Dust spots are a fact of the life of digital photographers
using DSLRs with interchangeable lenses (only the Canon D30, D60, 10D
and 300D seem to be less prone. We have the feeling that this maybe more
luck than design because the Canon 1D and 1Ds show more dust).
Now Nikon came up with a neat idea to implement a feature in their
D70 and D2h that allows to photograph a "dust map" photo and should
help to reduce/remove dust from existing raw files.
Reason enough to have a closer look into the theory and practice of
this new feature in Nikon
Capture 4.x. We used the new feature on three images with
different levels of complexity and our 2 day old D70 was a good test
Note: This is always the same dust spot
in the D70. All images are not sharpened because we do dust removal
as one of the first steps.
Round #1: Dust in the sky
We remember when we first saw a dust spot with our
Nikon D1 4 years ago and panicked. What is this and life is over :-).
We actually cleaned the D1 with canned air and made matters worse (spilled
residue onto the sensor). Today we use the Photoshop healing brush
all the time and would be rich if we would get a $1 per spot. Cleaning
about 30 dust spots in the sky takes us today less than 30-60 seconds.
Dust spot in sky
What if there would be a better way?
So we tried the "Dust Off" feature in NC 4.x. We took a "dust
photo as described in the D70 camera manual and tried to clean the
spot in Nikon Capture 4.1.
Cleaned with NC 4.1
There is only a slight impression left
of the spot.
Cleaned with CS Healing Brush
Took me 10 seconds in CS and the result
is slightly better.
Round #1: "Dust Off" could be nice
Round #2: Dust in the sky near objects
This time it gets more complicated.
Dust near objects
"Cleaned" with NC 4.1
This was not very helpful and failed
to help in real life. Also notice the color shift.
Corrected in CS with Healing Brush
Using the healing brush here is not
trivial. We need to use selections. This technique is described in
our handbook DOP2000 (sorry
we have to finance our site). The solution is way from perfect but
could be improved spending more time. But you would hardly see this
in a print.
Round #2: Lost by NC4.1
Round #3: Dust on more complex patterns
Now it gets even more tricky.
Dust spot on shirt
Corrected with NC 4.1
Also here NC 4.1 failed to do the trick.
Using Healing Brush
Again not a perfect solution but hard
to find in a final print.
"Dust Off" by Nikon is a great idea.
The implementation disappoints.
Disclaimer: If this would be the result
of a bad dust reference file then it would mean:
- Why did it work in sample 1?
- The process maybe very error prone