Printing photos for archiving, home printer vs. commercial printing companies.

[Gadget]

DNG is a raw format developed by Adobe (Photoshop, Lightroom, etc).  DNg produces larger files and tend to be used by professional photographers. I use that format for my 'prof' photos but not for old pics that have been scanned. You can think of them as like old negatives that are then processed to get the best quality pic. 

To use them you need a specialist program like photoshop/lightroom, etc. I'm not sure if Gimp and other such progams can convert them/manipulate them for printing. 

I would stick to tiff for what you require.


Gadget

[Gadget]

For more info on DNG see

https://en.wikipedia.org/wiki/Digital_Negative

I see that they say that it is based on Tiff

DNG is based on the TIFF/EP standard format,

Gadget

[I forget]

 Thanks Gadget,
I'll stick to Tiff and I know my scanner has it as an option.
 

Oh ok, that is interesting, learn something new every day.

[Guy Etchells]

Thank you Guy,

That is a very comprehensive answer. 

I think I'm pretty sussed on what I need to do about the prints (ie: photos from negatives etc, pre dating digital): let me know if I have missed something...

Scan at highest resolution possible.

No scan at the highest possible optical resolution, most scanners use interpolation (looking at adjacent pixels and adding a pixcel(s) equal to the average tone/colour of those pixcels) in other words to gain a higher than optical resolution the software will add pixels guessing what colour they should be

I've not heard of DNG before, but I've got TIFF as an option on my (old) scanner) I'll need to check what the scanner is capable of and if I might need to invest in a new one that does negatives as well.
Keep all originals in archive conditions as much as I can.
Print 'new' copies of a small selection of the best for family enjoyment.
Keep several copies of the scanned files.


However, can I please clarify your opinion on digital camera pictures:

Copy the original files in the original formats and keep as many copies as possible, check regularly

Is that it? So is printing out digital camera pictures to keep them as a 'hardcopy' of these files a waste of time?
I always thought 'hard copies' was a good back up? (hence boxes of all the prints cluttering my shelves, I also print out downloaded census sheets etc). 

The alternative is to only print out a small selection of the 'best' and hope that the multiple copies of files will be sufficient. (which would make my husband happier!!! Maybe I just need a museum standard shed  )

If I have misunderstood anything, please let me know.  :-)

Cheers.

When you archive something you want to archive the original or near to original copy of the item, in the case of digital images that is the RAW file, however RAW files are manufacturer specific so there may be problems in the future reading such files.
DNA files are RAW files but they may be read on any software that can properly read the DNG format in other words it is almost a standard. In addition the DNG format includes checksum information in the file to detect and prevent file corruption.

In archiving terms printing the files is a waste of time and money as the resulting images will not last as long as the digital data and will not be as good as the original digital image, though I would print a number of interesting ones.

Cheers
Guy

PS good quality commercial scanners (Planetary Scanners) do no damage to the item they scan as they do not require high intensity light to scan the image/book etc.

[I forget]

Phew! Thanks Guy, that's given me a lot to think about. I think you've probably also made my husband happy as I won't be printing out as many in future.  Though I guess I'm going to need the money to sort out the scanning side. 

Have to say it's strange for me to hear that hard copy isn't the extra peace of mind back up I thought it was (having read so much about how computer files are not to be trusted, become obsolete and can be lost so easily).

*goes off to read more about optical resolution and file types and rethink my whole strategy*
 

This is getting more complicated than I thought. eeek!

I forget

 

[Treetotal]

A simple answer given to me by a professional photographer friend was to use the tiff format for scanning. For storage, use photo storage boxes layered with acid free paper. As a collector of old photos, I also use postcard albums with 6 up plastic wallets, some landscape and some portrait. The ones I have come in red or blue and are ring binder style at a cost of around £24 including 10 wallets.
Carol