Resolution of photo paper?

"Joseph Meehan" wrote in message
...
Andrew wrote:
What's the resolution of photo paper? Googling for terms
such as dpi and noritsu, I came across marketing claims
from minilab manufacturers claiming 400 and 500 dpi. Is the
the current bottleneck the paper or the equipment used to
project light onto the paper?

I just bought a 10D. I am going to print primarily 4x6's and
I've decided to scale down the raw image to 75% (2304x1536)
to generate jpegs suitable for printing at 4x6. This gets
me 384 dpi.

I found that when printing the same G3 photo at 4x6 and 5x7
(378 dpi vs. 324 dpi) that I could discern the difference in
detail and the the 4x6 had a noticably more tack-sharp
quality, but this could be due to the sharpening settings
being more optimal for the 4x6 print.

Here are some of the first images from my totally digital
10D (not to be confused with the totally obsolete D60 ).
I'm using Breezebrowser with quality factor 99. This keeps
all my images under walmart.com's 3MB upload limit.

http://w3.kill-9.com/batterypark.jpg
http://w3.kill-9.com/liberty.jpg
http://w3.kill-9.com/relative.jpg

Andrew

As you know sharpness can't really be measured. It is perceived by
the
human eye. Not only that, but each of us sees a little different.

Most authorities seems to believe that about 300 DPI is it. More is
OK,
but few if anyone will be able to see the difference. Less than 300 DPI
and
people start being able to notice the difference.

As you have noted other factors like sharpening settings and sampling
of
a larger image can be more important.

--
Joseph E. Meehan

26 + 6 = 1 It's Irish Math



A REALLY major factor in perceived sharpness (and often overlooked) is the
ability to produce continuous tones. I've seen 200 dpi look great and 600
dpi look terrible based on this factor alone.

As for the OP's question (which sounded to me like a photographic limitation
question), some of the
best macro lenses only resolve slightly over 100 lp per inch.

George

"George" wrote in message
...
SNIP
..., some of the best macro lenses only resolve slightly over
100 lp per inch.

Make that millimetres, and we can debate it.

Bart

"George" wrote in message
...
SNIP
..., some of the best macro lenses only resolve slightly over
100 lp per inch.

Make that millimetres, and we can debate it.

Bart

"Bart van der Wolf" wrote in message
...

"George" wrote in message
...
SNIP
..., some of the best macro lenses only resolve slightly over
100 lp per inch.

Make that millimetres, and we can debate it.

Bart


For the mathematically challenged:

100 lp/in * 1/25.4 in/mm = 4 lp/mm (roughly)

On Tue, 31 Aug 2004 16:06:07 +0100, David Littlewood
wrote:

In article , Andrew
writes
What's the resolution of photo paper? Googling for terms
such as dpi and noritsu, I came across marketing claims
from minilab manufacturers claiming 400 and 500 dpi. Is the
the current bottleneck the paper or the equipment used to
project light onto the paper?

What do you mean by "photo paper"? From the words, I would take it to
mean traditional light-sensitive emulsion coated paper; for this,
maximum resolution is probably around 60-70 lp/mm - and this for good
B&W papers, most colour neg/pos paper would probably be lower.

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

If you mean inkjet paper, I don't know, but I suspect the printer has
more control over this than the paper - not that the paper has no
influence.

One of the non-printer specific brands (Ilford) quote a DPI size the
papers are rated for (approx 1400dpi but I dont have one to hand to
double check!) obviously this is a dpi not a ppi as most inkjets
actually print and colour mix using smaller droplets than the actual
pixels. The reported pixels coming back from the printer drivers at
highest quality seem to be between 600 and 750 depending on make.

I'm guessing the 1400dpi is saying that any dot that small is not
going to suffer bleed or distortion... smaller dots and I have no
idea, perhaps they might be to small to give acceptable drying or
would soak up to quickly to either allow the colour into the paper or
allow enough to remain on the surface to give the correct reflective
colour.

Can you point me in the direction of a simple discussion of lp's and
how they work and are used in ratings and tested.


David

--
Jonathan Wilson.
www.somethingerotic.com

On Tue, 31 Aug 2004 16:06:07 +0100, David Littlewood
wrote:

In article , Andrew
writes
What's the resolution of photo paper? Googling for terms
such as dpi and noritsu, I came across marketing claims
from minilab manufacturers claiming 400 and 500 dpi. Is the
the current bottleneck the paper or the equipment used to
project light onto the paper?

What do you mean by "photo paper"? From the words, I would take it to
mean traditional light-sensitive emulsion coated paper; for this,
maximum resolution is probably around 60-70 lp/mm - and this for good
B&W papers, most colour neg/pos paper would probably be lower.

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

If you mean inkjet paper, I don't know, but I suspect the printer has
more control over this than the paper - not that the paper has no
influence.

One of the non-printer specific brands (Ilford) quote a DPI size the
papers are rated for (approx 1400dpi but I dont have one to hand to
double check!) obviously this is a dpi not a ppi as most inkjets
actually print and colour mix using smaller droplets than the actual
pixels. The reported pixels coming back from the printer drivers at
highest quality seem to be between 600 and 750 depending on make.

I'm guessing the 1400dpi is saying that any dot that small is not
going to suffer bleed or distortion... smaller dots and I have no
idea, perhaps they might be to small to give acceptable drying or
would soak up to quickly to either allow the colour into the paper or
allow enough to remain on the surface to give the correct reflective
colour.

Can you point me in the direction of a simple discussion of lp's and
how they work and are used in ratings and tested.


David

--
Jonathan Wilson.
www.somethingerotic.com

In article , Jonathan Wilson
writes
On Tue, 31 Aug 2004 16:06:07 +0100, David Littlewood
wrote:

In article , Andrew
writes
What's the resolution of photo paper? Googling for terms
such as dpi and noritsu, I came across marketing claims
from minilab manufacturers claiming 400 and 500 dpi. Is the
the current bottleneck the paper or the equipment used to
project light onto the paper?

What do you mean by "photo paper"? From the words, I would take it to
mean traditional light-sensitive emulsion coated paper; for this,
maximum resolution is probably around 60-70 lp/mm - and this for good
B&W papers, most colour neg/pos paper would probably be lower.

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

If you mean inkjet paper, I don't know, but I suspect the printer has
more control over this than the paper - not that the paper has no
influence.

One of the non-printer specific brands (Ilford) quote a DPI size the
papers are rated for (approx 1400dpi but I dont have one to hand to
double check!) obviously this is a dpi not a ppi as most inkjets
actually print and colour mix using smaller droplets than the actual
pixels. The reported pixels coming back from the printer drivers at
highest quality seem to be between 600 and 750 depending on make.

I'm guessing the 1400dpi is saying that any dot that small is not
going to suffer bleed or distortion... smaller dots and I have no
idea, perhaps they might be to small to give acceptable drying or
would soak up to quickly to either allow the colour into the paper or
allow enough to remain on the surface to give the correct reflective
colour.

Can you point me in the direction of a simple discussion of lp's and
how they work and are used in ratings and tested.

Line pairs per millimetre - or cycles per millimetre - used as a measure
of frequency of an optically modulated signal or image. It refers to the
pairs of lines (black/white) used in photographic test targets. The
specification of "pairs" is to make it clear the there is one black line
and one white line in each cycle - in past times unscrupulous
advertisers would count the black and white lines separately to defraud
customers.

Any good discussion of photographic print quality should guide you. The
best I have found is "Post Exposure" by Ctein.
--
David Littlewood

In article , Jonathan Wilson
writes
On Tue, 31 Aug 2004 16:06:07 +0100, David Littlewood
wrote:

In article , Andrew
writes
What's the resolution of photo paper? Googling for terms
such as dpi and noritsu, I came across marketing claims
from minilab manufacturers claiming 400 and 500 dpi. Is the
the current bottleneck the paper or the equipment used to
project light onto the paper?

What do you mean by "photo paper"? From the words, I would take it to
mean traditional light-sensitive emulsion coated paper; for this,
maximum resolution is probably around 60-70 lp/mm - and this for good
B&W papers, most colour neg/pos paper would probably be lower.

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

If you mean inkjet paper, I don't know, but I suspect the printer has
more control over this than the paper - not that the paper has no
influence.

One of the non-printer specific brands (Ilford) quote a DPI size the
papers are rated for (approx 1400dpi but I dont have one to hand to
double check!) obviously this is a dpi not a ppi as most inkjets
actually print and colour mix using smaller droplets than the actual
pixels. The reported pixels coming back from the printer drivers at
highest quality seem to be between 600 and 750 depending on make.

I'm guessing the 1400dpi is saying that any dot that small is not
going to suffer bleed or distortion... smaller dots and I have no
idea, perhaps they might be to small to give acceptable drying or
would soak up to quickly to either allow the colour into the paper or
allow enough to remain on the surface to give the correct reflective
colour.

Can you point me in the direction of a simple discussion of lp's and
how they work and are used in ratings and tested.

Line pairs per millimetre - or cycles per millimetre - used as a measure
of frequency of an optically modulated signal or image. It refers to the
pairs of lines (black/white) used in photographic test targets. The
specification of "pairs" is to make it clear the there is one black line
and one white line in each cycle - in past times unscrupulous
advertisers would count the black and white lines separately to defraud
customers.

Any good discussion of photographic print quality should guide you. The
best I have found is "Post Exposure" by Ctein.
--
David Littlewood

David Littlewood wrote:

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

Can a human detect 30 line pairs/mm without using a loupe (or a
microscope) ?
--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html

David Littlewood wrote:

Note however that 60-70 lp/mm is way in excess of what the keenest human
eye can detect; that limit is closer to 30 lp/mm.

Can a human detect 30 line pairs/mm without using a loupe (or a
microscope) ?
--

Alfred Molon
------------------------------
http://groups.yahoo.com/group/Olympus_405080/
Olympus 5060 resource - http://www.molon.de/5060.html
Olympus 8080 resource - http://www.molon.de/8080.html