Medium format versus digital sharpness

"Neil Gould" wrote:

Still, comparing top-of-the-line options would suggest a professional drum
scan (and not a "fake" drum scan e.g. something like the Imacon).

OK.

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

David J. Littleboy
Tokyo, Japan

Recently, Noons posted:

On Oct 30, 11:38 am, Raphael Bustin wrote:

Canon 1Ds vs. scanned 645:

http://www.jjsviewbox.com/Articles/6451ds.htm

This is a curious choice to "prove" quality differences...

A top-of-the-line DSLR compared against a Bronica with a zoom lens? Better
would be a top-of-the-line camera and lens.

The "film" was scanned in all likelihood without a glass film holder, as
it would have been worth mentioning if it was. My ArtixScan 120tf is
essentially the same scanner, and there is a *huge* difference in scann
quality when the glass film holder is used.

Still, comparing top-of-the-line options would suggest a professional drum
scan (and not a "fake" drum scan e.g. something like the Imacon).

Not terribly objective and is quite typical of the comparisons I've seen
on-line, but it "confirms" what some people want to believe.

Neil

Recently, David J. Littleboy posted:

"Neil Gould" wrote:

Still, comparing top-of-the-line options would suggest a
professional drum scan (and not a "fake" drum scan e.g. something
like the Imacon).

OK.


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

I do like this comparison much better than Rafe's, David, but, it still
has issues. As presented:

* Scanning details would be a good thing, rather than just stating the
type of scanner. What resolution and optimizations were used to make the
scan? One can purchase "cheap" professional scans, and one can do poor
scans on a good scanner, too. ;-)

* Post-processing adds too many variables for the both digital and film
workflows. I can see no reason to involve these manipulations in an
objective comparison.

Finally, I don't think that the results support Litomisky's conclusions.
Even accepting the above issues and just looking at these shots as
presented raises questions. The image from the 5D has more contrast, but
loses detail (a condition that is favored by Photoshop's bicubic
algorithms, btw), as can be seen by comparing interior portions of the
branches, faces of the leaves, and mortar between the bricks to the
Hasselblad shot.

So, I still think that what one thinks is "best" all depends on what one
wants in an image.

Neil

"Neil Gould" wrote:
Recently, David J. Littleboy posted:
"Neil Gould" wrote:

Still, comparing top-of-the-line options would suggest a
professional drum scan (and not a "fake" drum scan e.g. something
like the Imacon).

OK.

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

I do like this comparison much better than Rafe's, David, but, it still
has issues.

It demonstates that 645 and the 5D are rather similar beasts, and that 35mm
is sick by comparison.

Which of 645 and 5D is "better" is an argument that splits hairs far finer
than I'm interested in.

All these make it abundantly clear that 645 and 5D are _roughly_ equivalent.
If you find one of these not good enough for a particular application (e.g.
a 30 x 40 advertising poster that people can walk up to), what you really
need is a larger format or a lot more pixels. The other won't be enough of
an improvement.

That is, 645 is, for all practical purposes, equivalent to 12 or 16MP or so.
645 is "worth" a lot more than 8MP and a lot less than 24MP. (With decent
technique, 645 is always better than 8 and worse then 24MP.)

So 6x7 (having 1.66 times the information of 645) is "worth" a lot more than
13MP and a lot less than 40MP. Which is rather different than QG's 100MP. QG
is off by a factor of four.

As presented:

* Scanning details would be a good thing, rather than just stating the
type of scanner. What resolution and optimizations were used to make the
scan? One can purchase "cheap" professional scans, and one can do poor
scans on a good scanner, too. ;-)

Quibble quibble. Those are quality, professional drum scans.

* Post-processing adds too many variables for the both digital and film
workflows. I can see no reason to involve these manipulations in an
objective comparison.

Those are the standard, agreed techniques for making high-quality
enlargements. But I see your point.

He's playing a similar game to this guy.

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

That is, they're both making prints that are (in my opinion) way beyond
reasonable for either format.

But that's actually a good way to compare, because the differences are more
visible.

At 12x18 (where I think 645 and the 5D womp 35mm), some people think 35mm
looks great.

At 16x20 (where I think 6x7 womps 645/5D), some people think 645 and the 5D
look great.

Finally, I don't think that the results support Litomisky's conclusions.
Even accepting the above issues and just looking at these shots as
presented raises questions. The image from the 5D has more contrast, but
loses detail (a condition that is favored by Photoshop's bicubic
algorithms, btw), as can be seen by comparing interior portions of the
branches, faces of the leaves, and mortar between the bricks to the
Hasselblad shot.

He's using Velvia, and the grain is seriously ugly at that enlargement.
Provia 100F wouldn't look so bad, and TMX100 would probably hold a bit more
detail.

So, I still think that what one thinks is "best" all depends on what one
wants in an image.

We're in some sort of agreement he I don't think there's enough of a
difference to call a winner in the 645 vs. 5D fight.

David J. Littleboy
Tokyo, Japan

Recently, Scott W posted:

Neil Gould wrote:
Recently, David J. Littleboy posted:

"Neil Gould" wrote:
Still, comparing top-of-the-line options would suggest a
professional drum scan (and not a "fake" drum scan e.g. something
like the Imacon).
OK.



http://www.ales.litomisky.com/projec...anon%205D).htm
I do like this comparison much better than Rafe's, David, but, it
still has issues. As presented:

* Scanning details would be a good thing, rather than just stating
the type of scanner. What resolution and optimizations were used to
make the scan? One can purchase "cheap" professional scans, and one
can do poor scans on a good scanner, too. ;-)

* Post-processing adds too many variables for the both digital and
film workflows. I can see no reason to involve these manipulations
in an objective comparison.

Finally, I don't think that the results support Litomisky's
conclusions. Even accepting the above issues and just looking at
these shots as presented raises questions. The image from the 5D has
more contrast, but loses detail (a condition that is favored by
Photoshop's bicubic algorithms, btw), as can be seen by comparing
interior portions of the branches, faces of the leaves, and mortar
between the bricks to the Hasselblad shot.

So, I still think that what one thinks is "best" all depends on what
one wants in an image.

What I see is pretty typical of film vs. digital. Film can get fine
detail, as long at the contrast in the detail is very high. But more
subtle parts of the scene the film misses all together, in the 5D
image I can see that the leafs are not flat but have a ripple to
them, in the Hasselblad image this is mostly missing.

Neither the Hasselblad nor 5D rendering of the leaves look flat on my
monitor.

If you can look at both the Hasselblad image and the 5D and say that
you think the Hasselblad has better image quality then you would
watch a naked man walk down the street and say that "yes the emperors
new cloths are mighty fine", IMO.

I wouldn't say either one of them is "better". They differ, and I've
merely pointed out some of the differences. Let's not overlook the fact
that whether this particular image "works" or not is not the issue. If
details are lost, as they are with the 5D rendering, that can be just as
much a problem as a film image being less contrasty. Which camera might do
a "better" job comes down to what is important to present in the image,
and that would be the basis for my picking up one or the other.

Neil

On Wed, 7 Nov 2007 08:58:56 -0600, "Neil Gould"
wrote:


The "film" was scanned in all likelihood without a glass film holder, as
it would have been worth mentioning if it was. My ArtixScan 120tf is
essentially the same scanner, and there is a *huge* difference in scann
quality when the glass film holder is used.

Still, comparing top-of-the-line options would suggest a professional drum
scan (and not a "fake" drum scan e.g. something like the Imacon).


Neil, do you have any scan samples that look substantially
better than those I've posted on my "scan snippets" site?

If you do, I'd love to see them. From your LS-120 or from
any other scanner.

And if you don't, I think there's no other conclusion that
well-scanned 645 matches up pretty well with the output
of a Canon 1Ds or 5D, when the latter are up-rezzed to
match the pixel dimensions of the film scan.

In my experience, a glass holder allows for better
uniformity of focus across a given slide or negative.
But critical focus can be achieved -- at least on a
portion of the film -- without it.


rafe b
www.terrapinphoto.com
scan snippets:
www.terrapinphoto.com/jmdavis

"David J. Littleboy" wrote in message
...

"Neil Gould" wrote:
Recently, David J. Littleboy posted:
"Neil Gould" wrote:

Still, comparing top-of-the-line options would suggest a
professional drum scan (and not a "fake" drum scan e.g. something
like the Imacon).

OK.

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

I do like this comparison much better than Rafe's, David, but, it still
has issues.

It demonstates that 645 and the 5D are rather similar beasts, and that
35mm is sick by comparison.

Which of 645 and 5D is "better" is an argument that splits hairs far finer
than I'm interested in.

All these make it abundantly clear that 645 and 5D are _roughly_
equivalent. If you find one of these not good enough for a particular
application (e.g. a 30 x 40 advertising poster that people can walk up
to), what you really need is a larger format or a lot more pixels. The
other won't be enough of an improvement.

That is, 645 is, for all practical purposes, equivalent to 12 or 16MP or
so. 645 is "worth" a lot more than 8MP and a lot less than 24MP. (With
decent technique, 645 is always better than 8 and worse then 24MP.)

So 6x7 (having 1.66 times the information of 645) is "worth" a lot more
than 13MP and a lot less than 40MP. Which is rather different than QG's
100MP. QG is off by a factor of four.

First, I don't want to argue with someone as knowledgable as Mr. Littleboy.
(suck-up mode off)

The figures I've heard were that 35mm (24x36mm) film was roughly equal to
32-36 Mpixels. This would put 645 equal to about 100 Mpixels, based on
pixels per square millimeter. Where does my math fall apart?

I also wonder about making comparisons between a digital photo and a film
negative online. After all, the film neg has to be scanned to be posted
online. It seems to me that the only valid comparison would be to view both
photos in person. What time should I come over?!

Ken Hart wrote:

The figures I've heard were that 35mm (24x36mm) film was roughly equal to
32-36 Mpixels. This would put 645 equal to about 100 Mpixels, based on
pixels per square millimeter. Where does my math fall apart?

Well, 32-36 Mpixels is unrealistic for any normal 35mm film.
It would be enough for a really sharp 16x24 inch print.
(Something like Eastman 5360 is easily sharp and grainless
enough, but it doesn't qualify as a normal film.)

16*300*24*300 = 34560000 or about 33 megapixels.

Medium speed 35mm film can make a really nice 8x12 in good
cases. That means 8.25 megapixels is more realistic.

Peter.
--

"Ken Hart" wrote:
"David J. Littleboy" wrote:

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

I do like this comparison much better than Rafe's, David, but, it still
has issues.

It demonstates that 645 and the 5D are rather similar beasts, and that
35mm is sick by comparison.

Which of 645 and 5D is "better" is an argument that splits hairs far
finer than I'm interested in.

All these make it abundantly clear that 645 and 5D are _roughly_
equivalent. If you find one of these not good enough for a particular
application (e.g. a 30 x 40 advertising poster that people can walk up
to), what you really need is a larger format or a lot more pixels. The
other won't be enough of an improvement.

That is, 645 is, for all practical purposes, equivalent to 12 or 16MP or
so. 645 is "worth" a lot more than 8MP and a lot less than 24MP. (With
decent technique, 645 is always better than 8 and worse then 24MP.)

So 6x7 (having 1.66 times the information of 645) is "worth" a lot more
than 13MP and a lot less than 40MP. Which is rather different than QG's
100MP. QG is off by a factor of four.

The figures I've heard were that 35mm (24x36mm) film was roughly equal to
32-36 Mpixels. This would put 645 equal to about 100 Mpixels, based on
pixels per square millimeter. Where does my math fall apart?

There's nothing wrong with your math.

The problem is with the meaning of "roughly equal to 32-36 Mpixels."

In real life, 12MP dSLR images simply look way better than 35mm. In prints.
Every time.

It's not even close.

So what does it mean to say 35mm is "roughly equal to 32-36 Mpixels"?

I don't know. It seems to be complete nonsense.

What does it mean to you?

David J. Littleboy
Tokyo, Japan

On Thu, 8 Nov 2007 08:29:56 -0600, "Neil Gould"
wrote:


The question is whether critical focus was achieved on the portion of film
presented in the comparison. It doesn't look like it to me, but in truth,
I don't know. I also don't know if you've used a Polaroid 120 or Artixscan
120tf, but I can tell you that if one uses autofocus (another reasonable
presumption, IMO), the glass holder makes a lot of difference in the
resulting image.

I haven't personally used the LS-120 but I could easily gain access
to one if I was so inclined.

The Nikon LS-8000/9000 have autofocus as well, but it can be
directed at any spot you choose on the film. So even if the film
is warped to hell, you can get perfect focus on one spot, at least.

From samples I've seen (and posted on my snippets site,) the LS-120
is roughly comparable to the LS-8000/9000 in overall sharpness.
At 4000 dpi, my scan samples cover 0.25" by 0.25" of film surface,
so *uniformity* of focus isn't an issue.


rafe b
www.terrapinphoto.com