Re: Nikon and Megapixels

"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.


Cornered (not to mention wrong about several things such as the lenses I showed to be sharper at higher f-numbers and the output resolution equation from Kodak) you can't put up, can you?

You cornered or me? I dont understand.
I (or you) have no idea what or how that formula works.

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.

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.



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!!!


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...

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.

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...


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.


It is no longer being discussed as I explained earlier

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

(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!


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...


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.


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!


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...


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.

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...

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



PROPOSED RULES
--------------

See above and try to understand it.

.

Relevant Pages

  • Re: Nikon and Megapixels
    ... 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. ... In effect, what the formula says is that no matter how good the lens, ... But when the lens performance lags so far behind the sensor already as most zooms, all lenses at f16 etc do then theres not much if any actual image improvement by improving the sensor further! ... You CANNOT increase thew resolution from a lens by having a bigger pixel count. ...
    (alt.photography)
  • Re: 18-200 Lens
    ... Being shown an image with consistent 1-pixel resolution over the whole ... That's because there is no DSLR and its lens in the ... all at the 1 pixel level, and at the two pixel level what resolution it ... Not so in the lens and P&S camera that I used and use. ...
    (rec.photo.digital)
  • Re: Noise levels as a function of pixel size
    ... with a larger sensor produces the same result as one taken with a smaller sensor. ... >resolution limit has nothing to do with f-number of the fully open>lens. ... It is NOT, however, an acceptable baseline for the extrapolations that you have made and which have resulted in a pixel size which no physical lens could ever resolve. ...
    (rec.photo.digital)
  • Re: Nikon and Megapixels
    ... 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. ... In effect, what the formula says is that no matter how good the lens, ... You CANNOT increase thew resolution from a lens by having a bigger pixel count. ... As for lenses, 5 of my 7 are up to the sensor in the camera. ...
    (alt.photography)
  • Re: Matching Pixel Size and Telephoto
    ... with pixel scale that is at least 1/2 of it. ... We have variable apertures, and we tend to buy cameras with the pixel pitch that the manufacturers happen to churn out. ... I never heard of anyone checking available lens resolution figures before buying more megapixels in the latest camera body - but you do hear the occasional whine that existing lenses can't match sensor resolution, which is probably true in some cases. ...
    (rec.photo.digital)