Bird photography

Short-billed Dowitcher

2009-10-22T10:22:00.000-07:00

Juvenile, NYC in September

Wilson's Phalarope

2009-10-22T10:21:00.000-07:00

Tests on 5D Mark II settings

2009-10-13T10:12:00.000-07:00

Prompted by discussions with a friend concerning his new 7D I did the following tests on my 5D Mark II :

1. Default Picture Code settings do not affect RAW file appearance in Lightroom. Not a great surprise this, since RAW files are supposed to evade most or all processing policies that effect in-camera JPG files. I shot an IT8 target with RAW+JPEG. Of interest was that there was some difference in color reproduction in the reds between "Faithful" and "Neutral" in the JPGs.

2. High ISO Noise Reduction settings do affect RAW appearance. This test was shot against a defocussed white wall (i.e. "featureless" image) at 2 stops underexposure at ISO 1600. There was a marked difference in appearance of the JPG files, with much less evident grain in Standard and Strong settings than at Low or Disabled. Standard was fairly close to Strong. This pattern was also evident in file sizes (more noise = larger files). For the RAW files there was a subtle difference for the same shots - more or less invisible for the lower ISO (400?) that I tested the previous evening but just visible at ISO 1600. I did not test sharpness reduction, but that's the usual trade-off. Canon, however, in this document, indicate that Adobe Camera Raw ignores this setting.

3. Noise patterns at all ISOs. Everything from 100 to 3200 in 1/3 stop increments with the same -2 stop underexposure as the previous test. Notably, stops 1/3 below the "standard" ones showed less noise, but also a little more exposure. In fact for ISO 160 the featureless noise shots perhaps showed nicer noise appearance than ISO 100. The 5D Mark II has this tendency to produce grid noise artifacts at lower ISOs. The ISO 1/3 stop above the standard ones fared least well. This pattern has been commented on previously at the Dpreview.com forums, and despite the high bs level much of the content in those forums, it appears to have a basis in fact.

Central Park, October 6th

2009-10-13T08:29:00.000-07:00

Black-throated Blue Warbler (first fall male)

Scarlet Tanager (first fall male - notice the molt limits in the coverts)

Sora

2009-10-02T09:01:00.001-07:00

DeKorte Park, Lyndhurst, Sept 26th 2009

More megapixel obsessions

2009-09-03T08:23:00.000-07:00

Starting this May I largely stopped using the professional level EOS-1D Mark 3 and have subsequently mostly used the EOS-5D Mark 2. The autofocus performance of the latter is quite a lot worse, particularly in flight, but I had found that the images were noticeably sharper in some instances and generally had more "pop". I still use the 1D3 for flight shots.

I process RAW in Lightroom so in principle things will be normalized but there is a real difference in image quality. The 5D2 has many more pixels (21.1 Mpix vs 10.1), and more per square mm since the 1D3 pixel density is equivalent to 10.1*1.3*1.3 = 17.1 Mpix. The factor of 1.3 comes in because the APS-H sensor on the 1D3 is smaller than the full frame 5D2. The 5D2 appears to be sharper even on a per-pixel basis probably because of a weaker aliasing filter.

Enter the newly-announced Canon 7D which is the common APS-C sensor size (1.6x crop factor) and 18 Mpix. Running the numbers the 7D pixel density is equivalent to 17.9*1.6*1.6 = 45.8 Mpix on a full frame size. No, that's not a typo. It has twice the pixel density of the 5D2 and almost 3x that of the 1D3. You can't ignore that.

There will be the usual concerns about noise level at higher ISOs, and how much actual sharpness you can realize off any lens combination. If you shoot the 17-40/4L wide open the actual resolution of the lens is worse than that of the chip. However the supertelephotos that I use have a lot of inherent sharpness. Some of that sharpness is lost when using the 1.4x teleconverter - it's not difficult to see that in test shots but I can also see it in real life photos in the rare situations when I get to take the 1.4x off.

Which brings me to the thing that most excites me about the 7D - thinking about the number of megapixels on the subject using different lens combinations. This is the same thing as considering pixel density, but adding in a factor for focal length conversion. The equation normalized to full frame is pretty simple:

Effective pixels = Mpix * chip-factor * chip-factor * focal-length-factor * focal-length-factor

Chip factors are 1.0 for the 5D2, 1.3 for APS-H like 1D3, 1.6 for APS-C like 7D. Focal length factor is normalized (i.e. 1.0) to a 700mm f5.6 which is what I use with the 500mm/f4L + 1.4x. (Edit: updated for a 16 mpix APS-H EOS-1D Mark IV, aka 1D4).

These are in Mpix on a "subject" of the same nominal size, so bigger = better.

	1D3	1D4	5D2	7D
500mm	8.7	13.9	10.8	23.4
600mm	12.6	20.2	15.5	33.6
500+1.4x	17.1	27.4	21.1	45.8
800mm	22.3	35.7	27.5	59.8
600+1.4x	24.6	39.4	30.3	66.0

The absolute #s are not relevant because you couldn't image a subject with that many Mpix on it, but the relative numbers hold. I could shoot with the bare 500mm f4 on the 7D and have more pixels on a subject than the same subject with the 500mm+1.4x on the 5D2. Depending on how much these lens combinations outresolve the 7D sensor, and issues with the aliasing filter, the 7D could resolve as much as twice as much detail as the 5D2 for telephoto-type subjects where the subject does not fill the frame. The 5D2 still wins for landscape subjects where the 1.6x crop factor on the 7D kills the widest focal length one can achieve.

Apart from sharpness the wider apertures of bare lenses w/o teleconverters allow lower ISOs or faster shutter speeds to be used in dark conditions. As the analysis indicates it's worth taking a very hard look at this camera for bird subjects because there might be a substantial effective resolution gain. Remains to be proven, however, as many factors can come into play to degrade image quality.

Red-necked Phalarope, Jamaica Bay WR

2009-08-27T21:47:00.000-07:00

Pretty much the only thing I photographed in a relatively brief visit to the East Pond ahead of two days of scheduled rain. This is an adult in basic plumage.

Upland Sandpiper

2009-06-22T10:00:00.000-07:00

Sheyenne National Grasslands in the vicinity of the Nature Conservancy's Brown Ranch, ND. I think this swath of wetland was actually owned by the Nature Conservancy.

Say's Phoebe

2009-06-20T11:09:00.000-07:00

Theodore Roosevelt National Park, south unit, Medora ND

Lark Bunting, WY

2009-06-19T09:53:00.000-07:00

Male Lark Bunting at Thunder Basin National Grassland, Wyoming, June 2009

Dusky Grouse

2009-06-18T09:56:00.000-07:00

Dusky Grouse (formerly Blue Grouse) at Grand Teton National Park in Wyoming, June 2009. This rather tame male was sheltering from the periodic drizzle under an evergreen at dawn, but also singing with a series of almost inaudibly low-frequency hoots. In dark conditions this was taken without the teleconverter at ISO 1600 at something absurd like 1/30th at f4. Nevertheless only required only moderate work with Noise Ninja to get a decent result.

Gray Jay

2009-06-16T10:04:00.000-07:00

Shoshone National Forest in Wyoming, to the east of Yellowstone National Park and to the west of Beartooth Pass.

Black Rosy-Finch

2009-06-15T10:10:00.000-07:00

Adult Black Rosy-Finch in breeding plumage, feeding on a snow field at the east (MT) side of the eastern summit of Beartooth Pass. There were about 30 of them milling around. The following morning there were none here or anywhere along Beartooth Highway.

Mountain Bluebird

2009-06-15T09:50:00.000-07:00

The male of a fairly cooperative pair at Makoshika State Park at Glendive, MT on the MN-ND-WY trip.

Nelson's Sharp-tailed Sparrow

2009-06-14T10:12:00.000-07:00

They are never supposed to be this cooperative, but this adult male Nelson's Sharp-tailed Sparrow (now called Nelson's Sparrow) was singing on the reed-covered fence line at Lostwood National Wildlife Refuge. Probably helped that at the time there were two males there, so competition for this small piece of habitat was relatively fierce.

Brewer's Blackbird

2009-06-13T11:02:00.000-07:00

One of the few cooperative ones from the MN-ND-WY trip, roadside at Lords Lake National Wildlife Refuge near Bottineau, ND

Yellow-headed Blackbird

2009-06-12T11:05:00.000-07:00

Displaying male Yellow-headed Blackbird, Sheyenne National Grasslands, ND

Mourning Warbler

2009-06-11T11:33:00.000-07:00

Adult male, alternate plumage, MN in June 2009

Barn Swallow

2009-06-11T11:06:00.000-07:00

Sheyenne National Grasslands, ND

Willow Flycatcher

2009-05-30T11:59:00.000-07:00

Adult male Willow Flycatcher, Franklin Twp, NJ in May. Several areas in Franklin hold them, at least in part because Franklin Twp makes some effort to keep a fair amount of open space. Some of these grasslands are invaluable for declining birds like Grasshopper Sparrow and Bobolink, although Willow Flycatcher is a little more versatile and not under quite so much pressure as those two specialists.

Golden-winged Warbler

2009-05-19T12:02:00.000-07:00

Adult male, NY in May. Rapidly declining under the twin pressure of habitat loss and hybridization with the more dominant Blue-winged Warbler, there are still a few pockets of this species to be found in the north-east.

Bay-breasted Warbler

2009-04-26T12:05:00.000-07:00

Very early but not totally unprecedented, this adult male Bay-breasted Warbler was seen on April 26th in Central Park. This species is more commonly associated with being found in the warbler weather of May 10th or later.

Yellow-throated Warbler

2009-04-12T12:35:00.000-07:00

Adult male (possibly first spring), alternate plumage, Central Park

Canon hits the wall ?

2008-11-05T13:11:00.000-08:00

The most recent review of the Canon 50D by dpreview.com suggests that the successor to the 40D hasn't eked much more resolution out of the images than its predecessor.

Ever since the introduction of the first "prosumer" digital SLR with the D30, Canon have done an epic job of increasing pixel count (and therefore resolution) of this line of cameras while keeping the noise level down:

D30, 3.1 megapixel, 10.1 micron pixels, [full-frame 7.9 mpix]
D60, 6.3 megapixel, 7.4 micron pixels, [full-frame 16.1 mpix]
10D, 6.3 megapixel, 7.4 micron pixels, [full-frame 16.1 mpix]
20D, 8.2 megapixel, 6.5 micron pixels, [full-frame 21.0 mpix]
30D, 8.2 megapixel, 6.5 micron pixels, [full-frame 21.0 mpix]
40D, 10.1 megapixel, 5.7 micron pixels, [full-frame 25.9 mpix]
50D, 15.1 megapixel, 4.7 micron pixels, [full-frame 38.7 mpix]

(all the chip sizes are essentially identical for this series of cameras)
The full-frame values are what you'd get in a full-35mm-size chip of the same pixel density.

The review suggest that both resolution and noise levels on the 50D are no better (or, in the case of noise level, worse than) the 40D. Have we finally hit the limitations of resolution with these Bayer matrix sensors ?

And for those who are wondering why I care: here's an explanation.
To oversimplify: pixel density is more relevant for telephoto shooters, while the total number of pixels is more relevant for people that can fill the frame with their subject.

Harris's Sparrow

2008-11-01T12:42:00.000-07:00

Vagrant Harris's Sparrow at Brandywine Creek State Park in Delaware.