Blooming
Behind this strange word there is a defect which is well-known for
everybody who practices in the field of a digital photo. It appears,
when the image has strong local contrast. What is the local contrast?
This is the area where the light object is in the neighborhood with
the dark area. If you look at these areas of the image under
magnifying glass will find out that pixels on the border of two areas
have not that color which it is necessary. Photosites on border cannot
simply understand a similar situation. They "pass" to the next area
that gives wrong brightness and distribution therefore there is an
effect of blooming of the next photosites.
For the decision of this problem manufacturers have developed various
hardware and program decisions. For example, Foveon with the sensor
control 3 xs has decided to impose against each other three
CMOS-SENSOR CONTROLS, each of which is sensitive to the color. This
decision has allowed to neutralize blooming effect though has led to
the occurrence of some problems in other areas.
Other companies have preferred program decisions. The data sent by a
sensor control on the circuit, are processed so that to reduce to a
minimum the blooming effect.
Noise
Word "noise" usually connects not with images, and with a sound,
however with the advent of digital cameras it began to associate and
with this area. As "noise" understand the pixels of light shades
observable in dark areas though there they should not be. The result
reminds particles of a dust. As it has been told above, these defects
are consequence of amplification of the signal leaving a sensor
control. If the photosensitivity of a sensor control is less, it is
necessary to strengthen a signal more strongly, and the there will be
"noise" more. Therefore manufacturers should equip the models with the
various program or hardware decisions lowering effect of "noise" after
amplification.
What to prefer?
In results of our discussion it is possible to tell, that CMOS-SENSOR
CONTROL Canon is equivalent on quality to the CCD-SENSOR CONTROL.
Technology Fuji Super CCD is interesting alternative of the cameras
providing (though with cunning) the high sanction under the
comprehensible price. The technology today is quite fulfilled, so its
quality does not cause censures.
As to the size of a sensor control it comes to limits. Advantage from
increase in number of photosites today any more so is obvious,
especial if to take into account the high price and a considerable
level of "noise". As to compact models with a sensor control 1/1,8 "
six millions pixels here hardly it is necessary to count technological
achievement. Taking into account a way of use of similar cameras (more
often, it is listing of photos 10x15), the sensor control on 4 million
photosites will cope with work not worse (and, can, and it is better)
for the smaller price. The same concerns and for printing with
half-professional cameras equipped 2/3 " a sensor control. The gain of
quality from eight millions photosites, in comparison with five
millions, is not obvious, is especial if to take into account problems
with increase of a level of "noise".
If to look at a situation only from the point of view of a sensor
control, not accepting in attention compactness of the camera the best
choice will be, certainly, the CCD-SENSOR CONTROL of format APS on six
millions photosites. It can be in SLR-cameras such as Nikon D70. Or it
is possible to take the CMOS-EQUIVALENT at Canon 300D. These cameras
have the best parity of the quality / price and give better quality of
the image for amateurs, and its size will be sufficient for listing on
a format down to A3
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