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Old Aug 25, 2003, 4:42 AM   #1
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Default r digital cameras more sensitive than conventional? how?



i'm doing a research assignment for school and one of the questions is
"are digital cameras more sensitive than conventional cameras and how?"
well i hope that someone could help me
thanks
katina
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Old Aug 25, 2003, 4:53 AM   #2
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What do you mean by sensitive?

What do you mean by conventional cameras?
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Old Aug 25, 2003, 7:30 AM   #3
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Sensitive and conventional are very relevant questions.

Here is an analogy. You turn on your Walkman radio, it's very 'sensitive' you turn up the volume the music gets louder, but when the music is quiet, you hear lots of hiss. You know that's not in the real music, because you bought the CD.

So your radio was very sensitive, but it couldn't make the music loud without adding the hiss, so the quality went down.

Is it better to have a very sensitive radio that has a lot of background hiss, or a less sensitive one which most of the time gets a good signal but without the hiss?

Digital and film images for that matter have a lot in common with this simple explanation of what is called 'noise' - Those unwanted additions produced in the system itself.

As this is a school assignment, they have presented a question which requires answers with a number of qualifications, ifs and may be's'. You will be marked on how well you have discussed the 'variables' between digital and film, what makes them different or similar and how they react in real usage - again similar or different.

Your answer will not be a one liner! Your conclusion will not be that digicams are, or are not more sensitive - they may be in certain circumstances which you will have explained evaluated compared and qualified. VOX
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Old Aug 25, 2003, 10:53 AM   #4
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Great reply Vox, as usual.

And it also depends if you're talking about a cheap digital camera like a $50 JamCam, or a $10,000 dSLR (digital SLR).

I know that digital cameras are more sensitive to being dropped! :lol:
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Old Aug 25, 2003, 1:35 PM   #5
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Don't forget the camera response time. If you have a fast digital camera with noise and easy to break would it be as sensitive as a cardbox camera?
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Old Aug 26, 2003, 11:05 PM   #6
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As I understand it, the smaller the CCD is, the more sensitive it must be to get the same signal. Of course, there is the exception, which is resolution. A 1.3mp 1/2.7 CCD will not to be as sensitive as a 5mp 1/1.8 even though the CCD is 50% larger in length and width. The reason is that the sensitivity is based on a sensor by sensor basis.

A better way to measure sensitvity is by pitch. Pitch is a ratio most commonly seen in things like roofing (rise over run). Pitch is the amount of micrometers per pixel or more commonly seen like this 18Ám. Of course, the amount of pixels per Ám changes with the camera's CCD. The higher the Ám, the less sensitive the camera needs to be.

Now as to whether CCD's are more sensitive than film, that's up to you to figure out. To make matters worse, film changes sensitivity due to grain size. Also, there are CCDs that are larger than 35mm.

Just thought I'd give you a head start,
Hope I didn't conuse you,
Dan O.
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Old Aug 26, 2003, 11:13 PM   #7
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You can see as well that most digital cameras can see near infrared while you need special film to do that with a film camera.
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Old Aug 26, 2003, 11:14 PM   #8
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My camera weeps when it sees a newborn baby or a perfect sunset. I think it's just a pansy.
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Old Aug 27, 2003, 2:21 AM   #9
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............As I understand it, the smaller the CCD is, the more sensitive it must be to get the same signal..............

That's not quite true. Light is energy (photons) the larger the area of light coverage the more 'sensitive' will be the camera. The problem is consumers want smaller whilst bigger ccd's and lenses are more expensive to manufacture - so manufacturers make everything smaller and use cheaper digital processing on the smaller signal and noise reduction in software as a compromise. VOX
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Old Aug 27, 2003, 8:30 AM   #10
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Quote:
That's not quite true. Light is energy (photons) the larger the area of light coverage the more 'sensitive' will be the camera. The problem is consumers want smaller whilst bigger ccd's and lenses are more expensive to manufacture - so manufacturers make everything smaller and use cheaper digital processing on the smaller signal and noise reduction in software as a compromise. VOX
True.

The reason I put it that way is because most often upping the ISO, or increasing signal gain in any way is often called upping the sensitivity.

So the question arrives, is a small pixel sensor the same sensitivity as a larger one, simply because the camera manufacturors have upped the signal gain?

In this case, we have gone nowhere in our discussion because if the senstivity is always the same no matter the pixel size, then we still have no idea how sensitive it is! Unless of course, upping the sensitivty is an unaccurate decription of increasing the signal gain.

Now I'm left with more questions than answers, thanks voxmagna!
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