Hi, new to digital cameras (have a Sony W-7) and was reading an article in this month's PC World Aug 05 recommended something and I am kind of confused.
They state something to the effect of "take a pic at the highest resolution that your camera will allow" for printing, even at 4x6. OK I understand this but then they go on to say that the picture should be saved as a TIFF because compressing (ie JPEG) causes image quality loss.
OK, well my camera will only save in JPEG (or maybe RAW I have not checked this out yet)
BUT, if I take a picture at 7.2 megapixals, the highest resolution allowed, it still saves it as a JPEG. From what they are saying I am suppossed to try and transfer it to the PC and then convert to a TIFF?
I could try this but since the picture was originally taken as a JPEG if I "uncompress" and save it as a TIFF is this really doing me any good for printing?
I am very happy with the quality of my pictures and prints taken even at VGA quality, but for those "special pictures" I want to get the best print quality possible, can anyone let me know about this?
The tip on saving your files in TIFF format is assuming that you are working with files saved in an uncompressed format and already in your computer. The tip has more to do with your RAW files after it has been manipulated by using a photo editing program. So, with that, you are correct in stating that JPEG is already a compressed format and converting it to a different file format will really not do any good because the original file was already compressed.
The reason saving as TIFF is suggested is the assumption that you will be doing edition to the file. Every time you resave a JPEG it re-encodes the file and you suffer some data loss; JPEG groups the file in 8-pixel blocks when it compresses & this is why it's called a "lossy" compression. Some images can be resaved a few times before the compression effects become noticeable, while others (termed "fragile" images) will show the effects very quickly.
If your camera only saves in JPEG, just be aware that you should minimize the number of times you resave the image from an editing program. Converting to TIFF will allow you to resave the image many times at the current state without causing any more loss, until you convert back to JPEG. The advantage of JPEG is it's much smaller than TIFF or RAW. For example, my 20D produces approximately 8MB RAW files which convert to 48MB TIFF or about 2-3MB JPEG.