Best file type for prints jpg or tiff

I have read several book on digital photography. They all recommend after downloading the photos and post processing save the file in "TIFF" format not "JPG" One author claims "JPG" format loses minute quality each time it is opened. Also the best format for prints is "TIFF."

What file format type do you use for prints?

Thanks
Bob

That is wrong. When you SAVE a jpg more than the initial save it degrades the image quality. Opening a file never corrupts a file. TIFF is better to print from if you can.

The TIFF format is usually not compressed, and if you use a compressed TIFF format, it is a lossless compression. JPG files, on the other hand, are always compressed, though one can choose how much they are compressed. The compression is a lossy thing as well. Once information in an image is lost via JPG compression, it can never be recovered.

If you take even the highest quality JPG file and do the following sequence of three steps 20 times, you will easily see the corruption of the image: 1) Open the JPG file, 2) Save the JPG (back to the original file), 3) Close the JPG file.

To see the difference radically, make a copy of the original JPG file to do the 20-cycle test on and then you can compare the original to the one you saved 20 times. There will be a huge difference.

The test above shows why you do NOT want to open, edit, and save a JPG more than once or possibly twice. Note the test above does not even include any editing steps.

Thanks everyone for your comments

Bob

I have always known this but tried your test since I am bored and rained in from tropical storm Ernestso. I saw a slight degradation after 20 saves.

What I can't figure out is why did my chosen file started out at 403kb and wound up at 411kb at the 20th save ?

For prints save a copy as a Q10 or Q12 JPG, TIFF is unnecessary and they're huge. Make sure you save a copy in psd or tiff if you plan to edit it again.

I have RAW files of most of my photos and i save the RAW files only, when i save i can choose between jpeg or tiff, but nowadays i try to use more tiff saving files as it is much better in IQ than jpeg and no affected with many save repeating, so i can produce jpeg from RAW or tiff only and i don't edit jpeg several times when needing, i just pp RAW or Tiff, and i will try to pring my most or all photos by tiff, no problem with size as i got lots of DVD's to copy and burn in (DVD+/-RW) so i can go to print it to lab studio without fear of losing quality.

I have something else on my computer.
I use DPP to process my raw files. I have converted the same raw file to tiff and jpeg, using 8 bits tiff and best quality jpeg. And both images are now not exactly the same in terms of colour, when looked at on my computer. So I assume it would be the same on paper. Can someone explain?

In the begining, your saved .jpg and .tif might look the same and print about the same. Problem is down the road. Tif's do not change in size = nothing lost. Jpg will change in size every time you save = not your original pix, just a good guess about what it looks like. My favorite "archival" formats are .tif .png and/or .jp2

The largest I have printed anything is 16x20. I've printed 16x20's in both TIFF and JPEG and the difference is so minute that it isn't worth the time uploading the TIFF file to my lab's website. I'd say do a test...print two of the largest sizes you intend to print on a regular basis. Shoot RAW, convert one to TIFF and one to JPEG, do all your tweaks and print them. I'd bet from a normal viewing distance you won't see a difference.

I just did some experiments, take a look on this thread.

After ALL PP work I always save as tif for archive, but any files for printing I just resize/crop as required and save as Quality 12 jpeg's and either upload them or put them on CD - I would defy anyone to tell the difference between this and a tif file that gets printed with the naked eye.