Raw Files And Jpgs And Why Does My Resolution Drop?

[nellypope]

I have my camera (SONY RX100) set to shoot photos in RAW and JPG format. I then open them in Photoshop (CS6). When I open the JPG the resolution is 350, however when I open the RAW file (and then of course save it as a PSD or High quality JPG) the resolution has dropped to 240! I was under the impression that there was no resolution difference between the two formats, is there any way to preserve the 350 pixels/inch or is it just that my RAW files are of a lower quality?

[Old_Geezer]

My guess is that resolution can be anything you set it to be. Without knowing anything of your camera, I'd advise looking at the camera and the Photoshop settings to see what they are instructed to save the file as. My suspicion would be that Photoshop is set to create/save small jpeg files rather than high resolution ones ?

[nellypope]

Thanks, Yes on further inspection I can adjust the resolution when working on the RAW file. Im afraid Im not very experienced working with RAW files, I always assumed that increasing the resolution on any image file was pointless as the computer cant replace pixels that werent there in the first place. Im hoping that RAW files are different???

[Sharingan]

A RAW file is not actually a finished image of any sort, it's just information. you firs have to process it to make it what you want it to be. It's explained simply and more fully here.
http://www.rondayphotography.com/Understanding%20the%20RAW%20File%20Format.htm

[Old_Geezer]

I'm not that knowledgeable either but I believe the format of the RAW file holds all information on each individual pixel, so can be very large. I guess one way to reduce the size if the loss of information isn't critical is to sling some of the pixels yet still have a RAW format file.

Jpegs, of course, are designed to hold general information on the picture, as opposed to full pixel details, and one sets the amount of approximation one requires to balance file size against accuracy. Slinging out high frequency (i.e. rapid change over short distance) data to achieve the size reduction.

PC photo editing programmes can use what is know as interpolation to guess what a missing pixel probably would have held, when increasing pixels, but it is up to the viewer to decide how well it does.

[nellypope]

So can I assume, that a RAW file is non resolution specific? That the software (Adobe Camera Raw) simply defaults to 240 but that number is not representative of the image?