Originally posted by indy Thanks, I was aware of the above. My post was intended to be 1/2 smarta** comment on antichimping and part serious inquiry into some detail as to why some camera companies embed such large jpegs into their raw files. Apparently Nikon embeds very high quality jpegs in their raws, but Ricoh embedded very low res jpegs in the GR raws. With file sizes getting as large as they are, I would not mind having a raw with no jpeg component. I would have smaller raws and could have the best of both worlds by shooting raw+jpeg, then easily delete what I choose. As it stands now (if I understand things correctly)I am really shooting raw+jpeg+jpeg. Doesn't that extra jpeg data just waste space and slow down processing? Heck if this is the case, you could just embed the highest quality jpeg in the raw file, get rid of the jpeg option all together and put a button in photoshop or whatever that strips the two apart should one decide to keep the images and work with both.
In theory the embedded JPEG is there to speed up display when using an image browser, either in your computer or in camera. Nowadays I am not sure if it's actually worth bothering since both computer and camera processors are so much faster they could probably decode the RAW quickly enough so you may not notice the delay. It does probably save a tiny, teeny bit of battery power when browsing in camera, but somehow I doubt we'd notice the difference if the RAW was just a RAW. There are processors with embedded hardware for encoding and decoding JPEGs pretty near to instantly so a camera manufacturer has less work to do if they just use those designs. If they leave out the embedded JPEG they would have to design a similar decoder for RAW just so you can see your images on the camera's screen. Less design work to do if the camera chipset can only encode a RAW, not decode it for the screen, plus of course the chipset ends up with a lower component count which makes it cheaper.
As for slowing down processing, it actually need not slow it down at all. As the data is fetched from the sensor one chip in the camera can be producing the RAW while another chip (or another part part of the same chip) is encoding the JPEG. It uses more power, yes, but many chips and chipsets can do more than one thing at a time nowadays. It does make the files bigger though, which is why I am with you in wishing embedding JPEGs in a RAW would stop. I don't think we need it with today's faster processors.