Digital Camera Notes - November 2004:
I just took a quantum leap in the quality of the bird pictures I can
easily get by jumping to a DSLR camera with a long lens. In particular,
the one I got is the new Canon 20D 8 megapixel back and the 100-400mm f/5.6
Canon lens. This is the tool used by Stuart Healy (http://www.aztrogon.com/)
in Arizona as part of his birder guiding business. After seeing his pictures
and reading his raves (see his Photography pages), I realized that he was
doing a lot better than I was. And his raves ring true for me as well.
Many things that used to be hard about bird photography have suddenly become
easy. For example, I had always been using a tripod and remote shutter
release for my high zoom shots. But the super high sensitivity with low
noise of the 20D lets me shoot at 1/1000 second now so I can hand hold
most of my shots. Add to that the image stabilization of the lens, and
it's a nature photographers dream. Also the speed of auto focus and lack
of shutter delay makes getting flight pictures relatively easy. I had given
up on those when using cameras with various delays built in.
At the right is one of my first-day-of-ownership shots of a Red-tailed
Hawk who zoomed over me. This was taken with the 18-85mm kit lens set at
85mm. |
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As an extreme example, one morning I was
out early when the light was dim. So I cranked the camera ISO up to 3200.
(On my Konica Minolta A2 it was hard to go above ISO 200 due to the digital
noise). Later a Nuttal's woodpecker appeared in the nearby woods. I was
using aperture priority with f/7 set.in order to get low depth of field
with my 400mm lens. Forgetting about the high ISO I clicked away and
the camera
set the shutter speed at 1/8000 sec! No problem with hand holding at
that speed. The resulting picture is shown at the left.
It is true that I have post processed this image
in Photoshop, and used Noise Ninja lightly to reduce the digital noise.
But to get such a usable image at ISO 3200 was amazing to me. That is six
stops of exposure compared to ISO 200. That can be utilized to increase
the shutter speed as here, or to make lower light photos that can still
be hand held.
This bird was some 60 feet away from me when I got the picture.
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| One last example. Here is what you can do
when fortunate circumstances conspire to let you get close to the bird.
Here
I was only about ten feet from this Ruby-crowned Kinglet with my 400mm
lens. By setting the aperature nearly wide open, you get small depth of
field. So the background is nicely out of focus, but the small feathers
on the bird are sharply in focus. Compare this to the picture of the Scrub
Jay below. There the background sticks are in focus as well as the bird.
Which is better? It's a matter of opinion. The Kinglet image seems more
'arty'. But the Jay image is closer to what you would see through binoculars.
You have to decide what you want. |
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Digital Camera
Notes (pre November 2004)
I began trying to take bird photos three years ago with
a 6X zoom 2 megapixel camera. Got some fine shots, but discovered that
for really good ones I had to be within 20 feet of the birds. Most birds
don't like you getting that close. So, conclusion #1: For good
bird photography, you need all the optical zoom and megapixels you can
get. Great conclusion for justifying to my wife why I needed
a bigger and better camera each year!
Most of the pictures on this site were taken with an Olympus
750UZ that features 10X optical zoom and 4 megapixels. Add to that a
1.7X teleconverter, tripod, and remote shutter release.
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But the Scrub Jay shown above (who has just finished preening and fluffing)
is my first photo taken with the new Konica Minolta A2. This camera has only
a 7X optical zoom, but makes up for that with an 8 megapixel sensor. And I
added on my old Olympus TCON 17 teleconverter to obtain 12X optical zoom.(This
is a 340mm equivalent in 35mm parlance). Then the 2X digital zoom was invoked
(see below) making the total zoom 24X.You see the result.
Digital zoom: I have always considered digital zoom an advertising
gimmick. It is equivalent to enlarging and cropping, something done better
and with more control in Photoshop post processing. But with the Minolta A2
I have finally found a use for it as built into the camera. On the A2 there
is a 2X digital zoom button near the shutter release. When you push it, not
only will the camera record a 2X image (but with only 1200x1600 pixels), but
the image in the electronic viewfinder doubles in size. Since the resolution
of the A2 EVF is four times that of the A1 (now 900,000 pixels!) this is really
useful. It's like having a 7X binocular that with the push of a button becomes
14X and image stabilized as well. One can tweak up the auto-focus using the
manual focus ring, for instance. Then you can either record the 2X image, or
drop back into normal mode and record the well-focussed image.
Shutter delay: This is a bane of digital cameras used for
bird photography. The Olympus 750UZ is a great camera, but the time delay between
tripping the shutter and getting the picture was a problem.The delay caused
by time for auto focussing and setting auto exposure was a few tenths of a
second. But the IR remote shutter release had a 2 second delay! Frequently
the bird would have flown away in that time.The A2 removes both those delays.
Since the zoom and focus can both be set manually, there is no delay there.
And the shutter delay is in the 50 millisecond range. Lastly, the anti-shake
feature lets me depress the shutter manually. Under most conditions the camera
movement induced does not show up in the picture.
Put your dollars into optical zoom or more megapixels? For
bird photography, optical zoom usually wins. It translates into more stand
off distance from the bird for the same quality photo. Doubling the 6X optical
zoom to 12X actually doubles the distance. But pixels fill an area. So if you
double from 4 megapixels to 8 megapixels, the linear scaling factor is not
2X, but the square root of 2, which equals 1.414X. I conclude that if you
have enough megapixels for the size prints you hope to make, spend your extra
money on longer focal length optics. There is a depth of field consideration
too. Long focal lengths tend to yield smaller depth-of-field photos. Whereas
digital zooming does not change the depth-of-field of the photo. Many bird
photographers like a small depth-of-field and the out of focus background that
results. It makes the bird stand out and gives the picture an "arty" look.
For me, I want my photo to more closely resemble what you would see through
good binoculars. That means the background should be fairly well focussed.
Given the Lens Blur tool that Photoshop CS has, it is possible to do a reasonable
job of blurring the background in post processing. There are many artistic
choices to be made here.
What pixel per inch resolution should you rescale to for printing? My
choice is 288 ppi. You want something near to 300 ppi to get a good, high resolution
ink jet print, or for magazine use. Display screen resolution is 72 ppi. So
if you make a 4 x 6 inch photo at 288 ppi, it will appear huge on the computer
screen. But divide 288 by 4 and you get 72, and a nicely scaled photo for screen
display. Most software uses a quick and approximate algorithm to rescale figures
for screen display, and they introduce some fuzziness in the process. But when
the rescaling is simply division by an integer, the quick rescaling yields
a sharp result. So viewing my 288 ppi image at 25% on screen, I am better able
to judge its inherent sharpness. I'm not sure how important this is, but it
works for me. Of course, when the photo is destined for Web presentation, it
must be rescaled to 72 ppi and JPEG compressed. Photoshop and many other programs
have a 'Save for Web' tool that automates this and makes it easy. All the photos
on this site use the 70% JPEG compression setting. This choice is a compromise
between wanting small files that will download quickly, but also files that
do not show compression artifacts too much. The Scrub Jay shown above was processed
this way.
Newest Pix
Notes on using the Raynox 2.2X teleconverter lens on the A2
Photo test: A2 with TCON17 vs A2 with Raynox 2.2X
Tripod Bracket for A2 with the Raynox 2.2X teleconverter
