How many megapixcels equivalent to 35 mm in quality

Malcolm Smith wrote:
I would be intereested in you pointing me to something less stale!
Presumably to be stale you must have seen soemthing more recent to
make Nornam Koran article stale.

Malcolm

Malcolm,

http://www.normankoren.com/Tutorials/MTF7.html

The top of the page indicates that the last update was September 17, 2005,
and that most of the text was written in 2002 and 2003. Six years is a
long time in digital photography. There are considerably more recent
cameras and lenses than the article mentions, reflecting different takes
on the strength of anti-aliasing filters, for example, and I suspect that
the Foveon was seen in a more favourable light then than now. The growth
of pixel count in small-sensor cameras has been much greater than the
article suggests.

More recent articles include those by Roger Clark and Emil Martinec.

http://www.clarkvision.com/imagedeta...ensor_analysis

http://theory.uchicago.edu/~ejm/pix/...ise/index.html

Cheers,
David

I am familar with Roger Clarks work and have fount it very interesting and
useful. I hadn't cone across Martinec but have printed out his paper and
will read it tonight. I quoted the Norman Koran work as directly answering
the OP's question of when digital equals film (if I have quoted correctly)
and I havn't seen anything in Rogers work before exactly on this topic.

I am putting together some of my ideas on sharpening which I should get on
my web site in a few weeks and find this type of web information very useful
(particularly Roger Clarks writing on visual acuity) and interesting.

All the best
Malcolm

"David J Taylor" wrote:
Malcolm Smith wrote:
I would be intereested in you pointing me to something less stale!
Presumably to be stale you must have seen soemthing more recent to
make Nornam Koran article stale.

Malcolm

Malcolm,

http://www.normankoren.com/Tutorials/MTF7.html

The top of the page indicates that the last update was September 17, 2005,
and that most of the text was written in 2002 and 2003. Six years is a
long time in digital photography. There are considerably more recent

Koren updates his web page with fair regularity. The
point is that for a discussion of "How many megapixcels
equivalent to 35 mm in quality", virtually *nothing* has
changed since the 2005 update to that particular page.

cameras and lenses than the article mentions, reflecting different takes
on the strength of anti-aliasing filters, for example, and I suspect that
the Foveon was seen in a more favourable light then than now. The growth
of pixel count in small-sensor cameras has been much greater than the
article suggests.

More recent articles include those by Roger Clark and Emil Martinec.

http://www.clarkvision.com/imagedeta...ensor_analysis

Roger Clark's index page that you cite above lists his
article on that topic, "Film versus Digital Cameras: How
many Megapixels?"

http://www.clarkvision.com/imagedeta...digital.1.html,

It was written in May 2002, and thus is older than
Koren's article.

http://theory.uchicago.edu/~ejm/pix/...ise/index.html

An article that says absolutely *nothing* about film
(the word never occurs in the entire article). How is
that article relevant to the topic?

--
Floyd L. Davidson http://www.apaflo.com/floyd_davidson
Ukpeagvik (Barrow, Alaska)

Heres a dedicated review site for cameras 'Steves Digicams'
(http://steves-digicams.com/), if you are not already aware of, there
are test shots that you can DL and print, another one is 'DP reviews'
(http://www.dpreview.com/reviews/specs.asp)

I use a Canon A650 just for general purpose and wanting to take decent
photos, you can tell the only thing I know about cameras is that you
smile in the devil while someone presses a button

One thing that you really need to consider I'd say, is not as much as
the pixel size.... more important is the sensor size that sits behind
the lens, usually the bigger the better ... 'this link might explain. '
(http://tinyurl.com/ah7nc).

It's not what you asked but just might throw some light for you.

davy

Mark Thomas wrote:


As to the original question, here's my opinion, assuming a reasonable
sized sensor...

Normal 100-200 print film - 6-8 Mp

This I believe

Pro quality 100-160 print film - 8-12 Mp

What do you mean by this? I have always felt, and felt strongly, that
"pro" film was always inferior to the latest generation "drugstore" film,
simply because the latter was always a generation later.

I will admit that Ektar 25 was very special indeed, and under the
absolute best conditions just might beat an 8 MP digital
in certain ways, especially ultimate resolution limit at
low MTF readings.


Slide film* (Velvia, Kchrome) - 12-24 Mp

This I disagree strongly. The "impression" of superiority here was always
the exceptionally high contrast of slide film. The down side was
hopelessly bad dynamic range.

Doug McDonald

"Mark Thomas" wrote:

As to the original question, here's my opinion, assuming a reasonable
sized sensor...

Normal 100-200 print film - 6-8 Mp
Pro quality 100-160 print film - 8-12 Mp
Slide film* (Velvia, Kchrome) - 12-24 Mp

People who have actually looked, find that 12.7MP (i.e. the 5D) looks very
similar to _645_ slide film, and 24x36mm is nowhere close to either.

http://www.ales.litomisky.com/projec...anon%205D).htm

http://www.shortwork.net/equip/review-1Ds-SQ-scantech/

David J. Littleboy
Tokyo, Japan

On Sat, 31 May 2008 00:10:23 +0900, David J. Littleboy wrote:

"Mark Thomas" wrote:

As to the original question, here's my opinion, assuming a reasonable
sized sensor...

Normal 100-200 print film - 6-8 Mp
Pro quality 100-160 print film - 8-12 Mp
Slide film* (Velvia, Kchrome) - 12-24 Mp

People who have actually looked, find that 12.7MP (i.e. the 5D) looks
very similar to _645_ slide film, and 24x36mm is nowhere close to
either.

http://www.ales.litomisky.com/projec...sus%20Digital%
20Shootout%20(Hasselblad,%2035mm,%20Canon%205D).ht m

http://www.shortwork.net/equip/review-1Ds-SQ-scantech/

Point of Order: The links you site as well as all the others sited in
this thread, and all those I've read, but not mentioned here, do NOT
truly compare digital to film. Instead they compare digital to digitally
scanned film, and therein lies the caveat. Any advantages film might or
does have would be negated either partly or wholly by the scanning
process. In reality, you are comparing a digital "original" to a copy of
an original. Is that an equitable comparison? I think not.

A true test of digital vs film would be direct out of the camera to
photographic emulsion 20X prints with only overall color balance and
density corrections permitted, and only during the printing process;
then second 20X prints where any manner of manipulation is permitted to
make the best possible prints.

I have never found such a test in all my searches: The film is always
scanned.

Maybe, I'll do it myself. I have a friend who has a Canon 5D. Now all I
need to do is find someone with a Canon film camera, so the same lens can
be used. Or I could just use my 30 year old, all manual Nikons for the
film part, but that might bias the test toward film due to the vast
superiority of old manual Nikkors over today's plastic, loosie-goosie AF
lenses. ;-)

Stef

"Stefan Patric" wrote:
On Sat, 31 May 2008 00:10:23 +0900, David J. Littleboy wrote:

People who have actually looked, find that 12.7MP (i.e. the 5D) looks
very similar to _645_ slide film, and 24x36mm is nowhere close to
either.

http://www.ales.litomisky.com/projec...sus%20Digital%
20Shootout%20(Hasselblad,%2035mm,%20Canon%205D).ht m

http://www.shortwork.net/equip/review-1Ds-SQ-scantech/

Point of Order: The links you site as well as all the others sited in
this thread, and all those I've read, but not mentioned here, do NOT
truly compare digital to film. Instead they compare digital to digitally
scanned film, and therein lies the caveat.

No caveat required. People who have compared the wet projection prints
they've made to prints made from scans find that scanning makes as good or
better prints. Partly because the projection system itself degrades the
image, but mostly because the last generation of scanners (Nikon 5000, Nikon
9000) were quite good.

Any advantages film might or
does have would be negated either partly or wholly by the scanning
process. In reality, you are comparing a digital "original" to a copy of
an original. Is that an equitable comparison? I think not.

I think so. I shot a lot of medium format, scanned it on a Nikon 8000, and
checked the film carefully with a 20x loupe and a 60x microscope. The scan
gets by far the vast majority of the valid photographic information that's
actually on the film.

The "scanning doesn't get all the information" is a common claim by film
fans, but it's nothing more than hopeless grasping at straws. A 5D file
simply captures more useful photographic information than 24x36mm of film
does. (This might be different for gigabit film, but its a slow, high
contrast B&W film that's not practical for actual photography.)

A true test of digital vs film would be direct out of the camera to
photographic emulsion 20X prints with only overall color balance and
density corrections permitted, and only during the printing process;
then second 20X prints where any manner of manipulation is permitted to
make the best possible prints.

20x enlargements from film (any film that you'd actually want to use) are
really really ugly. Even the best films are either grossly soft, grossly
grainy, or both at 13x. If you care about the quality of your prints, you
make 8x and smaller enlargements.

I have never found such a test in all my searches: The film is always
scanned.

Again, lots of people who are now scanning pulled out their wet projection
prints and found that the scans were as good, or more often, simply better.

What I'm saying is that the differences between desktop scanning, drum
scanning, and the best wet projection printing are tiny compared to the
differences between different film formats. You just aren't going to make
35mm look like 645 by buying a Leitz enlarger and Leitz enlarging lenses. At
12 x 18, 645 is an 8.2x enlargement, and at 12x18, 35mm is a 13x
enlargement. If you care about print quality, the difference is large with
any of the better printing technologies.

But the 5D produces images that are in the 645 class. And there's no way to
make 35mm look that good.

Maybe, I'll do it myself. I have a friend who has a Canon 5D. Now all I
need to do is find someone with a Canon film camera, so the same lens can
be used. Or I could just use my 30 year old, all manual Nikons for the
film part, but that might bias the test toward film due to the vast
superiority of old manual Nikkors over today's plastic, loosie-goosie AF
lenses. ;-)

You are wasting your time. Again, the 5D produces images that are roughly on
par with 645 film. If I shoot TMX100 in my (6x7) Mamiya 7, I see slightly
higher resolution for sharp architectural detail than I get with the 5D. But
there's no way to make 645 beat out the 5D in any visually significant way.

David J. Littleboy
Tokyo, Japan

David J. Littleboy wrote:
"Mark Thomas" wrote:
As to the original question, here's my opinion, assuming a reasonable
sized sensor...

Normal 100-200 print film - 6-8 Mp
Pro quality 100-160 print film - 8-12 Mp
Slide film* (Velvia, Kchrome) - 12-24 Mp

People who have actually looked

David, there is a rather unkind implication in that (and one I dispute,
but who would believe anything written on usenet anyway..)

find that 12.7MP (i.e. the 5D) looks very
similar to _645_ slide film, and 24x36mm is nowhere close to either.

Huh? I don't follow this - you refer to a 5D (which is full frame
24x36) and 645, and then say 24x36 is "nowhere close to either"? I
presume you mean 35mm film is nowhere close?

Yes, the 5D is arguably a bit beyond all 35mm films, but "nowhere
close"?? It depends on what films and under what shooting conditions,
and this is just one full-frame camera - not exactly representative of
all 12Mp cameras. I *didn't* nominate particular selected cameras nor
did I or the OP specify full-frame. If you are going to do that, the
comparisons change.

Also, I was using ball park figures in regard to resolution only,
because I referred to other issues like d-range and noise/grain
elsewhere in my post (the bits you cut out). Saying it "looks very
similar" is obviously taking all that other stuff into account.

http://www.ales.litomisky.com/projec...anon%205D).htm

As above, this is a full-frame camera. Where are the samples from other
12Mp cameras?

http://www.shortwork.net/equip/review-1Ds-SQ-scantech/

And again, another full-frame. I agree, full-frames are in the league
of medium format, but not all cameras are full-frame...

At Roger Clark's site, he agrees that Velvia needs 10-16 Mp for a rough
resolution equivalence, very much in line with what I posted. I defer
to your extensive experience in these matters and am totally in
agreement with almost everything you post, but I think moving the
discussion so that it only includes full-frame is a bit odd!


mt

wrote:

?? But I am specifically referring to resolution only here. I
addressed the topic of dynamic range elsewhere in that post, and of
course you are right that most transparency film is contrasty and has
very limited drange.

A nailed K25/Velvia slide (with good technique) will clearly outrun an
8Mp image in terms of detail/resolution.
Here, the much quoted Roger Clark site indicates he puts Vevlia at
between 10 and 16 Mp.
http://www.clarkvision.com/imagedeta....summary1.html


That's not been my experience.

In real life, 12x18 prints from the 5D simply look better than 12x18 prints
from any 35mm film you'd actually want to use. You have to go to 645 to
compete with the 5D at 12x18. Even with Velvia (which is quite grainy; more
so than Provia 100F or Velvia 100F).

If you look at micrographs of test charts taken with K25, K64, and Velvia,
you do see a lot of detail, a lot more than the 5D captures. But when you go
out and take real photos and make real prints, they don't do anywhere near
as well as the numbers indicate.

So numbers based on high contrast test charts don't reflect practical
reality.

But as I mentioned in my other note, when you make a 13x enlargement from
any of these films, it looks quite bad close up (say viewed at 10" from the
print). But 12x18s from 12.7MP look real nice, even at 10".

Of course, getting _sharp_ 12.7MP images from the 5D is like falling off a
log (at 35mm and longer; corners on superwides are a problem, sigh), but it
may be a bit harder to get sharp images on 12MP APS-C cameras, and nearly
impossible with 12MP P&S cameras...

David J. Littleboy
Tokyo, Japan