DSLR v Consumer Image quality

Scott W wrote:

http://www.sewcon.com/300dpi_test/IMG_3302.jpg

The bottom photo does not suffer from jpg artifacts. The two photos
have been filtered to have different MTF curves, the top photo has no
detail past a certain point but has high contrast below that, the
bottom photo has a longer tail on the MTF curve but has lower contrast
at lower spatial frequencies.

So which picture of the ocean liner do you like better? I strongly
prefer the top picture at 100% and the bottom picture at 200% zoom.
Didn't want to waste money printing it out, but I assume the top
would look better on an inkjet and much better with offset printing.

wrote:

I think this says more for the FZ20 than about DSLR models.
Most consumer digicams have lots of image problems, including
purple fringing at wide angle,

Do you mean chromatic aberration?

I'm not sure. With old film cameras and telephoto lenses,
chromatic aberration usually expressed itself as green/cyan
on one side of objects and purple/red on the other side,
especially objects near the corners.

Purple fringing with digital cameras also occurs primarily
in corners, but at wide angle, and usually it's just purple.

Scott W wrote:

http://www.sewcon.com/300dpi_test/IMG_3302.jpg

The bottom photo does not suffer from jpg artifacts. The two photos
have been filtered to have different MTF curves, the top photo has no
detail past a certain point but has high contrast below that, the
bottom photo has a longer tail on the MTF curve but has lower contrast
at lower spatial frequencies.


How did you filter it? Sounds like an unsharp mask. The bottom pic is
clearly sharper and a bit of a halo around the bright parts such as the
two white 'balls' in the middle. Those same round features become flat
looking in the bottom, spherical in the top.

How does all this change in a print?

Scott W wrote:


rafe bustin wrote:

I disagree that you need a print to properly see or
judge a digital image. There have only been a few
situations (in my experience) where a print revealed
flaws that were not evident on-screen.

It is not so much that a print will reveal flaws that you can not see
on the screen as the other way around, flaws that you see on the screen
will often not be visible on the final print.

Exactly why I don't bother to ever post images to this group. People with
something to prove will FIND artifacts that never show up in print to "make
their point"..

Why they find depends on which camera made the images and what they need to
prove. I've had two different people say the same image looks noisy and was
too smooth with too much noise reduction at the same time because it was a
brand neither of them use. No one ever makes a print from different cameras
and compares using that, guess they are too lazy? They all want to look at
200% blowups looking for things they'll never see and that don't mater as
far as "image quality" in the final result anyone would ever normally use.
Yes if you're making 5X8 foot prints it might matter but who does that?

--

Stacey

wrote:

In message ,
Bill Tuthill wrote:


I think this says more for the FZ20 than about DSLR models.
Most consumer digicams have lots of image problems, including
purple fringing at wide angle,


Do you mean chromatic aberration?


Is that the same thing or is there a special digital purple flavor
fringe? I understand that CA is due to mis-scaling of different colors
from the center and can be corrected with software that separates &
matches those mis-scaled colors. The PS RAW plugin does this.

In message ,
Larry wrote:

There have been times when the 12mp picture seemed to have more detail, but
not often, and not much.

Yeah, I guess with the zoom lens you need optimal aperture and the
sweetest part of its range, perhaps, plus a shake-free exposure to get
the last bits of sharpness out of the lens.

The concept I was endorsing probably applies more to the 3MP/6MP models.
--


John P Sheehy

In message ,
Larry wrote:

Sometimes its C.A. (lens) and sometimes its Sensor Bloom.

I would not call CA "purple fringing".
--


John P Sheehy

In article , says...
I would not call CA "purple fringing".
--


John P Sheehy



Niether would I, but from the way I see it discussed from time to time, a
large amount of people cant tell the difference.

I've seen the "fringing" on a Sony F-828 called C.A. (repeatedly) and it isnt
C.A. its sensor "bloom".


--
Larry Lynch
Mystic, Ct.

In article , says...
The concept I was endorsing probably applies more to the 3MP/6MP models.
--


John P Sheehy




I have that one two, and I use that one in 6mp mode because the difference is
MUCH more noticable, and usually for the better. That one is my "outdoor
nature shooter" because of the 10x lens.



--
Larry Lynch
Mystic, Ct.

"Stacey" wrote:
rafeb wrote:
Owamanga wrote:

Agggh! but the whole point of capturing the image (in *most* people's
use of a DSLR) is to PRINT IT.

Well, actually a lot of folks claim that
they're not interested in prints, but
rather in seeing their images on a CRT.

Show me a monitor that can display a dSLR image at full resolution.

You've missed the point: lots of people use their cameras only for email and
web display. They always downsample. Presumably many people do it in the
camera.

Most of such people don't need a dSLR.

David J. Littleboy
Tokyo, Japan