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# 91 29-10-2006 , 11:06 AM
enhzflep's Avatar
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Join Date: Oct 2006
Location: Melbourne
Posts: 313

Originally posted by mirek03

can i find that info in my camera manual?? its only a little one chip (ccd, i know that much user added image )sony.

what is 'cmos' and what is 'film back ' (size of film??) mean in english.

Well, CMOS is an acronym that stands for Complementary Metal Oxide Substrate. What the?? Basically, it's just an image sensor-type.

Remember the old video-cameras, with CCD or Charge Coupled Device sensors. Due to the way they work, there's at least 2 limitations I know of, however they produce richer tones and cleaner hues than CMOS.

CMOS Good Points:
----------------
1)Very cheap to manufacture - uses same fabrication plants & lines as other computer chips.
2)Nice fast sensor.

CMOS Disadvantages:
--------------------
1) Can only see intensities of light, cannot distinguish colour.
2)Somewhat prone to 'noise' in the image.
3)Filtered colour representation of varying accuracy;


The first disadvantage mentioned is what the whole push towards RAW images is all about.

Since the sensor doesn't see in colour, it must be 'tricked' with either (a)the use of a filter or (b) the use of a corrective computer algorithm based on the sensitivity of a particular sensor technology to each of the 3 primary colours.

In the RAW mode, these 3 data sets R, G and B are all stored uncompressed and un-composited, Allowing _much_ greater control over exposure etc.


Anyway, if the prog's asking about the sensor it's probably so it can set a threshold to avoid noise (and unduly heavy processing) in the image.

As for for the 'film-size' I'm guessing that that has something to do with the size of film that is suited to a lens of a particular focal length and f-Stops. Though I'm a hardware guy, so plz forgive any mistakes I may make.
Anyway, on the box or the instructions or even on the front of the camera &/or lens it should tell you what it's equivalent to. I've got a vid cam that says the following:

f=3.0~45mm F1.2 Ø 30.5
JVC VIDEO LENS
15x OPTICAL ZOOM / AF.

I take that to mean that the aperature can close down to f=3.0 and open up to f=1.2. The focal length changes from 45mm to 30.5mm, putting it in the range of a 35mm camera.

If there wasn't a drop-down combo-box with selections in it already i.e 8mm, 35mm, 70mm. then i would just try changing the values around, observing the resultant changes until (a) I worked it out, or (b) I was going krazy and had to ask for help.

Once again, not so sure if I am correct Re: the lenses.
Hope it helps you and if I have screwed it up and somebody knows better, I'd love to learn.

Simon