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Author Topic: Is This The End Game?  (Read 19990 times)

Ray

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« Reply #40 on: August 19, 2005, 01:08:37 am »

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As long as dynamic range is not objectionably compromised by doing so
As I understand it, the problem is 'read out' noise. Each value of each pixel has to be 'read'. That process introduces some inevitable degree of noise. The 'read out' noise is not proportional to pixel size. The read out noise of a 1 micron photosite is essentailly the same as the read out noise of a 10 micron photosite. Right?
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Gary Ferguson

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« Reply #41 on: July 16, 2005, 12:38:12 pm »

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Can I get $50,000 for my left kidney?

If it's a "50 Jahr" limited edition kidney then why not!
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Ray

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« Reply #42 on: July 17, 2005, 12:21:13 pm »

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“At 50 lp/mm, close to the resolution limit of the 1Ds”
Where do you find this information?
It's difficult to find precise information on such matters, so one has to extrapolate from other more readily available information. Dpreview has some very thorough analyses, but they are based on jpeg images. Norman Koren has a very detailed analysis of his Canon 10D which puts the resolution limit at 54 lp/mm. The 10D sensor is denser than the 1Ds sensor, as well as having lower noise per pixel, so one can be sure the 1Ds is going to have a lower limit than that by a significant margin.

I believe the resolution limit of the 1Ds is around 45 lp/mm, but I'm not certain.
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BernardLanguillier

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« Reply #43 on: July 17, 2005, 11:01:06 pm »

Let's assume for a second that Hansel Adams is someone whose work can be trusted.

My view of his work is that he devoted 90% of his energy to the control of the exposure, what we would call today DR (I know I am over-simplifying, but you get the idea).

That is IMHO the area of digital imaging where progress could actually result in images that most people would perceive as better.

Very few images are printed at sizes larger than those at which a 1Ds2, D2X or digital backs already excell (without even mentioning the possibility to stitch).

Those 1% of the images will benefit from higher resolutions, while the 99% remaining would only benefit from more DR and better transitions to blown highlights.

This is why I see the sensor of the Fuji S3 as one of the most interesting development of the recent years. It doesn't take much to anticipate the delivery of a high res digital back from Fujifilm based on this technology, although this is pure speculation at this point of time. The high ISO performance of the F10 that I bought about a month ago makes me think that they could push the enveloppe real far this time...

Regards,
Bernard

Jonathan Wienke

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« Reply #44 on: July 18, 2005, 05:06:11 pm »

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To my eyes the image is FULL of interpolation artifacts and
gross oversharpening.  It tend to hide the low contrast
details in hairs and foliage, and make them jump out
suddenly when the local contrast passes a threashold.
And where in the image are you referring to? The only artifact I see is just a bit of a halo between the hand and the background which doesn't really show up when printing. Everything else is pretty faithful to the original scene/subject.
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Mark D Segal

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« Reply #45 on: July 18, 2005, 10:36:55 pm »

Ray, your contribution has just synthesized in my mind the pointless character of alot of the discussion in this thread - I too looked at Jonathan's image and quite frankly it tells me nothing about any technological end game - which by the way I think is also a pointless concept. It has been proven time and again that there is no such thing in so many scientific/technical fields, I am surprised we are even discussing it here. Continuous advances in materials technology and other scientific research always ends-up standing today's perceived limitations and technology forecasts on their heads. And there is no reason to expect it to be different in the field of digital imaging any time soon.

All Jonathan's image tells me is that one has enormous post-capture latitude with image processing to make them look as "film-like" or "digital-like" as one wants - I put those expressions in quotations because as I use them I find they are also nonsensical. My contribution further back about the tired subject of film versus digital was precisely to make this point - with enough skill and effort and beyond a certain threshold of technical quality in the hardware and software with post-capture processing we can just about make anything out of anything to taste and it will be hard for all but the best honed, most experienced eyes to tell what it started from - within say an A3 size constraint for non-MF work.

Yes, sensor type X will be better and worse than sensor type Y in different respects simultaneously - but given the limitations of what our printers can replicate, I would think it useful to see this discussion focus on real world differences in printed results eminating from all these learned observations about the laws of physics and MTF charts. That might constrain the meaningful content of the discussion quite a bit!
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Mark D Segal (formerly MarkDS)
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Ray

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« Reply #46 on: July 18, 2005, 09:08:40 pm »

I see what leping is talking about. The image has a slightly brittle, overly bright and contrasty appearance as opposed to the more mellow and natural, smooth gradations one would expect with MF film. The image 'jumps out' at you in a startling fashion. Nevertheless it's very appealing.

In any case, if Jonathan has deliberately manipulated the image in this way in an attempt to highlight 'pixel' definition, then that's to be expected, and as always, one would expect the final result on the print to be slightly different because print is a refective medium and one's monitor is transmissive.
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Jonathan Wienke

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« Reply #47 on: July 19, 2005, 11:46:21 am »

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Pure information theory dictates the fact that a Foveon sensor with 3 million pixels has 9 million photosites, which is 3 times more than a 3 million pixel sensor using bayer interpolation. It will therefore deliver 3 times more information.

I am fully aware that the resolution will not be 3 times higher, since resolution is very much influenced by the tone which is captured in each an every of the 3 million pixels of the Bayer sensor, just like it is by the Foveon sensor. But I didn't write "resolution", I wrote "information", which is the same as "data" in my mind.
That's where the quibbling starts to crop up; information and data are not quite the same thing. Data can contain information, but if there is less information than data, tha data can be compressed down to approximately the size of the actual information it contains. For example, Canon 1Ds RAW files pack about 11MB of information into about 16.5MB of data, which means that lossless compression can reduce the data size to the match the amount of actual information, approximately 11MB. Similarly, a 1000x1000 pixel TIFF image that is pure white (RGB 255,255,255) can be compressed very small because the only real information it contains is "make a 1000x1000 pixel white square" even though the uncompressed file contains 3 million bytes (assuming 8-bit) of image data. On the other hand, a 1000x1000 pixel landscape image with lots of foliage and wispy clouds and a stone wall contains much more real information even though the amount of data is identical, and therefore it cannot be losslessly compressed nearly as much as the white square.
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Jonathan Wienke

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« Reply #48 on: July 19, 2005, 11:49:03 pm »

How about a practical one?

Here's the 100% crop of the portrait I posted recently, but straight from the RAW converter, no USM or anything else:



At this point the image is rather soft and mushy-looking, and lacks contrast and "snap". After applying several rounds of USM at varying radius and amount settings to sharpen and add local contrast, it looks a lot crisper, but still has a certain "softness" to the edges due to the AA filter:



At this point the image is in the condition in which most people make the "3MP Foveon = 6MP Bayer" comparison, rightly pointing out that the Foveon image has better edge "crispness" and more easily distinguished single-pixel detail than the Bayer image. But as the next image shows, this conclusion is a bit premature.



A pass with Focus Magic deconvolutes the AA filter blur, and now the pixel-level clarity of the Bayer sensor image is much closer to that of the Foveon. The Foveon sensor still enjoys  some advantages, such as being relatively immune from moire and some color interpolation artifacts (especially in highly saturated colors) meaning it can still deliver slightly more accurate colors in fine details, but it's no longer a night and day difference, and I'd be willing to bet that most pixel peepers wouldn't be able to guess the source sensor type much better than 50% in a blind comparison test.
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Jonathan Wienke

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« Reply #49 on: July 20, 2005, 12:17:33 pm »

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Regarding Foveon, where did you get these 120 to 200% values from if I may ask? Aren't those figures experimental data that were impacted by the noise resulting of the Foveon implementation of the multi-layer sensor idea? I still don't see any theoretical justification for those.
I'm basing that on my comparisons of 100% crops of SD9 and SD10 images to 100% crops from my 1Ds and 1D-MkII. I'm only putting those figures out as a rough estimate, not as something scientifically precise. I'm not sure that anyone has devised a way to objectively measure image quality that goes beyond simple S/N  and resolution measurements, and takes into account color accuracy, the visual acceptability of whatever image artifacts may be present, and other such issues. Given that, there is currently no way to precisely quantify the image quality differences betwen Bayer and Foveon.

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Your example would probably be closer to the reality if water and oil were mixed to create a suspension. Removing a fixed amount of liquid on the top would affect less oil than if no water had been added, but it will still affect some.

No, my analogy is accurate as-is. When you manipulate an image, the rounding errors and entropic losses are introduced in the least significant bits, and gradually work their way into the more significant bits as one performs more edits to the image data. The whole point of 16-bit editing is to keep the rounding errors and other entropic reductions in the bits that are made-up anyway, so losing some of them does not compromise the actual information.

Another way of looking at it: if you edit a 16-bit image to the point that only every eighth level is populated, you have invalidated or lost the least significant 3 bits of image data (2^3 = 8). If you continue editing until only every 32nd level is populated, you have now invalidated or lost the least significant 5 bits (2^5 = 32). Since the true image information is contained in the most significant bits of the image data, you have to lose/invalidate approximately 7 bits worth of image data (toothcombing the histogram so that only every 128th level is populated) before you start corrupting or losing any of the real image information. That's pretty tough to do; a sensible workflow (convert RAW, adjust levels/curves, moderate color tweaks, and sharpen) is only going to introduce 1-3 bits of entropy losses (maximum toothcombing of the histogram to every eighth level or so), which still leaves you at least 3-4 bits worth of buffer between the real image information and the entropic garbage.

Digital audio editing works the same way; it is common to record with either a 16 or 24-bit DAC, pad the data with zeroes to make it 32-bit, edit, and then downsample to 16 bits for the final output. If done correctly, the error of greatest magnitude in the final output data will arise from rounding to the nearest 16-bit value. All of the entropic losses and rounding errors introduced during editing are buried in the least significant 4-8 bits of the data bits that are thrown away anyway. The rounding error inherent to downsampling to 16-bit audio is far greater in magnitude, but is still acceptable because the 16-bit audio format is good enough, and is still the best it can possibly be.
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Mark D Segal

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« Reply #50 on: July 19, 2005, 10:02:29 am »

Bernard,

Unlike some contributors to this website who are either real or self-imagined experts on the INPUT side of these issues, I am neither, but I do trust my vision and my common sense, so I tend to focus on RESULTS. Looked at from that perspective, whatever the mathematical merits of the Foveon sensor, any test results I have seen really don't give it any "gotta have it" advantages over the more traditional CMOS sensors now being used by Canon and Nikon in their professional cameras. The theoretical basis of this technology sounds promising - getting three for one because of the layering, but its operational superiority remains to be demonstrated.
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Mark D Segal (formerly MarkDS)
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etmpasadena

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« Reply #51 on: July 21, 2005, 11:44:15 am »

Jcarlin sums it up nicely.

Now for Mark, if you want to see how the demosaic process can affect image quality and resolution simply get your hands on a Kodak SLRn/c file (preferably a landscape with lots of fine detail) and decode it in both Kodak's Photodesk and in ACR. You'll find there's quite a bit of difference based on the two different ways those programs decode the files.

Granted, my example probably only applies to the Kodak cameras. But it does show nicely how the demosaic process can effect perceived resolution.
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budjames

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« Reply #52 on: July 22, 2005, 03:30:27 am »

Perhaps the "end game" is not here yet if you consider that my Canon 1Ds Mk2 with 100-400mm IS lens and a camera bag with 24-70 L and 16-35 L lenses, a flash unit and tele extender plus misc accessories is a pain to carry around all day.

If the weight of carrying all of this fine technology and optics could be cut in half, that would be real progress!

I think the next technical challenge is making the stuff smaller and lighter without compromising speed or resolution.

My 2 cents.

Bud James
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jani

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« Reply #53 on: August 09, 2005, 05:15:17 am »

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Where will sensors top out?  They may not, at least anytime near term.  Our society's consumption of technolgy will have to say Enough!, if it's to top out.  I'd think that won't happen anytime soon.
Well, you have a good chance of being wrong on this one count.

Sensors are physically constricted by the limitations of the wavelengths of visible light. So unless you plan to capture images in the far, far ultraviolet, the ease of capturing photons reliably will be a limiting factor. The consumers can't change that.
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Jan

Jonathan Wienke

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« Reply #54 on: July 16, 2005, 12:48:27 pm »

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Can I get $50,000 for my left kidney?
For that much, I'd sell you my ex-wife!!!
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ddolde

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« Reply #55 on: July 17, 2005, 11:36:33 am »

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which states Michael's projection that the P45 would provide
scanned 8x10 film quality highly improbable.
Ditto that.  I think the P25 will NEARLY match drum scanned 4x5, ie. close enough.
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Ray

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« Reply #56 on: July 18, 2005, 12:24:36 am »

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Clark's figures are seriously inflated.  He claims you need 31 mp just to match 645.  That's hooey.

My Kodak 16mp back easily outperforms 6x6 scanned film. Not just in resolution but in dynamic range, ease of use, and general image quality.
I don't believe it's a case of inflated figures but different goals. Most people do not take photos with the object of achieving the greatest resolution. There are other more important consideration such as content, emotional impact, color accuracy, ease of use and handling of the equipment etc etc.

So your statement, Doug, can be quite valid for your purposes and Clark's statement could also be true for his purpose of comparing ultimate resolution limits.

It's a well known fact that, with a good prime lens, a sturdy tripod, flawless technique and the right type of film developed in the appropriate developer to bring out the greatest detail, it's possible to record detail up to 100 lp/mm on 35mm film.

How does this compare with the 45-55 lp/mm limit of the 1Ds?

However, having achieved such high resolution on the film, there would be the next problem of getting it scanned. The average 4000 dpi scanner just wouldn't do, even if it were a drum scanner. My guess is you'd need the best drum scanner available and the film would need to be scanned at 8000 or 10,000 dpi.

Outside of the laboratory it's difficult to imagine any need for such rigorous procedures. I suppose if I were spying on a military installation from a distant hideaway, trying to photo stationary vehicle number plates with my one tripod-mounted telephoto lens and I had a choice of a 1Ds digital body or an EOS-1V film body loaded with Kodak Technical Pan, then it would make sense to use the 1V. I'd get the film developed appropriately and extract the number plate information with a microscope. The 1Ds would be much more convenient to use, but just wouldn't have the resolving power for those distant number plates  :D .
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lepingzha

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« Reply #57 on: July 18, 2005, 02:20:55 pm »

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Look particularly at the pores on the back of her left hand, the threads in her blouse, and her eyebrows and eyelashes. This image has had my normal midtone sharpening performed on it, as well as a Focus Magic pass at radius 2, strength 75%. The Focus Magic pass does an excellent job of reversing the effects of the anti-aliasing filter and really bringing out the detail without introducing artifacts.
To my eyes the image is FULL of interpolation artifacts and
gross oversharpening.  It tend to hide the low contrast
details in hairs and foliage, and make them jump out
suddenly when the local contrast passes a threashold.

The ultimate test for resolution is large prints.  Maybe
the client's taste is changing and they just don't
see all the artifacts and oversharpening that is so
common on those raved prints from digital captures.

Leping Zha, Ph.D.
www.lepingzha.com
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BernardLanguillier

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« Reply #58 on: July 18, 2005, 05:43:57 pm »

Hi there,

Resolution in a Bayer sensor is perhaps not 3 times lower, but the information captured is without any possible doubt 3 times less.

This lack of information is probably preceived in some subtle way just, sometimes not.

Regards,
Bernard

Ray

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« Reply #59 on: July 18, 2005, 09:39:32 pm »

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Comparing results, the 1Ds will still outperform the most carefully executed film scan using slow color film that has excellent shadow detail and a Minolta Dimage 5400 PPI scanner. I know this is an old story by now, but from my personal, immediate - NOW for NOW experience - that's just how it is.
No doubt about it, but even the Minolta Dimage at 5400 dpi will not extract all the detail from the finest grained, highest MTF, sharpest B&W film, such as T-Max 100 and Technical Pan.

Recently doing a net search for comparison details on scanners, I got the impression that a Nikon 4000 dpi scanner would not capture anything beyond 60 lp/mm (but I think this figure was in relation to color film). The Minolta was slightly better. In fact I saw a figure as high as 74 lp/mm from B&W film. Not quite good enough, however, to capture the 100+ lp/mm that could be there on the film.

Unfortunately, as someone has already mentioned, we are rarely able to appreciate the full potential of film because, to get the data digitised, it needs to be photographed a second time (scanned).

There would seem to be little point to be obsessive about technique, to restrict oneself to using just a few types of high res films, to go to great expensive getting a 10,000 dpi drum scan etc etc, when one could just buy a digital camera  :D .
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