Noise

Hi

I own 3 Digital cameras which I am experiencing Noise or banding. The
Cameras are a 1mp Sony DCE 101E using a Memory Stick, a Kodak Easyshare 2mp
using a SD and an Olympus C765 4mp using a XD card.

I notice with all of them specks of colour in sky shots and sometimes in the
body of the photograph. It is noticeable when using zoom but has occurred
when used without zoom.. I only use optical zoom. The Olympus is much better
than the other two.

PS7 does provide filters to cure most of it but I did wonder if there is a
way of preventing it in the first place.

It is also interesting to observe that PS7 reports the resolution as being
72dpi for the memory stick and XD, and 230dpi for the SD. Any reason why
this should be so ?

Nancarrow

In article 1095795541.P1diKW5Jx1/79VuN0nqIlQ@teranews,
..uk says...

Hi

I own 3 Digital cameras which I am experiencing Noise or banding. The
Cameras are a 1mp Sony DCE 101E using a Memory Stick, a Kodak Easyshare 2mp
using a SD and an Olympus C765 4mp using a XD card.

I notice with all of them specks of colour in sky shots and sometimes in the
body of the photograph. It is noticeable when using zoom but has occurred
when used without zoom.. I only use optical zoom. The Olympus is much better
than the other two.

PS7 does provide filters to cure most of it but I did wonder if there is a
way of preventing it in the first place.

It is also interesting to observe that PS7 reports the resolution as being
72dpi for the memory stick and XD, and 230dpi for the SD. Any reason why
this should be so ?

Nancarrow

First, you may be thinking that JPG artifacts are noise. They cause similar
problems with images, but are different. Try some tests: uses lowest ISO
setting and lowest JPG capture. Look at the sky area again and see if you get
the problems you list.

Next, if you open the image in Photoshop (maybe in other, similar programs,
but I don't use any of them), and look at the Channels, you are likely to see
that real noise appears mostly in one Channel - look at Blue first. You can
run Gaussian Blur on that one Channel and usually cut down on the noise. You
might want to experiment on JPG artifacts too.

Hunt

In article 1095795541.P1diKW5Jx1/79VuN0nqIlQ@teranews,
..uk says...

Hi

I own 3 Digital cameras which I am experiencing Noise or banding. The
Cameras are a 1mp Sony DCE 101E using a Memory Stick, a Kodak Easyshare 2mp
using a SD and an Olympus C765 4mp using a XD card.

I notice with all of them specks of colour in sky shots and sometimes in the
body of the photograph. It is noticeable when using zoom but has occurred
when used without zoom.. I only use optical zoom. The Olympus is much better
than the other two.

PS7 does provide filters to cure most of it but I did wonder if there is a
way of preventing it in the first place.

It is also interesting to observe that PS7 reports the resolution as being
72dpi for the memory stick and XD, and 230dpi for the SD. Any reason why
this should be so ?

Nancarrow

First, you may be thinking that JPG artifacts are noise. They cause similar
problems with images, but are different. Try some tests: uses lowest ISO
setting and lowest JPG capture. Look at the sky area again and see if you get
the problems you list.

Next, if you open the image in Photoshop (maybe in other, similar programs,
but I don't use any of them), and look at the Channels, you are likely to see
that real noise appears mostly in one Channel - look at Blue first. You can
run Gaussian Blur on that one Channel and usually cut down on the noise. You
might want to experiment on JPG artifacts too.

Hunt

In article 1095795541.P1diKW5Jx1/79VuN0nqIlQ@teranews,
says...

Hi

I own 3 Digital cameras which I am experiencing Noise or banding. The
Cameras are a 1mp Sony DCE 101E using a Memory Stick, a Kodak Easyshare
2mp
using a SD and an Olympus C765 4mp using a XD card.

I notice with all of them specks of colour in sky shots and sometimes
in the
body of the photograph. It is noticeable when using zoom but has
occurred
when used without zoom.. I only use optical zoom. The Olympus is much
better
than the other two.

PS7 does provide filters to cure most of it but I did wonder if there
is a
way of preventing it in the first place.

It is also interesting to observe that PS7 reports the resolution as
being
72dpi for the memory stick and XD, and 230dpi for the SD. Any reason
why
this should be so ?

Nancarrow

Noise will decrease with
- increased sensor size (with same amount of megapixels)
- decreased ISO setting.

ad 1) Sensor Size:
Most consumer camera's have a 1/2.7" sensor: 5.27 x 3.96 mm
Most more expensive consumer camera's have 1/1.8": 7.18 x 5.32 mm

If you want low noise ... get an SLR with a sensor that is like 22x15mm

Ad 2) Decreased ISO:
On consumer cameras there is usually little noise at the lowest ISO
setting.
My A70 had unacceptable noise at ISO 400, and even at ISO 200 it was
doubtfull if I wanted to make pictures ... The S60 I have now is
slightly better ...

There is a difference between camera's of the same sensor size, even
with the same ISO rating ... The differeces because of the hardware are
probably small, but some cameras have software noise reduction to make
things better ...

The kind of memory you use has no effect on the noise in the photos ...

Wouter


--
Wouter F. Wessels
Gouda, the Netherlands
http://www.wwessels.cistron.nl/picofday.shtml