Re: Nikon and Megapixels

Burgerman wrote:
"Alan Browne" <alan.browne@xxxxxxxxxxxxxxxxxxxxx> wrote in message news:UZydndBkXvh2_67UnZ2dnUVZ_tjinZ2d@xxxxxxxxxxxxxxx
Burgerman wrote:
"Alan Browne" <alan.browne@xxxxxxxxxxxxxxxxxxxxx> wrote in message news:KZidnThM5PcLvq7UnZ2dnUVZ_vGdnZ2d@xxxxxxxxxxxxxxx


FIRST OFF. Don't start replying to this post until you have read the bottom section.


I read it. its pointless and you still dont get it.
It is an empirical formula from Kodak. Kodak have shown it experimentally. (Note: I used to think that the worst resolution (lens or film/sensor) determined the outcome, but it is the combination of the two according to Kodak's testing.)

Well I have no idea where you got this wonderful bit of information but its plain wrong.
If you take a photo with a 50 million pixel sensor using a milk bottle bottom for a lense you get a huge file of a crap low res image.

Right. And that formula would say so. But of course we're not talking
about milk bottle lenses, are we?

In effect, what the formula says is that no matter how good the lens,
you can never get the full res of the sensor AND no matter how good the
sensor, you can never get the full res of the lens.

Or - The sum of the parts is less than the least of the parts.

In the same way that in the good old days of hi fi it was better to spend money on a good cartridge and turntable. Garbage in / garbage out but louder.

Soory but its just plain wrong.

You CANNOT increase thew resolution from a lens by having a bigger pixel count. You cant put back the detail that was lost. No matter what your formula says.

The formula does not say that. The formula says that the RESULT is not
the worst of lens or sensor, but the combined effect of both making the
whole worse than the worst of the two no matter how good either one is.
Run the numbers and it will be clear to you quick enough.

I on the other hand have shown you that no lenses that fit 35 mm sensor size can reach 24m pixel resolution or even get close already. But you obviously dont understand that.

You have not shown that at all.

ALL the lens manufacturers OWN figures and the charts on DP Review show exactly that extremely clearly if you understood what you were looking at.


In fact the dpreview of the a900 shows,
at low ISO more detail in the test image than from the FF Nikon (12 or so Mpix). (Look for the little green label logo of a head in profile).

Yes It does. Using the highest res lens possible at its best aperture. And even then the resolution is at best only slightly better. Your lense at F16 would on the same chart be way behing that!!!

Please stop harping on f/16. I'm challenging you to the best aperture
on your best lens. Be a man and step up to the plate.

(And again, I posted lenses that are at their sharpest at f/11 - f/16
.... but you don't seem to like facts, do you?)





1. I never said that we had to shoot a compare at f/16.

I agree.

Good! I hope that means we're going forward with a test (Don't reply yet - see the bottom of the post first).

No you said "compare".
I said that using F16 as in your image will totally remove any advantage that 24m pixels could give. Different arguments that you are now avoiding...

I NEVER said that. Stop harping on f/16. The reason I posted my very
first shots from my camera at f/20 and f/18 was simply that my lights
cannot be dialed any lower than that for the way I was shooting and I
did not have 77mm ND's at hand. I NEVER claimed that was the sharpest
they could be. LET GO OF THAT.

Obviously at 5.6 with a prime in a studio and a good lense technique will give a marginal improvement as seen months ago when DP review tested your camera. It was then after seeing the lens resolution tests, and the noise that I ordered the D700 because the D3X will most likely be the same. In the real world in 90 percent of images and all images that dont use a perfect prime at its best aperture and lab conditions the resolution will be less than a 12 million pixel sensor can capture. Pointless.

Well, the the D3X will absolutely be a 24 MPix camera. See dpreview.

As for lenses, 5 of my 7 are up to the sensor in the camera.

You choose whatever aperture you are most happy with.


Its not about which aperture I am happy with but about matching lens maximum possible resolution to try and make use oif your noisy 24m sensor.

Puh-leaze, stop the empty rhetoric.

Its noit empty. There are hundreds of lens tests aqnd manufacturers OWN resolution figures to look at. They show quite clearly that 24 million pixels is just a waste without better lenses if thats even possible. Or a bigger still sensor (MF??)


FOR YOUR LENS, SHOOT THE SHARPEST
APERTURE.

And believe me. At ISO 200 it not any more noisy than a Canon or Nikon of similar pixel density. At 800 it begins to show noise (of no consequence in a print up to 20" or so).

Your camera shows nasty noise at even 400! Look at the samples and test results on DP Review! Its the very reason I am not waiting for the D3x... Its only of any use in a studio on a tripod or in nevada at mid day... Its all thise extra pixels crammed in that dont really help! But I digress...

Look Tony, either PUT UP or SHUT up. I've suggested a compare test that is simple and eliminates most error sources. Any variance would be much less than the 41% resolution difference.

I have yet to see ANY lens used at f16 that comes close to matching 24m pixels, and only a few that can match (almost) 12million. Which is the point of this entire thread.

Stop coming back to f/16 as an issue.

Why? That was the point. I sauid lenses, even really good primes, struggle to achieve that resolution at their best aperture. Your sensor is wasted on your f16 shot. You only gain bigger files and a bigger 100 percent image on screen. The detail provided by the lens does not match this as all the manufacturers own figures clearly show.

I've told you 3 times now that I shot closed down for a lighting reason.
I was not attempting to get max sharpness. I also showed you 4 lenses
(and there are many more) that achieve peak sharpness in the f/11 f/16
range. So just let the whole f/16 issue GO...


It is no longer being discussed as I explained earlier

You mean you no longer want to discuss it!!!

Asked and answered several times. I'd rather get to YOUR claims of
sharpness at the best aperture for a lens whatever it is for that lens.


(and I also referred to those lenses that do peak
at f/11 to f/16 ... and some that peak at f/11 but certainly have not rolled off into the gutter at f/16.

If a lens is so bad that it takes f11 to clean it up its highly unlikely to be very sharp in the first place, and only the very best primes can aproach this kind of resolution needed. And all lenses suffer the effects of diffusion equally. All suffer the same give or take at the same apertures.

Show me your lenses manufacturers resolution chart? Most likely by 16 it will be crap!

Just head over to the library. (and I hardly think Voightlander produces crap).

2. The reason I shot my first samples at a high f number were explained [eg: those were the lighting conditions]. And they had nothing to do with achieving max resolution.

Change of plan/discussion?

Yes and no. Yes in the sense of "walking the walk".

What does this actually mean?
Two photos taken in different conditions proves nothing...

I've proposed a protocol that eliminates pretty much all variance that
could explain a dfference between tests in two locations:

-Same lighting.
-Scaled to FL distance.
-Same target.
-Raw files.

At worst the conclusion will be no advantage to 24 Mpix or that the
results are equivocal. I'm betting that the results with my lens and
sensor will be demonstrably sharper than a 12 Mpix sensor.

The time you spend wasting in rebuttal could be spent proving you are right.




No in the sense that my first tests of the a900 camera had nothing to do with achieving maximum performance.

I already said that if you had to shoot at that F number to get the dof you need then so be it. But then 12 million pixels is all you need. More is pointless and wasted. You only increase noise, and file sizes with no resolution increase. This can be clearly seen on any of the lens resolution test results at your favourite dp review! I posted lots of links to these so you could see the effect of difusion at small f numbers. You keep ignoring these facts.

No. I stated earlier that many lenses peak in sharpness at f/11 to f/16.


Then by definition they are never sharp enough to aproach your 24m sensor at ANY aperture. None escape the circle of confusion, its plain maths.

And so what? I'm proposing you shoot with YOUR best lens or the best
lens you can borrow.

And I'll do the same.

What's so hard about that?




I posted the references of a few (leafing through Cd'I). There
are of course many more. You posted that some peak wider open. I don't disagree. But you have to accept that some lenses peak at smaller apertures whether that fits your preconceived notions or not.


Yes but you missed the point again. All lenses suffer at small apertures. The fact that they "peak" here generally just means they are not good enough opened up! Thats not a good thing!

And so what? I'm proposing you shoot with YOUR best lens or the best
lens you can borrow.

And I'll do the same.

What's so hard about that?

Pick an aperture for your lens as you see fit. Make a similar or whatever composition of objects that have some fine detail in them with contrast. Shoot under incandescent lights with a tripod and MLU.


A change in the type of lighting, or subject matter means a perception of sharpness or detail or resolution is simply subjective rather than objective and therefor completely pointless. The fact that you cannot see that bothers me more than this whgole discussion!

Oh please. You saw below: I said "similar conditions". By that I meant I would shoot tungsten as well. Regarding subject, see the bottom of this post before you reply.


Sorry but unless its the same or as close to the same lens as poss, and in CONTROLLED conditions with an identical setup, lighting and subject its just subjective. Even the fact that your eyes may decieve you due to differences in noise, micro contrast etc means the test would be meaningless at these levels.
Thats why they make test charts... And we already know that with the best prime lens under lab conditions with the lens set to its best possible aperture its resolution exeeds the 12m pixel cameras. Unfortunately at any other situation, ie with a zoom, or f16 in your case its does not. So in all real world useage it only vhas disadvantages. In DPs conclusion it says "class leading resolution - if your lenses are good enough" and mostly they are not. An none are at f16...

For this challenge I did not say I would shoot at f/16.

Your arguments above are specious. With:

- same lighting sources
- same target
- scaled for lens FL
- tripod, MLU and release cable

the conditions are more than controlled _enough_ to see a difference in
image quality due to the sensor and lens at best resolution.

To do this kind of test in a meaningful way - like your dp review resolution test chart - requires controlled conditions and proper test charts. Two photos taken in different places at different ev values with different lighting of different subjects is absolutely meaningless.

Target? See the bottom of this post for a proposed target that we each easily have access to.

A difference of a few EV is absolutely meaningless for this test.

No its not.
Since the results will be mostly technique and lens linited rather than sensor limited and in the absense of a proper chart then the results will be subjective and mostly not related to sensor megapixel level. We will be looking ar=t lense ability and technique, lighting, subject differences. Pointless.

You are wrong. The experiment as proposed is controlled well enough to
see a difference between a 24 Mpix and 12 Mpix camera.

The proposed target has fine enough detail where enough distance from
target is provided.

We're
not testing color, merely contrast. We'll end up within a couple EV of each other in any case and that will have no bearing.

So, dig in, be a man and walk the walk you talk.


I dont think you quite get it...

Oh I get it. You're too afraid to even try. C'mon be a sport in the best British tradition.

What's the worst that can happen?


See above its completely pointless and can prove nothing other than who has thed best technique and the best lens since in real world use the sensor is better than both...

So now you think I have superior technique. C'mon, you must be MUCH
better than I am.

And again, in real world use, the output is worse than the worst of
sensor and lens (eg: run some numbers through the Kodak equation.)

Plus I have only power saving bulbs, never heard of your papoer and

Do you mean Compact Fluorescent? Me too. And I'm willing to use those
in lieu of tungsten.

You live in England and have never heard of The Economist?

You sound much too well educated for that!! This is one of the most
widely circulated business magazines in the world with a weekly
circulation of about 1.3 M.

Well, it does not matter, any quality newsstand near your home (pretty
much anywhere in the world) will certainly have it.

(And reading it will no doubt be a bonus as well.)

cannot be bothered to go out in search for a subjectuive test. Even the papers (should I find one) vary in print quality from page to page never mind from area to area! Sorry but subjective tests with so many variablews is pointless.

Print quality is much finer than the 40% resolution difference.

You have only proven to me that you've realized under controlled
conditions that a test like this will show the difference and now you're
inventing reasons to avoid trying to prove what you claim.

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