Resolution - when is Enough ENOUGH? (a personal view)

In the previous thread
5 Megapixels Compared to Velvia, Kodachrome, Portra and 200 Gold
(see reference posts quoted below)
posed some interesting scenarios.

Many people here hold that 200PPI is good enough for photo quality
prints.

I regard about 10x8 as the largest print that one is likely to go
nose-to-paper or want close scrutiny.

Anything larger would (hopefully) be viewed at more "normal" distances
and not engender such demanding scrutiny

If that is the case then we had reached "Enough" quality at the 3Mp
level since the average 2048x1536 will produce 10.1"x7.7" prints at
200ppi.

I am not arguing 200ppi produces very satisfactory prints
(afterall I have produced 10x7.5" prints from 2Mp and even 0.8Mp that
although not exactly "sterling" were nothing to be ashamed of - and
are actually currently exhibited)

However with the reference thread I had re-visted printing out crops
to the equivalent of 10x7.5 from sample test images from
imaging-resource.com and inspecting for quality. I used the 11.4Mp
Canon EOS 1Ds as a benchmark and looked at highly rated 3Mp, 4Mp, 5Mp
and 6Mp digicams/DSLRs.

Just using visual inspection and with the aid of a regular (~2.5x
linear) magnifying glass - I can see -

3Mp (200ppi) just starting to show some image breakdown on finer
details - but I can see this only really with the magnifying glass.

4Mp (227ppi) does not have the image breakdown.

5Mp (259ppi) gains some visual crispness - but I cannot quantify it.

11+Mp (406ppi) I could detect enough improvement over the 5Mp image -
there were obviously characteristic differences that make comparisons
difficult (for example much less in-camera "sharpening" for the EOS
1Ds)

Just from this ad-hoc comparison I would hazard that somewhere between
227ppi and 259ppi - we have hit the point of diminishing returns at
least for the Photo printer I was using (Epson Photo Stylus 780 using
Epson Matte Heavyweight paper at 1440dpi).

200ppi was good - but for me still somewhat marginal.

[an aside: I found that current 3Mp digicams like the "budget" but
popular Canon A70 produces better prints to my eyes than say the once
top 3Mp resolution king of the Sony S75 or even the previous 4Mp
resolution king -Sony S85]

So is a current 5Mp "good enough"?

In a word YES.....

But some may argue that one needs some margin for cropping imperfectly
framed shots - or being able to use a smaller area to enlarge.

Some (and that includes me) used to argue that 300ppi was really
needed for true photo quality - and
Please Remember - my comparisons are self-limited by the quality of
the output from my home photo printer/paper combination - commercial
digital photo printing can produce higher technical quality prints.

If we use 300ppi as a yardstick for 10x8 - then that's
3000x2400 pixels = 7.2Mp

Allowing for the typical 4:3 aspct ratio of digicams -
3200x2400 = 7.7Mp

With 3200x2400 (7.7Mp) one can produce a
13.3"x10" print at 240ppi
16x12 print at 200ppi
21"x16" print at 150ppi

So for me the peg in the ground - or to replace all my photo gear
would be somewhere around 7.7Mp

With the prosumer Sony F828 we have already reached that level - it's
probably not too long before compact digicams will use 8Mp......

Your thoughts?

--
Vincent
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5 Megapixels Compared to Velvia, Kodachrome, Portra and 200 Gold

and

 

Agree!


But there are reasons for more Mpixels than 5-6-7 or so.

1. You want bigger prints that still are sharp.

Then you really also want bigger sensors as it is difficult
to make lenses that are sharp enough otherwise. You can of
course use stitching instead if you want bigger pictures
(or wider angles).

2. You want to avoid aliasing with a stronger anti alias filter.

If you want to remove almost any trace of aliasing, you need more
pixels and a stronger anti alias filter. You could also use
a Foveon sensor, which is much more insensitive to aliasing.


Roland

 

Vincent,
(Ooh, named after my favorite painter, are you?...)

Right you are.
I would say that for holiday snapshots, 3 megapixels are quite enough.
(They are mostly printed in just small hand-sized prints.)

For most professional work, about 6 megapixels does fine.
(A good 6-megapixel image can easily be printed in a double-spread
magazine size. And really, I don't see that size used too often
anyway.)
(What I make with my D100 is better than anything I ever managed with a
35mm camera. And I did rather better than most on such.)

Beyond 6 megapixels is only needed for rarified professional uses, and
for art freak Ansel-Adams wannabes like me, who get all wet thinking
about huge pictures with pinsharp details and tones.

Eolake Stobblehouse

 

How very right you are, EXCEPT for cropping ....

 

You may well be right on that -

However I think at 240ppi for 10x8 for me probably is good enough
(that's about 5Mp) - so 7.7Mp would give quite a "healthy" margin for
cropping and using a smaller area for enlargement.

For me, the most I have cropped under normal circumstances was to
about 80% (linearly) of the orignal image - but I'll also admit to
probably being influenced (subconsciously?) by a lack of quality
beyond that.

So an 80% scaled (linearly) image from the 3200x2400 (7.7Mp) image
would be one of 2560x1920 - which is close to 5Mp.......
that will allow a 10x8 print to be made at 240ppi......
(neat how the numbers seem to just fall into place )

Thanks for the input.

 

How appropriate, given you needed 146 lines for your reply, which took
what, all of one line?
________________________________________________________
Ed Ruf Lifetime AMA# 344007 ()
http://members.cox.net/egruf
See images taken with my CP-990 and 5700 at
http://members.cox.net/egruf-digicam

 

Yep, this is a personal view kind of issue.

Myself, I like 300 to 400 ppi for printing.

I want to be able to print 12" x 18" images
without upsizing.

For this calculation, I'll use 360 ppi.

12 x 360 = 4,320
18 x 360 = 6,480

4,320 * 6,480 = 27,993,600

So I'll be momentarily happy when we get 28 MB sensors.

When will we get such a sensor in a 35-mm frame
size in a sub-$2000 body ?

Perhaps never. Perhaps by 2010. I'm guessing the latter.

Amazing little revolution we're getting to enjoy.
As noted by many, 6 MP in a DSLR is Very Good,
and things are only getting better.


Stan

 

That doesn't leave you any slack for cropping, though.

4MP would give you that little bit extra.

7.2 is the point where you hit 300dpi on a 8x10 print, so 8MP might be
the magic - to give some cropping room and still have the snob-appeal of
300dpi.

I should have kept reading. You're covering everything I've said.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
mike 'at' metalmangler.com |
<http://www.metalmangler.com>| Caledon, Ontario, Canada

Lousy photographer with a really nice camera - Olympus C3020Zoom.
<http://www.metalmangler.com/photos/photos.htm>

 

I'm not expert on Ansel Adams, but I expect he'd rather hop naked on a
pogo stick through a feminist picnic than have to use a 35mm camera to do
his landscapes... I thought he was a dyed-in-the-wool medium-format
photographer. But I could be wrong...

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
mike 'at' metalmangler.com |
<http://www.metalmangler.com>| Caledon, Ontario, Canada

Lousy photographer with a really nice camera - Olympus C3020Zoom.
<http://www.metalmangler.com/photos/photos.htm>

 

His initial conditions included the assumption that at sizes over 8x10,
viewing distance will also increase and thus no increase in resolution
is necessary. This is a common stance, but obviously for some applications
may not be ideal.

 

I can already see very high quality, low noise 16MP full sized sensors
looming on the horizon.

Logic:
My 10D has 6MPix and excellent low noise, high quality images. If the
sensor had the same pitch, but bigger, it would make a 16MPix full frame
sensor. This MUST be currently possible, even if at an expensive price.

It wouldn’t take too much development to use a finer pitch (sensels closer
together) and make a 24MPix full frame sensor. This would give the ability
to crop half the width and half the height to give a 6MPix image which
would print to a decent size without pixelisation. That’s some pretty nice
cropping ability.

With film, how big could you print a picture that is cropped to ½ x ½ and
still have a clean and sharp picture?

I am sure that digital will be good enough for 99.9% of photographers soon
enough. It may not happen within the next 2 years, but by 2020 it will
have happened!

 

Ansel Adams' artistry was in the darkroom. He took summer Maine sky
shots (dramatic clouds) and put them over otherwise boring shots of
western mountains and deserts. he used his hands. Maybe he would have
done the same thing with a computer today. Or ... maybe not?

Marty

 

Sorta. Medium format to Ansel was 4X5, while 35mm he called miniature

He did use a Hasselblad later in his life.

 

He used them from the day they came out. From his autobiography:

"The Hasselblad has been my camera of choice for the past 20 years. ... I
met Dr. Victor Hasselblad in New York in 1950. On my return to SF, I found
one of his first cameras awaiting me: the 1600F model, ...
The next model, the Hasselblad 1000F was much more satisfactory in all
respects."
....
"I have made many of my well-known photographs with the Hasselblad, but to
single one out, a favorite is Moon and Half Dome, Yosemite National Park,
1960."

David J. Littleboy
Tokyo, Japan

 

FWIW- Recently there was an exhibition at the Western Forestry Center here
in Portland, OR of Adams work. One of the pictures they had was "Moonrise,
Hernandez, NM", which I looked at quite closely. I was surprised to note the
lack of detail when you got within a few inches, and remember thinking that
my Sony F717 could have gotten more detail.

Now if only I could find a store to purchase a hundredth of his talent!

Ozymandius

 

I have thought about this, and I suspect that a lot of the talent of
high-end nature photographers is patience.

--
=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Mike Graham | Metalworker, rustic, part-time zealot.
mike 'at' metalmangler.com |
<http://www.metalmangler.com>| Caledon, Ontario, Canada

Lousy photographer with a really nice camera - Olympus C3020Zoom.
<http://www.metalmangler.com/photos/photos.htm>

 

Before Ansel Adams died, digital photography was in its infancy, and he
is reported to have been very very interested in it.


I think we often make erroneous assumptions when we look at famous
people who reached a high mastery of one form, we might think that they
would look down on other forms.

 

Actually it is sold as a replacement for film and chemicals. Not as a
replacement for vision or for cameras, though it does allow some new and
interesting formats (just as new films allowed new formats - roll film and
35mm for example)

Who cares whether it is a "valid media"? What does that mean anyway?

-Jack

 

This implies never needing to crop an image.