jagged angled lines

  • Thread starter Thread starter Dewdman42
  • Start date Start date
Ah ha.. 21 jaggs exactly. And yes I do have very good eye sight...

I still don't understand why Overture seems capable of creating angled
lines without these jags...and why the scanned bitmap also looks better
to my eyes. to me the scanned bitmaps looks like a nice photocopy. A
little smeared out, the edges are not sharp..but there are not "jagged"
edges. My feeling right now is that perhaps the natural smearing that
occurs while scanning it actually creates a more pleasing edge then
what PS can do on a 300dpi printer because PS will try to create a
razor sharp edge that has to be stair-stepped this way. But with a
higher res printer, the stair stepping effect would be reduced to a
point of not being seen, while still mainting the sharp edge. My
honest opinion would be that with a 300dpi printer a better PS RIP
would smear out the edges a little bit for the sake of hiding the stair
step effect...at least for angled lines. but no matter...it doesn't
work that way and I have a new printer coming anyway.. :-)

The overture angled line output looks sharp though. I have already
uninstalled that app, but maybe i will install it later and try to see
what it looks like again. Its just confusing to me why Overture makes
nice angled lines with clean edges and finale does not.

thanks for your feedback..the 21 steps at least helps to know there is
nothing else going on here but an old lame printer.
 
My
honest opinion would be that with a 300dpi printer a better PS RIP
would smear out the edges a little bit for the sake of hiding the stair
step effect...at least for angled lines. but no matter...it doesn't
work that way and I have a new printer coming anyway.. :-)
Click to expand...

In general, laser printers can't smear. Each of the 90,000 dots in a square
inch is either black or white.

It's possible -- probable in fact -- that the scanned image has a slightly
uneven line, going back and forth by a pixel or two. Though the line
wouldn't be as sharp, your eye compensates for that, and so it looks
smoother. In fact, the line is probably even more jagged than the PS-drawn
line, but because the flaws are uneven, your eye doesn't notice them as
strongly. Our minds evolved to detect patterns, not randomness.

The same principle is involved in antialiasing on screen; it makes letters
slightly fuzzy -- you actually lose information -- but your eye is happier
because it looks smoother, and the information lost isn't critical to
reading.

And similar reasons may explain why curves look better: curves seldom
maintain that almost-rectilinear mode for very long. When they become more
diagonal, the jaggies are less apparent, and the jaggies are unevenly
spaced because of the curve, making them less obvious.

Now, what I said about each dot being black or white isn't strictly true of
the 4ML. I found a little info about it in a history document on HP's web
site. 1993 ... a little older than I was thinking. It had HP's "REt",
resolution enhancement technology. That isn't enough for them to claim
extra pixels, but IIRC it turned the laser on or off partway through
imaging a pixel, resulting in slightly better resolution. But this works
better at some angles than at others. You might find, for example, that an
almost-vertical line shows less jaggies than an almost-horizontal line. Or
vice versa. ;-) Or even that the upper and lower edges of the line differ
in their jaggedness. I never had a REt printer, so I don't have eyes-on
experience with the phenomenon.

Finally, it's possible that the REt isn't kicking in for some cases, though
I'd have no idea why. Or that this early generation of REt was flaky.
The overture angled line output looks sharp though. I have already
uninstalled that app, but maybe i will install it later and try to see
what it looks like again. Its just confusing to me why Overture makes
nice angled lines with clean edges and finale does not.
Click to expand...

No, I don't have a good explanation for that either.
thanks for your feedback..the 21 steps at least helps to know there is
nothing else going on here but an old lame printer.
Click to expand...

Perhaps I should have made it The 39 Steps ...

But don't forget that printer on its way out ... it was a marvel in its
day. We too will be lame before long. ;-)

Edward
 
That is what I meant when I said "smeared". Randomness. this is
superior to the ps 300dpi output in my opinion. but opions may vary.
 
That is what I meant when I said "smeared". Randomness. this is
superior to the ps 300dpi output in my opinion. but opions may vary.
 
So I think maybe I figured out why Overture has what seems like cleaner
angled lines. They are beaming notes with lines that are angled more.
They are further away from horizantal than what finale is doing. Not
by much, but by enough that it eliminates visible stair stepping. So
that explains that.

As far as why the lo-fi scanned bitmaps look better to my eyes than the
stair step at 300dpi, your explanation sounds the best. Maybe if the
300dpi RIP or the rET technology in that old printer did a better job
of this..it would have a low fi look that is fuzzed out enough that the
edges don't look as sharp and clean..but the stair step is gone. To
me, that would be a preferable way to do it. but I can see now that
I'm going to be perfectly happy with my 1200dpi printer when it gets
here, so all is good... At least I think I understand what is going on
now.

thanks for all your insights..
 
That is what I meant when I said "smeared". Randomness. this is
superior to the ps 300dpi output in my opinion. but opions may vary.
Click to expand...

Varies depending on the situation and intended use too.

Graphics design is complicated ...

Yeah, after all the discussion, I definitely think you will like the new
printer.

Edward
 
So I think maybe I figured out why Overture has what seems like cleaner
angled lines. They are beaming notes with lines that are angled more.
They are further away from horizantal than what finale is doing. Not
by much, but by enough that it eliminates visible stair stepping. So
that explains that.
Click to expand...

Ah, yes that would definitely explain it. If you want, you could confirm it
with that 5-line PS test -- change the 205 to 210, then 215, 220, resulting
in 2, 3, and 4 times as many steps. No real need, though -- there's no
doubt that slight differences in angle make a lot of difference in these
low-angle ranges.

Edward
 
Back
Top