RAW with embedded JPEG

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JoelKlein

JoelKlein

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I’m having this question kicking around in my brain for a while.

When I shoot RAW ONLY, it’s about 50mb. There is a Jpeg embedded in it, what’s the size of the jpeg? Is it low, or high quality? Because we use it all to zoom in 100% to check for critical information, it has to be a higher quality, which means the jpeg is a decent size.

How much of the 50mb RAW is the actual RAW file, and how much is the embedded?

I have more questions about this, but first I need more information about the embedded jpeg and its implementation.

Thanks.
Joel.
 
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JoelKlein said:
I’m having this question kicking around in my brain for a while.

When I shoot RAW ONLY, it’s about 50mb. There is a Jpeg embedded in it, what’s the size of the jpeg? Is it low, or high quality? Because we use it all to zoom in 100% to check for critical information, it has to be a higher quality, which means the jpeg is a decent size.
Click to expand...

AFAIK the embedded jpg is (or was) the smallest size and lowest quality. Back then the rear LCDs were tiny so this might have changed, but I think that a low quaity small jpg will be good enough for a rear LCD, even today's bigger ones.
 
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JoelKlein said:
I’m having this question kicking around in my brain for a while.

When I shoot RAW ONLY, it’s about 50mb. There is a Jpeg embedded in it, what’s the size of the jpeg? Is it low, or high quality? Because we use it all to zoom in 100% to check for critical information, it has to be a higher quality, which means the jpeg is a decent size.

How much of the 50mb RAW is the actual RAW file, and how much is the embedded?

I have more questions about this, but first I need more information about the embedded jpeg and its implementation.

Thanks.
Joel.
Click to expand...

Not direct answer but related. For some applications (eg pulling critical focus on a wide-open lens) I use a good external monitor.
 
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dabhand16 said:
AFAIK the embedded jpg is (or was) the smallest size and lowest quality. Back then the rear LCDs were tiny so this might have changed, but I think that a low quaity small jpg will be good enough for a rear LCD, even today's bigger ones.
Click to expand...
Photo mechanic is flying through photos all in gorgeous quality in jpegs. Can’t be that low.
 
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Joel, if I recall, you can extract the jpg from the RAW file in PM. Try doing a few different and check the size of the jpg and let us know.
 
I've heard but dont remenber where, that there are two, one for the thumbnail and one for the preview. I've read the smaller one is around .3 megapixels, and the larger around 2 megapixels.
 
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Another way to extract JPEGs from RAW is to use a free program called RawPreviewExtractor available from company that makes FastRawViewer program (fastrawviewer.com) .
 
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My understanding is there are three JPEG files embedded in the NEF file. One is a Small Basic file. One is a Large JPEG used for a 100% view and for a JPEG extraction. I heard there is a third embedded JPEG but I don't know the details - possibly a Medium file but with higher quality compression but it could be a very small JPEG used for thumbnails. In Photo Mechanic these embedded JPEG files are used to generate the thumbnail, the full screen image, and various levels of zooming up to 800%.

It makes sense that the RAW portion of the NEF file is relatively small. It has data, but no image and it can be compressed a great deal. The various JPEG files can have different amounts of compression applied.

I just checked Photo Mechanic. From Z8 images, I saved Highest quality full size JPEG from the native NEF. The embedded JPEG is used for that file - there is no editor or NEF converter in PM. The resulting file was 37.6 MB for an image at ISO 800 and 30.7 MB for an image at ISO 64. The compressed NEF of the ISO 64 file was 52.5 MB.
 
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No hard rule for embeded JPEGs... I've seen manufacturers that embeded full size normal quality jpgs, and manufacturers that embeded a 1920x1080 that wasn't good enough to check focus on...

I've seen cameras from the same manufacturer use difderent embeded JPEG sizes...
 
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In terms of the size breakdown, it's hard to give an exact percentage without knowing specific camera details, but typically the RAW data itself constitutes the bulk of the file size. The embedded JPEG is usually a smaller portion, but still significant enough to provide useful previews.
If you're looking to delve deeper into the technicalities or explore ways to optimize your JPEG files for better storage or sharing, you might want to check out compress jpeg. It's a handy tool that can help reduce file sizes without compromising image quality.
 
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