What's the best file format to save pictures in?

[boristhemoggy]

Hi
I presently take raw and jpg, and use the jpg's for displaying. However at some point they are going to degrade as jo's do, I don't know when that's going to be.
Someone suggested png's but I've read that they're lossie alos like jpg's.
So I need to store my pictures in a reliable format but I don't know which one. Can anyone help?

[Douglas]

I believe the highest quality is Tiff. Thats usually what I see as recommended. File sizes are huge though. Like 40mb huge.

[kewk]

Originally Posted by boristhemoggy

Hi
However at some point they are going to degrade as jo's do, I don't know when that's going to be.

What do you mean by this? I believe I know what you are saying but it is not possible so I am not positive I do actually know what you are saying...

[Stercus Vultus]

Originally Posted by Douglas

I believe the highest quality is Tiff. Thats usually what I see as recommended. File sizes are huge though. Like 40mb huge.

Indeed, TIFF is lossless. And therefore huge files. BUT... they are compressible to .zip with no image quality loss! Saves between 30% and 60% of disk space...

[Stercus Vultus]

Originally Posted by kewk

What do you mean by this? I believe I know what you are saying but it is not possible so I am not positive I do actually know what you are saying...

JPG and PNG are 'lossy' formats. They discard image data every time they're saved. Degrading image quality more every time, of course.
To be sure: opening, perusing, and closing a JPG or PNG unchanged won't degrade it's image quality. But (re)saving will.
The higher the JPG or PNG image quality ( = the lower the compression rate), the slower the image degradation by resaving will be, as the least amount of image data is discarded each time. But some image data IS discarded everytime you save a JPG or PNG!

[Briodan]

I always shoot and store on my computer, raw. Then when I'm ready to archive (and create disks for the client) I use the batch feature of Lightroom to create JPGs from the raw files. That allows me to use the smaller jpgs for previewing (I use the same names, just substitute jpg for nef) emailing and web and I store the nef in it's own folder (TIF if it is a client DVD so they can take it directly to my recommended lab). When I want to print a file, I convert the corresponding to a TIF to send to the lab.

This is the best of both worlds. The JPGs on the CD will never degrade since they are not re-saved. The NEFs (or whatever your flavor of RAW is) are smaller than the TIF so they get saved with all of the original data intact an are ready for whatever is needed.

[JDArt]

Originally Posted by boristhemoggy

So I need to store my pictures in a reliable format but I don't know which one. Can anyone help?

This is a good question. I store images in the format in which they come out of the camera, but once I work on them, I always save and store them in the native PhotoShop PSD format. Who knows whether this will present problems years down the road. For now and for the foreseeable future, at least, PhotoShop will be the image editor I use, so it makes sense to store photos in that program's native format.

[boristhemoggy]

Well here's some points to consider.
My 5D saves RAW files as .cr2. Do these degrade in any way at all? I save these for each and every shot so perhaps there's my problem solved. When the jpg starts getting dog eared I simply make a new one.
What is Adobe's DNG format like? It's sold as the ability to make your own RAW file, does that last forever and is it lossless?
Taking a random image, it's RAW file was 13,967 KB. A jpg off it was 6,362 KB. A GIF off it was 4,873 KB and a TIF was 15,912 KB.
A tif therefore was larger than the original raw file. The GIF was (LOL) as you'd expect in quality. The jpg fine, but lossless.
As the RAW file was only double the size of the jpg, mybe that's the way to go for storage assuming they are lossless?
Edit**
Whilst I was busy writing the above Briodan and JDart both replied and so have kind of answered my question. As long as RAW files are lossless I'm going to hang on to them and not have to worry.

[boristhemoggy]

Originally Posted by Briodan

I always shoot and store on my computer, raw. Then when I'm ready to archive (and create disks for the client) I use the batch feature of Lightroom to create JPGs from the raw files. That allows me to use the smaller jpgs for previewing (I use the same names, just substitute jpg for nef) emailing and web and I store the nef in it's own folder (TIF if it is a client DVD so they can take it directly to my recommended lab). When I want to print a file, I convert the corresponding to a TIF to send to the lab.

This is the best of both worlds. The JPGs on the CD will never degrade since they are not re-saved. The NEFs (or whatever your flavor of RAW is) are smaller than the TIF so they get saved with all of the original data intact an are ready for whatever is needed.

I've only just discovered Lightroom and am getting the hang of it. Are you saying you don't need the JPG's if you ahve the raw files to view? Then you make a JPG as and when you need one through a batch file?

[felix.reichardt]

Originally Posted by Stercus Vultus

Indeed, TIFF is lossless. And therefore huge files. BUT... they are compressible to .zip with no image quality loss! Saves between 30% and 60% of disk space...

Explain the savings with TIFF:

Example:

5D II RAW: 27.2 MB
Lossless TIFF: 120 MB
Zipped (RAR actually) lossless TIFF: 94 MB
Makes the zipped TIFF 3.5 times bigger than the RAW!

Adobe DNG lossless: 24.9 MB

I'd rather convert to DNG or keep the RAW's

[Stercus Vultus]

I think chances are that well-established, standardized TIFF files can still be read and edited in 10 years time, felix. While I'm not 1/100th as sure about all them different RAW flavors, versions, and derivatives. And I don't like to gamble with those images, and I am allergic to lock-in.

But I keep the RAWs too... I can afford to run the risk as I have the TIFFs!

[felix.reichardt]

Originally Posted by Stercus Vultus

I think chances are that well-established, standardized TIFF files can still be read and edited in 10 years time, felix. While I'm not 1/100th as sure about all them different RAW flavors, versions, and derivatives. And I don't like to gamble with those images, and I am allergic to lock-in.

Well, if there is a new file format I will convert them. But you have absolutely NO savings with TIFF files as you claim. Instead you are blowing them up by factor 3.5 zipped. I rather have 1 disk full of images than three and a half.

[Stercus Vultus]

Storage has never been cheaper and my archive is now about 750GB on 2x 1TB Raid1 external HDs.
I'm considering a Drobo next.
In any case the cost of data storage is so low per GB now that price isn't the issue for me. Only size, convenience, and reliability.

[Briodan]

Originally Posted by boristhemoggy

I've only just discovered Lightroom and am getting the hang of it. Are you saying you don't need the JPG's if you ahve the raw files to view? Then you make a JPG as and when you need one through a batch file?

Boris,

Yes. And the nice thing is that you can convert just one file to jpg or a whole set. You can even re-name them from the original raw file name. AND resize them. What I usually do is select to make the long side 800, then no matter what the aspect ratio, the pic will keeps its proportion. I could probably put together a tutorial on working with raw and jpgs in lightroom if that would be of interest.

Dan

[Briodan]

Originally Posted by Stercus Vultus

I think chances are that well-established, standardized TIFF files can still be read and edited in 10 years time, felix. While I'm not 1/100th as sure about all them different RAW flavors, versions, and derivatives. And I don't like to gamble with those images, and I am allergic to lock-in.

But I keep the RAWs too... I can afford to run the risk as I have the TIFFs!

All raw files will be readable in the years to come. There are SO many third party programs out there that read and convert the files, that it is really quite crazy when you think about it. I have even written a number of converters.

Your best bet is to just save RAW. Yes it is big, but nowhere near the size of a TIFF and having experience with software, you never know what happens to your image when you compress it, (zip) and then uncompress it, I have seen some strange things happen.

In my case, my NEF files are about 15 to 17 MB (MegaBytes) but when I am done in post and ready to send a TIFF to the lab, they are 45 to 60 MB... so I RARELY keep TIFFs on the computer... only when I make client DVDs do I make all of the files for print into TIFFs. Why waste storage?

[Douglas]

Can you save a processed file as raw though?

[Stercus Vultus]

Originally Posted by Briodan

All raw files will be readable in the years to come.

A bold statement. Are you ready to put money on that, Briodan?

Originally Posted by Briodan

Your best bet is to just save RAW. Yes it is big, but nowhere near the size of a TIFF and having experience with software, you never know what happens to your image when you compress it, (zip) and then uncompress it, I have seen some strange things happen.

Test it IRL on your own TIFFs. And learn to trust your own, real test results over some forum stalker's loud prophecies of doom.

[Stercus Vultus]

Originally Posted by Douglas

Can you save a processed file as raw though?

Yes. It will add another small file containing all the edits. Re-opening the saved RAW file will also open, and apply, the small file's edits to the image. So you'll get your RAW complete with edits on screen.
So an edited and saved RAW file consists of two files.

[swampler]

Originally Posted by Douglas

Can you save a processed file as raw though?

In the case of Canon, if you use DPP, it saves all the changes within the file so when you carry the RAW file to a new computer with DPP, the changes are there. If using Lightroom, then you have a catalog to contend with. So, I say that question will depend on the software and is a very good point!

[Briodan]

Originally Posted by Douglas

Can you save a processed file as raw though?

To answer the question directly, I have never done that as I have not had a reason to.

That is actually one of the reasons that I REALLY like Lightroom. It is non destructive to your original file. So my NEF is like the master and any changes that get made to it are instructions that get performed when the image is converted to a jpg or tiff. You can even select back in the history and only have pp that has been performed up to a certain point be output, but I always have my original raw file if I want to do different pp. AND Lightroom allows you to make a virtual copy, so if there are other pp steps that you want to perform, you can have an unlimited number of post processed images shown in the catalog, but they are all derived from the one original RAW file. Your catalog is your collection of pp to each image and as such can be saved and backed up... at a MUCH smaller disk use than saving a number of different post processed images of the same picture.

My point being; the raw file is your master. It is exactly what your sensor saw when the shutter opened (with lens affects) with no "intepretations" made to the image other than those limitations inherently impossible when going from analog to digital. So protect the raw image. Save it off on a catalog of DVDs etc.