Mailinglist Archive: opensuse (1367 mails)

< Previous Next >
Re: [opensuse] Writing coments on photos problem - yes, again! O:-)
On 2016-02-01 15:54, Anton Aylward wrote:
On 01/31/2016 04:21 PM, Carlos E. R. wrote:

Both programs write exif tags and comments. The problem appears when
each photo has 3 files:


Ie, the camera generates both XXXX.nef and XXXX.jpg.

Well its not really 3, but I see your problem.
You don't have a single unambiguous "original'.

*YOU* have chose to set your Nikon to generate "RAW+JPG".

That's my setting. The camera generates both a .nef and a .jpg (good).
The other choices are raw only, or jpeg only (good, medium, or simple).

So two from the camera, and a third file, a jpeg, generated by shotwell
(using names such as DSC_XXXX_NEF_shotwell.jpg)

I see the point in using RAW only or RAW+JPG, but not in using the JPG
setting alone - maybe on emergencies, hundreds of shots to do and no
space in the card, no spare cards.

The point is that the JPG it generates can be any one of the 'scene" and
manipulation options your Nikon has.

The camera has less processing power, but knows best the hardware and
the camera settings for the scene.

I read reviews of cameras I think about upgrading to at DPReview, for
example, and see in their detailed reviews many critical analysis of the
RAW-to-JPG conversion in the camera.

This motivates me not to use the "RAW+JPG" and simply to do the
conversion to JPG using Darktable from the single unambitious original
RAW file. Its about quality.

Well, you can simply not use the JPG the camera generates, or move to
another directory, and then generate your own, of course.

I should point out that darktable also lets me do manipulations that are
way beyond what the camera can do, making, shading, spot elimination,
applying various correction filters, a wider range of "scene" settings,
playing with grey-scale, overlay, and of course it can also produce TIFF
and other 16-bit formats that are less lossy than JPG or GIF.

So my list of files ends up as

original camera generated RAW to which I apply the copyright
darktable generated sidebar file
any number of JPG files generated by darktable
any number of tiff files generated by darktable
any number of JPG-2000 files generated by darktable

and so on.

Yes, I understand that. I have tried to use darktable, but I couldn't do
much with it. Much too learning to make.

Many of my photos are night shots without flash: buildings or objects
outside illuminated by the moon or a very small torch (same one I use to
get to the place in the dark). Or the moon during the eclipse, or trying
to capture the Catalina comet two weeks ago (I got an unconfirmed shot).

My camera is not really suited to this. If I try to enhance the stars
there is a lot of noise in the form of red dots or granules. Automatic
focus simply fails, and manual focus is too sensitive to the touch.
Infinite is not the end of the ring turn, but a millilitre or two before
the end. To my dismay, several of my unrepeatable (except to immortals)
shots are unfocussed :-/

I have learned how to handle it, but still a percent are bad.

But the noise of the sensor has no remedy. Yes, a building can be shot
at the lowest ISO, but not the stars: more than 5 seconds exposure with
the 200 mm and the stars start to morph from dots into lines. Of course,
the remedy is to buy a motorized stand for astronomy, but I'm not an

When shotwell
imports them, it generates another jpg file.

Are you saying that it automatically generates them on import?
I don't like that. But such is your choice.

You can choose, use the camera generated one or the software one. I
started with the first setting (I think it is the default), but bugs in
the software meant it did not always detect both nef and jpg to be the
same photo.

Huh, the sport setting. My camera is too slow focusing, sometimes going
in one focus direction while the object is going in the other direction
and completely blurring it, so much that I lose track of it and miss the
shot :-(

Happened with kids, eagles and seagulls.

But often it works and the shots are worth it. Good thing that I don't
have to pay for the film rolls ;-)

I think the comments are
saved to the jpg file, but I'm not sure. It can not write to the .nef file.

A photoeditor should NEVER alter the original.
My point about adding copyright to the RAW is that I'm paranoid about
getting in there before any derivatives can be made. If my camera
allowed me to insert the author/copyright information "at source" then I
would use that. It doesn't, so I edit the RAW files with exiftools.

Mmm... good point. I'll have a look.
What would be a suitable string to write there?

Digikam does not see the comments or tags of these photos. I don't know
yet why. It does see them if made on cameras that generate a single jpg

There are many cameras, not least of the camera capabilities of
cellphones, that ONLY generate GIFs or JPGs. I'm not saying that a
cellphone can't produce a great photographs; put one in the hands of a
professional and he or she will produce consistent quality just as
easily as of were a high end DSLR or a 1950s Kodak box camera.
Ultimately skill and creativity will trump technology. But that's not
what we're talking about here.

Oh, I always have my cellphone with me, so they are very good for chance
shots. I know that :-)

Neither does digikam notice that those 3 files are a single photo.

Of course not, its not a semantic scene analyser, some form of AI.
its only a photo editor. if I adopted it after generating 50 to 60
variations on one RAW file, apply various 'scene' pre-sets, using
darktable, it wouldn't recognise those either. The only reason
darktable "does" is that it has its own database and history. So we're
back to something 'external'.

digikam is also a photo organizer, and this is what I want most. For
this role I'm using shotwell, and one problem is that one does not see
well the organization that the other made, only partially. I would
understand it of proprietary software, but not of open source.

It is *YOU* who have chose to set the camera to produce "RAW+JPG"

It is at that setting.

and it
is *YOU* who selected the scene setting from which the camera's internal
algorithms produced that JPG from the RAW. If you don't like that then
why are you also producing the RAW, uploading it and using an image
editor on it? Why not use just RAW and then "Hmm, that's a flower, OK
apply pre-set flower and see what I get. Hmm, don't like that, go back
to the raw and mask out the foreground and apply "bokeh" filter to the
background. Better. Now lets play with the colour curve of those
petals." BTDT.

Ah, but I'm not in that street yet :-)

A street near me has, fashionable, what looks like old gaslights even
though they are actually electric. A RAW of that taken in brilliant
sunlight on a cloudless day, make B&W in darktable, ad back spots of
colour, highlight grain using solarization to give the effect of rain
and most, , a wonderful "noir" Victorian street at dusk.

Sorry, there's no camera "scene" setting to do that. This is art. The
camera is a tool. While I'm happy to let it do the focusing and for me
and get the exposure close to what I want, that's mechanics. "Render
unto the computer" and all that as Norbert Weiner said.

If I were dong this 40 years ago in the darkroom I had set up in the
basement, with the enlarger, baths of chemicals, different types of
paper, filters, pieces of cotton, mesh and wire and more, the database
would be my notebook. Like they say, YMMV.

So be asking yourself: Why are you using a photeditor at all if you are
taking the camera's idea of what the editing of the RAW to JPG should be?

No, I'm not using a photoeditor. Shotwell primary use is as organizer.
It has a quick edit mode, yes, and it can launch external editors.

And if shotwell automatically generates a JPG on loading, then what
algorithm is being used there? And is that a setting you can turn off?

If it fails to detect the JPG generated by the camera, it will ignore
the photo. This is some bug, because it sees most of them.

I can tolerate 'automation' making low level decisions for me, when to
turn the furnace on for the heating as the temperature falls, things
like that. But making strategic, creative decisions, that's another
matter. I very much doubt that shotwell could do recognise "ah a single
close-up of a plant..." and apply the example reasoning, evaluation,
masking and choice of enhancement that I gave in the above example.
So why have it automatically generate a JPG you don't want?

No, the idea is simply to see the photos. If I then want to apply
further "development", then I'd take the raw and do it. But that would
be on a single photo out of hundreds.

Cheers / Saludos,

Carlos E. R.
(from 13.1 x86_64 "Bottle" at Telcontar)

< Previous Next >
Follow Ups