Quick drive-by question Photo "imaging"

And I figgered I just hop on over and ask real quick.

My gf and I have been disputing the nature of deep space imaging, i.e.,
images of distant galaxies... not optical images of local objects, but those
derived from radio and other telescopes.

She calls them photos. I say that most of these images have been
color-enhanced for emphasis and clarity (and face it, drama) and are more
akin to photo-illustrations.

This came about during a discussion in which I questioned whether or not ANY
enhanced or manipulated photos should be eligible for consideration in the
annual World Photojournalism show. A patently enhanced PET scan was included
in an earlier show, and I questioned whether or not it should be considered
any different to a PhotoShop'ped image...

This question IN NO WAY means I don't love and appreciate these deep space
images... I do. I wish I had enormous blowups of a lot of 'em.

Thanks in advance for your answers and attention.

Jim M.

ghost wrote:

And I figgered I just hop on over and ask real quick.

My gf and I have been disputing the nature of deep space imaging, i.e.,
images of distant galaxies... not optical images of local objects, but those
derived from radio and other telescopes.

She calls them photos. I say that most of these images have been
color-enhanced for emphasis and clarity (and face it, drama) and are more
akin to photo-illustrations.

Yes and no. Yes because when depicting, for example, the spatial
distribution of radio signals there's no colour in the original, so
it must be artificial. But no in that the colours have specific
meanings, being calculated from the raw data in a rigorous manner;
while aesthetics (and, as you say, "drama") may play a role in the
choice of colours and other parameters (resolution, orientation,
scale, &c.) and there may be all kinds of processing applied (e.g. to
subtract background or reduce noise) there shouldn't be any
'artistic' manipulation of the underlying data.

This came about during a discussion in which I questioned whether or not ANY
enhanced or manipulated photos should be eligible for consideration in the
annual World Photojournalism show. A patently enhanced PET scan was included
in an earlier show, and I questioned whether or not it should be considered
any different to a PhotoShop'ped image...

There seems to me a large grey area here; where one chooses to draw
the line is going to be pretty arbitrary in the long run. Do you
allow unusual combinations of shutter speed and exposure? UV or
polarizing filters? Tinted filters? "Pushed" processing? Colour
balancing? Emulation of traditional darkroom techniques like "dodge"
and "burn"? Unsharp masking? "Stacking" multiple frames to enhance
detail? Vignetting? Colorizing? Photocollage? ...

Even in traditional optical astrophotography on film there's often
manipulation done to compensate for 'non-linear response' of
emulsions and the like -- should that be considered 'cheating'? With
digital photography, for an example of a 'retouched or not?'
situation, it's quite common to produce an image of a nebula with an
exposure at the invisible (near-IR) "H-alpha" frequency substituted
for, or combined with, the red channel in an RGB composite: as far as
I'm concerned such images are 'real' enough -- but no eye, no matter
how sensitive optical aid might make it, could ever see these objects
the way they're so portrayed.

--
Odysseus

"ghost" wrote in message
...
And I figgered I just hop on over and ask real quick.

My gf and I have been disputing the nature of deep space imaging, i.e.,
images of distant galaxies... not optical images of local objects, but
those
derived from radio and other telescopes.

She calls them photos. I say that most of these images have been
color-enhanced for emphasis and clarity (and face it, drama) and are more
akin to photo-illustrations.

This came about during a discussion in which I questioned whether or not
ANY
enhanced or manipulated photos should be eligible for consideration in the
annual World Photojournalism show. A patently enhanced PET scan was
included
in an earlier show, and I questioned whether or not it should be
considered
any different to a PhotoShop'ped image...

This question IN NO WAY means I don't love and appreciate these deep space
images... I do. I wish I had enormous blowups of a lot of 'em.

Thanks in advance for your answers and attention.
Some sky images, are actually 'more correct', than a 'normal' film image...
You are into a problem here these days. Even 'normal' film images, will have
allmost certainly been digitally enhanced. Over 90% of film printing, is now
done using digital systems, that scan the negative, and print the image.
These unless deliberately overridden, _will_ enhance the image (they perform
contrast stretch in the shadows, and white point adjustments without user
intervention). Such systems are used by many newspapers now, while others
have gone 'fully digital', so if you exclude any manipulated image, you
would probably have to exclude just about every image offered.
Ignoring 'digital' enhancements, you then have conventional darkroom
adjustments etc..
You then run into the fact that the 'colour space' of a paper print, does
not match that of either a slide, film negative, or the original scene, and
the designers of these systems, will have 'tweaked' the relative
sensitivities to give a 'natural look'. This 'tweak' has been applied by the
films creators, but is still there (hence the knowledge that certain films
will be 'better' for some types of image).
The most accurate 'colour' imaging technique, was one used in the very early
days of photography, with three seperate black and white images, taken
through three seperate colour filters, then reproduced, by projecting these
images through the same filters. This is at it's heart the technique used
for many deep sky images. These are potentially more colour accurate, than
any other images commonly produced, especially since the sensors do not
exhibit reciprocity failure, which affects the colour balance of film.
You then have two basic type of 'artificial' colour images. The first is
'psuedo colour', and the second 'false colour'. The first is an artistic
creation (applying a suitable colour to make the scene 'look good'). The
second, though artificial, is a 'real' image. In the second, the image is
treated as if our eyes had sensors for different wavelengths. If the sensors
in our eyes, responded to radio wavelengths, instead of (so called)
'visible' light, you can produce an 'image', as if seen by these imaginary
eyes. This technique to a lesser extent is allready used in 'normal'
photography (if for instance, you take a black and white image through an IR
filter - this is a 'real' image, but is not one that we could see, without
IR sensors instead of our eyes). As with the IR image, these images can be
generated in the darkroom, as well as by using digital techniques.
Historically there have also been many other darkroom modifications to
colour (sepia prints for instance), which is a 'psuedo colour' process,
while using seperate mono images, and then modifying these before recreating
a colour print (solarising one colour for instance), has been a 'false
colour' process, used for years, without the need for digital intervention.
If you wish to exclude false colour, or reconstructed 'true colour' images
from astronomical sources, then you should really exclude all other images
which have undergone any form of colour processing. Basically most pictures
made....

Best Wishes