From: Wally on
On Wed, 30 Sep 2009 13:27:15 +0200, Wolfgang Weisselberg
<ozcvgtt02(a)sneakemail.com> wrote:

>ColinD <nospam(a)nowhere.com> wrote:
>
>>> A chain being only as strong as the weakest link, I feel that
>>> resolution is already being limited by most lenses outside
>>> their best apertures at lower than the present megapixels.
>>> (I don't think you'll get a noticeably better image from a wide
>>> open EF 50mm f/1.4 at 18MPix than at 8MPix + sensible upscaling
>>> (e.g. Lanczos scaling) where needed, for a drastic example.)
>
>> Even if the lens cannot equal the sensor for resolution, the image will
>> still be better than with fewer pixels.
>
>Sure, if you use arbitrary wrong definitions for 'better'.
>
>> The resultant resolution is
>> always a function of both lens and sensor. I've pointed this out
>> several times in the past.
>
>Point out as much as you want. Doesn't mean it's true or relevant.
>
>> The maximum resolution obtainable in practical photographic work is
>> limited both by the camera lens and by the film/sensor. The formula
>> often used to predict the resolution of a camera original is:
>
>See how you went from "better image" to a "*prediction* of
>resolution"?
>
>By your logic infinitely small sensor sizes, unable to capture
>even a single photon, would produce 'better' images than any
>other sensor with the same lens. Even you should be able to
>see several catches with that.
>
>Your claim, *as it stands*, is obviously wrong.
>
>And misses a very important word to be relevant to practical use,
>"noticeable" or "visible".
>
>> 1/Rt2 = 1/Rs2 + 1/RL2 (Higgins, G.C.Appl. Opt. 3, v.1, 9, Jan 1964)
>
>Ah, yes, a formula from the good old days a decade before the
>first digital image sensor, back when higher resolution meant
>slower films with finer, less notable grain.
>
>> As you can see, system resolution is not just lens resolution alone.
>
>I can see that you probably don't understand 'better' or
>'noticeable' --- or what tinier pixels do unless you raise the
>technology in between.
>
>Maybe you should look at the independent lens test sites and
>see if your formula comes up with the right answers as you test
>the same lenses at the same format size against different sensor
>resolutions ...

What would that show?

Wally

Wally
From: ColinD on
Wolfgang Weisselberg wrote:
> ColinD <nospam(a)nowhere.com> wrote:
>
>>> A chain being only as strong as the weakest link, I feel that
>>> resolution is already being limited by most lenses outside
>>> their best apertures at lower than the present megapixels.
>>> (I don't think you'll get a noticeably better image from a wide
>>> open EF 50mm f/1.4 at 18MPix than at 8MPix + sensible upscaling
>>> (e.g. Lanczos scaling) where needed, for a drastic example.)
>
>> Even if the lens cannot equal the sensor for resolution, the image will
>> still be better than with fewer pixels.
>
> Sure, if you use arbitrary wrong definitions for 'better'.
>
>> The resultant resolution is
>> always a function of both lens and sensor. I've pointed this out
>> several times in the past.
>
> Point out as much as you want. Doesn't mean it's true or relevant.
>
>> The maximum resolution obtainable in practical photographic work is
>> limited both by the camera lens and by the film/sensor. The formula
>> often used to predict the resolution of a camera original is:
>
> See how you went from "better image" to a "*prediction* of
> resolution"?
>
> By your logic infinitely small sensor sizes, unable to capture
> even a single photon, would produce 'better' images than any
> other sensor with the same lens. Even you should be able to
> see several catches with that.
>
> Your claim, *as it stands*, is obviously wrong.
>
> And misses a very important word to be relevant to practical use,
> "noticeable" or "visible".
>
>> 1/Rt2 = 1/Rs2 + 1/RL2 (Higgins, G.C.Appl. Opt. 3, v.1, 9, Jan 1964)
>
> Ah, yes, a formula from the good old days a decade before the
> first digital image sensor, back when higher resolution meant
> slower films with finer, less notable grain.
>
>> As you can see, system resolution is not just lens resolution alone.
>
> I can see that you probably don't understand 'better' or
> 'noticeable' --- or what tinier pixels do unless you raise the
> technology in between.
>
> Maybe you should look at the independent lens test sites and
> see if your formula comes up with the right answers as you test
> the same lenses at the same format size against different sensor
> resolutions ...
>
> -Wolfgang

Well, if one removes the sarcasm from your reply, there's practically
nothing left of it. *Of course* resolution is a function of both
film/sensor and the lens. If it were not so, then every lens would
deliver an image dependent only on lens resolution, regardless of sensor
resolution, a conclusion that is patently incorrect. Whether you can
'notice' a 'visible' difference depends on the manner in which you view
the image, but that is irrelevant; a difference will exist whether you
can see it with naked eye or not.



And the age of the formula is totally irrelevant also - or has E=MC^2
passed it's use-by date as well?

--

Colin D.
From: Wolfgang Weisselberg on
ColinD <nospam(a)nowhere.com> wrote:

I see you still misuse other peoples' domains and email addresses.

> Well, if one removes the sarcasm from your reply, there's practically
> nothing left of it.

Sure, if you relabel valid criticism --- like pointing out your
asocial misuse of the email address you knowingly falsely claim
as yours --- as sarcasm ...

> *Of course* resolution is a function of both
> film/sensor and the lens.

Obviously. Even
R = min(R_S, R_L)
is a function of both sensor and lens.
Now go away with your strawmen and *prove* your 'equation'.
You can find some data at photozone.de --- you should be able
to correlate the observed resolutions for the same lens/focal
length/aperture settings at different sensor resolutions.

But of course that would be work and it would turn out that your
claim is neither as clear-cut nor as correct as you'd like it
to be.

> Whether you can
> 'notice' a 'visible' difference depends on the manner in which you view
> the image, but that is irrelevant; a difference will exist whether you
> can see it with naked eye or not.

A difference that has no impact has no relevance.
Differences that cannot be seen are thus irrelevant to visual arts.

Of course, that truth will be labled 'sarcasm' by you.

> And the age of the formula is totally irrelevant also - or has E=MC^2
> passed it's use-by date as well?

Not yet(!). It may yet end as phlogiston did, or be outdated Newton's
laws of gravitation --- the future will tell.

-Wolfgang
From: Wolfgang Weisselberg on
Wally <Wally(a)luxx.com> wrote:
> On Wed, 30 Sep 2009 13:27:15 +0200, Wolfgang Weisselberg

>>Maybe you should look at the independent lens test sites and
>>see if your formula comes up with the right answers as you test
>>the same lenses at the same format size against different sensor
>>resolutions ...

> What would that show?

It would show if the formula was correct. Spot checks say
it's off.

-Wolfgang
From: Wally on
On Thu, 1 Oct 2009 15:09:46 +0200, Wolfgang Weisselberg
<ozcvgtt02(a)sneakemail.com> wrote:

>Wally <Wally(a)luxx.com> wrote:
>> On Wed, 30 Sep 2009 13:27:15 +0200, Wolfgang Weisselberg
>
>>>Maybe you should look at the independent lens test sites and
>>>see if your formula comes up with the right answers as you test
>>>the same lenses at the same format size against different sensor
>>>resolutions ...
>
>> What would that show?
>
>It would show if the formula was correct. Spot checks say
>it's off.

You are not very convincing!

Wally