How does Camera Raw "export" the image to Photoshop

[andreasfidler]

I want to know which file type camera raw sends to photoshop, is it a jpeg or tiff?
Secondly if it is a jpeg how can i change it to a tiff? I already changed my photoshop mode to 16bit.

[gary_sc · Accepted solution]

Hi Andrea,

That's an excellent question and the good news is that it's actually much easier than that: if you open a raw image, the raw image is sent to Photoshop. If you open a jpeg in ACR, and then open that image from ACR to Photoshop, it will be a JPEG image. Same with a TIFF image.

The issue here is that Photoshop, by itself, doesn't know diddly what to do with a pure raw image, that image needs to be (what's called) demosaiced before PS has something to work with. A raw image is pure data that essentially has no organized image in a format that PS understands. But the 32-bit image that left ACR is the same 32-bit image that goes into PS.

If you do not convert the raw image into a DNG image, than PS will use the sidecar XMP file to know what to do with the raw image. If you do convert the raw image into a DNG, than the demosaic data is contained within the DNG. The same goes for a JPG or TIF images, they contain the ACR data.

If you take a JPG image, do some stuff with it with ACR and send that image to someone who does not have ACR or any Adobe applications, the JPG will open up as it was before you did anything to it in ACR, the person will see the original JPG image. If they have ACR and other Adobe applications, the image opens up in ACR first before it will be passed onto PS or whatever application you wish to use. That's why both JPG and TIF images should be reserved (Save as...) if you wish to send them to other people.

Oh, by the way, a JPG image can ONLY be 8-bit but a TIF can be either 8- or 16-bit. And ACR will open up a flat TIF image but if the TIF has any layers than ACR cannot open it. However, if you take that TIF image (with layers) and flatten it, than it can be opened up in Bridge.

I know that's a lot more than you think you asked for but I hope that helps.

[D Fosse]

Or to look at it from a different angle:

An open file doesn't have a file format. It's just an array of pixels sitting in memory. A file format is a storage encoding - it only applies to a file on disk.

IOW - the file format is decided when you save the file, not before. When you open from ACR into Photoshop, it's just an open image. You decide in Photoshop which format you want to save as.