Sky Too Bright?

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Bright sky and dark foreground are not a happy combination for photographers unless both can be captured. This difficulty is not unique to digital photography. Although sometimes the available dynamic range of the digital camera (or film) is inadequate, often the light meter is simply fooled. The three photos above illustrate this problem. All photos were taken within a short time (but the clouds were moving quickly) with my G9 mounted on a tripod, evaluative metering, Av mode at f5.6, ISO 80 and shooting raw + jpg. The photos above were downsized from the in-camera jpg and sharpened for web viewing (PK Sharpener ) but are otherwise unprocessed.

For the bright sky problem, the hoped-for-solution is the “correct” exposure. Think about a bright sky scene from the point of view of the exposure meter. If there is only a little sky, then the exposure is based on the ground – 1/160 sec in Photo #1 above. If the composition is mostly sky, the exposure meter thinks there is a lot of available light – 1/640 sec in Photo #2. As the camera operator, uh, photographer, you might manually set an in-between exposure value. Some metering systems attempt to do this automatically; Photo #3 was taken at 1/320 sec as determined automatically by the G9. So Photo #1 has good ground but no sky detail; Photo #2 has a beautiful sky but dark ground; Photo #3 is sort of a blah in-between.

While taking photos 1, 2 and 3 above, the live histogram of the G9 indicated that Photo 1 was overexposed –a little more than a full f-stop. Photo 2 was slightly underexposed – about a half stop. Photo 3 is slightly overexposed – perhaps a half stop. So the “best” exposure would have been about f5.6 and 1/400 sec manual exposure (not very far off Sunny 16 for the G9) or by dialing in a -2/3 exposure compensation for Av mode. I didn’t get a shot at f5.6 and 1/400; however, I was shooting with +/- 1 auto exposure bracketing so I’m pretty sure of those relative effects.

I was interested in comparing the in-camera jpgs for normal, graduated neutral density filter and a polarizing filter; these photos are shown below (Photo 3 is repeated). Again, all photos were taken in Av mode using evaluative metering without exposure compensation.

In Photo #4, the 50/50 split, graduated neutral density filter (Tiffen ND 0.6) performed as expected but the upper clouds were darkened excessively. At 1/250 sec, it is slightly underexposed – perhaps 1/3 stop. Photo #5 shows the effects of a polarizing filter (Tiffen Circular). The filter was rotated for maximum sky detail. Unlike my G3, the effects of rotating the polarizing filter could be seen in the G9 LCD display. At 1/160 sec, the polarized exposure is just about right according to the histogram.

Nest is a comparison of raw and jpg; shooting in raw + jpg mode allowed a direct comparison. The third set of photos (below) compares Photo 3 (the in-camera jpg from the first and second sets) to the processed raw version, Photo 6. Similarly, Photo 7 is the raw version of Photo 5.

Both raw files (6 and 7) were processed in Adobe Camera Raw using the same settings. Surprisingly, no exposure adjustment was needed -- even though I’d previously noted that Photo 3 was slightly overexposed. The “Recovery” adjustment compensated for this highlight recovery. The ACR settings for Photo 6 and 7 were:

WB: Daylight
Exposure adjustment: 0
Recovery: 15
Fill: 10
Black: 8
Brightness: 40
Contrast: 0
Clarity: 40
Vibrance: 8
Saturation: 3
A “Medium Contrast Curve”
Sharpening: 80
Radius: 0.8
Detail: 30
Masking: 0
Luminance Noise Reduction: 0
Color Noise Reduction: 25

All other ACR settings were at zero. After opening in ACR, “Smart Sharpening” at 100 was applied in Photoshop CS3. No other post processing was applied.

In retrospect, I should have applied a bit more saturation to Photos 6 and 7 just for purposes of comparison to Photo 3 because Canon’s in-camera jpgs are a bit saturated (some say over-saturated).

Lessons learned? Well, I’ll continue to shoot in raw and will be using my polarizing filter more often.

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Consumers Union on Digital Cameras

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Consumers Union is preparing an article on digital cameras for their June 2008 issue of Consumer Reports. For background information, they are asking for input from photographers. Here’s your chance to voice your comments, complaints and wish list.

Here’s what I submitted:
1. Shutter lag is a huge complaint. Unbelievably, shutter lag is a problem even on cameras that can be set to full manual mode!
2. Noise at high ISO sensitivity, especially above about ISO 200 to 400. Many users voice a pseudo-technical explanation and wish for fewer pixels as a compromise to reduce noise.
3. Wide angle lens. Most digicams have a 35mm equivalent focal length as the widest angle on the zoom. A 28mme would be far better for many scenes, especially indoor family snapshots. Some people even want 24mme.
4. Accurate optical viewfinder. The LCD display is difficult to see in bright sunlight. Existing optical viewfinders (many digicams don't even have one) suffer badly from parallax and reduced field of view.
5. On-camera flash, low power and red-eye are common complaints. Personally, I'd like a simple way to add an external flash but placed off-camera.
6. Faster shot-to-shot cycle times.
7. I personally prefer shooting in raw mode but many digicam users do not.
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Was it really focused?

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When the G9 has acquired focus, it actually beeps twice (very quickly) and the AF frame on the LCD is green. If the G9 is confused about the focus, it beeps only once and the AF frame on the LCD is yellow. Granted, the beeps are difficult to distinguish and sometimes the yellow vs green is not so obvious either but this is the way the G9 tells you that it thinks it is focused.
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G9 on Parade

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I took my G9 to a St. Patrick’s Day Parade this weekend. It was nice day, an even nicer outing and a nice parade. I was able to get some good snapshots but no real prize winners. Photographing the parade reminded me of several shortcomings of the G9:

1. No built-in sun screen and the G9 is too small to provide shade.
2. No built-in fluid reservoir in the G9
3. No built-in features to clone away the power lines
4. Can’t read the LCD display if wearing polarized sunglasses
5. Lensmate (or Canon) adapter interferes with the optical viewfinder
6. Optical viewfinder is not accurate, must offset for parallax
7. Shutter lag makes capturing the “decisive moment” difficult

All in all, I had a good day at the parade -- and the G9 was part of it.
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Swiss Army Camera

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I set this up because I like Swiss Army Knives and wanted to emphasize the versatility of the G9. As if the fully automatic camera features were not enough, the G9 has features like slide shows, direct printer connection, voice recorder, calendar, clock and more. Is a knife soon to be on the list? (Summarized from my longer essay at MyCanonG7.)

More of my Swiss Army Knife photos are on Smugmug.
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G9 Macro

Does this look weird? Here’s is an old Konica 135mm telephoto lens reversed and mounted to the Lensmate adapter on my G9. I’ve always thought that one lens reversed and mounted on another was one of the strangest setups in photography. How did anyone ever think to do this? Doing this takes a special coupler with one set of threads to match the Lensmate and another to match the filter threads of the reversed lens. The coupler I used was 58mm on one side to match the Lensmate and 55mm on the other side to match the Konica telephoto. Why do this? The idea is to use existing equipment to get extreme closeups. But the G9 already has macro! Why mess with a good thing? Well, let’s try a few shots. (The cable release was extremely useful, thanks, Richard!).

First of all, strictly speaking, none of these shots are true macros. Macro is supposed to mean a full sized image on the negative. The G9’s sensor is so small that true macro capability might not be very useful; besides, the definition of macro photography has been considerably stretched and is now understood to mean close-ups. Without any accessories, here’s a penny at the closest focus distance for the G9 – about 5/16 of an inch from the front element of the lens when at the shortest focal length (wide angle). The photo is uncropped; it is impressive (click for a larger view) but the subject was very difficult to light because the lens is so close. The light source is pointing almost horizontally through the small space between penny and lens.

Going to the opposite extreme – again without accessories – here’s a shot at maximum focal length (max zoom) and the minimum focus distance (about 20 inches). In this configuration, the subject was much easier to light but the field of view is much more than was desired. Again, the photo is uncropped.


Here’s an uncropped shot taken with the 135mm reversed telephoto. The setup was almost exactly as shown in the introductory image. The telephoto was set at its widest aperture (f4) and infinity focus. The G9 was at max zoom and minimum focus distance. The penny was moved until it was in focus. The G9 aperture was f8 (in spite of diffraction) to maximize depth of field; however, depth of field is always a problem in macro photography.

Another strange aspect of the reversed auxiliary lens is that a reversed wide angle lens provides greater magnification than a reversed telephoto. Here’s a shot with a reversed 40mm Konica Hexanon. Again, the image is uncropped; the 40mm was set at f1.8 and infinity focus. The G9 was at maximum zoom and near minimum focus. The physical distance between reversed 40mm lens and penny was less than for the reversed 135mm lens. This was the maximum magnification that I was able to obtain; it is probably near true macro with respect to the G9 sensor.

Of course, there are simple screw-on closeup magnifier lenses that look almost like filters. Here’s an uncropped image shot with a +4 closeup lense screwed into the Lensmate (no coupler required). The G9 lens was set for f8, maximum zoom and minimum focus distance. The penny was moved into the field of focus. Again, this image is uncropped. This configuration and setup would be very useful for similar subject sizes.

The G9 minimum focus distance is about 20 inches at maximum zoom but a fraction of an inch at wide angle. In-between those focal lengths, the minimum focus distance is, well, in-between. It seems to me that a good working combination is at mid-zoom and minimum focus of about 7 to 10 inches on the G9 manual focus scale. Here’s a shot at mid-zoom with the +4 closeup lens attached. Not quite as much magnification as at full zoom but potentially very useful.

Lessons learned? The +4 closeup lens is very useful. It provides good magnification and versatility while allowing enough separation between lens and subject to allow variations in lighting. If an extreme closeup – near true macro – is needed, then I’ll use the reversed 40mm Hexanon.

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G9 and In-Camera Noise Reduction

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After writing about how to tune the in-camera jpg from the G9, I've been asked about tuning the noise reduction as well. Although some cameras have adjustable noise reduction/treatment settings, the G9 does not. Noise reduction is applied to all JPEG images as deemed necessary and appropriate by Canon. To get around the in-camera G9 noise reduction process, you’ll have to shoot in raw mode.
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