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> From: "Robert Inglis" <>
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> Subject: Some notes on digital still cameras for bird photography: Part4a
> Date: Fri, 26 Jul 2002 08:09:50 +1000
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> Hello again digi-birders,
>
> It appears that I have had trouble sending Part 4 of my notes and comments on
> digital cameras for bird photographers in one complete missive.
> So, I have split it into 2 parts.
>
> This is Part 4a of my notes and comments on digital cameras for bird
> photography.
> In this part I will discuss:
>
> - CCD pixel count (in Part 4a)
> (Part 4b will cover resolution and picture quality):
>
> [Note: the following is a simple explanation ;-)....]
>
> The component of a digital camera which makes it all happen is the 'Image
> Sensor'.
> This is the electronic device or 'chip' that takes the place of the film in
> non-digital cameras.
> There are two types of sensor currently in use and a third type is being
> developed but we won't talk about that one.
> The most common is the CCD (Charge-coupled Device) with a few cameras being
> fitted with a CMOS (Complimentary Metal-oxide Semiconductor).
> It is not necessary to know what the names mean or how they work (technical!!)
> to be able to use the camera they are in, however, the two types do have some
> different characteristics that may be of interest.
> Note: CCD is pronounced: see-see-dee while CMOS is pronounced see-moss.
>
> CCDs and CMOSs are basically similar in construction in that they consist
> of a rectangular matrix of light-sensitive semiconductors with a mass of
> electrical connections to a microprocessor.
> These semiconductors are referred to as 'Pixels' (from Picture Elements).
> Each pixel registers a part (or dot) of the image being recorded by the
> camera.
> Image sensor chips these days consist of up to 6 million pixels in an area
> about
> the size of a thumb nail!
> The resultant picture is thus made up of millions of dots similar to the
> photos
> printed in a newspaper except that the dots in the picture from the digital
> camera are square or rectangular and not round as in the newspaper photo.
> It should be realized, therefore, that the more dots, or pixels, in a digital
> photo the better the photo will look due to there being more 'information'
> recorded.
> For that reason, I suggest that a digital camera intended for bird photography
> should have an image sensor with a pixel count of 2 million or more.
> The usual way to refer to such a camera is to call it a '2 mega-pixel' camera
> or
> a '3 mega-pixel' or '4 mega-pixel' etc.
> Incidentally, for digital images to achieve the equivalent 'resolution' of
> film
> the Image Sensors will have to grow to far more than 6 mega-pixels.
> The physical size of Image Sensors is often described in the list of
> specifications as measuring: 1 / 4.7 inches (one example only).
> This is a measurement style that I find hard to fathom not being a
> mathematical
> type person.
> But I figure that's about half an inch wide.
>
> CCDs have been around for a long time now and have been well developed; most
> digital cameras use CCDs.
> CMOSs were first used in 'low-end' digital cameras but are now appearing in
> 'pro' digital cameras such as the Canon EOS D30 and D60 models.
> CCDs are said to be more responsive, especially in low light, than CMOSs.
> CCDs also produce 'cleaner' images without the 'noise' (something like static)
> that CMOSs have been guilty of producing (CMOSs are getting better).
> On the other hand, CMOSs are cheaper than CCDs and are said to reproduce
> 'highlights' such as the glint of sunlight off water better.
> A big problem with CCDs that is not apparent with CMOSs is that they can,
> unfortunately, produce a 'bloom' or 'halo' around very bright spots in an
> image.
> In my experience this is more noticeable when using high magnification
> lenses, a real downer for bird photographers.
> This 'bloom' can really spoil an image if it is excessive and is quite
> difficult
> to 'edit' out even with very good image software programs.
> As all of the 'consumer' digital cameras that will be attractive to bird
> photographers use CCDs this problem is something to be aware of.
> That's about all you can do, be aware of the problem, as it is often
> impossible
> to avoid scenes with bright spots in them.
> However, if you find that some of your pictures display this 'halo' (it will
> be
> obvious) it is not your fault, blame the CCD!
> For this reason I am reluctant to pay out good money on a teleconverter with a
> power greater than 2x.
> This restricts my present set-up to an equivalent of 780mm.
>
> (continued in Part 4b)
>
> If anyone would like to see examples of the images I have taken with the
> Olympus
> C-700 Ultra Zoom, contact me at and I will send you a
> couple of JPEG versions as e-mail attachments.
>
> Yet to come:
> - Viewfinder types;
> - LCD monitor screens;
> - Storage media;
> - Flash;
> - Accessories;
> .....Lens and filters;
> - Power;
> - Digiscoping.
>
> More soon,
>
> Bob Inglis
> Woody Point
> Queensland
> Australia
>
> (Disclaimer:
> Please note that these are my personal opinions gained from personal
> experience
> and observation; other people may have other opinions and different
> experiences.
> What I have written below is not intended to be absolute.
> Anyone contemplating purchasing a digital camera for any reason or purpose
> would
> be advised to seek advice from other sources as well.
> Note that, except where a particular model of digital camera is mentioned,
> these
> comments and notes are meant to be general by nature.
> These comments and notes are not intended to be an endorsement for or a
> statement against any particular brand or model of digital camera; they are
> intended only to be a point of discussion for those people who may be
> considering purchasing and/or using digital cameras for bird photography.
> It should be realized that changes are occurring seemingly daily in this field
> and therefore features and usability of digital cameras are changing also.
> The types of digital cameras will change regularly as will the quality of
> image
> produced.)
>
>
>
>
>
>
>
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