Whats happening when you open a raw file?

Hair Bear

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I was kindly sent a Nikon D80 and then D70 raw file to look at.

When I open the D70 image I in PS (mac OS10.3.9) I get a programm pop up that allows me to adjust and tinker before it hits PS.

What surprised me is that I can spec the end file size and therefor make a much larger end file.

There doesn't appear to be any difference in the end file so whats happening to original image during this process.

Is the data actually in the raw file or is the software making it up?
 
From what I understand, the RAW file contains all the image data that the sensor captured -- no adjustments or processing. I can't speak for all RAW files, but I know that mine is split up into two files: the raw data and the settings file that records your camera settings at the time of exposure.

When you open that RAW file in PS, it's just showing you what the output image will look like based on the settings you've chosen. When you acutally open the file, PS has to read the RAW data and appy those settings to create a new image.

You'll notice that if you open the RAW file into PS from the Camera RAW interface and you try to save, it will ask you for a filename and probably try to force saving as a .PSD file. That's because you can't actually edit the RAW file. You can edit the RAW settings file, but the RAW data will remain in it's original form.
 
If you are making the image bigger PS is taking the information from the raw file and interpolating it to make a bigger filer. It's basically analyzing the file to make a good guess on what would be there if it was bigger
 
If you are making the image bigger PS is taking the information from the raw file and interpolating it to make a bigger filer. It's basically analyzing the file to make a good guess on what would be there if it was bigger

Thats what I thought was happening.

I think PS is doing a good job but its just the same as me making the image size larger.
 



Thanks for the link, a very interesting read. Here is quote from it:-

RAW allows you to enlarge digital images to a larger size with higher quality when done in the RAW converter than if you enlarge them later in Photoshop or using most other enlarging software. This can be remarkable, allowing superb-quality prints from even small digital files.
 
I was surprised when I looked at my memory card in Windows Explorer in thumbnail mode -- there were no previews!

So once I get the RAW files into PSCS2, what is the best format to save them? PSD or TIFF? I know JPEG compresses them so it's probably not the best method.
 
I've seen that a lot of photographers either save them to a TIFF or a DNG (Digital Negative) due to the fact that all raw files are proprietary and may not be supported forever. But even the DNG is somewhat up in the air since Adobe introduced it. I tend to save them as PSD files, but I know this is probably not the best method of preserving my work -- shame on me. It's just more convenient for me.
 
Is photoshop a photoshop-only format? It's tough to imagine file types not lasting. Film from 50 years ago can still be used to make a print, but maybe any format we use today will be obsolete in 5 years.

I guess I'd be best to save them in tiff?
 
I'm not sure if anything else will open a photoshop format -- maybe some open source stuff for linux. I'm banking on the hopes that the psd format won't disappear, but who knows.

So, yes, TIFF is probably the safest format. But I would do some research on that DNG stuff. I don't know what the benefits of it are but there's got to be something to it.
 
If there was only a way to scan our final images onto negatives or slide film :(
 
RAW allows you to enlarge digital images to a larger size with higher quality when done in the RAW converter than if you enlarge them later in Photoshop or using most other enlarging software. This can be remarkable, allowing superb-quality prints from even small digital files.


hmmmm. FWIW, I just tried this. I took a 6mp RAW and in the RAW plug-in I enlarged it to a 25mp image and saved it as a quality 10 JPG. Then I the same orginal raw and saved it as a JPG. I resized the 2nd jpg to the same dimensions as the newly created 25mp jpg from the first image and overlayed them. They were completely identical. Maybe I'm misunderstanding what the authors point is but I'm disappointed, I was hoping for better results.
 
If there was only a way to scan our final images onto negatives or slide film :(

well at least for slide film that is done by several labs .. it is not called scanning then though ;)
 
well at least for slide film that is done by several labs .. it is not called scanning then though ;)

:p I couldnt think of the right word. How much would it cost to have digital photos put onto slide film?
 
hmmmm. FWIW, I just tried this. I took a 6mp RAW and in the RAW plug-in I enlarged it to a 25mp image and saved it as a quality 10 JPG. Then I the same orginal raw and saved it as a JPG. I resized the 2nd jpg to the same dimensions as the newly created 25mp jpg from the first image and overlayed them. They were completely identical. Maybe I'm misunderstanding what the authors point is but I'm disappointed, I was hoping for better results.

you do not get better result by enlarging your photo to a higher resolution......because your camera only captured 6M effective pixels....anything extra would come "software guess", which would not yeild the same quality compare to the original resolution. That is why when you resize the second JPG to the same resolution as the first they look identical.....because that is all the information you have........the only way you would see different quality result is when you compare a non compressed image and a highly compressed image......not resized versions of the same image
 

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