John Williamson wrote:
Lossy compression is the reason I always use the RAW file option on my
cameras where available. Phones do not offer the facility, as the
image is compressed on the camera chip.
Not sure what iPhones allow, but Pixel phones allow shooting in RAW.
AFAIK that's a significant part of Google's "computational photography"
so that once your images reach their data centres various enhancements
take place?
Can the RAW version be downloaded from the phone as taken and does itWhen enabled, each photo is saved as .jpg and .dng
use an available format that allows conversion to such as DNG?
Woody wrote:
Can the RAW version be downloaded from the phone as taken and does itWhen enabled, each photo is saved as .jpg and .dng
use an available format that allows conversion to such as DNG?
On 28/05/2026 12:42, Andy Burns wrote:
Woody wrote:The cynic in me is asking how that .DNG file is created.
Can the RAW version be downloaded from the phone as taken and does itWhen enabled, each photo is saved as .jpg and .dng
use an available format that allows conversion to such as DNG?
On 28/05/2026 11:03, Andy Burns wrote:
John Williamson wrote:If true, I may need to change my phone, then. :-)
Lossy compression is the reason I always use the RAW file option on my
cameras where available. Phones do not offer the facility, as the
image is compressed on the camera chip.
Not sure what iPhones allow, but Pixel phones allow shooting in RAW.
AFAIK that's a significant part of Google's "computational photography"
so that once your images reach their data centres various enhancements
take place?
Strangely, their website only mentions the AI cleverness and the optical zoom on the Pixel 10, not the RAW facility.
It may save me having to carry a camera round with me.
On 28/05/2026 10:41, Tweed wrote:
John Williamson <johnwilliamson@btinternet.com> wrote:The tech is good enough for the intended purpose. The intended purpose
On 28/05/2026 08:35, Old John wrote:
On 27 May 2026 at 07:28:10 BST, "Woody" <harrogate3@ntlworld.com> wrote: >>>They all do the same things, except that the compression and adjustment
Two comments:
Smartphones are even worse than you might think. They start off by
taking a picture, editing it for colours etc, and then compression it >>>>> (usually in img format) to save in memory. Then if you attach it to an >>>>> email or WhatsApp etc it gets compressed on insertion, and the transport >>>>> medium compresses it even more. My daughter took a picture on her iPhone >>>>> that was a tad under 4M. When it was attached it reduced to (IIRC) a bit >>>>> over 1M, and the final that landed on me was 243K! Looks good on the >>>>> phone screen, but put it on a 27" PC monitor and it looks awful.
In the end I asked her to extract the picture through the Lightning
connector and send it to me through a large file site (I use
WeTransfer). What arrived was 3.9M and a perfectly good picture - not as >>>>> good as a 9M+ jpg from my Nikon dSLR but acceptable nonetheless.
Was the an Android phone or an Apple IOS phone?
algorithms used by the camera chips are proprietary to the makers. (The
compression and some picture adjustments happen even before the rest of
the phone sees the file.)
IrCOd suggest that the technology has got good enough. My iPhone 16 Pro
produces stunning pictures that display exceptionally well on my large
screen iPad Pro, even when zoomed in on the iPad. All of this without any
need to manually edit. Of course things will get degraded if you use
multiple stages of compression. After all, a concert performance doesnrCOt >> sound too great on a 78 disc.
I suppose the real problem is ensuring that somebody else can view the same >> image without any compression intervening. I could possibly share the same >> image with another Apple platform user without it degrading, but once you
try to leave that ecosystem anything can happen.
is to show an acceptable result on a screen a few inches across at arm's length.
My phone (Pixel 8a) has a 64MP IMX787 sensor, which it treats as thoughThe cynic in me is asking how that .DNG file is created.
By the way, the .DNG format allows-a the use of both lossless and lossy compression.
John Williamson wrote:
My phone (Pixel 8a) has a 64MP IMX787 sensor, which it treats as thoughThe cynic in me is asking how that .DNG file is created.
By the way, the .DNG format allows the use of both lossless and lossy
compression.
it's a 16MP sensor 4624x3472, comparing two files, jpg is 5.4 MiB vs dng version 18.4 MiB, so I presume that's uncompressed.
It opens in darktable, but I don't know how to use it, parts of the
image which are jet black in the jpg look to be light grey in the dng version.
IrCOd suggest that the technology has got good enough. My iPhone 16 Pro produces stunning pictures that display exceptionally well on my large
screen iPad Pro, even when zoomed in on the iPad. All of this without any need to manually edit. Of course things will get degraded if you use
multiple stages of compression. After all, a concert performance doesnrCOt sound too great on a 78 disc.
Not sure what iPhones allow, but Pixel phones allow shooting in RAW.
AFAIK that's a significant part of Google's "computational photography"
so that once your images reach their data centres various enhancements
take place?
Tweed <usenet.tweed@gmail.com> wrote:
IrCOd suggest that the technology has got good enough. My iPhone 16 Pro
produces stunning pictures that display exceptionally well on my large
screen iPad Pro, even when zoomed in on the iPad. All of this without any
need to manually edit. Of course things will get degraded if you use
multiple stages of compression. After all, a concert performance doesnrCOt >> sound too great on a 78 disc.
Looking for a lightweight camera, I recently dragged out of a drawer an iPhone 5S (2013), a Galaxy S4 (2013) and an iPhone SE (2016). Watching people comparing the video quality with modern phones, in good lighting there's little difference. What is more noticeable is that way modern
phones 'enhance' pictures by making the sky bluer or the detail sharper than they actually are. But where they really make a difference is in difficult situations like low light or fast moving subjects, which the older phones
can barely handle at all.
Marques Brownlee did a video on the subject recently: https://www.youtube.com/watch?v=coX4duwUCpw
and a series of comparison videos:
Every iPhone in daylight: https://www.youtube.com/shorts/jru9Gsz3kJY
Every iPhone in low light: https://www.youtube.com/shorts/pvjivZ6C6CA
Every Samsung phone: https://www.youtube.com/shorts/as_NEJAP8ew
Every Google phone: https://www.youtube.com/shorts/s3DrGkDvgNw
Theo
Tweed <usenet.tweed@gmail.com> wrote:
[...]
Of course things will get degraded if you use
multiple stages of compression. After all, a concert performance doesn|o-C-Ot
sound too great on a 78 disc.
I don't follow that; one of the best things about performances on 78 rpm
(and 80 rpm) discs was that they never used automatic compression - and
when manual compression was used, it was so subtle that it is difficult
to detect.
Budget 78s pressed on poor material, scratched, worn-out and played on a cheap record player with the wrong stylus and the wrong playback characteristic, are no guide to what could be achieved by the format
when it was used properly. Some 78s are absolutely stunning if they are played on the correct equipment.
On Thu 28/05/2026 08:35, Old John wrote:
On 27 May 2026 at 07:28:10 BST, "Woody" <harrogate3@ntlworld.com> wrote:
On Tue 26/05/2026 21:06, John Williamson wrote:
On 26/05/2026 20:46, J. P. Gilliver wrote:Two comments:
On 2026/5/26 20:18:6, John Williamson wrote:I was very impressed by my first digicam that saved uncompressed files. >>>> Phone cameras in particular have the lossy file compression dialled up >>>> to max, to make the files small enough to fit in the available memory. >>>>
On 26/05/2026 19:26, J. P. Gilliver wrote:Yes - they seem to be offering two, one about 20 and one about 26.
I wouldn't even want huge resolution, though I doubt anything of that >>>>>>> size would have other than a pretty huge resolution.The one they are trying to sell now does 26.1 megapixels. Most of the >>>>>> decent DSLRs now hover round 50 megapixels.
300 dpi (Art quality) printed on A2 size paper needs about 30 MP.
I'm not really seriously into the hobby - certainly not printing out on >>>>> big paper; when I did dabble in digital a while (decade maybe?) back, I >>>>> found as often as not I didn't use what I had then at maximum
_resolution_. However, I felt a lower (nominal) _resolution_ image taken >>>>> with a good lens gave - me, subjectively - a better image than a higher >>>>> nominal resolution one with a poor lens. (In particular, the pictures >>>>> from the smartphone I had then I thought significantly inferior to the >>>>> [Fuji, I'm pretty certain] camera I had then, despite being nominally a >>>>> lot more megapixels.
Smartphones are even worse than you might think. They start off by
taking a picture, editing it for colours etc, and then compression it
(usually in img format) to save in memory. Then if you attach it to an
email or WhatsApp etc it gets compressed on insertion, and the transport >>> medium compresses it even more. My daughter took a picture on her iPhone >>> that was a tad under 4M. When it was attached it reduced to (IIRC) a bit >>> over 1M, and the final that landed on me was 243K! Looks good on the
phone screen, but put it on a 27" PC monitor and it looks awful.
In the end I asked her to extract the picture through the Lightning
connector and send it to me through a large file site (I use
WeTransfer). What arrived was 3.9M and a perfectly good picture - not as >>> good as a 9M+ jpg from my Nikon dSLR but acceptable nonetheless.
Was the an Android phone or an Apple IOS phone?
iOS
I don't know how relevant this is and heaven knows I'm no expert. But I thought I'd try some experiments, so I went out into the garden and took a Live photo of some roses on my iPhone 11 Pro Max. Obviously it finished up in Photos.I took a photo with my Samsung Android phone, using Samsung's Camera
I Shared it from there to a folder in Files. It was a .HEIC, size 3.8 MB, HEIF
image.
I then moved to my M4 iMac and used Export Unmodified Original, and got the same file plus a 6.8 MB .mov file.
Next I just used Export and got a .jpg file size 5 MB.
I tried sending all these as attachments via Mail.app. All survived unscathed,
at any rate as far as size was concerned.
Going from the sublime to the ridiculous, I sent the .jpeg file via Messenger.
It wouldn't let me save the result for some reason but I was able to Copy it and open it in GraphicConverter. Saved as .png, its size was a massive 743 KB - yes, KB. Saved as .jpg, it was 139 KB. Of course, all EXIF etc data was stripped out.
Finally, more or less as an afterthought, I Shared it by email from Photos. I was offered various compressed sizes and original size, which I chose. Looked at on the iMac, it was 5.3 MB and included all the Information including Map location.
Apart from Messenger's rather pathetic attempt, all look pretty much the same on the iMac to my aged and bleary eyes. Of course, if I had chosen to use GraphicConverter to zoom in (I could go up to 5000%, where individual pixels are over 5mm square on the iMac) the results would be very different.
Tweed <usenet.tweed@gmail.com> wrote:
[...]
Of course things will get degraded if you use
multiple stages of compression. After all, a concert performance doesn|o-C-Ot
sound too great on a 78 disc.
I don't follow that; one of the best things about performances on 78 rpm
(and 80 rpm) discs was that they never used automatic compression - and
when manual compression was used, it was so subtle that it is difficult
to detect.
Budget 78s pressed on poor material, scratched, worn-out and played on a cheap record player with the wrong stylus and the wrong playback characteristic, are no guide to what could be achieved by the format
when it was used properly. Some 78s are absolutely stunning if they are played on the correct equipment.
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tweed <usenet.tweed@gmail.com> wrote:
[...]
Of course things will get degraded if you use multiple stages of
compression. After all, a concert performance doesn|o-C-Ot sound too
great on a 78 disc.
I don't follow that; one of the best things about performances on 78 rpm (and 80 rpm) discs was that they never used automatic compression - and when manual compression was used, it was so subtle that it is difficult
to detect.
Budget 78s pressed on poor material, scratched, worn-out and played on a cheap record player with the wrong stylus and the wrong playback characteristic, are no guide to what could be achieved by the format
when it was used properly. Some 78s are absolutely stunning if they are played on the correct equipment.
However you might argue about the terminology, information is lost between
a live concert performance and reproduction via a 78 disc. The very best 78 disc has a cutoff at around 10kHz. As with human perception of digital photographs, whether the losses are important is in the ear or eye of the beholder.
Tweed <usenet.tweed@gmail.com> wrote:
Liz Tuddenham <liz@poppyrecords.invalid.invalid> wrote:
Tweed <usenet.tweed@gmail.com> wrote:
[...]
Of course things will get degraded if you use multiple stages of
compression. After all, a concert performance doesn|a-o|e-C|e-Ot sound too >>>> great on a 78 disc.
I don't follow that; one of the best things about performances on 78 rpm >>> (and 80 rpm) discs was that they never used automatic compression - and
when manual compression was used, it was so subtle that it is difficult
to detect.
Budget 78s pressed on poor material, scratched, worn-out and played on a >>> cheap record player with the wrong stylus and the wrong playback
characteristic, are no guide to what could be achieved by the format
when it was used properly. Some 78s are absolutely stunning if they are >>> played on the correct equipment.
However you might argue about the terminology, information is lost between >> a live concert performance and reproduction via a 78 disc. The very best 78 >> disc has a cutoff at around 10kHz. As with human perception of digital
photographs, whether the losses are important is in the ear or eye of the
beholder.
The Decca ffrr system was developed during WWII to extend the frequency
range to over 15 Kc/s and the BBC 'D' system had a similar range. The
ratio between the surface speeds at the same radius on a 78 and a 33+1/3
disc is about 2.34 : 1 and the ratio of the dimensions of a Standard to
a Microgroove reproducing stylus is 2.5 : 1.
This means that the theoretical frequency limits of the two systems
aren't hugely different but the harder material of a
shellac-and-slate-dust solid-stock pressing gives it a slight advantage
over the more compliant PVC material used for L.P.s. The difference is audible: I copied a skiffle record for a CD re-issue from both the 78
and the 45 versions - both the pressings were in mint condition. There
was no doubt that the 78 sounded better and that was the version that finished up on the CD..
However good the disc is, itrCOs not lossless.
I don't know how relevant this is and heaven knows I'm no expert. But I >thought I'd try some experiments, so I went out into the garden and took a >Live photo of some roses on my iPhone 11 Pro Max. Obviously it finished up in >Photos.
I Shared it from there to a folder in Files. It was a .HEIC, size 3.8 MB, HEIF >image.
I then moved to my M4 iMac and used Export Unmodified Original, and got the >same file plus a 6.8 MB .mov file.
Next I just used Export and got a .jpg file size 5 MB.
I tried sending all these as attachments via Mail.app. All survived unscathed, >at any rate as far as size was concerned.
Going from the sublime to the ridiculous, I sent the .jpeg file via Messenger. >It wouldn't let me save the result for some reason but I was able to Copy it >and open it in GraphicConverter. Saved as .png, its size was a massive 743 KB >- yes, KB. Saved as .jpg, it was 139 KB. Of course, all EXIF etc data was >stripped out.
Finally, more or less as an afterthought, I Shared it by email from Photos. I >was offered various compressed sizes and original size, which I chose. Looked >at on the iMac, it was 5.3 MB and included all the Information including Map >location.
On Fri, 29 May 2026 11:02:50 -0000 (UTC), Old John
<watcombeman@yahoo.co.uk> wrote:
I don't know how relevant this is and heaven knows I'm no expert. But I
thought I'd try some experiments, so I went out into the garden and took a >> Live photo of some roses on my iPhone 11 Pro Max. Obviously it finished up in
Photos.
I Shared it from there to a folder in Files. It was a .HEIC, size 3.8 MB, HEIF
image.
I then moved to my M4 iMac and used Export Unmodified Original, and got the >> same file plus a 6.8 MB .mov file.
Next I just used Export and got a .jpg file size 5 MB.
I tried sending all these as attachments via Mail.app. All survived unscathed,
at any rate as far as size was concerned.
Going from the sublime to the ridiculous, I sent the .jpeg file via Messenger.
It wouldn't let me save the result for some reason but I was able to Copy it >> and open it in GraphicConverter. Saved as .png, its size was a massive 743 KB
- yes, KB. Saved as .jpg, it was 139 KB. Of course, all EXIF etc data was
stripped out.
Finally, more or less as an afterthought, I Shared it by email from Photos. I
was offered various compressed sizes and original size, which I chose. Looked
at on the iMac, it was 5.3 MB and included all the Information including Map >> location.
All of this makes me very glad I've never owned an Apple product of
any descripton, as it seems that with their system you're hardly in
control of anything. Every digital camera or phone camera I've owned
since I got the first one in year 2000 has saved pictures as JPG files
which remain unchanged after I copy them to my computer.
They've been a succession of Nikon or Sony cameras and various Android
phones mostly Samsung, and my standard practice has been to copy
pictures to my computer manually, either with a USB cable, or lately
with a neat little program I've found called 'Localsend' (for Windows,
Linux or Android) which can do it wirelessly. Nothing is backed up
directly from the phone to 'the cloud', only to my computer, which is
backed up automatically every day to local drives by a program called
"Second Copy", which does just what its name suggests - it simply
copies the files. If I don't edit the pictures in any way, the files
remain unchanged throughout.
Picture files sent via Whatsapp do get reduced in size, though for
sharing family snapshots on phone screens (the usual reason for doing
this) you can't tell, and if it's vital to send somebody an original unchanged, a traditional email attachment will achieve that.
Rod.
Mark Carver <mark@invalid.com> wrote:
[...]
There's no getting away from
the fact, getting a decent image with lots of depth of field requires
lots of light getting to the sensors, and that means lots of glass.
I thought larger lenses (apertures?) meant less depth of field.
On 2026/5/26 18:27:48, John Williamson wrote:
On a vaguely related subject: I remember when the transition from filmhttps://petapixel.com/2020/04/13/the-im-back-35-lets-you-add-a-digital-sensor-to-your-old-film-camera/
to digital was getting going, there were a few attempts to make a
digital sensor that could be fitted in place of the film, so people
could still use all their existing lenses, camera bodies, and so on. But apart from a few what were clearly really prototypes, or _very_ small production runs, these seemed to disappear. Anyone know why?
On Tue May 26 17:23:18 2026 liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote:
Mark Carver <mark@invalid.com> wrote:
[...]
There's no getting away from
the fact, getting a decent image with lots of depth of field requires
lots of light getting to the sensors, and that means lots of glass.
I thought larger lenses (apertures?) meant less depth of field.
No Adrian, nobody would work "wide-open", the aberrations caused by using the edges of the elements are really obvious. f/5.6 used to be the standard, f/4 would be acceptable.
On Tue May 26 17:23:18 2026 liz@poppyrecords.invalid.invalid (Liz Tuddenham) wrote:
Mark Carver <mark@invalid.com> wrote:
[...]
There's no getting away from
the fact, getting a decent image with lots of depth of field requires
lots of light getting to the sensors, and that means lots of glass.
I thought larger lenses (apertures?) meant less depth of field.
No Adrian, nobody would work "wide-open", the aberrations caused by using the edges of the elements are really obvious. f/5.6 used to be the standard, f/4 would be acceptable.
On Tue 26/05/2026 20:25, John Williamson wrote:
On 26/05/2026 19:47, J. P. Gilliver wrote:
It was found that a 50mm lens on a 36 x 24 frame gave the closest you
Yes, but how did that situation come about? How did "everyone" learn
that it was a 50mm lens, rather than a 45 degree lens, that they were
used to? I'd have thought 45 degrees - an eighth of a circle - was more
intuitive than 50mm.
could get to the way most people see the view.
By a similar route, they worked out that the best full,frame head shot
portraits needed between 85 and 105mm focal length, to avoid large nose
syndrome.
| Sysop: | Amessyroom |
|---|---|
| Location: | Fayetteville, NC |
| Users: | 74 |
| Nodes: | 6 (0 / 6) |
| Uptime: | 02:35:46 |
| Calls: | 1,194 |
| Files: | 1,353 |
| D/L today: |
2 files (1,590K bytes) |
| Messages: | 291,195 |