Converting RAW files to jpeg

[ArmandoG]

I am hoping someone can shed some light to something here that has me confused. I shoot RAW on occassion when for myself or when i shoot formals at weddings and such.
What i usually do is open up my RAW files in Photoshop CS and do the necessary modifications such as check white balance, add exposure, etc.
When i am done, i then save the file as a tiff file. From there i will convert the file to a jpeg file.
So my question is how come a RAW file which was about 8mb turn into a 2.5 or so jpeg file after the conversion? This to me seems to defeat the purpose of shooting in RAW if you are going to end up with a smaller jpeg file.
By the way i dont use Photoshop CS to convert my tiffs to jpegs since it doesn't allow me, or if i can do the conversion in Photoshop CS i have not found out how too.
I use Digital Photo Professionl which is a program which came with my 20D to convert my tiffs to jpegs.
I hope i am making sense here, I just wanted to know if someone can explain to me how to keep the converted jpeg file to be about the same size as the original RAW file.

Thanks

[Supermanny]

I think the short answer here is you can't and you don't want to.

Converting throws away most of the information in the raw file which you don't need anymore after the adjustments are made. Additionally jpeg compresses your image to save space.

You can read more about RAW here:
http://www.luminous-landscape.com/tu...aw-files.shtml

You can save your tiffs as jpeg if you convert them to 8-bit/Channel. On the PS menu Image > Mode. Jpeg does not support 16-bit/channel.

Hope that helps.

[kronos2818]

Originally Posted by ArmandoG

I am hoping someone can shed some light to something here that has me confused. I shoot RAW on occassion when for myself or when i shoot formals at weddings and such.
What i usually do is open up my RAW files in Photoshop CS and do the necessary modifications such as check white balance, add exposure, etc.
When i am done, i then save the file as a tiff file. From there i will convert the file to a jpeg file.
So my question is how come a RAW file which was about 8mb turn into a 2.5 or so jpeg file after the conversion? This to me seems to defeat the purpose of shooting in RAW if you are going to end up with a smaller jpeg file.
By the way i dont use Photoshop CS to convert my tiffs to jpegs since it doesn't allow me, or if i can do the conversion in Photoshop CS i have not found out how too.
I use Digital Photo Professionl which is a program which came with my 20D to convert my tiffs to jpegs.
I hope i am making sense here, I just wanted to know if someone can explain to me how to keep the converted jpeg file to be about the same size as the original RAW file.

Thanks

Well, let's start with RAW files: This type of files contain all the data that your camera captured for that photo. That is why you can adjust the white balance, exposure and contrast. You will also notice that what ever you make changes in RAW the files size stays the same. That is because it use only the data contained in the file.

Now for TIFF files: This type of files are called uncompressed files, meaning it does not removed data from the file when ever you make changes. It will add data to the file like if you add a layer to the file the file size will grow.

JPEG files are compresed files: These file will remove unneeded data from a file everytime you save the file. So when you convert the tiff file to a JPEG and save, all the unneed data in the file is removed that is why the file gets so small. That is the nature of the JPEG file type you can not avoid that. So JPEG files will always be smaller the RAW versions of the same photo.

Now to convert TIFF files to JPEG's in photoshop. All you have to do is to: Open the tiff file then go to file>save as>then select jpeg in the file format box then save.

I hope his helps
Good Luck

[johnastovall]

Originally Posted by ArmandoG

I am hoping someone can shed some light to something here that has me confused. I shoot RAW on occassion when for myself or when i shoot formals at weddings and such.
What i usually do is open up my RAW files in Photoshop CS and do the necessary modifications such as check white balance, add exposure, etc.
When i am done, i then save the file as a tiff file. From there i will convert the file to a jpeg file.
So my question is how come a RAW file which was about 8mb turn into a 2.5 or so jpeg file after the conversion? This to me seems to defeat the purpose of shooting in RAW if you are going to end up with a smaller jpeg file.
By the way i dont use Photoshop CS to convert my tiffs to jpegs since it doesn't allow me, or if i can do the conversion in Photoshop CS i have not found out how too.
I use Digital Photo Professionl which is a program which came with my 20D to convert my tiffs to jpegs.
I hope i am making sense here, I just wanted to know if someone can explain to me how to keep the converted jpeg file to be about the same size as the original RAW file.

Thanks

JPEG is a lossy compression format and only has 8bits thats why they are small and you don't want JPEG.

You can not get a JPEG not to throw away data.

[ArmandoG]

Thanks for the information everyone.
So can I then get some decent enlargements with the "jpegs" that were converted from the original RAW files? If I wanted to get at least a 16 X 20 , could I expect to get a decent enlargmment, eventhough the original RAW file that was 8mb got compressed to a 3mb file? That was another reason I wasn't sure about the the compression of the jpeg file.

[toverman]

I convert my RAW files directly to JPEG and still end up with large (yet compressed) files. I usually turn them into at least 350 dpi JPEGs, a setting you should be able to determine in the conversion.

In answer to your question this morning, I think you can probably get a 16x20 enlargement no problem from a decent JPEG file, depending on its resolution and dimensions of the image in the file. I've gone even bigger from a 35mm negative with great success, but that's a story for another time.