A few noobie questions about RAW processing.....

Hello everyone!

I shoot with a Canon A710 IS. This past weekend I was playing around with the RAW Hack that allows the A710 to shoot raw.

I downloaded the DNG for powershot and it works fine, allowing me to use the RAW pictures with my PhotoShop Elements 5.

My question.... Why are the RAW pictures out of the camera approximately 14mb, and after only just a little post processing with Elements 5, I save the image and its approximately 40mb!! Whew!

Am I doing something wrong? Or is there a way to reduce the mb to something smaller to be able to upload them to a photo printing website?

Thank you very much for any help!

The size of the image after post processing will be essentially the same whether you did the post processing or not - because it's a question of what format used to save the image - not the post processing itself (I am making one assumption - namely, that you are not creating additional layers).

Here's the story - formats such as TIF (without compression) are going to be very simply, 3 bytes for every pixel, assuming 8 bit RGB format. If you are saving in 16 bit RGB format, then it is 6 bytes per pixel. All you have to do now is calculate the total byte count from the Megapixel count.

For example, starting with your 7 Megapixel camera and saving in 16 bit TIF will result in 42 Megabyte files. Saving in 8-bit RGB reduces that to 21 MB and saving in a high quality JPG will reduce that to about 3 MB.

So after final post processing of the RAW image file, I should save it as a high quality JPG file?

snatiep wrote in post #3285781
So after final post processing of the RAW image file, I should save it as a high quality JPG file?

That depends on how much more work you plan to do. If you are only going to sharpen and print or use for web then most definitely.

snatiep wrote in post #3285781
So after final post processing of the RAW image file, I should save it as a high quality JPG file?

Depends! If you plan on doing extensive post processing in Photoshop, you should retain as much info as possible. Save as TIFF or PSD. IF, however, that is your final output, save as high qual JPG (or indeed resized cropped etc JPG) AS LONG AS you keep the original RAW! Then you can always go back and recreate the image.

Once you save in JPG you have LOST info you can never get back from that file.