Megapixels vs. Zoom Which is more important?

Kathy wrote:
> Having poor vision, I have often taken a picture of something far away
> just to find out what is is by magnifying it when I get it to the
> computer. With a 2 megapixel camera it has usually been too jagged
> (pixelated?) to tell. I thought I needed more megapixels, but a
> salesman told me I need more zoom.
>
> Is this correct?
> a. With more megapixels, I can magnify the whole picture on the
> computer more and still have it clear, but the files take up more
> space.
> b. With more zoom, only the part I am trying to see gets magnified, and
> the files remain small.
> c. In fact with a very big zoom, I could use it like binoculars.
>
> I appreciate any clarification you can give me about these 2
> characteristics of a camera.

It takes a lot of megapixels to have the same effect as a long range
zoom lens. To get the same quality of image of a 4x optical zoom by
doing an image crop you will need 16 times the megapixel count. This
translates to 80mp to get the same crop image from a 5mp sensor with a
4X optical zoom lens.
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

Zoom & pixels--
Don't forget Lens quality and depth of field. The sensor is much smaller
than the standard 35mm film frame. The end result is that the lens needs to
be a high quality lens. Another issue is focus. Most of the current models
have a marginally workable or no manual focus. This makes depth of field an
issue.
3.1 MP with a decent lens, wide depth of field, and auto focus -- will
produce snapshots with a good resolution.
5-7MP produces a better picture, and can be used to produce good 8x10
prints.
8-16MP good for uses bordering on the professional, and professional with
high quality lenses and equipment.
Zoom lenses beyond 3-4x require image stabilization and/or a tripod for best
quality, and may require higher light levels for good pictures. Focus- lack
of a good manual focus function may be an issue.

"Michael Johnson, PE" <cds.RemoveThis@erols.com> wrote in message
news:2bmdnSbL3f8tmmDZnZ2dnUVZ_t-dnZ2d@giganews.com...
> Kathy wrote:
> > Having poor vision, I have often taken a picture of something far away
> > just to find out what is is by magnifying it when I get it to the
> > computer. With a 2 megapixel camera it has usually been too jagged
> > (pixelated?) to tell. I thought I needed more megapixels, but a
> > salesman told me I need more zoom.
> >
> > Is this correct?
> > a. With more megapixels, I can magnify the whole picture on the
> > computer more and still have it clear, but the files take up more
> > space.
> > b. With more zoom, only the part I am trying to see gets magnified, and
> > the files remain small.
> > c. In fact with a very big zoom, I could use it like binoculars.
> >
> > I appreciate any clarification you can give me about these 2
> > characteristics of a camera.
>
> It takes a lot of megapixels to have the same effect as a long range
> zoom lens. To get the same quality of image of a 4x optical zoom by
> doing an image crop you will need 16 times the megapixel count. This
> translates to 80mp to get the same crop image from a 5mp sensor with a
> 4X optical zoom lens.
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

On Mon, 4 Sep 2006 Kathy wrote:

>Having poor vision, I have often taken a picture of something far away
>just to find out what is is by magnifying it when I get it to the
>computer. With a 2 megapixel camera it has usually been too jagged
>(pixelated?) to tell. I thought I needed more megapixels, but a
>salesman told me I need more zoom.
>
>Is this correct?
>a. With more megapixels, I can magnify the whole picture on the
>computer more and still have it clear, but the files take up more
>space.
>b. With more zoom, only the part I am trying to see gets magnified, and
>the files remain small.
>c. In fact with a very big zoom, I could use it like binoculars.
>
>I appreciate any clarification you can give me about these 2
>characteristics of a camera.

I agree with all the previous replies. But note that all references to
zoom so far apply to optical zoom, not digital. Digital zoom just
spreads the pixels from the centre of the non-zoomed image over the
whole of the detector or the viewing screen. You don't get any greater
detail in your image by digital-zoom.

That having been said, digital zoom is probably useful to get a better
view on the camera screen. A large optical zoom plus digital zoom
probably make for a good monocular (not binocular).
--
Thoss
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

Digital zoom is a major part of the manual focusing problem with the current
crop of digital cameras.
It seems that digital zoom is typically used to create a zoomed box in the
center of the LCD display. As a result, it is very difficult to tell if a
good focus is obtained. The latitude of CCD sensors is quite a bit less than
film, just to add to the problem.

"thoss" <usenet DeleteThis @thoss.plus.com> wrote in message
news:CXeuFLA3tW$EFwTH@thoss.plus.com...
> On Mon, 4 Sep 2006 Kathy wrote:
>
> >Having poor vision, I have often taken a picture of something far away
> >just to find out what is is by magnifying it when I get it to the
> >computer. With a 2 megapixel camera it has usually been too jagged
> >(pixelated?) to tell. I thought I needed more megapixels, but a
> >salesman told me I need more zoom.
> >
> >Is this correct?
> >a. With more megapixels, I can magnify the whole picture on the
> >computer more and still have it clear, but the files take up more
> >space.
> >b. With more zoom, only the part I am trying to see gets magnified, and
> >the files remain small.
> >c. In fact with a very big zoom, I could use it like binoculars.
> >
> >I appreciate any clarification you can give me about these 2
> >characteristics of a camera.
>
> I agree with all the previous replies. But note that all references to
> zoom so far apply to optical zoom, not digital. Digital zoom just
> spreads the pixels from the centre of the non-zoomed image over the
> whole of the detector or the viewing screen. You don't get any greater
> detail in your image by digital-zoom.
>
> That having been said, digital zoom is probably useful to get a better
> view on the camera screen. A large optical zoom plus digital zoom
> probably make for a good monocular (not binocular).
> --
> Thoss
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

"Chuck" <Chuckk2nospam DeleteThis @cox.net> wrote in message
news:fybLg.6971$SZ3.2268@dukeread04...
> Zoom & pixels--
> Don't forget Lens quality and depth of field. The sensor is much smaller
> than the standard 35mm film frame. The end result is that the lens needs
> to
> be a high quality lens. Another issue is focus. Most of the current models
> have a marginally workable or no manual focus. This makes depth of field
> an
> issue.

Does it? In my experience, depth of field with a typical digital camera is
less of an issue than with a 35mm film camera, thanks to the smaller lens
and sensor. In fact getting a restricted depth of field when you want one
seems to be virtually impossible except with extreme close-ups.

> 3.1 MP with a decent lens, wide depth of field, and auto focus -- will
> produce snapshots with a good resolution.
> 5-7MP produces a better picture, and can be used to produce good 8x10
> prints.
> 8-16MP good for uses bordering on the professional, and professional with
> high quality lenses and equipment.
> Zoom lenses beyond 3-4x require image stabilization and/or a tripod for
> best
> quality, and may require higher light levels for good pictures. Focus-
> lack
> of a good manual focus function may be an issue.

If the OP's taking pictures of objects that are far away, as she says,
surely the camera will be focussed on infinity so manual focussing wouldn't
make a difference...?
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

Zoom.
---
Mike Russell
www.curvemeister.com/forum/
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

The digital cameras generally are LESS sensitive to light than a 35mm with a
good lens and high speed color film.
This requires that the digital camera lens be set to an F stop that lets in
more light than that typically used by the 35mm, or use of slower shutter
speed equivilents.
So depth of field and focus actually become more of an issue.
(Unless you are talking about typical consumer digital cameras with an
everything's in focus non removable lens.)


Does it? In my experience, depth of field with a typical digital camera is
less of an issue than with a 35mm film camera, thanks to the smaller lens
and sensor. In fact getting a restricted depth of field when you want one
seems to be virtually impossible except with extreme close-ups.

"Rich Wilson" <rich DeleteThis @spam-spamson.co.uk> wrote in message
news:rwQTg.52722$WV2.35614@newsfe2-gui.ntli.net...
>
> "Chuck" <Chuckk2nospam DeleteThis @cox.net> wrote in message
> news:fybLg.6971$SZ3.2268@dukeread04...
> > Zoom & pixels--
> > Don't forget Lens quality and depth of field. The sensor is much smaller
> > than the standard 35mm film frame. The end result is that the lens needs
> > to
> > be a high quality lens. Another issue is focus. Most of the current
models
> > have a marginally workable or no manual focus. This makes depth of field
> > an
> > issue.
>
> Does it? In my experience, depth of field with a typical digital camera is
> less of an issue than with a 35mm film camera, thanks to the smaller lens
> and sensor. In fact getting a restricted depth of field when you want one
> seems to be virtually impossible except with extreme close-ups.
>
> > 3.1 MP with a decent lens, wide depth of field, and auto focus -- will
> > produce snapshots with a good resolution.
> > 5-7MP produces a better picture, and can be used to produce good 8x10
> > prints.
> > 8-16MP good for uses bordering on the professional, and professional
with
> > high quality lenses and equipment.
> > Zoom lenses beyond 3-4x require image stabilization and/or a tripod for
> > best
> > quality, and may require higher light levels for good pictures. Focus-
> > lack
> > of a good manual focus function may be an issue.
>
> If the OP's taking pictures of objects that are far away, as she says,
> surely the camera will be focussed on infinity so manual focussing
wouldn't
> make a difference...?
>
>
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

"Chuck" <Chuckk2nospam.DeleteThis@cox.net> wrote in message
news:Q3aUg.881$XX2.807@dukeread04...
> The digital cameras generally are LESS sensitive to light than a 35mm with
> a
> good lens and high speed color film.

....possibly because their lenses and sensors are smaller?

> This requires that the digital camera lens be set to an F stop that lets
> in
> more light than that typically used by the 35mm, or use of slower shutter
> speed equivilents.

Really? To get an equivalent physical aperture size the F number on a
digital camera would surely have to be lower because the focal length is
smaller. Do you actually mean the *physical aperture size* has to be larger?

> So depth of field and focus actually become more of an issue.

Have you actually proved this with a real camera?

> (Unless you are talking about typical consumer digital cameras with an
> everything's in focus non removable lens.)

I'm talking about a typical compact digital camera like mine (which is a
Sony DSC-S600).
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

"Rich Wilson" <rich.RemoveThis@spam-spamson.co.uk> wrote in message
news:FeeUg.81506$DB3.46713@newsfe6-gui.ntli.net...
>
> "Chuck" <Chuckk2nospam.RemoveThis@cox.net> wrote in message
> news:Q3aUg.881$XX2.807@dukeread04...
>> The digital cameras generally are LESS sensitive to light than a 35mm
>> with a
>> good lens and high speed color film.
>
> ...possibly because their lenses and sensors are smaller?
>
>> This requires that the digital camera lens be set to an F stop that lets
>> in
>> more light than that typically used by the 35mm, or use of slower shutter
>> speed equivilents.
>
> Really? To get an equivalent physical aperture size the F number on a
> digital camera would surely have to be lower because the focal length is
> smaller. Do you actually mean the *physical aperture size* has to be
> larger?
>
>> So depth of field and focus actually become more of an issue.
>
> Have you actually proved this with a real camera?
>
>> (Unless you are talking about typical consumer digital cameras with an
>> everything's in focus non removable lens.)
>
> I'm talking about a typical compact digital camera like mine (which is a
> Sony DSC-S600).

Facts about Depth of Field (plenty of detail):
http://en.wikipedia.org/wiki/Depth_of_field

--
CSM1
http://www.carlmcmillan.com
--
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

An example--
Oly c8080wz Wide open "f" stop 2.4-2.7 (Zoom lens)
Film speed equivilent (settable) 50-100-etc, 400 max useful. (due to noise)

35mm Oly OM-10 film speed - I generally use no slower than 400 for color
film, and usually much faster film. Wide open "F" stop 1.5

It is true that the light from the lens gets focused on a smaller area with
the CCD sensor, since the sensor is smaller than a 35 mm frame.
It's also true that the CCD sensor is less sensitive to light than the usual
35mm color film I use, based upon noise.

If I use very rough numbers just for talking purposes-- twice the light
intensity but 1/4th the sensitivity. (100vs. 400 ASA)

This is not really accurate, since the CCD sensor is not 1/2 the size of the
35mm frame.
The CCD Sensor is listed as 1/1/8" ?
Lens 7.1-35mm equiv to 28-140mm (35mm camera) If I use this as indicating
that the sensor is 1/4 the size of a 35mm frame, the light intensity on the
CCD would be 4x when compared to the 35mm. (Same light source, same lens,
same "F" setting.)

35 MM Camera uses either a 28mm lens at F2.8, a 50mm at 1.5, or a Zoom
75-140 F2.8

Another issue is circle of confusion when it comes to focus.

Note: Oly refused to give me specs on depth of field or circle of confusion
for the C8080 lens.
One reason for the lesser ccd sensitivity is the loss thru a filter on the
front of the ccd.



"Rich Wilson" <rich.TakeThisOut@spam-spamson.co.uk> wrote in message
news:FeeUg.81506$DB3.46713@newsfe6-gui.ntli.net...
>
> "Chuck" <Chuckk2nospam.TakeThisOut@cox.net> wrote in message
> news:Q3aUg.881$XX2.807@dukeread04...
> > The digital cameras generally are LESS sensitive to light than a 35mm
with
> > a
> > good lens and high speed color film.
>
> ...possibly because their lenses and sensors are smaller?
>
> > This requires that the digital camera lens be set to an F stop that lets
> > in
> > more light than that typically used by the 35mm, or use of slower
shutter
> > speed equivilents.
>
> Really? To get an equivalent physical aperture size the F number on a
> digital camera would surely have to be lower because the focal length is
> smaller. Do you actually mean the *physical aperture size* has to be
larger?
>
> > So depth of field and focus actually become more of an issue.
>
> Have you actually proved this with a real camera?
>
> > (Unless you are talking about typical consumer digital cameras with an
> > everything's in focus non removable lens.)
>
> I'm talking about a typical compact digital camera like mine (which is a
> Sony DSC-S600).
>
>
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

Game over. Although I respect your great attention to technology behind
your images, with the exception of medium format, this ship has sailed.
Film is not longer economical for amateurs, and it offers no quality edge
for professionals.

Entry level prices are so low that film and development costs make digital
cheaper than film for amateurs, and the quality of cameras like the Canon
EOS Mark II 1DS have exceeded that of 100 ISO 35mm film.
http://www.engadget.com/2005/05/13/popular-photography-says-that-canon...6-megap

BTW - re circle of confusion - this is a lens only number and most
manufacturers simply do not speak in these terms. In an integrated imaging
system, the Modulation Transfer Function is used to characterize the
resolving power of the lens and sensor system. This may be calculated by
photographing a test pattern and calculating the standard deviation of the
patterned areas.
--
Mike Russell
www.curvemeister.com/forum/

"Chuck" <Chuckk2nospam.DeleteThis@cox.net> wrote in message
news:NSAUg.989$XX2.577@dukeread04...
> An example--
> Oly c8080wz Wide open "f" stop 2.4-2.7 (Zoom lens)
> Film speed equivilent (settable) 50-100-etc, 400 max useful. (due to
> noise)
>
> 35mm Oly OM-10 film speed - I generally use no slower than 400 for color
> film, and usually much faster film. Wide open "F" stop 1.5
>
> It is true that the light from the lens gets focused on a smaller area
> with
> the CCD sensor, since the sensor is smaller than a 35 mm frame.
> It's also true that the CCD sensor is less sensitive to light than the
> usual
> 35mm color film I use, based upon noise.
>
> If I use very rough numbers just for talking purposes-- twice the light
> intensity but 1/4th the sensitivity. (100vs. 400 ASA)
>
> This is not really accurate, since the CCD sensor is not 1/2 the size of
> the
> 35mm frame.
> The CCD Sensor is listed as 1/1/8" ?
> Lens 7.1-35mm equiv to 28-140mm (35mm camera) If I use this as indicating
> that the sensor is 1/4 the size of a 35mm frame, the light intensity on
> the
> CCD would be 4x when compared to the 35mm. (Same light source, same lens,
> same "F" setting.)
>
> 35 MM Camera uses either a 28mm lens at F2.8, a 50mm at 1.5, or a Zoom
> 75-140 F2.8
>
> Another issue is circle of confusion when it comes to focus.
>
> Note: Oly refused to give me specs on depth of field or circle of
> confusion
> for the C8080 lens.
> One reason for the lesser ccd sensitivity is the loss thru a filter on the
> front of the ccd.
>
>
>
> "Rich Wilson" <rich.DeleteThis@spam-spamson.co.uk> wrote in message
> news:FeeUg.81506$DB3.46713@newsfe6-gui.ntli.net...
>>
>> "Chuck" <Chuckk2nospam.DeleteThis@cox.net> wrote in message
>> news:Q3aUg.881$XX2.807@dukeread04...
>> > The digital cameras generally are LESS sensitive to light than a 35mm
> with
>> > a
>> > good lens and high speed color film.
>>
>> ...possibly because their lenses and sensors are smaller?
>>
>> > This requires that the digital camera lens be set to an F stop that
>> > lets
>> > in
>> > more light than that typically used by the 35mm, or use of slower
> shutter
>> > speed equivilents.
>>
>> Really? To get an equivalent physical aperture size the F number on a
>> digital camera would surely have to be lower because the focal length is
>> smaller. Do you actually mean the *physical aperture size* has to be
> larger?
>>
>> > So depth of field and focus actually become more of an issue.
>>
>> Have you actually proved this with a real camera?
>>
>> > (Unless you are talking about typical consumer digital cameras with an
>> > everything's in focus non removable lens.)
>>
>> I'm talking about a typical compact digital camera like mine (which is a
>> Sony DSC-S600).
>>
>>
>
>
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

"Chuck" <Chuckk2nospam.TakeThisOut@cox.net> wrote in message
news:NSAUg.989$XX2.577@dukeread04...
> An example--
> Oly c8080wz Wide open "f" stop 2.4-2.7 (Zoom lens)
> Film speed equivilent (settable) 50-100-etc, 400 max useful. (due to
> noise)
>
> 35mm Oly OM-10 film speed - I generally use no slower than 400 for color
> film, and usually much faster film. Wide open "F" stop 1.5
>
> It is true that the light from the lens gets focused on a smaller area
> with
> the CCD sensor, since the sensor is smaller than a 35 mm frame.
> It's also true that the CCD sensor is less sensitive to light than the
> usual
> 35mm color film I use, based upon noise.
>
> If I use very rough numbers just for talking purposes-- twice the light
> intensity but 1/4th the sensitivity. (100vs. 400 ASA)
>
> This is not really accurate, since the CCD sensor is not 1/2 the size of
> the
> 35mm frame.
> The CCD Sensor is listed as 1/1/8" ?
> Lens 7.1-35mm equiv to 28-140mm (35mm camera) If I use this as indicating
> that the sensor is 1/4 the size of a 35mm frame, the light intensity on
> the
> CCD would be 4x when compared to the 35mm. (Same light source, same lens,
> same "F" setting.)

Hang on... same lens, same F number with different sizes of film/sensor
means *different pictures* - so the comparison isn't valid.

> 35 MM Camera uses either a 28mm lens at F2.8, a 50mm at 1.5, or a Zoom
> 75-140 F2.8
>
> Another issue is circle of confusion when it comes to focus.
>
> Note: Oly refused to give me specs on depth of field or circle of
> confusion
> for the C8080 lens.
> One reason for the lesser ccd sensitivity is the loss thru a filter on the
> front of the ccd.

I'm sorry but you haven't convinced me. My camera has a CCD which is,
according to the specification "1/2.5" inches in size, i.e. around 10mm.
That would give it an area of around 8% of the equivalent piece of 35mm
film. The lens appears to be scaled by approximately the same linear factor.
So the total amount of light falling on the CCD will be around 8% of the
amount falling on the film.

The camera operates, most of the time, at the equivalent of ISO 80. If we
say that ISO 400 film would give the same image quality, the film is 5 times
as sensitive as the CCD. But the film is 12.5 times the size of the CCD,
therefore the CCD has more sensitivity per unit area. Therefore, if you took
identical photos with the two cameras, with the same shutter speed, the
digital one could do it with a smaller physical aperture size and therefore
less of a problem with depth of field.

Or, forget all the maths and just flippin' try it! I've just taken a few
photos of the objects along my desk and to get any sort of noticable depth
of field effect I had to get really close the the front object - around 12cm
or so. In normal photography, particularly of distant objects as the OP
required, depth of field simply isn't an issue with cameras like mine.
 >> Stay informed about: Megapixels vs. Zoom Which is more important? 

Trouble is that the film camera has smaller physical aperture sizes
available than the digitals usually do.

I agree, let's not beat dead horses. <G>

"Rich Wilson" <rich DeleteThis @spam-spamson.co.uk> wrote in message
news:iIBUg.45327$cx.41127@newsfe1-gui.ntli.net...
>
> "Chuck" <Chuckk2nospam DeleteThis @cox.net> wrote in message
> news:NSAUg.989$XX2.577@dukeread04...
> > An example--
> > Oly c8080wz Wide open "f" stop 2.4-2.7 (Zoom lens)
> > Film speed equivilent (settable) 50-100-etc, 400 max useful. (due to
> > noise)
> >
> > 35mm Oly OM-10 film speed - I generally use no slower than 400 for color
> > film, and usually much faster film. Wide open "F" stop 1.5
> >
> > It is true that the light from the lens gets focused on a smaller area
> > with
> > the CCD sensor, since the sensor is smaller than a 35 mm frame.
> > It's also true that the CCD sensor is less sensitive to light than the
> > usual
> > 35mm color film I use, based upon noise.
> >
> > If I use very rough numbers just for talking purposes-- twice the light
> > intensity but 1/4th the sensitivity. (100vs. 400 ASA)
> >
> > This is not really accurate, since the CCD sensor is not 1/2 the size of
> > the
> > 35mm frame.
> > The CCD Sensor is listed as 1/1/8" ?
> > Lens 7.1-35mm equiv to 28-140mm (35mm camera) If I use this as
indicating
> > that the sensor is 1/4 the size of a 35mm frame, the light intensity on
> > the
> > CCD would be 4x when compared to the 35mm. (Same light source, same
lens,
> > same "F" setting.)
>
> Hang on... same lens, same F number with different sizes of film/sensor
> means *different pictures* - so the comparison isn't valid.
>
> > 35 MM Camera uses either a 28mm lens at F2.8, a 50mm at 1.5, or a Zoom
> > 75-140 F2.8
> >
> > Another issue is circle of confusion when it comes to focus.
> >
> > Note: Oly refused to give me specs on depth of field or circle of
> > confusion
> > for the C8080 lens.
> > One reason for the lesser ccd sensitivity is the loss thru a filter on
the
> > front of the ccd.
>
> I'm sorry but you haven't convinced me. My camera has a CCD which is,
> according to the specification "1/2.5" inches in size, i.e. around 10mm.
> That would give it an area of around 8% of the equivalent piece of 35mm
> film. The lens appears to be scaled by approximately the same linear
factor.
> So the total amount of light falling on the CCD will be around 8% of the
> amount falling on the film.
>
> The camera operates, most of the time, at the equivalent of ISO 80. If we
> say that ISO 400 film would give the same image quality, the film is 5
times
> as sensitive as the CCD. But the film is 12.5 times the size of the CCD,
> therefore the CCD has more sensitivity per unit area. Therefore, if you
took
> identical photos with the two cameras, with the same shutter speed, the
> digital one could do it with a smaller physical aperture size and
therefore
> less of a problem with depth of field.
>
> Or, forget all the maths and just flippin' try it! I've just taken a few
> photos of the objects along my desk and to get any sort of noticable depth
> of field effect I had to get really close the the front object - around
12cm
> or so. In normal photography, particularly of distant objects as the OP
> required, depth of field simply isn't an issue with cameras like mine.
>
>
 >> Stay informed about: Megapixels vs. Zoom Which is more important?