Canon 1Ds Mark III Exposure
Canon EOS 1Ds Mark III Exposure
Being a professional model, the Canon EOS 1Ds Mark III provides only the essentials in terms of exposure modes. The modes consist of Program AE, Aperture-Priority, Shutter-Priority, and full Manual mode, along with a Bulb mode for manually timed exposures. The full Auto, Depth of Field AE and various Scene modes found on lesser Canon models are absent. The majority of the exposure modes are fairly self-explanatory, as Program AE, Aperture Priority, Shutter Priority, and Manual modes provide varying degrees of manual and automatic exposure control. While available apertures vary with the lens used, shutter speeds range from 1/8,000 to 30 seconds in all modes except Bulb, which keeps the shutter open as long as the Shutter button is depressed. (Interestingly, Bulb mode has no time limit, other than the available charge in the battery.) Canon's optional RS-80N3 remote switch and TC-80N3 Timer Remote Controller allow you to take long time exposures without having to hold your finger on the Shutter button.
A Custom menu setting can enable a "Safety Shift" option, which automatically adjusts the primary variable (aperture or shutter speed) in Av or Tv modes, if the setting you've selected won't permit a good exposure under the current lighting conditions. This could come into play if you were shooting in shutter-priority mode to achieve a motion-blur effect, but the light suddenly got brighter, pushing the required aperture value beyond what the lens could provide. In this situation, the camera would automatically boost the shutter speed the minimum amount needed to achieve a good exposure. Safety Shift can instead automatically adjust ISO from 100 to 1,600 in P, Av or Tv modes, if so enabled in the same Custom menu (C.Fn 1-8).
As you'd expect, in Program AE mode, turning the Main dial on top of the camera cycles through a range of equivalent exposure settings, allowing you to pick the best exposure with an emphasis on either aperture or shutter speed, while letting the camera determine the exposure. (This is commonly referred to as a "program shift" or "vari-program" option.)
Metering options include a 63-zone Evaluative metering mode, Partial (approximately 8.5% of viewfinder at center), Center Spot (approximately 2.4% of viewfinder at center), AF-point Linked Spot (approximately 2.4% of viewfinder), Multi-spot (a maximum of eight spot meter readings can be entered) and Center-weighted Average options. Metering range is 0 to 20 EV (at 23°C/73°F, with EF 50mm f/1.4 USM lens, ISO 100).
The Multi-Spot metering option bases the exposure on as many as eight separate readings from different parts of the image. In Multi-Spot metering mode, the central spot metering sensor is activated, and a meter reading is taken every time you press the "FEL" button on the top front of the camera. As you take successive readings, the exposure readouts in the viewfinder show the current aperture and shutter speed settings the camera has computed, while the vertical exposure level indicator shows the relative light levels corresponding to each of the points you measured. This is a pretty powerful exposure option, giving the photographer great control over the final exposure. The exposure level indicator gives you a pretty good idea of how much dynamic range the shot requires, and you can choose to give more weight to a given area of the image by taking multiple readings there.
The Canon EOS 1Ds Mark III's Exposure Compensation setting allows the user to increase or decrease the metered exposure by up to three stops positively or negatively, in one-third or one-half EV increments. An automatic exposure bracketing feature lets you set the Canon EOS 1Ds Mark III's total exposure variation (across 2, 3, 5 or 7 shots) at anywhere from +/- one-third or one-half EV, all the way up to +/- 3 EV. You can also specify the order of the sequence: 0, -, + or -, 0, + or +, 0, -.
ISO Sensitivity Options
Noise Reduction Options
AE Lock / FE Lock
The Canon EOS 1Ds Mark III has the simplified AE Lock button, which unbundles the AF Lock feature from the old button on the older EOS cameras. Marked with an asterisk (*) symbol, the AE Lock button simply holds the exposure at one setting while you recompose the image. It's very useful when spot metering, but also when dealing with subjects where you want to draw your exposure from one place, while autofocusing on another. Pressing the Flash Exposure Lock ("FEL") button with an external flash mounted activates the FE Lock function, which fires the flash and locks the proper exposure for the following frame(s).
White Balance Options
A White Balance bracketing option snaps only one image, but then writes three successive files from that single capture. Bracketing steps are from -/+ 3 stops in whole-stop increments. (Each stop corresponds to five mireds of a color conversion filter, for a total range of +/- 15 mireds. This corresponds to about a +/- 500K shift at a normal daylight color temperature of 5,500K.)
Highlight Tone Priority (HTP)
HTP's action is pretty subtle, but the results are very evident when dealing with strong highlights under harsh lighting. The way it works is to set the camera's base ISO up one notch, to 200, so it's only half-filling the sensor's pixels with charge during the exposure. The Canon EOS 1Ds Mark III then alters its tone curve, basically compressing the top half (that would normally be blown out) into a smaller range, thereby preserving the highlight detail. You can do this yourself when working from RAW files, you just need to significantly underexpose most of the scene, and then fiddle with the tone curve to drastically reduce the contrast, but only in the extreme highlights. If that sounds difficult, it is; it can be a real time-sink, and very difficult to make the end result look natural. Canon's HTP does this for you automatically, though, and the results look just great: You have no sense that the camera has been making radical adjustments to its tone curve; you just see all the detail in the highlights that otherwise would be missing. HTP is controlled via C.Fn II-3, giving you options to Disable (the default) or Enable it.
Continuous Shooting Mode and Self-Timer
The Canon EOS 1Ds Mark III's Drive setting also accesses two Self-Timer modes, which open the shutter 10 or 2 seconds after the Shutter button is pressed, giving you time to dash around in front of the camera, or to avoid camera shake from depressing the shutter on a tripod. There is also a Mirror Lockup function to avoid camera shake due to mirror-slap.
The images above were taken from our standardized test shots. For a collection of more pictorial photos, see our Canon EOS-1Ds Mark III Photo Gallery .
Not sure which camera to buy? Let your eyes be the ultimate judge! Visit our Comparometer(tm) to compare images from the Canon EOS-1Ds Mark III with those from other cameras you may be considering. The proof is in the pictures, so let your own eyes decide which you like best!