It is spelled Houston. No "e." Thanks for the post!
Sorry, I just cut and pasted the title from the website - its not my own. ;D
Ah corners... I vaguely remember those being troublesome before the stitching days...
Ah corners... I vaguely remember those being troublesome before the stitching days... Wasn't there also something called light fall off?Right on! But only if you didn't use the center filter.
I did a little testing on my Leica R's the other day and from f5.6 to f8.0 is the sweet spot no difference between the 2, softer above f8 and below 5.6 so for sharp corners I'll be using f8 same is true for the IQ180/Rodenstocks lenses get better at f8, sensor is better at f5.6
Marc
How is this a problem?
However if you like me want to make large high resolution prints I cannot just look at the sensor megapixel and go from that, resolution is now so high that it is more relevant to look into how lenses for the system performs. My conclusion was that for my application a 36 megapixel Nikon camera with Nikon lenses does not produce as high resolution pictures as 33 megapixels on a Tech camera with Schneider or Rodenstock lenses.That makes sense if one is comparing also to MF options, not just to other 35mm format options. What I would like to see is something like resolution measurements (maybe by the standard of 50% MTF) for center and corner performance of various lens-body combinations --- and this will become easier as the sensor resolution gets so high that the measurements are primarily about lens performance.
That makes sense if one is comparing also to MF options, not just to other 35mm format options. What I would like to see is something like resolution measurements (maybe by the standard of 50% MTF) for center and corner performance of various lens-body combinations --- and this will become easier as the sensor resolution gets so high that the measurements are primarily about lens performance.
Great.. so we have to stitch because the lenses aren't up to the task in the corners.... makes sense... ???
I appreciate the benefit of stitching (I truly do) - but some of us (myself included) don't want to have to stitch. I'm old school - I like to try and capture my images in a single frame.
I guess you want to discuss this solenmly again, don't you? ;D
Following your comments about an - imaginary - lack of weather seals and worst camera body... today's D800 issue is the wide angle lenses?
Perhaps you can start by clarifying at what f stop these Australian 24mm "tests" were performed?
Cheers,
Bernard
No need to take that tone - totally unnecessary.
I already stated that the website is not my own - so I have no further information to add to their own report (you would have to email them and ask them yourself).
Guess you missed my comment about not shooting the messenger :P Seems anytime anyone posts anything that might possibly be considered a swipe at the D800 it draws you out guns blazing.... take a chill pill. Its just gear dude - it aint' oxygen!
Hint: we could have the same conversation about whatever other camera you decide to trash talk.
Cheers,
Bernard
That makes sense if one is comparing also to MF options, not just to other 35mm format options. What I would like to see is something like resolution measurements (maybe by the standard of 50% MTF) for center and corner performance of various lens-body combinations --- and this will become easier as the sensor resolution gets so high that the measurements are primarily about lens performance.
However if one is wiling to deal with the cost and complications of "a Tech camera with Schneider or Rodenstock lenses", the D800E should be evaluated with the best available lenses. So I look forward to that site's testing with the Zeiss 21mm and Nikon 24/1.4G.
Hint: we could have the same conversation about whatever other camera you decide to trash talk.
Cheers,
Bernard
Its just the body that sucks (IMO) and the weather sealing which is laughable.
And BTW: I have never trash talked a camera - so don't try and drag down my comments.
Just re-read the 2 sentences above...I agree.......but it is best to stop.....
But yes, I'll stop here.
Cheers,
Bernard
No ones trash talking anything - I have already said the sensor in the D800 is amazing. Its just the body that sucks (IMO) and the weather sealing which is laughable. As to the original link - the evidence speaks for itself - more to the issue of Nikons lens line up than anything else.So I take it you have taken the D800 apart or taken in out in a hard rain and had it fail? If you haven't then yes you are trash talking a camera.
And BTW: I have never trash talked a camera - so don't try and drag down my comments.
So I take it you have taken the D800 apart or taken in out in a hard rain and had it fail? If you haven't then yes you are trash talking a camera.
And the blog article you originally linked to? They spelled "Houston" correctly.
Yes, he dunked it momentarily when he slipped in a river; but it filled with water in that moment.Perhaps this is a viable solution (http://nikonrumors.com/2012/05/31/using-the-nikon-d800-with-cambo-x2-pro-and-medium-format-lenses.aspx/)
What are we discussing here people? That lenses generally tend to have worse corners than center? I guess that would be the news for those living under a rock, or waking up from a hundred-year coma.
What are we discussing here people? That lenses generally tend to have worse corners than center? I guess that would be the news for those living under a rock, or waking up from a hundred-year coma.
Would a 645 lens on A D800 show better edge to edge performance with the 35mm sensor being within the sweet spot?It would have to be of the same focal length, 24mm, for the comparison to be relevant.
Here comes my story why I'm so curious about the pixel peep performance of the D800.
In the past it was quite well-defined what a camera could do. Each genre had its camera. 35mm for photojournalism, 6x7 for portraits, 4x5" for still life and landscape. This is no longer true, the D800 may be the first camera that truly extends of the the whole range from 35mm to 4x5". It is fast, it can do short DOF it can do high resolution.
A few months ago I started to think if I should change system. I had a Canon system. Landscape photography my main interest and also an interest in large and/or high-resolution prints. To support my prints I'd ideally like to have something like 60 sharp megapixels. I did stitching at the time but I prefer one-shot images. My mentality is such that I always want to shoot with the best gear I have, so when I happen to shoot an image with artistic quality enough for putting on the wall the technical quality should allow large prints.
D800 was on the way, but not released yet. I did a simple experiment with my TS-E 24mm II and an APS-C 7D, shifted to the full-frame corner and tested how sharp it was, that would correspond to 45 megapixels. It was then clear to me that one of the sharpest 24mm lenses on the 35mm system would not deliver even 40 sharp megapixels. Wide angles are known to be hard to make sharp corners with though.
Another aspect I had discovered is that tilt and shift had become almost an necessesity for my shooting style. With increased resolution the tilt function becomes even more important. Also my shooting style is very slow so I did not really make much use of the quickness of the DSLR format. And where's the 35mm wide tilt-shift lens, my most important field of view? The best performing solution today seems to be a TS-E 24mm 2 with 1.4 III tele converter, or use APS-C. A DSLR more and more seemed like a compromise, although a very affordable one.
I started to look at 4x5" film and scanning solutions. The long turn-around times with film was a problem though for me as an amateur with limited shooting time, I really gain from immediate feedback of digital in my artistic development process. I looked at scanning backs for 4x5" but those were a bit too limited even for me. So for fun I started to look at MF digital and tech cameras. Since MF guys like to say "it is so much better than 35mm digital" all the time it was a bit tricky to find out its limitations. Also MF digital tech cameras have problems with wide angles, all formats have. But to a lesser extent. This format seemed to support my desire for those ~60 megapixels in the long term, and of course you get tilt/shift for all available focal lengths, the shifts are often a little smaller than possible on DSLR shift lenses though (which is not too big a problem since tasteful pictures cannot swallow large shifts anyway).
As we all know, MF digital pricing is crazy though. Oh well, Schneider "large format digital" lenses are actually quite affordable, and the tech camera bodies no worse than a pro DSLR body, but the digital backs... ouch! For an amateur there is the option to buy second hand though, then an older 33 megapixel back can be had for 1.5x the price of a D800, and the whole mint second hand system ends up 2x the price of corresponding new D800 system with tilt-shift lenses (3x if you compare to second hand D800). If new digital backs costed say $5000 instead of $20,000 I think many more amateurs would choose the tech camera path ahead of a DSLR.
I ended up chosing a second hand MF tech camera system rather than buying a new D800 system. Still kept large parts of my Canon system though which I use for more action-like photography.
But now when the D800 is out I am still indeed curious about how all the available lenses performs with it. If the DSLR systems get too good I may very well switch back. I'm already a bit in love with the 100% mechanical tech cameras though, it will be hard to part from it.
I foresee an evolution in mirrorless cameras, like a pro style NEX camera with FF sensor, such a camera would take essentially any lens, Leica R, Leica M, MF and LF. Lens cast would still be an issue. I would expect something like that show up at Photokina. It's just common sense...
That'd be cool! Let's hope that Sony keeps pushing the enveloppe.
It will also be interesting to see how Canon decides to enter the mirrorless market.
Cheers,
Bernard
"The power has shifted from the manufacturer to the photographer."
Do not kid yourself, the people with the power are those at the top of the wealth ladder. At the moment there is some trickle down from the top cameras to the lower tier cameras. The high end DSLR/MF(or other high end camera) market will change. Canon and Nikon will realize as the wealth differential continues to change in the industrialized world, the wealthy will pay exorbitant amounts of money to have the top of the line gear. This gear must be marketed as significantly better than what the general population can buy.
This is already manifesting itself in the high end home audio industry. Just last year 20k+ for speakers was considered expensive. Now some manufacturers have 3 different models of speakers above $100,000.00. At a show here in socal one of the demo rooms is proudly displaying the price of a pair of speakers, preamp, cables cd player and amplifier for a grand total of $275,000.00. Dealers are locating there stores near where the mass of the super wealthy live.
Why try and sell many $5,000.00 speakers, where one has to work to convince people it is worth the money to upgrade from their HTIB. Much easier to sell $50,000.00 speakers and associated crap to the uninformed who need it to validate their own existence and ego.
Sure there are "vanity" products around which some people will pay silly money for but is that a bad thing? It is all economic activity and whilst a little trivial it is still better than working 6 days a week, 12 hours a day down a coal mine. Each camera that is sold at whatever price pays wages and taxes and creates employment and the higher the price the more added value goes into creating employment and tax. I would much rather that rich individuals recycled their wealth in this way than put it in an off shore bank account and sat on it. $100,000 MF camera - bring it on. Some rich fool will buy it. LOL
Some rich fool will buy it. LOL
You mean the idiot who has managed to make more money than you and can actually afford to drop a ton of money on something that would give him or her pleasure?
Of course, the message here is for those who are concerned that the 36.3mp of the D800 are of little use unless one has superb lenses. Lenses are certainly not sharpest at F11, however good they may be, and are certainly worst in the extreme corners, however good they may be.
The D800E delivers better resolution even in the extreme corner which is representative of a very poor lens.
To get the topic back on track, below are some comparisons between my D800E and D700. The shots were hand-held, using the 14-24/2.8 zoom on each camera at 14mm, the focal length at which the lens is sharpest.
I used F11 because this seems an appropriate aperture if one wants everything reasonably sharp from foreground to infinity, and especially if one wants maximum corner sharpness. It also reduces concerns about misfocussing.
Both images have been processed similarly, and the same amount of sharpening applied in ACR, which was: Amount 50, Radius 1 pixel, and Detail 100. No noise reduction or masking was applied.
As regards corner resolution, bottom left corner, the hand-held procedure has resulted in the D700 having a slight advantage because the FoV was just a bit more towards the left and a little bit lower, so the corner detail in the D700 shot, in the comparison, is just a little bit further away from the extreme corner. I always like to give a slight advantage to the underdog.
The day was dull and cloudy, but almost totally calm, so any resolution differences cannot be attributed to subject movement.
However, I should mention a disclaimer. Two of the three pieces of equipment used in this test, the 14-24 lens and the D700 body have been completely submerged in water for at least two seconds, when I recently stumbled whilst crossing a river, waist deep. There's no doubt that water entered the camera, because the LCD screens later misted up with condensation from the inside. I had to dry out the camera body in the sun, all day long, with lens and body cap removed. The camera is still not completely functional but is useable. The lens seems unharmed.
Of course, the message here is for those who are concerned that the 36.3mp of the D800 are of little use unless one has superb lenses. Lenses are certainly not sharpest at F11, however good they may be, and are certainly worst in the extreme corners, however good they may be.
The D800E delivers better resolution even in the extreme corner which is representative of a very poor lens.
Ray,
I miss out on a couple of issues:
1) Images both scaled to D800 resolution?
No, only the D700 was scaled to D800 resolution. ;D
Erik means both samples were scaled to D800 resolution on the D700 shots, which is what the title bars say. I'm sure you know it will degrade the image.
Wondering if lensezone.de will use a D800E to test new lenses. Aliasing can be used as a measure of lense sharpness if the input signal is known beforehand.
The false color artifacting is also very much Raw converter dependent. I don't think it would be useful to also add Rawconverter effects in the mix when one really only wants to test the lens. The sensel pitch is already a variable in lens testing, so IMHO they might want to settle for the D800 instead.
The false color artifacting is also very much Raw converter dependent. I don't think it would be useful to also add Rawconverter effects in the mix when one really only wants to test the lens. The sensel pitch is already a variable in lens testing, so IMHO they might want to settle for the D800 instead.If the test input is monochrome (black lines on white bacground), there is no color (information) to record. If need be, this can be baked into a dedicated "demosaic" algorithm. I.e. input and output could be monochrome. One would need some kind of "white-balance" that normalized color-channel signal level. Hopefully this would be a global parameter.
Cheers,
Bart
Yes, I know. Just having a bit of fun. Hope Erik forgives me. ;D
The following image is a comparison of the bottom left corners showing the D800E downsampled to the D700 size. I've also shown the full corners, edge to edge, which demonstrates the slight advantage I've given to the D700.
Downsampling a higher resolution image throws away image information. Upsampling a lower resolution image retains all the initial data. I think upsampling is the more truthful comparison.
If the test input is monochrome (black lines on white bacground), there is no color (information) to record.
If the test input is monochrome (black lines on white bacground), there is no color (information) to record. If need be, this can be baked into a dedicated "demosaic" algorithm. I.e. input and output could be monochrome. One would need some kind of "white-balance" that normalized color-channel signal level. Hopefully this would be a global parameter.
I am suggesting this only as a means to investigate current lenses performance close to the limit of todays sensor resolution.
-h
Hi,
No issue ;-)
What I have seen is downsampling maintains edge contrast but looses resolution and may introduce fake detail.
Best regards
Erik
Unfortunately, that is not how a Bayer CFA decoding sees things. The most robust decoding is done by properly pre-filtering the image before sampling. And given that the average OLPF is not strong enough to avoid all aliasing, there will usually already some false color artifacting. There is no need to add even more artifacts, because the sampling density (which is identical between the D800 / D800E) will result in virtually identical resolution.A bayer CFA decoding written by me or you can "see" things however it like - the only fundamental limitation is what information it receives, and our skill. Both can be very real limitations. Imagine for a second that there was no CFA, just a regular sampling device (like an A/D converter). The regular setup is that you have a (non-realizable) brickwall lowpass-filter in front that removes everything >= fs/2, and Harry Nyquist and Claude Shannon takes care of the rest: the (bandlimited) waveform can be perfectly recreated.
Also, the effects of varying amounts of defocus between the different lens tests is probably larger than the difference between these two cameras. It requires very accurate and systematic testing to avoid focus errors, and a huge amount of images to find the best.I agree that this can be a problem, but it would be a problem with a hypothetical future 54MP D900(E) as well? Anyone that contemplate buying expensive lenses expecting to use it with several generations of DSLR houses might want to know such things.
We have already proven complete systems are able to produce images very close to nyquist. There is no point in yet another test.Are there reliable numerical measurements of MTF at 0.9x Nyquist or 0.99x Nyquist for 36MP 24x36mm sensors for the lenses out there?
I agree that this can be a problem, but it would be a problem with a hypothetical future 54MP D900(E) as well? Anyone that contemplate buying expensive lenses expecting to use it with several generations of DSLR houses might want to know such things.
Are there reliable numerical measurements of MTF at 0.9x Nyquist or 0.99x Nyquist for 36MP 24x36mm sensors for the lenses out there?
IMHO the lack of an AA-filter will only complicate the interpretation of limiting resolution results, because the inevitable aliasing will in real life no longer be separable from real detail and noise. It adds aliasing to the lens evaluation data, and it doesn't add meaningful resolution (which is determined by the sensel pitch).As I was trying to say, "aliased" data _can_ be as meaningful information as "non-aliased" data, but in many practical cases it is not. I think that you may be confusing your practical experience ("aliasing does not give me any more true image detail") with theory ("aliasing does not contain information"). It all depends on knowledge about the process that generated this data.
When doing multi-image super-resolution, one depends on minute spatial shifts and aliasing to reveal finer details than the sensor could reveal directly. In other words, aliasing together with knowledge of the capture process results in a better reconstruction.
I think that is a misunderstanding of how super-resolution works. It's not the aliasing that helps (on the contrary). Super resolution is useful when the image detail itself is lacking (low-pass limited), and the procedure depends on multiple slightly different alignments of image detail with the sampling grid. Aliasing never helps in reconstructing detail, it only obscures real detail at various lower spatial frequencies.This is what the contact person of photoacute software told me:
Cheers,
Bart
Removal of AA-filter should drastically improve the gain of our software. But, a special profile will be required for processing images taken with a camera with removed filter.
Does your Canon 7D already have AA-filter removed?
In the most common SR algorithms, the information that was gained in the SR image was embedded in the LR images in the form of aliasing. This requires that the capturing sensor in the system is weak enough that aliasing is actually happening. A diffraction-limited system contains no aliasing, nor does a system where the total system Modulation Transfer Function is filtering out high-frequency content.
Ray,
Perhaps color artifacts from cone cell stimulation in your eyes by sharp, high-contrast, high MTF stimulus.
What you are describing cannot be improved using super-resolution AFAIK, at least not established, generic algorithms. When you apply proper lowpass filtering in front, the signal is allready bandlimited. Shifting the sensor by a tiny amount does not record any new information, and therefore it is hard to see a significant gain from combining multiple images (besides SNR improvements).
Or perhaps more likely, some of you guys have never photographed standard test charts. ;D
... The aliasing artifacts themselves are not going to help and boost the resolution, also because aliasing is by definition larger than Nyquist.(http://upload.wikimedia.org/wikipedia/commons/thumb/2/28/AliasingSines.svg/675px-AliasingSines.svg.png)
Well that wouldn't be me then ;) . The color moiré that you see is the product of the regular sensel grid and the laser engraved pattern of the focus screen. Apparently they are both repetitive, but at different spatial frequencies, hence the moiré. You'l see similar effects between the sensel grid and the LCD on the camera, but they are all depending on a certain level of detail magnification, so it's hard to predict how it's going to look, or even if it shows.
However, such color moire and circular artifacts around straight B&W lines on a test chart are also apparent through an optical viewfinder when, presumably, the sensel grid is not involved.
If the (potentially filtered) signal that enters the point-sampler is allowed to take the shape of both sinuses, we cannot from the samples decide which it actually was, and therefore we cannot faithfully recreate the waveform.
If we filter the signal, or can make assumptions about the signal such that one of those sinuses are allowed, but the other is not, then we could recreate the waveform from the samples. A given set of samples generally corresponds to an infinite set of possible waveforms, but pre-filtering reduce that set to (ideally) exactly one waveform.
Yet another way to paraphrase: some frequencies wrapping over into other frequency bands does no harm if there are no other signals in that band to interfer with, and if we know which frequencies wrapped where.
It seems to me that you don't get the theoretical point that I am making, and I think that our discussions would be more fruitful if we are able to agree on those.
Yes, but we cannot recreate the higher frequency signal from the lower frequency one, because it might well be the correct waveform (or an alias from a number of possible higher frequencies).If the test chart is guaranteed to not contain the low frequency one, then we can be pretty certain that such a frequency did not enter the camera sensor, dont you think?
I have both cameras and I must say that the D800E is in a class of its own in comparison with the D800. I am getting edge effects between dark and bright areas on the D800 files. It shows like an extra contour of 2 pixels around rocks contrasting against a bright sky behind it. It is very significant and disturbing.
If the test chart is guaranteed to not contain the low frequency one, then we can be pretty certain that such a frequency did not enter the camera sensor, dont you think?
That's correct, a high pass filtered target projection, or one only containing frequencies above Nyquist, will produce only aliasing artifacts or a grey image.Which brings me back to the starting-point for our discussion:
Cheers,
Bart
Wondering if lensezone.de will use a D800E to test new lenses. Aliasing can be used as a measure of lense sharpness if the input signal is known beforehand.If the test-chart contains energy from fs/2 to fs, and the sensors response to such signals is known, then any attenuation should be due to lense-flaws. (assuming perfect focus, no camera movement etc)
-h