 10 mp? or are the Jpegs out of the K10D usually around 2-3 mps...

Thanks for your answers!

12-08-2008, 06:24 PM   #2
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That's weird, if it's set of 10MP it should still have 10MP even on 1,2 or 3 stars. I haven't had this happen on my K20D yet. Hopefully other K10D users can chime in.
12-08-2008, 06:28 PM   #3
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Hi bweild,

Jpeg compression varies based on the contents of the file.

A file with a lot of fine detail will be larger than a shot of pure blue sky.

I'm guessing that's what you're seeing here.

-Chris
12-08-2008, 06:38 PM   #4
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The compression of the file is supposed to be around that. The 10mp means megapixels, not megabytes, which is what the file size is.

12-09-2008, 05:31 AM   #5
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MegaPIXELS of an image (resolution) is NOT the same as the file size of the JPG (in MegaBYTES)
12-09-2008, 06:38 AM   #6
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Same as what the others above have suggest:

Have a careful look at whether the JPEGS are 2~3 MP or 2~3 MB

Getting 10MP (megapixel) JPEG files in the 2~3 MB (megabyte) range sounds about right to me.
12-09-2008, 11:59 AM   #7
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It's sound about right to me as well. JPG is a lossy format, even at the best settings. You have less bit depth and some details compressed.

You should easily see a significant difference from RAW to JPG.

When I take JPGs on my K10d they seem to range from 1 Mb (very little detail, night photos) to 3+ Mb (highly detailed and colorful photos) with 2-3 Mb an average file size.
12-09-2008, 12:03 PM   #8
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QuoteOriginally posted by emalvick Quote
It's sound about right to me as well. JPG is a lossy format, even at the best settings. You have less bit depth and some details compressed.

You should easily see a significant difference from RAW to JPG.

When I take JPGs on my K10d they seem to range from 1 Mb (very little detail, night photos) to 3+ Mb (highly detailed and colorful photos) with 2-3 Mb an average file size.
keep in mind that RAW is not an image format....

even "raw previews" are processed jpegs, RAW simply allows you to choose which image format to export as.

12-09-2008, 12:05 PM   #9
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Yep, see below for my little "essay" on WHAT RAW is....(not for you Gooshin, but for anyone else who is confused )

QuoteOriginally posted by Gooshin Quote
keep in mind that RAW is not an image format....
First off, your camera ONLY shoots RAW. When you select JPG, the camera takes the RAW data and pipes it into it's on-board JPG processor to generate the JPG "image" to save to the card.

When you shoot RAW, the RAW "data" goes directly to the card and is not an image.

To generate an image, you use a RAW processor (software on your PC) which turns the data into a viewable image, much like the camera's JPG processor. The difference is that YOU have complete control over the image generation process. You can change the white balance, adjust the contrast/brightness/black point/etc....

So you can leave these decisions up to the camera's little processor (and hope it makes the right decisions since they are irreversible), or save the decisions for later where YOU have complete control over it.
12-09-2008, 12:38 PM   #10
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MegaPixels vs. MegaBytes

QuoteOriginally posted by bwield Quote
Am I wrong to expect the files to be around 9 - 10 mp? or are the Jpegs out of the K10D usually around 2-3 mps...
In case you're still confused and since no one has explicitly pointed this out....

The 10mp number comes from multiplying the dimensions of the photo, the width multiplied times the height. These dimensions are in units of pixels. A photo taken at 10mp resolution will have the dimensions 3872 x 2592 which, not coincidentally, equals about 10 megapixels (mp).


The size in bytes (not pixels) for that same photo is going to range between 1.5 and 3.5 megabytes (mb). Thus you're confusing mp with mb. They are two different units of measurement.
12-09-2008, 02:59 PM   #11
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This thread prompted me to check the sizes of the jpegs I have taken recently. I am using a K20D but the jpeg setting is at 10 MP and 3 stars. My jpegs are all in the range of 9.8 - 10.9 MB. Maybe some of our members could check their results

Last edited by helios; 12-09-2008 at 03:01 PM. Reason: error in text
12-09-2008, 03:23 PM   #12
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QuoteOriginally posted by helios Quote
This thread prompted me to check the sizes of the jpegs I have taken recently. I am using a K20D but the jpeg setting is at 10 MP and 3 stars. My jpegs are all in the range of 9.8 - 10.9 MB. Maybe some of our members could check their results
I set my K20D to 10mp and 3 stars. I took a few shots around the house and file sizes in bytes ranged between 4.0 and 5.3 MB.

If you have a lot of photos around 10MB then it might be because they have a lot of detail and color.

At 4 stars my K20D photos range between 6 and 8 MB.
12-09-2008, 03:54 PM   #13
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People are confusing megaPIXELS (MP) and megaBYTES (MB). They are completely different things.

Megapixels will stay the same based on your setting. Megabytes (files size, not resolution) will vary based on the "quality" (meaning, the amount of compression) and the image subject.
12-09-2008, 06:03 PM   #14
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Just had a look at some of my latest K10D files, in jpeg.

They range from 2.5 to 3.9 meg in size, depending on how much detail i have.

Dave
12-09-2008, 07:21 PM   #15
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That file size sounds good to me! Normal with jpegs.
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