The other day I shot some graffiti under a bridge.
Half was in shadow, the other half in bright sunlight.
There were 6 stops difference in exposure between them.
Once I saw the images, I knew it would be very difficult
to produce an acceptable or even marginally exceptable final
image. But what I did notice was that my eyes had no trouble
seeing both sides of the graffiti whereas the digital camera
just did not have the dynamic range to accommodate it properly.
I'm wondering what they'll come up with to finally (if possible)
deal with this problem. I'm beginning to really love overcast days.
> The other day I shot some graffiti under a bridge.
> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 6 lines]
> I'm wondering what they'll come up with to finally (if possible)
> deal with this problem. I'm beginning to really love overcast days.
Take two or three shots 2 stops apart and composite them with the new 32
bit compositing feature of PS CS2. Works great.
RichA - 10 Jul 2005 22:00 GMT
>> The other day I shot some graffiti under a bridge.
>> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 9 lines]
>Take two or three shots 2 stops apart and composite them with the new 32
>bit compositing feature of PS CS2. Works great.
I may have been overstating the case. I'll try your suggestion as
well. But, after fooling with the histogram function, I managed to
get the image to a point that approximated how my eye saw it.
http://usera.imagecave.com/rander3127/graffiti.jpg
Rudy Benner - 10 Jul 2005 22:26 GMT
>> The other day I shot some graffiti under a bridge.
>> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 9 lines]
> Take two or three shots 2 stops apart and composite them with the new 32
> bit compositing feature of PS CS2. Works great.
"32-bit High Dynamic Range (HDR)—Step into the future, with the creation and
editing of 32-bit color, High Dynamic Range (HDR) images, ideal for 3D
rendering, advanced compositing and professional photography. With advanced
technology that adapts to the full spectrum and range of visible light in
the same way as the human eye, HDR ensures your final images will display
your creative vision to the last detail, with the most richly detailed
shadows and highlights at your command. Let the new Merge to HDR take you
beyond the state-of-the-art, by automatically combining bracketed digital
exposures into a single 32-bit HDR image, creating breathtaking images that
are otherwise impossible to capture with traditional cameras."
Rudy Benner - 10 Jul 2005 22:42 GMT
>>> The other day I shot some graffiti under a bridge.
>>> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 20 lines]
> digital exposures into a single 32-bit HDR image, creating breathtaking
> images that are otherwise impossible to capture with traditional cameras."
Look for it in Bridge. I could not find the function in Photoshop. Seems to
work. This could be fun.
> The other day I shot some graffiti under a bridge.
> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 6 lines]
> I'm wondering what they'll come up with to finally (if possible)
> deal with this problem. I'm beginning to really love overcast days.
Welcome to the world of photography. It was no difference in the days
of film.
David Littlewood - 11 Jul 2005 01:17 GMT
>> The other day I shot some graffiti under a bridge.
>> Half was in shadow, the other half in bright sunlight.
[quoted text clipped - 9 lines]
>Welcome to the world of photography. It was no difference in the days
>of film.
Well, slightly. You can to some extent control the contrast ratio of
film by controlling development time (or first dev time for colour
film). Works well for B&W film, works to a lesser extent for E6
(reversal) film, is barely possible with C41 (negative) film as the
process is usually so rigidly automated.
It would sometimes be nice to have sensors with variable contrast,
though to be fair they do start out with a higher range than most films,
and the techniques already mentioned serve instead.
David

Signature
David Littlewood
> But what I did notice was that my eyes had no trouble
> seeing both sides of the graffiti whereas the digital camera
> just did not have the dynamic range to accommodate it properly.
Your eyes don't take a picture; they piece the scene together from multiple
"samples", plus memory, and present it to you that way. You can, of course,
do the same thing in Photoshop. :) (Well, minus the memory part.)
Have you ever had this happen to you: you're on a dark street at night,
with some street lights and lights from houses around. Way down the street
you see something, but you're not sure what it is. You think it might be a
person. Or an animal? Or... something in the road? You look at it, move
your head, look again, maybe walk to get a slightly different angle and
look again; finally, you suddenly identify it as a car parked on the side
of the road. Your brain finally got enough visual information to piece
together into that.
Now, every time you look at it, whether you look away or not, all you can
see is a car parked on the side of the road. Whatever you initially may
have thought it could be is gone, and you can't even see how you ever
thought that, even if you return to your original vantage point. You're
still seeing the same thing you saw before, but now your brain is filling
in the missing pieces and you see a car.
Your camera can't do that.

Signature
Jeremy | jeremy@exit109.com
Chrlz - 11 Jul 2005 04:01 GMT
> now your brain is filling in the missing pieces
>...
>Your camera can't do that.
Exactly. And in terms of not only exposure, but also resolution. Your
eye/brain has got a *lot* less in common with a camera than most folk
think. Go back to that graffiti site, and stare fixedly at one part of
the scene. While you remain staring fixedly at that point, can you
actually read something, or truly see *new* detail, in the other
brighter/darker areas outside those couple of degrees that are in sharp
focus and correctly 'exposed'? Try it right now, focus on this little
dot:
.
Can you genuinely read anything 3 lines above or below? Can you
*really* see detail in bright or dark areas in the rest of your field
of view? The rest of your view is of much lower resolution, and while
your eye is adjusted for an area of one brightness it cannot adjust for
other areas. So the *brain* takes over and fills in memorised or
'fake' detail, or increases/reduces your perceived 'exposure' of the
other areas outside that narrow tunnel. It is only when your eye
moves, and then the pupil dilates/shrinks, that it can cope with the
dynamic range of the scene. In other words... it cheats!
The camera, of course, has to try to capture everything in the scene
all at once (so that your eye can wander over the final image and cheat
again!). So IMO, the eye isn't so much 'better', it's just
*completely* different..
Steve Cutchen - 11 Jul 2005 13:09 GMT
> > But what I did notice was that my eyes had no trouble
> > seeing both sides of the graffiti whereas the digital camera
[quoted text clipped - 21 lines]
>
> Your camera can't do that.
How do you know he shoots Nikon and not Canon?
<G>
Instead of compositing in Photoshop, you might be able to pull out the
shadow contrast with some simple Levels adjustment.
> But what I did notice was that my eyes had no trouble
> seeing both sides of the graffiti whereas the digital camera
> just did not have the dynamic range to accommodate it properly.
> I'm wondering what they'll come up with to finally (if possible)
> deal with this problem.
www.truview.com
RichA - 13 Jul 2005 20:51 GMT
>> But what I did notice was that my eyes had no trouble
>> seeing both sides of the graffiti whereas the digital camera
[quoted text clipped - 3 lines]
>
>www.truview.com
Thanks! I see how it works.
-Rich
Read the subject and just couldn't resist the urge to respond "Well no
sh.t, Sherlock."
The human eye's sensitivity to dynamic range with visible light has
always elipsed the livin crap out of any recording medium consumers
have ever had remotely economical access to (be it reasonably sized
print film, slide film, or digital sensors).
Half of the technical aspect of photography involved figuring out how
to work around the medium's limitations and dynamic range.
Best Regards,
--
Todd H.
http://www.toddh.net/