Digital quality (vs 35mm): Any real answers?

nitzsche writes:

OK, I'll take a shot at it...

It used to be "Film is cheap,' now it's "Cameras are cheap."

1. What is the resolution of a 35mm film anyway?
- For practical purposes, it's infinite.

Not in this universe. For practical purposes, it's somewhere between
30-75 cycles/mm, most of the time.

snip

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.

"BeamGuy" writes:

A 2MP DSLR often does better than a 35mm camera because the depth
of field is so much greater for the tiny focal length lens. Another thing you
might ask is how many pixels are you actually using in your eye?

Well, at 40 cycles per degree, and perhaps a 140-degree horizontal
field of view, it's over 10,000 pixels across. We don't have any
display that can approach it.

snip

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.

"BeamGuy" writes:

A 2MP DSLR often does better than a 35mm camera because the depth
of field is so much greater for the tiny focal length lens. Another thing you
might ask is how many pixels are you actually using in your eye?

Well, at 40 cycles per degree, and perhaps a 140-degree horizontal
field of view, it's over 10,000 pixels across. We don't have any
display that can approach it.

snip

--
-Stephen H. Westin
Any information or opinions in this message are mine: they do not
represent the position of Cornell University or any of its sponsors.

"Toralf" wrote in message
...
Hi.

I'm still wondering about how good the image quality of modern digital
cameras (especially SLRs) really is, in particular how it compares with
35mm film. I've seen many articles on the subject on the Net, but few of
them seem to give you a lot of tangible information (I want to see the
numbers, please),

I don't think there are any numbers that are going to satisfy you. First of
all, there are the variables of the film, the scanner, and the subject (are
you talking about a picture of a high-contrast B&W test target using slow,
fine grain film with a prime lens and scanned with a high-end drum scanner?
If so, that's going to yield idealized results that don't match the
practical experiences of photographers comparing film to digital). And then
there's the judgement call with respect to grain-- when you've reached a
scanning resolution where additional detail can still be extracted but the
grain of the film is obvious and objectionable--do you still count that as
useful resolution? And if not, who decides at what point the grain is
obtrusive enough that addtional resolution is of no value?

Mark

"Toralf" wrote in message
...
Hi.

I'm still wondering about how good the image quality of modern digital
cameras (especially SLRs) really is, in particular how it compares with
35mm film. I've seen many articles on the subject on the Net, but few of
them seem to give you a lot of tangible information (I want to see the
numbers, please),

I don't think there are any numbers that are going to satisfy you. First of
all, there are the variables of the film, the scanner, and the subject (are
you talking about a picture of a high-contrast B&W test target using slow,
fine grain film with a prime lens and scanned with a high-end drum scanner?
If so, that's going to yield idealized results that don't match the
practical experiences of photographers comparing film to digital). And then
there's the judgement call with respect to grain-- when you've reached a
scanning resolution where additional detail can still be extracted but the
grain of the film is obvious and objectionable--do you still count that as
useful resolution? And if not, who decides at what point the grain is
obtrusive enough that addtional resolution is of no value?

Mark

I spent ages working out all the details. I came to the conclusion that if
you measured the area of a perfect print from a 35mm negative or 35mm slide
in inches and then divided the dimensions by 150 you'd be able to work out
the vertical/horizontal pixels of the image. Then simply multiply the two
together to get megapixels. That's the theory anyway.

In practice, how big is the biggest print you normally make? If your normal
biggest print is 10x8 then 3 megapixels is all you ever need (two at a
pinch).

But the biggest limitation is your printer. How many of us can afford an A3
or greater printer or even the ink to make A3 prints?

How many A4 prints can you hang on your wall?

I decided to settle on 3 megapixels. It's adequate for my needs and as with
slides, I ensure my photos are perfect before I squeeze the button. I claim
3 megapixels is the perfect equivalent of 35mm for most purposes. 6mp just
eats up storage space for no visible advantage.

--
Yours

Zebedee

(Claiming asylum in an attempt
to escape paying his debts to
Dougal and Florence)

I spent ages working out all the details. I came to the conclusion that if
you measured the area of a perfect print from a 35mm negative or 35mm slide
in inches and then divided the dimensions by 150 you'd be able to work out
the vertical/horizontal pixels of the image. Then simply multiply the two
together to get megapixels. That's the theory anyway.

In practice, how big is the biggest print you normally make? If your normal
biggest print is 10x8 then 3 megapixels is all you ever need (two at a
pinch).

But the biggest limitation is your printer. How many of us can afford an A3
or greater printer or even the ink to make A3 prints?

How many A4 prints can you hang on your wall?

I decided to settle on 3 megapixels. It's adequate for my needs and as with
slides, I ensure my photos are perfect before I squeeze the button. I claim
3 megapixels is the perfect equivalent of 35mm for most purposes. 6mp just
eats up storage space for no visible advantage.

--
Yours

Zebedee

(Claiming asylum in an attempt
to escape paying his debts to
Dougal and Florence)

Zebedee wrote:

I spent ages working out all the details. I came to the conclusion that if
you measured the area of a perfect print from a 35mm negative or 35mm slide
in inches and then divided the dimensions by 150 you'd be able to work out
the vertical/horizontal pixels of the image. Then simply multiply the two
together to get megapixels. That's the theory anyway.

In practice, how big is the biggest print you normally make? If your normal
biggest print is 10x8 then 3 megapixels is all you ever need (two at a
pinch).

But the biggest limitation is your printer. How many of us can afford an A3
or greater printer or even the ink to make A3 prints?

How many A4 prints can you hang on your wall?

I decided to settle on 3 megapixels. It's adequate for my needs and as with
slides, I ensure my photos are perfect before I squeeze the button. I claim
3 megapixels is the perfect equivalent of 35mm for most purposes. 6mp just
eats up storage space for no visible advantage.


I have 50x60 (cm) B&W photo paper which I use for the right pictures.
I doubt 3 (or 6) megapixels will do the job...

Chris

"Chris Loffredo" wrote in message
...
Zebedee wrote:
I have 50x60 (cm) B&W photo paper which I use for the right pictures.
I doubt 3 (or 6) megapixels will do the job...

50cm = 19.7 inches
60cm = 23.6 inches

19.7 x 150 = 2955 pixels
23.6 x 150 = 3540 pixels

2955 x 3540 = 10.4607 megapixels

It could be a little stretch for a 6mp camera or you could even use the
Kodak 14mp SLR

Having said that, it's a really unusual size and more suited to medium
format than for 35mm.

--
Yours

Zebedee

(Claiming asylum in an attempt
to escape paying his debts to
Dougal and Florence)

"Chris Loffredo" wrote in message
...
Zebedee wrote:
I have 50x60 (cm) B&W photo paper which I use for the right pictures.
I doubt 3 (or 6) megapixels will do the job...

50cm = 19.7 inches
60cm = 23.6 inches

19.7 x 150 = 2955 pixels
23.6 x 150 = 3540 pixels

2955 x 3540 = 10.4607 megapixels

It could be a little stretch for a 6mp camera or you could even use the
Kodak 14mp SLR

Having said that, it's a really unusual size and more suited to medium
format than for 35mm.

--
Yours

Zebedee

(Claiming asylum in an attempt
to escape paying his debts to
Dougal and Florence)