Konica Minolta DiMAGE A2Konica Minolta updates their top-end electronic SLR with a higher resolution sensor, much-improved electronic viewfinder, a faster 3D autofocusing system, and high-speed USB 2.0 connectivity, among other improvements.<<Optics :(Previous) | (Next): Shutter Lag & Cycle Time Tests>> Page 6:Exposure & FlashReview First Posted: 07/13/2004 |
Exposure
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The DiMAGE A2 offers excellent exposure control, with very fine-grained
adjustment of such image attributes as sharpness, contrast, and color saturation.
While I found the camera's user interface a little confusing at first, with
its myriad buttons, dials, and switches, I liked it a lot once I got the hang
of it. (The combined use of functional dials, selection buttons, and the rotating
command wheel is similar to the design of Minolta's film cameras, and very reminiscent
of the earlier Sony DSC-D700, DSC-D770, and DKC-FP3, three closely-related cameras
that developed a significant "cult" following. While something of
a departure for the digicam market, this interface has proven very popular with
users of both Minolta's film cameras, and the much earlier Sony models.)
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The Mode switch on the rear panel selects the basic operating mode: Record,
Playback, or Movie. Within Record mode, the Exposure Mode dial selects the camera's
exposure mode. Choices are Manual, Shutter Priority, Aperture Priority, Program
AE, Auto, Memory Recall, Portrait, Sports, Sunset, and Night Portrait modes.
In straight Auto mode, the camera controls everything about the exposure, except for flash, zoom, and focus. Program AE mode keeps the camera in charge of the exposure, while you have control over all other exposure options. While in Program AE mode, you can rotate either of the control dials to scroll between a range of equivalent exposure settings. Thus, you can bias your exposure toward a faster shutter speed or greater depth of field as circumstances dictate. Aperture Priority mode lets you select the lens aperture setting, from f/2.8 to f/11 depending on the zoom setting, while the camera selects the most appropriate corresponding shutter speed. In Shutter Priority mode, the user selects the shutter speed, from 1/4,000 to 30 seconds, while the camera chooses the best corresponding aperture setting. Switching to Manual mode gives you control over both shutter speed and aperture, with a Bulb setting available for longer exposures. Exposure time in Bulb mode is determined by how long you hold down the Shutter button, up to a maximum of 30 seconds. (I strongly recommend use of the optional wired remote in Bulb mode, as the pressure of your finger on the shutter button is bound to jiggle the camera somewhat, blurring the image. - Oddly, Konica Minolta implemented a true "time" exposure option (press the shutter button once to open the shutter, then again to close it) on their new Z2 long-zoom consumer camera, but not on the high-end A2, where you'd much more expect to see it.) A new function accessible via the Custom option of the Function dial, DOF Preview lets you view a scene through the electronic viewfinder or LCD with the aperture stopped down, giving you an idea of the depth of field available before actually capturing an image. This is a very welcome addition that gives you confidence that your subjects are within the field of focus, and is actually even more useful on an EVF camera than on traditional SLRs, since the sensitivity of the image sensor can be cranked up to give you enough light to determine focus (on a traditional SLR camera, closing the aperture down reduces the available light reaching the viewfinder, making it harder to see the viewfinder image).
As described above, the DiMAGE A2 also offers four preset scene modes (referred
to as Digital Subject Programs), accessed via the Exposure Mode dial. Portrait
mode produces better-looking people shots by enhancing skin tones and decreasing
the depth of field (to create a slightly blurred background). Sports mode provides
faster shutter speeds to freeze action, and maintains focus on quickly moving
subjects. In Sunset mode, the camera employs slightly slower shutter speeds
to let in more of the ambient light, and lets you record the warm colors of
the scene without compensating for them in the white balance system. In Night
Portrait mode, the camera also uses a slower shutter speed to allow more ambient
light into the image, however it also records true black values and preserves
the bright colors of artificial lighting. The Exposure Mode dial also features
a Memory Recall setting, which lets you save as many as five registers of settings.
Selecting a setting automatically applies the settings to the camera, which
can be recalled by turning the Exposure Mode dial to another position.
The DiMAGE A2's default metering mode is a 300-segment evaluative system, which
takes readings throughout the image to determine exposure. Center-Weighted and
Spot metering options are also available via the Function Dial. Spot metering
is useful for high-contrast subjects, as it bases the exposure reading on the
very center of the image, letting you set the exposure based on a small portion
of your subject. Optionally, the Spot metering can be linked to the Flex Focus
Point AF area with the "Spot AE Area" function, allowing you to meter
from the same point as the camera is focusing on, wherever in the frame that
may be. Center-Weighted metering also bases the exposure on the center of the
image, but the camera takes its readings from a much larger area in the middle
of the frame. You can also hold or lock the exposure reading for a particular
part of the image by pressing the AE Lock button on the back panel. This button
can be programmed to act as either a "hold" or "toggle"
control. "Hold" mode does just that, it holds the current setting
until you release the AE Lock button again. Toggle mode locks and releases the
exposure/focus setting with successive actuations of the AE Lock button. Halfway
pressing the Shutter button also locks exposure and focus, but only in autofocus
mode.
The DiMAGE A2's light sensitivity can be set to Auto, or to ISO equivalents
of 64, 100, 200, 400, or 800. As with other consumer and prosumer digicams that
sport ISO 800 options though, I didn't find the ISO 800 setting to be particularly
useful, because the image noise level was so high. A Noise Reduction option
is available for longer exposures and higher ISO settings, and greatly reduces
the amount of image noise that would otherwise result, but doesn't have any
effect on shorter exposures at high ISO. Exposure compensation is adjustable
from -2 to +2 exposure equivalents (EV) in one-third-step increments, and an
auto-bracketing option can snap three shots in rapid succession, varying the
exposure between each in steps of 0.3 or 0.5 EV units. Exposure compensation
is adjusted using the Digital Effects dial, while auto bracketing is activated
by rotating the Function Dial to the Drive position, pressing the center, and
then rotating the Control dial until the auto bracketing icon appears in the
LCD or EVF display. Exposure step size for auto bracketing is set through an
option in the record-mode menu system.
Like the DiMAGE A1 before it, the DiMAGE A2 offers very flexible control over
white balance, color rendition, and tonal range. Its white balance system offers
a total of seven options, including Auto, Daylight, Tungsten, Fluorescent, Cloudy,
Shade, and Custom, which is the manual setting. The Custom Set mode determines
white balance by snapping a picture of a white card. The camera then adjusts
its color balance to render the white card with a neutral hue, and saves the
setting as the Custom option. As many as three Custom settings can be saved,
very useful if you need to switch back and forth between different lighting
conditions quickly.
Contrast and Color Saturation controls are adjustable in 11 steps across a fairly
broad range of settings, using the Digital Effects dial on the camera's left
side in conjunction with the Front Control dial next to the Shutter button.
To make adjustments, you rotate the Digital Effects dial to either setting,
press the button at its center, and then rotate the Control dial to choose the
desired setting. The DiMAGE A2 also offers a Filter setting on the Digital Effects
dial. Depending on the color mode selected through the Custom Settings menu,
the Filter option adjusts the overall color cast of the image, again in 11 steps.
The color range here varies from rather blue to rather yellow, exactly the color
axis that you'd want to adjust to compensate for different color temperatures
in your lighting. Positive adjustments warm the image, while negative adjustments
produce a cooler color balance. In Black and White mode, the Filter effect tones
the image from neutral to red, green, magenta, blue, and back to neutral (zero
position).
The combination of fine steps and wide adjustment ranges in the Digital Effects
controls mean you can really customize the A2 to exactly suit your preferences
for color and tonality. Most cameras offering saturation, white point, and contrast
variations treat them more as special effects, rather than as adjustments for
fine-tuning camera response. We seem to be seeing more evidence of other manufacturers
offering "fine tuning" options like this (Olympus prominent among
them), but I'd really like to see it become even more widespread.
The Color Mode option of the Record menu offers Natural and Vivid sRGB color
modes, as well as Adobe RGB, Embedded Adobe RGB, Black and White, and Solarization
settings. Adobe RGB color space has a much broader gamut or range of reproducible
colors than does sRGB, the color space used by most digital cameras and computer
monitors. (The Embedded option simply means that the color space information
is embedded in the image file.) Adobe RGB images will look rather dull when
displayed on monitors tuned to the sRGB standard, but when used in a color-managed
work environment, they can capture and reproduce a much greater range of colors.
For its part, Solarization partially reverses the tones in an image, while the
Exposure Compensation adjustment controls the intensity of the effect. The record
menu also offers a Sharpness adjustment, for controlling the amount of in-camera
sharpening applied to an image.
Continuous Modes
The DiMAGE A2 features a range of continuous shooting modes, accessed via
the "Drive" setting on the left-side Function dial. In addition to
the standard Continuous Advance mode, the DiMAGE A2 also offers Interval, High-Speed
Continuous, Ultra High Speed Continuous, and Interval and Time-Lapse Movie modes.
(Note that the Drive setting also access the Self-Timer and Auto Exposure Bracketing
modes as well.) In standard Continuous Advance, the DiMAGE A2 captures approximately
1.8 frames per second, for the first three frames. Depending on the resolution
and quality settings, as well as the amount of memory card space, the subsequent
frame rate and maximum number of frames will vary. In my testing, I found Continuous
mode cycle times slowed to approximately 6.4 seconds per frame for the fourth
through the eighth frames when shooting at the highest resolution and lowest
JPEG compression, recording to an 80x Lexar CF card. (With a 40x card, the first
three frames shot at the same speed, but subsequent shots came at 8.6 second
intervals.) When shooting at smaller image sizes, the camera seemed to quickly
capture groups of three frames, with pauses of about 3.3 seconds between each
group. The first three frames are caught at approximately 1.9 frames per second,
and subsequent groups of three images are each at 0.66 frames per second, with
pauses between groups of a bit over 3.4 seconds.
High-Speed Continuous mode captures a series of full-size images at approximately 2.7 frames per second. Behavior was otherwise very similar to that of normal Continuous mode.
Ultra High Speed Continuous mode captures a series of 640 x 480 pixel images at approximately seven frames per second. With a fast memory card, the run length in Ultra High Speed mode can be quite long - With an 80x Lexar CF card, I managed to capture 184 frames before the camera stopped, after which it took 70 seconds for it to process all the data and flush it to the card.
Interval mode captures a series of images at specific intervals over time, providing a built-in time-lapse capability. The DiMAGE A2 can capture up to 240 images in the sequence, with frame intervals ranging from 30 seconds to 60 minutes, and a delayed start time from 30 minutes to 24 hours.
Interval and Time-Lapse Movie modes both capture a series of images, at the
Interval setting specified through the Record menu. Interval mode records the
images as a series of still images, while Time-Lapse Movie mode assembles the
individual images into a 640 x 480 movie clip.
As mentioned above, the Drive setting also accesses the Self-Timer and Auto
Exposure Bracketing modes. The Self-Timer fires the shutter either two or ten
seconds after the shutter button is pressed. (Select between the two delay options
by using the rear-panel command dial.) The shorter delay is very handy when
you need to prop the camera on something to take a photo in dim lighting, and
don't want the pressure of your finger on the shutter button to jiggle the camera.
The ten-second delay is long enough that you can run around to get into the
photo yourself. An LED lamp on the front of the camera blinks and the camera
beeps as the self timer is counting down, the blink and beeps becoming faster
in the last few seconds.
Auto Exposure Bracketing mode captures a series of three images (one at the
metered exposure, one underexposed, and one overexposed). You can set the exposure
variation between exposures to 0.3, or 0.5 EV. The A2's automatic bracketing
options go beyond simple exposure bracketing though. Turning the Rear Control
dial cycles through a range of bracketing options, including Continuous-Advance
Bracket, Single-Frame Advance Bracket, and Digital Effect Bracket (which brackets
either Filter, Contrast, or Color Saturation settings). The ability to bracket
hue, contrast, and color saturation is really helpful for handling difficult
subjects.
Movie and Sound Recording
The DiMAGE A2 has a Movie mode that records moving images with sound, for
up to 15 minutes per clip. The amount of recording time appears in the LCD or
EVF monitor display, and varies with the resolution and frame rate of the movie,
the available CompactFlash card space, and the speed of the memory card. (The
full 15 minutes of recording time will only be available at the highest resolution
and frame rate if your memory card can support the data transfer rate.) Movies
are recorded at 544 x 408, or 320 x 240-pixel resolution, with frame rates of
approximately 15 or 30 frames per second. Through the Record menu, you can set
the movie mode to Auto, Standard, or Night. Night mode records black and white
movies in low lighting situations, and is far more effective in dim lighting
than the vast majority of digicam movie options I've seen. The Auto setting
tells the camera to automatically decide between Standard and Night modes, based
on the exposure conditions.
One odd note about maximum movie clip length: When testing it, I initially used
a 2GB 80x speed-rated Lexar card, to verify that maximum record time really
was the 15 minutes shown on the camera's display. To my surprise, the camera
stopped recording after about 5 minutes. Thinking that the A2's circuitry might
somehow not be up to the extreme speed of the 80x card, I dropped back to a
1GB 40x card, and found that I could record movies for the full 15 minutes claimed.
Realizing that I'd changed two variables though (card size as well as
card speed), I next tried a 1GB 80x card. Voila, the camera again recorded for
a full 15 minutes. As a double-check, I returned to the 2GB 80x card, and again
found that recording time was limited to about 5 minutes. The conclusion? It
seems that the A2 somehow gets bogged down with memory cards larger than 1GB!
It still works fine, but can't seem to navigate the larger file system as quickly.
- So, feel free to use very large memory cards with the A2, but stay below 1
GB if you need to record maximum-resolution movies for more than 5 minutes at
a time. (Note though, that all movie settings other than the maximum size, 30
fps option will record to the full 15 minute limit. - 15 fps at maximum resolution
, or either 15 or 30 fps at the lower resolution work just fine.)
A Voice Memo mode records 15 seconds of audio to accompany still images. This
mode must be enabled before image capture. When enabled, a microphone icon appears
in the LCD/EVF display, and the camera automatically begins recording audio
for the specified amount of time immediately after image capture.
Flash
The
DiMAGE A2 features a built-in, pop-up flash, which operates in either Fill-Flash,
Red-Eye Reduction, Rear Flash sync, or Wireless modes. To release the flash
from its compartment, pull on the two small tabs on either side of the casing
and lift up the flash head. Close it again by simply pushing the flash head
back down. The Flash mode is changed through the Record settings menu, or optionally
through the Custom option of the Function dial. In Fill-Flash mode, the flash
fires with every exposure, regardless of lighting conditions. Red-Eye Reduction
fires a series of small pre-flashes before firing the flash at full power for
the exposure itself. This makes your subjects' pupils contract and reduces the
occurrence of the Red-Eye effect. The Rear Flash Sync mode fires the flash at
the end of the shutter time, rather than the beginning. If you have moving objects
in a relatively brightly lit environment, this will produce a sharp image of
your subject, with a "motion trail" following behind it. The flash
is in the Off position when it's closed. The Wireless mode lets the camera work
with wireless remote flash units, with four channels available through the settings
menu, so different camera/flash setups working in the same area won't interfere
with each other. (Konica Minolta makes two flash units that support the DiMAGE
A2's wireless capability, the Program Flash 5600HS [D] and 3600HS [D].)
The DiMAGE A2 is also unusual in that it offers two methods of flash metering.
Its default mode is called ADI, which stands for Advanced Distance Integration.
In this mode, it bases its flash exposure on the lens aperture and distance
feedback from the autofocus system, as well as on the light reflected back from
a pre-flash. By determining how far away the target subject is, the camera knows
how much flash power is required to illuminate it, and so is less likely to
be fooled by subjects that are unusually light or dark overall. As a fallback,
a Pre-Flash TTL (through the lens) method bases the exposure determination solely
on a small metering flash before the main exposure. Used in conjunction with
the spot autofocus option mentioned earlier, the ADI flash metering should be
much more accurate with small subjects against a different colored background
than the pre-flash method.
For use with studio strobes and conventional slave triggers, the DiMAGE A2 also has a manual flash power option. This lets you set the flash power to Full, 1/2, 1/4, 1/8, or 1/16 power manually. In this mode, the flash fires only once, at the moment of exposure. The single flash pulse prevents false triggering when working with conventional slave triggers.
The DiMAGE A2 also includes a top-mounted hot shoe for attaching an external
flash unit. The shoe design and contact arrangement are set up for Konica Minolta's
own dedicated flash units, but I imagine that compatible models are available
from the major third-party flash manufacturers (Sunpak et. al.). Konica Minolta's
own Program Flash models 2500(D), 3600HS(D), and 5600HS(D) work with the DiMAGE
A2, and two macro flashes (Macro Twin Flash 2400 and Macro Ring Flash 1200)
will work with an accessory macro flash controller.
An external flash sync terminal (the so-called "PC" style connector)
accommodates just about any third-party flash unit. This makes the DiMAGE A2
much more appealing to photographers who already have an existing strobe system
for the studio.
I had a chance to play a bit with a couple of Konica Minolta's dedicated flash
units back when I tested the earlier DiMAGE 7Hi, and must say I was impressed.
I only shot with the 5600 model (a conventional hot-shoe mounted unit, but with
the added capability of wireless control) in a fairly small area, so didn't
test the maximum range over which the wireless TTL control would function. (I'm
sure it has some maximum range over which it's effective, but don't know what
that is.) That said though, the camera/flash combination worked exceptionally
well. Very slick, given that no extra controller or other hardware is needed
to establish the wireless link between the flash and the camera. (This has to
be one of the neatest flash arrangements I've seen yet on a digicam, the only
equal I'm aware of being Nikon's advanced wireless system built around their
SB-600 and SB-800 strobes, and supported by the D70 and D2H SLRs.)
For closeup work, the T2400 macro twin flash is a very capable setup too. -
A large ring mounts to the front of the lens, and serves as a support mount
for a pair of tiny flash heads. The little flash heads are powered by a flash
controller that looks just like a normal hot-shoe flash unit, but has two sockets
on its front instead of the flash tube. The ring has multiple mounting points
around it for the little flash heads, so you can direct the light to come from
top, bottom, or either side with equal ease. The flash controller also lets
you set the power ratio between the two heads, so you can have a "main"
and "fill" light on your macro subject. Very flexible, very slick
(if not a little odd-looking). Highly recommended if you intend to do any really
extensive macro work. (This should be a great solution for people selling tiny
objects (coins, jewelry?) on eBay, looks like a sure winner for dentists looking
to document their work, entomologists wanting really good bug pictures, etc,
etc.)
Color Space
This is probably as good a place as any to talk about the DiMAGE A2's color
space. The original DiMAGE 7 used a proprietary color space with a much wider
color gamut than the sRGB space used by most digicams. (As well as by most computer
monitors, consumer-grade printers, etc.) The result was that it could capture
a much broader range of colors than other cameras, but this also meant that
the raw JPEGs straight out of the camera looked rather flat and dull when viewed
on a typical computer monitor. To get the full color to appear, you needed to
run the image files through Minolta's DiMAGE Viewer software utility, and convert
their color space back to sRGB. (Or whatever other working space you wanted
to use. Many graphics professionals work in the so-called "Adobe RGB"
space popularized by Photoshop(tm), which is supported by many graphics programs
and printers, and also offers an expanded color gamut.)
While the expanded color gamut was a real boon to graphics professionals and
others interested in breaking free of the constraints of sRGB, for the average
amateur it amounted to just one more step to go through before they could fully
enjoy their photos. Worse, if someone wasn't aware of the color space issue,
they'd probably write off the DiMAGE 7 as having rather flat, undersaturated
color.
With the DiMAGE 7i, Minolta stepped back closer to the mainstream in the color
space department, adopting a color space that was much closer to sRGB, to the
point that files from the 7i could be used in an sRGB environment without special
processing. While there was still some undersaturation in parts of the spectrum,
the 7i's unprocessed JPEG images were much more visually appealing than those
from the original 7.
With the DiMAGE 7Hi, Minolta further moved to embrace standard color space definitions,
but this time they also included an option for a space with a larger color gamut
than that supported by sRGB. The 7Hi had three color space options (plus black
& white and sepia), two based on sRGB, and two being the broader-gamut "Adobe
RGB" space. The two sRGB spaces are the default one, with normal color
rendering, and a "vivid" sRGB option, which boosts color saturation
a fair bit. The two AdobeRGB spaces are identical with the exception of whether
or not color space information is embedded in the image files. The DiMAGE A1
followed in the footsteps of the 7Hi in this regard, with the same color space
options available, as does the A2.
This increased color-space flexibility will come as a welcome addition for many
pros and advanced amateurs who want to use their cameras in a color-managed
environment. The Adobe RGB space avoids many of the color limitations of the
sRGB space, which are most evident in highly-saturated reds. Working in Adobe
RGB lets you maintain detail in bright reds and greens that can't be properly
represented in sRGB space. Switching to Adobe RGB for your photography does
involve a fair degree of commitment though, as you'll need to set up your entire
workflow to support it, including both screen rendering on your computer's CRT
or LCD, and printing to your printer. Computer monitors are built to the sRGB
standard, and require software support (as in Adobe Photoshop or other high-end
image manipulation package) to portray Adobe RGB images properly. Likewise,
most consumer-grade photo printers assume sRGB as the starting point, again
needing color management to properly output Adobe RGB files. (Many professional
photo printers are set up to work in Adobe RGB by default though, so check to
see what your printer's default color space is.)
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