350d embedded jpeg in raw

[jim_joh]

I have the Rebel 350d & I noticed that when you shoot raw only it is approx.7.2 mb and when I shoot raw + jpeg then the raw is approc 11 mb and the jpeg is approx. 3.2 mb. This tells me that in raw + jpeg there must be another embedded jpeg in the raw which is a complete waste of approx. 3.2mb or in other words there are 2 jpeg but the embedded one is not usable. Can anybody explain why this is?? By the way this is a wonderful camera & I am going to sell my 300d. thanking all Jim Johnston

[lancea]

Not having the 350D I couldn't confirm the sizes, but there is a jpeg embedded in all the RAW files for things like review. When you review a shot on the LCD the full file in never used, just the embedded thumbnail (which explains why it doesn't look so hot when zoomed - even allowing for lack of sharpening). But 3.2MB :shock: , that's much to much. I guess the question is - are you really sure ;) ?

[jim_joh]

Not having the 350D I couldn't confirm the sizes, but there is a jpeg embedded in all the RAW files for things like review. When you review a shot on the LCD the full file in never used, just the embedded thumbnail (which explains why it doesn't look so hot when zoomed - even allowing for lack of sharpening). But 3.2MB :shock: , that's much to much. I guess the question is - are you really sure ;) ?


Yes I am sure about the size. I made these seperate shots and the amounts shown in my post is correct and others in dpreview also confirm this.This has been discussed in the dpreview but if there is a full size jpeg embedded in the raw in addition to the seperate jpeg each shot then is over 14mb & that is way too much, Over there nobody seems to know what the reason is for Canon doing this. I guess the fix is to use raw only.
Jim Johnston

[lancea]

Yes I am sure about the size.
Not that I ever doubted you! That's not good. I wonder if the big jpeg is used for your LCD view, or there's still yet another jpeg in the RAW file? RAWs are big enough without that, and I'm still mulling over what format I'll choose on my next holiday (away from anything to download the files to). At least it will be fixable with a firmware update and Canon seems to produce them reasonably promptly when they see there is a need. Best of luck!

[guitarman3]

Jim,

I took a set of shots the other day at RAW + Jpg and most of the raw images are between 8 and 9 megs, while the jpg's average around 2.5 to 3 megs. I did get a few raws at 10 and 11 mb but most were 8 to 9. Your images must have an extraordinary amount of detail if they are averaging 11 MB. The smaller images I'm referring to above were just snapshots of my grandkids in the house mostly against white walls. The 10 & 11 MB shots were of a rhododendron bush outside in my front yard. Not sure if this helps any.

[ScottK]

Are you sure you're comparing the same shot? As Dennis alluded to, the size of the file varies with the amount of detail. So if your "raw only" shot had less detail, and your "raw + jpeg" shot had lots of detail, that might throw your comparison off. If you shot the exact same scene for both shots, then.... nevermind. :)

[jim_joh]

Are you sure you're comparing the same shot? As Dennis alluded to, the size of the file varies with the amount of detail. So if your "raw only" shot had less detail, and your "raw + jpeg" shot had lots of detail, that might throw your comparison off. If you shot the exact same scene for both shots, then.... nevermind. :)

Yes I made the same shots. Go to this thread http://forums.dpreview.com/forums/read.asp?forum=1031&message=13076301
which explains the same problem Jim Johnston