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Will the photos saved in my computer lose quality over time?

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    Can you clarify your idea(s) about lost quality? – Romeo Ninov Oct 29 '17 at 4:40
  • for me it seems like a simple photo prints vs digital files question. your photos fade, your files don't. sure, if something damages your computer, your digital files are gone. similarly, when your house is burned, you lose your prints. but neither of these events is "losing quality over time". – szulat Oct 29 '17 at 20:21
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    Trent, please clarify what do you mean by "quality" and "over time", what time frame is interesting to you? 1 year, 10 years, or 1000 years? – Oct18 is day of silence on SE Oct 29 '17 at 22:09
  • I started shooting digital around year 2000 or so. My photos from that time are bitwise exactly the same as when I shot them almost two decades ago. But compared to photos taken with current camera models the quality is not so good - resolution and dynamic range are completely different league now. Does this qualify as an answer to your question? – Jindra Lacko Nov 4 '17 at 8:53
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No. This is a defining quality of digital storage — every value is discretely rendered to a number, and those numbers are recorded. This means that digital files can be copied an infinite number of times without introducing error, and that as long as nothing happens to the underlying storage, the file itself will always be the same.

It is possible for the media (like hard drives or DVD) to develop errors, which render numbers unreadable (or occasionally flipped from one to another) — but this can actually be checked for and verified. Make sure that you have backups, and verify those backups periodically.

  • There is no digital photo without medium, so your answer is misleading. It does not look to me that the OP is interested in the very narrow sense that you choose to answer it with. There is actually not much difference between digital and analog photos, there is just different things that affect the medium. – Gnudiff Oct 29 '17 at 19:21
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    The answer is wrong. Bit Rot on storage media is a known phenomenon - bits do fliip. Which is why my Raid array is refreshing the stored data (read, then write) once per month. – TomTom Oct 29 '17 at 21:56
  • @TomTom is think mattdm added this info to last paragraph. What is hard is to get those errors "checked and verified" as when data corruption occurred, you need some extra information to recover or even notice (checksums :-) – Oct18 is day of silence on SE Oct 29 '17 at 22:11
  • @TomTom I'm not sure why you say it's wrong when I literally say exactly that. – mattdm Oct 29 '17 at 22:26
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Unlike printed media, digital photos will always remain exactly as they were when saved, unless the media holding them becomes corrupted for some reason. However it's easy to store a large number of copies at various datacenters in order to alleviate the problem.

That being said, digital photos do tend to lose quality in terms of our subjective perception. As camera tech develops our idea of what a "good photo" is will change as well. Perhaps in 100 years all pictures will work as interactive Harry Potter-like 360-degree panoramas and modern day shots will look the same to our descendants as photos from 1917 look to us. Or maybe the very idea of taking pictures will become obsolete as we'll all be able to relive a moment by plugging ourselves into a Matrix-like simulator. So while your photo might win you a Pulitzer today, it might as well be an archaic museum relic to future generations.

  • I don't think this is a very good answer. If they did degrade over time, it would be a huge blow to future civilizations. Many old silent films now days are extremely low-quality due to degradation of the film. It's always impressive to see one which is preserved very well. In fact, I'd say that they do not really lose quality in terms of subjective perception. Old photos and films are often so crappy looking because they degraded. If you were to go back to 1917 and looked at a fresh photograph, it would really look quite good. – forest Jun 10 '18 at 2:46
  • @forest at the very least a photo from 1917 would generally lack color, which I would say is a big improvement over black-and-white. And nowadays we have things like 360-degrees video, which was completely impossible back then. – JonathanReez Apr 25 at 19:09
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No, they do not loose quality.

But you could consider the following points, besides the fact that any storage medium may fail in doing its job (becoming corrupt, defect or any thing likes this):

  • While copying files from one medium to another errors can occur and destroy some bits or bytes. But it is possible to prevent this error.
  • Computer technology changes. A computer in 20 years may not be able to read your hard drive.
  • Display technology changes. Example: a display with high pixel density makes a picture looking sharper than on an older display with less pixel density.
  • People change their way they look at an image and what they think is good quality or not.
  • File formats of today may not be supported in the future. I don't expect to have a RAW converter available for todays camera in 30 or so years on the operating system and the photo software compatible of this time.

... list may be extended to some more points.

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    They mdo not loose quality, but their storage does. Look up "Bit Rot". Standard for storing things long term. – TomTom Oct 29 '17 at 21:57
  • @TomTom: this is what I mean with a storage medium becoming corrupt. – this.myself Oct 30 '17 at 10:24
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Technically yes.

While not that common nowadays, a hard drive may fail, a data disk can get degraded or scratched, plus, there are some infrequent occasions when file may be subject to bit rot.

This is typically circumvented by keeping several copies of data, as well as implementing error correction processes on hardware level

The main issue is uncaught data degradation -- if you do not touch a file for a long time, you have no idea if it is still valid.

My personal approach is to keep everything on a RAID-1 or mirrored hard drives, but if I were earning my living by photography, I would invest in a way of storing more copies and checking them frequently.

Really, if you downvote based on the idea of digital being perfect, you forget that nothing exists without medium.

Even film negatives tend to detoriate with time. So does whatever medium you store your digital photos on.

And possibly you haven't had the old CD-Rs die on you by having their outer layer come off in flakes.

However, the OP specifically said that he was asking about photos saved on his computer -- which is currently either a magnetic hard drive or a solid state disk. Both of which can and will detoriate.

And I speak from experience of doing digital preservation for a national library, so we had this question discussed and researched for quite some time before selecting the tools.

  • hard drives can fail. but digital photos are not hard drives! digital photos are numbers and numbers cannot be destroyed. they are eternal :-) – szulat Oct 29 '17 at 18:51
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    @szulat hmm. Ever tried to take untethered photos without a medium? :-) i would love to see some of them. – Gnudiff Oct 29 '17 at 18:54
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    there is space radiation that hits memory cells. In RAM, SSDs, and even HDDs perhaps. Effect of these changes on image quality is undefined, it can do nothing or render image file completely unreadable. – Oct18 is day of silence on SE Oct 29 '17 at 22:08
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    You mention RAID-1, which is simple mirroring. Fine, but what if you're doing the typical two-way mirroring, and one copy develops an error and the other doesn't (or even develops a different error)? How do you decide which copy is correct? – a CVn Jun 10 '18 at 11:19
  • To solve this with a simple mirroring setup you'd typically need at least three-way mirroring so that you'd have two out of three copies which hopefully agree, or you need some kind of checksumming in place to determine which copy is undamaged. (ZFS, Btrfs and I believe ReFS does checksumming to validate data on read. At least ZFS can be configured to do arbitrary n-way mirroring.) Outright storage failure, even partial failure (some sectors simply unreadable) is the easy case to handle. – a CVn Jun 10 '18 at 11:19
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I may have read past it, but I did not see anyone issue the caveat that if you repeatedly open compressed images and re-save them, you will incrementally degrade the image. Lossless image formats – raw, psd, tiff – will not degrade with repeated saves/overwrites.

CDs are not an archival media and can definitely degrade over time as is happening with some collections.

The biggest risk in long term digital storage is drive failure or obsolescence of the media type. For example, it would be quite a project to retrieve images from an old Syquest disk, Iomega Zip disk or Jazz cartridge!

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No. As stated above, that's the whole point of 'digital storage and photography'.

As long as the image is kept on good devices and in good conditions, the file will remain the same. However, over time, files might get corrupted or get errors which will result in rendering problems. But that's not something you should think about since almost all media storages nowadays will not develop this kind of issues.

  • Files, as such, do not get corrupted or get errors over time. – Zenit Oct 28 '17 at 21:40
  • As far as I was concerned, storage devices such as hard drives can develop errors (for example from a magnet) if not held in good conditions. Same for DVDs and scratches. If I'm wrong, I will edit my answer. – TudorPanait.ro Oct 28 '17 at 21:44
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    There's no such thing as a perfect storage medium. The most secure way to preserve a file is redundancy combined with error checking/correction. But even then, statistically over time there will eventually occur even a most improbable occurrence of simultaneous multiple errors to redundant data stored on discrete storage systems that can render the resulting data as only having a high probability of being identical to the original data. – Michael C Oct 29 '17 at 7:13
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    Every form of storage media can degrade over time. This is just basic physics. In fact servers are typically equipped with redundant ,memory and storage systems precisely for this reason. For photos consider archival quality CD and DVD+R (note the "+"). – StephenG Oct 29 '17 at 14:34
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    >almost all media storages nowadays will not develop this kind of issues. -- on the contrary -- all of them will, given sufficient time or even faster under favourable conditions. Also note that OP asked about photos saved on his computer -- not typically the safest location for average user – Gnudiff Oct 29 '17 at 19:18

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