Number One: A Big Deal
Digital Photography is not like film photography,
except that plenty of people shoot film and immediately digitize
it so they can play with it in digital form. The lenses, f-stops
and ISO notions are common to all photography, so those don't
count in this challenge either.
Your task is to rebel against the status
quo and discover what the puzzle is all about. Once that is done,
the practical result of it will join your growing digital photographic
awareness in a very useful way. Then the challenge will be this:
"Do I use the new found information or not? Or perhaps only
use the knowledge at certain times?"
The resolution to this is not earth shattering,
but it's not a calm walk in the park, either. You'll know when
you know. But the Lesson/Challenge/Puzzle/Test is named aptly
and the result of knowing its secret may help you immensely when
the chips are down.
What's really going on with the images
below? Roll your mouse over the images and some form of change
will happen. Not all changes are the same, but all are related.
The question is this: What, exactly and
precisely, is the root difference between example 1 (no mouse
over) and example 2 (mouse over) in these shots?
Each shot is cropped directly out of a
two layer stack of imagery and presented here for examination
at full scale from that stack.
This site is not known widely to the digital
photography community. It's a new thing, just a baby. So before
we get to Lesson #2, we'll let this one sink in for a while.
In January, 2004, the answer will be given.
If you think you really, really know what the answer(s) is to
the above puzzle, drop me
a line. Perhaps you will be among the list of those whose
ability to see, analyze and define with digital clarity.
Honestly, if I hadn't dreamed up this puzzle/challenge/lesson,
I don't know what my own reaction to it would have been. Good
--Peter iNova (firstname.lastname@example.org)
Ready? Sure you are. And now for the Big
Revelation: The top three crops are from the same frame, but
of course a second frame is revealed in the rollover. The difference
between the frames is...
Here's what the difference is NOT: Not
a difference in compression, f-stop, ISO, focus, sharpening,
contrast, colorimetry or RAW vs. Compressed. It's the same lens,
the same camera and the same exposure in each. The clue should
be "Notice how different they are NOT." Because differences
are minor. About the same amount of difference between shooting
the scene at f/5.6 and f/11 as far as sharpness goes, but that
can't be IT because the f-stop was the same for both shots.
The Big Difference was this: One was shot
at Full frame size, 3072 x 2048 pixels large, while the other
was shot at Medium frame size (2048 x 1360 pixels) and enlarged
in Photoshop up to the size of the full frame. Bicubic interpolation
was used, but no post-enlargement sharpening was added to the
one labeled Crop #2 and only a tiny amount of Unsharp Masking
was added to Crop #1 and Crop #3. This showed up as 0.3 pixels
at 87%, for those of you who use Photoshop's Unsharp Mask tool.
Just a tiny tweak to the finest contours without introducing
What's the point of all this? It should
be obvious by now, especially when you consider how LITTLE extra
you get out of shooting with the largest frame size. Don't get
me wrong, you do in fact get something extra with that biggest
frame option, namely the maximum detail, but if you shoot that
large frame at f/5.6 or f/16 and higher, you've lost all your
advantages. Your picture will be "diffraction limited"
and there's no way you're getting more detail onto that chip
when the lens has been prevented from resolving more detail by
Ma Nature and her cup of Physics.
One Big Benefit from shooting with the
Medium frame size is this: you get to store about 50% more images
per megabyte on your CF card. Meaning that your card goes farther
and you get more opportunities to find that perfect shot. Photography
is a game of moments, if you think of it that way, and the more
moments you collect, the better your chances of bagging the Big
One that Didn't Get Away. Or POTD*, whichever comes first.
About that fourth shot. I cheated. Just
to throw you off--and to make things more interesting--it's a
same-size, pixel for pixel comparison between a Nikon Coolpix
5700 (a 5-megapixel camera) and the Rebel with the Kit lens.
After much wrangling, the same size image was forced to cover
the same pixel count with both cameras so you could see directly
how much detail each format of lens/chip acquires per pixel.
But I think I'd have to repeat this test a few times to draw
major conclusions. Both cameras were on tripods, both were shot
at ISO 100 set for Daylight white balance. The crop here is at
100% so we would expect a certain amount of softness. The Nikon
image (slightly darker/bluer and seen only with the mouse rolled
over the frame) seems to reveal a bit of camera movement, and
that's possible since the tripod was a lightweight and the camera
was tripped manually.
What's it tell us? By and large the conclusions
seem to be this: Canon is getting a LOT out of every pixel. More
color differentiation, longer tonal scale and lower noise. Apparently
more detail, too. And with 512 more pixels in the image width,
same-size images from the DR would be 20% more detailed on a
same-size print, all things being equal, but with perhaps 30%
more native detail per pixel, that might actually show up as
around 50% more detail than the very capable 5-megapixel capture.
Not science, just experience. Anyhow, I'm
enjoying this camera A Lot.
-iNova (January 15, 2004)
*POTD is Picture Of The Day in many web contests.