Why are my max res jpgs read as 75dpi?

Archived from groups: rec.photo.digital (More info?)

Hi Ian!

The res level is not important. I own a CanonPro1 and the res is 180.
I'm not sure in PhotoPaint, but in Photoshop, when you open "image size" and
you uncheck "resample image", if you make it 20cm wide, your pixels will
jump to over 300. I hope this explanation is clear ;-)

Marcel


"Ian Roberts" <sorry@NOSPAM.com> wrote in message
news:cpmu1n$1qp$1@ngspool-d02.news.aol.com...
> Hi
>
> I'm a relative newbie to digital photos. Recently got an IXUS 500 and shot
> loads of pics at max res. Each jpg is around 2mb.
>
> When I open them in Corel PhotoPaint the x/y res is just 75dpi.
>
> If I try and resample when opening I'm not able to go above 75dpi.
>
> They look great but just wondered why is the dpi figure is so low?
>
> The images sizes are 91.4cm W x 68.6cm H.
>
> Also if I resize the images smaller - they get very pixellated quite
early.
> eg with the original image I can zoom in much deeper before it pixellates.
> When i make them smaller I cant zoom in as deep before they pixelate. Is
> there a way to avoid this?
>
> Hope one of you gurus here can help me up the learning curve!
>
> Thanks for any enlightenment!
>
> Ian
>
>

Archived from groups: rec.photo.digital (More info?)

Chris,
Aren't you saying the same thing I told him?
Marcel

"Chris Brown" <cpbrown@ntlworld.no_uce_please.com> wrote in message
news:9ce392-v3b.ln1@narcissus.dyndns.org...
> In article <cpmu1n$1qp$1@ngspool-d02.news.aol.com>,
> Ian Roberts <sorry@NOSPAM.com> wrote:
> >Hi
> >
> >I'm a relative newbie to digital photos. Recently got an IXUS 500 and
shot
> >loads of pics at max res. Each jpg is around 2mb.
> >
> >When I open them in Corel PhotoPaint the x/y res is just 75dpi.
> >
> >If I try and resample when opening I'm not able to go above 75dpi.
> >
> >They look great but just wondered why is the dpi figure is so low?
> >
> >The images sizes are 91.4cm W x 68.6cm H.
>
> That's why the dpi figure is so low.
>
> Change the image size to 22.85 * 17.15 cm *without* resampling, and watch
> the DPI magically jump to 300.
>
> It's just a number - it doesn't actually mean anything important, unless
you
> use those default dimensions to print (which, of course, you won't,
because
> they're stupidly huge).
>
> >Also if I resize the images smaller - they get very pixellated quite
early.
>
> That's because you are resampling them. You just want to change the image
> size in centimetres without resampling (i.e. keep the size in pixels the
> same).
>
> Essentially you have 3 variables when you change the size. The physical
size
> (in centimetres), the dpi, and the pixel count. Of these three, you get to
> chose which one stays constant when you change one of the others. If you
> change the physical size, but keep the dpi constant, then obviously it has
> to change the number of pixels to make it all fit.
>
> What you want to do is change the size, keep the number of pizels
constant,
> and let it change the dpi to the correct value. That way, you won't get
any
> pixellation.
>
> Hope that helps.

Archived from groups: rec.photo.digital (More info?)

Ian Roberts wrote:
>
> Hi
>
> I'm a relative newbie to digital photos. Recently got an IXUS 500 and shot
> loads of pics at max res. Each jpg is around 2mb.
>
> When I open them in Corel PhotoPaint the x/y res is just 75dpi.
>
> If I try and resample when opening I'm not able to go above 75dpi.
>
> They look great but just wondered why is the dpi figure is so low?
>
> The images sizes are 91.4cm W x 68.6cm H.
>
> Also if I resize the images smaller - they get very pixellated quite early.
> eg with the original image I can zoom in much deeper before it pixellates.
> When i make them smaller I cant zoom in as deep before they pixelate. Is
> there a way to avoid this?
>
> Hope one of you gurus here can help me up the learning curve!
>
> Thanks for any enlightenment!

forget dpi res.
the real res is image pixels divided by image size.
the image dimension are x pixels by y pixels.
the real res is (for my camera) 3000 pixels divided by say 10 inches,
and gives 300 pixels per inch for the image on an 8x10.
on a 20x30 print, 3000 / 30 = 100 which still looks pretty good.
at 100 inches, there are only 30 pixels per inch, and it shows.

you can resize the image.
if you make it smaller,
there are still enough pixels to make a good image.
if you blow it up larger,the number of pixels per inch of the larger
image goes down, and it shows.

>
> Ian

Archived from groups: rec.photo.digital (More info?)

"drwxr-xr-x" <bit-bucket@config.com> wrote in message
news:slrncrua93.1qio.bit-bucket@shell.config.com...
> On Tue, 14 Dec 2004 12:20:40 -0500, Marcel hath writ:
>> Chris,
>> Aren't you saying the same thing I told him?
>> Marcel
>>
> Maybe. But Chris didn't top-post.


Oh horrors! The dreaded top post!

Archived from groups: rec.photo.digital (More info?)

"Marcel" <cosmar@rogers.com> wrote in message
news:YNGdnUt2Wvf4vSLcRVn-jA@rogers.com...
> Chris,
> Aren't you saying the same thing I told him?
> Marcel

Essentially he is, but his explanation is much more complete and probably a
lot more helpful to the self-described newbie.

N.

Archived from groups: rec.photo.digital (More info?)

"Ian Roberts" <sorry@NOSPAM.com> writes:
> I'm a relative newbie to digital photos. Recently got an IXUS 500
> and shot loads of pics at max res. Each jpg is around 2mb.
> When I open them in Corel PhotoPaint the x/y res is just 75dpi.
> If I try and resample when opening I'm not able to go above 75dpi.
> They look great but just wondered why is the dpi figure is so low?

For an introduction to resolution and dpi/ppi take a look at this
small webpage: http://heim.ifi.uio.no/~gisle/photo/pixels.html .

Your concern is addressed in question 2.
--
- gisle hannemyr [ gisle{at}hannemyr.no - http://folk.uio.no/gisle/ ]
========================================================================
When you say you live in the real world, which one are you referring to?