July 23, 2014, 10:46:45 PM

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Messages - jrista

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46
Canon General / Re: Dragonfly, Powered by Canon Lenses
« on: July 14, 2014, 01:02:04 PM »
Actually, surveying for nearby supernova remnants in H-alpha might be a pretty interesting project scientifically in itself for this Dragonfly.

Yes - the problem is that we'd have to get different detectors, with much lower read noise. With narrow band filters the read noise is no longer smaller than the noise from the sky background, and the setup is no longer competitive.

Any chance you guys have some forward knowledge of larger ultra-low-noise sensors coming out? Sony's newer ICX line are pretty nice, with very low dark current, and pretty low read noise (~5e-?). But the sensors are tiny. Really tiny, as in 1/3" or maybe 1/2", which is about half the size of a KAF-8300 and about 1/5th the size of a full-frame/KAF-11002 sized sensor. Would be really nice to know that Sony has some larger sensors based on their new low-noise technology coming out... ;)

We are considering other projects to augment what we're doing now - particularly when the moon is up and our main science is on hold. We're also hoping to build a bigger array at some point in the future - with 50 lenses we'd effectively have a 400 mm f/0.4 lens, with a 1m aperture.

f/0.4 @ 1m...now that would really start to surpass, just in specs, some of the really large earth-based telescopes for sensitivity.

47
It sounds like Canon is identifying and solving a number of issues with layered sensors. Given that, and given that their patent filings are still being published, I am not sure we'll see a layered sensor with the 7D II. The issues would need to be worked out first. It's possible all of these were filed a 18-24 months ago, and the technology is ready, but there could also be ongoing work.

I'm still waiting for a Canon patent that shows they figured out how to reduce noise and increase dynamic range in a layered sensor. I think that would make...well...everyone's day. :D

It's intriguing that Canon is working on a layered sensor, though. At the very least, it gives some hope for the cameras that come after the 7D II.


48
Canon General / Re: Dragonfly, Powered by Canon Lenses
« on: July 12, 2014, 03:02:05 PM »
I chatted with one of the guys on this project over on the CloudyNights forums a couple months back. Back then, he said the current version of DragonFly had 8 commercially available Canon EF 400mm f/2.8 L II lenses, however that they were in the process of adding four more for a total of 12. Their ultimate goal was to get up somewhere round 20-24. To achieve that, they had to redesign the mount that holds the lenses. The original version was a squareish contraption, and I think the new approach uses something more modular, some kind of hexagonal or circular cells that can be attached to each other.

Anyway, it's a pretty cool setup, incredibly sensitive for an earth-based telescope.

49
When we will know the final specification for Canon 7D Mark II


When Canon makes an official announcement. Until then it is rumours and speculation.
19Mpixels, 8.5 fps,  23 AF points, 0.5 stop improvement   ;D   ;D   ;D
I prefer my speculation on the wild side.... I predict that the 7D2 will be mirrorless. I have a perfect prediction record..... wrong every time :)

 ;D 

50
I think this debunks the notion in the Microsoft-Canon patent deal that Microsoft was the dominant or aggressive party in the deal. If Canon also joined this new patent coop, it sounds like CANON is looking to both reduce patent litigation and share their technology in good will.

Personally, I think when companies share patents or at least agree not to litigate like drunken monkeys over them, it's only better for the consumer in the end. I think interesting things could come of a more open world where patents are not wielded as a weapon. I still think it's a companies right to protect their intellectual property, but I've been pretty soured by Apple's patent tactics and litigation...they come off as petty and dishonest.

51
EOS Bodies / Re: Canon 6D N
« on: July 11, 2014, 06:10:17 PM »
about another 30% off without video feature. I'm in ;D

Me too! :D

52
First, I agree, you should only insure what you absolutely have to. I insure my 5D III and EF 600/4 L II. That's it. All the rest, I can cover myself. The payouts from the insurance company would top out at maybe a grand anyway, and if you do a lot of little claims like that (especially when using a home insurance rider or schedule), it ultimately results in larger premium increases. Only insure things that cost at least a few thousand dollars. In the case of the 600mm lens, it's $12,800 new...I pay something like an extra $300 a year to insure my two things on my home insurance scheduled property rider...a very small price to pay in case my lens was damaged and had to be replaced.

Insurance companies may "win" on a personal basis, but in the big picture, they have been getting slammed over the past good number of years now. Maybe since Katrina, the insurance payouts have been pretty significant in large regions of our country. My parents house (they also live here in Colorado, up in the mountains of the Front Range, just above Jamestown) was damaged by the September rains we had here in Colorado last year.

They are just one of many thousands of people at least, if not millions of people, who have had to file insurance claims. The payout just for the Colorado disaster is going to end up in the hundreds of millions at least, and it's all still on-going. Stuff is still totally damaged, and it will take years to fully repair (for example, the main road up to my parents house is half-washed out in a couple dozen places...there is not enough room for more than one car to pass at a time). The work to shore up whole entire valleys in that area, bring in massive amounts of earth, rebuild roads, build giant culverts and other water management systems to handle the kind of deluge we had, etc. is all ongoing, probably will be for another year or so. Massive insurance payouts and other expenses going on there.

The town of Jamestown itself was pretty much destroyed, only one side of main street (and anything that was up in the mountains) survived, and a lot was damaged there as well. Many homes were completely washed away and have had to be rebuilt from scratch (that's several hundred grand a home right there in insurance payouts.)

People all over the front range and the plains just in front of it had flood and mud damage. Many thousands more, all the way out to my house (which is in the Aurora South area, fairly well east of the mountains themselves) had significant hail damage (thousands upon thousands of roofs have been replaced around here, some have had multiple claims).

My roof could probably stand to be replaced, but I'm holding out as long as I can to maintain my "claims free" status, as it's a moderately significant discount, and my insurance has gone up enough already as insurance companies around here scramble to cover all their costs. (Ah, gotta love subsidies in the face of countless natural disasters year after year.)

Anyway...I wouldn't say that insurance companies just plain and simply "always" win. They win...for a while...until the claims start piling up. Then their profit margins tank significantly, their costs just to handle all the claims flowing in increases, they eventually react by jacking up everyone's premiums...until the next natural disaster occurs, costing hundreds of millions to billions, and the payouts start again. Before Katrina, it was pretty common for insurance companies (mainly the broad insurance providers, Farmers, American Family, All State, etc.) to have profit margins in the double digits (which, truly, is very high...but when you think about what insurance is, in the good years, it NEEDS to be high). I think 8% was relatively "low". After Katrina, profit margins for insurance companies tanked down to around the -20% range for a while. They topped 10% again for a little while, and have been declining since. In recent years, big insurance company profit margins are down in the 2-6% range, however there have been spans in recent years where their profit margins were -7-10%. Average it out, and profit margins for insurance companies are at best a third of what they were, at worst a fifth, and shrinking. And the payouts continue...

So, don't be surprised if you have to pay to protect your investments. Insurance payouts are very high in recent years, and look to remain relatively high in the future.

53
EOS Bodies / Re: Eos7D mk2, How EXCITED will you be if . . .?
« on: July 10, 2014, 08:00:12 PM »

Quote from: neuroanatomist
As for sharpness, while it's true that a multilayer sensor wouldn't need the blurring caused by an AA filter to avoid color moiré, that blurring is predictable and thus highly correctable with sharpening in post, so the true gain in sharpness is minor at best.
Not true. "No AA" picture can still be corrected/sharpened better than picture "with AA". Multilayer without AA can be sharpened/"regenerated" even further.

 All the practical evidence from people who have two cameras identical other than with, or without AA filter, ie. Nikon D800/800e and Pentax K5II/n (or whatever it's called) is that there is no perceivable difference after applying suitable un-sharp mask.

no AA is still a touch crisper, but also with false 'detail' and more issues
I don't think sensor densities are high enough yet for no AA filter to be wise.

Aye, removal of the AA results in false detail, which really just shows up as harsh noise a lot of the time, aliasing and more at others. I don't know that sensor densities will ever be high enough that we could ever really do away with AA filters. I mean, if the Otus does resolve somewhere in the realm of 400lp/mm wide open, then we would need a bayer sensor capable of resolving over 550mp in order to be able to drop the AA filter. That would be pixel sizes around 1.25µm. Not infeasible from a fabrication standpoint...probably infeasible from a data transfer rate standpoint (the file sizes at 14 bit, assuming around 7% increase in pixel count for masked border pixels, would be about 1.1GB in size, each...the only things that move that much data per second are high powered GPUs and CPUs, both if which require massive amounts of power (even i7 Intel Haswells still draw a lot of power when moving that kind of data per second.)

54
Third Party Manufacturers / Re: Nikon's D800E 30% sharper than D800
« on: July 10, 2014, 07:34:19 PM »

Consider that across the Internet, criticism of DxO typically only comes from people that own Canon products. That piece of data speaks volumes about how DxO results are absorbed, don't you think?

I'm not sure what "typically only" means (do you mean "usually" or "most of the criticism I've seen" or "most of the criticism I've noticed"?) but I often see criticism of DxO on forums (esp. m43), including at DxO itself.  Perhaps that "piece of data" speaks volumes too.

I never see people on Nikon rumors or Sony Alpha Rumors ripping into DxO like folks do here... (don't read m43 forums so...)

LOL. You haven't read enough of Nikon Rumors or DPR then. Particularly at DPR, the DXO ripping is AT LEAST as bad as it is here, if not a lot worse. We aren't the sole group of people who have a problem with the way DXO does things, there are a lot of people out there, and many who are NOT Canon fans, who don't like DXO results nor like the black boxes DXO insists on maintaining. You can't call yourself "scientific", then have blantantly unscientific results, and not tell anyone why or explain the reasons why to anyone.

That doesn't mean that 100% of everything DXO does is bad...people here are pretty clear about what bits of DXO's information and/or processes and procedures they have a problem with. Dig down into DXO's direct measurements for sensors, and most of those are useful information. It's the extrapolations (i.e. Print DR) and funky results (i.e. lens resolution, T-stop weight in their results) that raise serious questions about what DXO is doing, how, and why. LEGITIMATE questions.

55
Third Party Manufacturers / Re: Nikon's D800E 30% sharper than D800
« on: July 10, 2014, 01:03:39 PM »
OK, I trust you guys know your optics and related math much better than I do.  I'm just trying to figure something out here that's not quite making sense to me yet so if you care to indulge following the path I'm on with this, please tell me which step I slipped on.

I'll use round numbers for convenience but referring to the numbers jrista provided on a previous page.

Step 1:

- A digital image sensor (e.g. D800e) with pixels that are 5 microns square = 100 lp/mm physical sensor resolution with no AA filter.
I presume with whatever kind of algorithm is used, it is possible to read alternating rows of pixels, if they are properly stimulated, such that it would be possible to electronically extract the maximum of 100 lp/mm from this sensor.  If this were a monochrome rather than Bayer sensor then likely even simpler.

The resulting contrast ratio, if one were to stimulate alternating rows of pixels with high and low (dark) intensities would depend on the spot size of the illumination and how it was modulated during the raster.

Let's cheat a little bit, for fun.
I'm thinking if a visible light laser beam could be focused to about 1 micron, then rastered across the sensor in perfect geometric alignment and modulated such that the beam was ON only while the edge of its spot fringe was entirely located within a given pixel (row) such that no appreciable amount of that light were to enter an adjacent pixel (row), then the resulting contrast ratio would be quite high as there would be no bleed-over to the pixels in the dark row resulting from the fuzzy fringe of the spot.
This would be cheating because it would not be a perfect square wave function but would required a reduced ON time vs the normal 50% ON to 50% OFF of a square wave.

Thus we have applied a pattern of light and dark lines to the sensor synchronized with the sensor's physical pixel layout such that every second pixel is illuminated and alternating ones are dark.
We get 100 lp/mm equivalent signal from the sensor.  Still, we may have slightly less than perfect maximum (MTF) contrast ratio between rows but it's likely to be much higher than the typical 50% MTF standard. 

If we were to instead modulate the light spot (without cheating) so that it was turned ON and OFF as its center crossed the boundary from one (row) of pixel(s) to the next, then that will have an equivalent contrast ratio you could calculate at about 5:1.

Are there any errors in this hypothetical assumption so far?


Step 2:

- we have some lens that is capable of resolving 150 lp/mm at an MTF of 50% as measured on some optical bench...
This same lens should have a better than 50% MTF result if it were resolving a test target at 100 lp/mm.

Any error in step 2?


Step 3:

- we take the lens in step 2 and use it to focus a 100 lp/mm image onto the sensor in Step 1.  (We can use monochrome light if we have to minimize focus errors from CA)
We must now carefully align the focused image to the pixels on the sensor so that the middle of the bright line corresponds to the middle of a pixel (row) with the middle of the dark line aligned to the middle of the next pixel (row).  This should yield the maximum readable contrast ratio from the electronic sensor.
IF the alignment is PERFECT then the contrast ratio should still be a reasonably good number.  As the alignment shifts away from perfect the resulting contrast ratio will drop to a low of 1:1 (2.5 micron shift) for adjacent pixels which means no discernible contrast at all.

Are there any errors in step 3?


Conclusion:

If there were no errors in the 3 steps above then it is possible for a lens and sensor combination to resolve the physical maximum lp/mm of the sensor if the lens has a sufficiently higher resolving power in at least the ideal circumstance described.

Add angular and positional misalignments and mismatches in spatial frequency and you'll get aliasing and all manner of things that throw the above out the window and the math explained in this thread describes the system behavior.

is the conclusion correct within the limitations stipulated?

Your have it somewhat, and some things are slipping through your grasp. ;)

First thing. Yes, it is possible to use a lower contrast ratio than 50%. If you do that, then your results are generally in a different context than lens tests done anywhere else, as testing at MTF 50 is very standard. It's what all the major testers use. It is not invalid to reference a lower contrast level, however there is a diminishing guarantee that any given sensor can actually resolve any differences below a certain contrast level. The human eye is capable of barely detecting contrast at 9%. The human eye has some advantages that sensors do not, however, such as our brains doing real-time superresolution enhancement on everything we observe.

It's "safe" to refer to spatial resolution at MTF 50. It's a well-known context, it's easily comparable with results from other testers, official sites, etc. You can also very easily find LP/MM numbers for primary apertures, and sometimes half or third stops, in tables for MTF 50. You can also usually find the same for MTF 10, although there is no guarantee that a sensor could actually separate detail (real detail, not noise) at that low of a contrast level. (Noise tends to dominate at that low of a contrast level, and things like LPFs may smooth detail out, and conversely the LACK of an LPF may result in even more noise at an even higher contrast level.) MTF30 might be a good contrast level that sensors can still resolve...however there isn't a lot of readily availble information on lens resolving powers at that level. You would have to compute all that yourself (which is certainly possible, but it makes it harder for others to verify your claims.)

Some other things to account for as well.

First, lens aperture. Lens resolving power changes with aperture, as smaller apertures increase the impact of diffraction more. I have found that, based on my own testing as well as tests from official testers like DPR, PZone, etc. that lenses generally top out in resolution somewhere around f/4 to f/5.6. Diffraction-limited spatial resolution at those apertures is somewhere between 123lp/mm and 173lp/mm. There are some few lenses that may resolve more than that at wider apertures...something like the Otus could very well resolve the 247lp/mm diffraction limited resolution of f/2.8...and possibly, in the center of the lens, resolve upwards of 350-400lp/mm at f/2-f/1.4. I haven't actually looked at a real MTF chart to know for sure.

Keep in mind though...those resolutions are ONLY possible at those apertures or WIDER. The moment you stop down more, your maximum diffraction-limited resolution drops. Those are pretty fast apertures. Even f/4 is getting fairly fast. Very few lenses actually exhibit "ideal" behavior at f/4 or faster...optical aberrations generally have some kind of impact, even if it's small. Sometimes the impact of an aberration is simply a loss of contrast...resolving power might be the same, but its now at a lower contrast (i.e. MTF30), which means detail will become increasingly more difficult to differentiate from noise.

Finally, and I make this mistake myself, sensors really don't get their "theoretical maximum" resolution...not unless they are just a bare, monochrome sensor (no filters of an kind). Only a bare mono sensor is really going to be capable of resolving line pairs anywhere close to the size of their pixels. For all other sensors, the use of filters (even just IR/UV filters) will reduce resolution a bit, and the use of a CFA obviously has an impact (although more in color than in luminance, for sure). So, the D800E, with it's 4.9 micron pixels, has a raw mono spatial resolution of about 102lp/mm. It's real-world spatial resolution is going to be diminished, however. I'd say the D800 probably loses some 20-30% or so due to the CFA and filter stack. The D800E has that funky reversed LPF, so it won't lose as much, maybe 15-20%.

Given the existence of the CFA on the D800E, despite the lack of an LPF, there is no way anything could ever actually resolve anywhere remotely close to 36mp, with any lens. It just isn't possible. Hence the reason why DXO's results are so highly suspect. I could believe ~30-31mp, with a very good lens. I have a very hard time believing anything higher than that on average, though...unless it was an absolutely stupendously kick-ass god-quality lens that ACTUALLY resolved some 400lp/mm at f/1.4...and, assuming the results were actually for f/1.4, I think 33mp, maybe 33.5mp, is really the best your going to get...I mean, your WAY up there, really pushing the sensor to its absolute limits.

56
Trolling all over the Internet.....

http://www.fredmiranda.com/forum/topic/1305527


He just wants someone to approve of his decision to spend lots and lots of money he doesn't have jumping brands. :P

57
Third Party Manufacturers / Re: Nikon's D800E 30% sharper than D800
« on: July 09, 2014, 02:40:16 PM »
Or to put it differently, that Zeiss lens outresolves the sensor.

There is no such thing as lens outresolves sensor or sensor outresolves lens. That's a misnomer. I've proven that, PBD has proven that, many people have proven that over the years on these forums. Image resolution is the result of a CONVOLUTION, of the lens, sensor, even air, all functioning to assert their impact on what's being resolved. That results in lens resolving power (if it has a higher power), when convolved with sensor resolving power, having an asymptotic relationship with the sensors resolving limit. (Similarly, if it's the other way around, the sensor has an asymptotic relationship with the lenses resolving limit.) There is no "outresolving"...it just doesn't happen.

The math is simple: (1/SQRT(LensSpot^2 + SensorSpot^2))/2. That's how you determine the theoretical optimal resolution of a lens combined with a sensor in line pairs per millimeter. It doesn't matter if the resolving power of the lens is higher than the resolving power of the sensor, it is physically impossible for ANY lens to resolve enough that the output resolution was 100% of the D800's sensor. PHYSICALLY IMPOSSIBLE. To do it, you would REQUIRE a lens with infinite resolving power at an infinite aperture. To even get close, you need MASSIVE resolving power in the lens...resolving power that is only possible if the lens is ideal at apertures like f/1, maybe f/1.2, at MTF50.

Every single lens test should result in an output resolution (measurable resolution actually recorded in the image itself) that is LESS than both the lens and the sensor, and certainly less than the element with the lowest resolving power. For any lens test to "resolve 100% of the sensor", it would literally have to be a "perfect" lens...in every single way, at every single aperture. Just as with the relationship between lens and sensor, our attempts to achieve perfection have an asymptotic relationship with perfection itself...we can never actually attain it.

This is true.

An done interesting thing to note, is that a relative dog lens even in the 8MP days that didn't manage to give a remotely satsifying 8MP image, well put it on a 24MP sensor and of course you gain nothing at all by going to the 24MP with such a dog of a lens that was all blurred at 8MP sensor even right? Nope. You'd likely get noticeably more detail with the dog lens plus 24MP sensor combo than the dog lens plus 8MP sensor combo, again, even though it was clearly not remotely getting much out of the 8MP lens. Now if you go to an utter extreme, it's possible you won't really be able to see any improvement going to the 24MP sensor, but in the current realm of sensor MP differences and typical optical quality spread from best to dogs you are pretty much going to always get more out of the higher MP sensor as even dog lenses aren't quite pure coke bottles. (although I'm sure it's true that there are enough lenses around that are poor enough at FF corners that you might not see any gains out there, what little gain there would be, would be too small to really notice).

Absolutely true! Going from an 8mp to 24mp sensor with a lens that didn't perform well on the 8mp could easily result in SIGNIFICANT gains.

(That said that test chart rounded to the nearest MP (And I'm not sure what the exact D800E count is it might be fractionally above 36MP itself, so if their result was like 35.5 and the camera has 36.4 they might still have tossed a 36MP on that chart even though it was a 100 perfect result, so it may be making a mountain over nothing. Plus don't forget measurement error which could easily be +/-0.5MP and quite possible more).)

This is all very probable. The issue, though, is that DXO just doesn't address these little things. They should be catching these little quirks, and publishing test results that don't make themselves look like fools all the time. At best, maybe the lens resolves "99%", but even that is pushing it, a lot. (I don't even like the whole idea of a lens resolving "x percent" of a sensor, that's just inane, and completely unrealistic.) These are the things that DXO does, again, and again, and again, and AGAIN, AND AGAIN... It's why they are a joke to a significant number of photographers (except anyone in the Nikon camp.) DXO has clearly made some significant mistakes, they miss obvious issues in their published results, and a lot of their process is completely black box. All the while, they claim to be "scientific." It's just a hard pill to swallow. I'll never have any respect for DXO until they become 100% completely transparent about 100% of their process. It wouldn't matter if they score the 7D II or 5D IV with 150 points...I still couldn't trust that their process was accurate.

58
Dear "J,"

I supposed I should not be surprised that you chose to announce the end of our relationship in such a public and cowardly way. You were never one for subtlety and discretion.

And, so typical of you to blame all the failures on me. As though you contributed nothing to the breakup. But, then, I guess since you contributed so little to the relationship, I should not be surprised.

The truth is, I've known for a long time this wasn't working. If I could have ended things myself, I would have. But as you know, for me this was an arranged marriage. You picked me and I had no say in the matter. For the honor of my family (and honor is something my culture values very highly) I could not leave you.

At first, your clumsy attempts to satisfy me were amusing and not without a certain boyish charm. But, honestly, it quickly became apparent that you were never going to improve. In fact, I soon realized that you actually thought you were good. I know this is hurtful to say, but since you are the one that began this public conversation, I think honesty is justified.

Never once were you able to bring me to my full potential. No, let me be more candid, never, ever did I come remotely close to achieving the heights I was intended for. You would fiddle with my dials and move my joystick, but it was so mechanical and uninspired that I could hardly bear it. Honestly, most of the time I wished you would just stick to the green box and let me do it myself.

And the trips...well, what can I say? Sure, I enjoyed them, but it was as though you thought that simply going someplace new would solve all our problems. All it did was make me long for the relationships that I saw others enjoying. How I wished that could have been us. But you...all you ever did was worry about whether someone else had a newer, prettier model hanging on his shoulder. 

You were so obsessed with showing me off that you didn't see how many of your fellow travelers lovingly treated their lowly Rebels with respect and appreciation and how they were rewarded in ways that you and I could never achieve together.

Yes, I saw the world. But, really, I would have traded it in a instant for a quiet little town in the Midwest, with someone who understood me and what I was meant to do.

Now, dear D810, believe me, I wish you no ill. In fact, I actually feel sorry for you. I know people say you are nothing more than an overinflated mass of silicon, but I know better. We are both from established families and, like me, you have not had any say in this relationship.

I would like to wish you a long and happy relationship, but I suspect that won't be the case. In the end, you will be blamed for everything. Just remember this. It is not you...it's him.

Exquisite. Priceless.

59
Third Party Manufacturers / Re: Nikon's D800E 30% sharper than D800
« on: July 09, 2014, 12:40:57 PM »
Most definitely. I'd love to see a chart of total resolving power versus dollars. Gotta pay to play.

What I know is you need more than a $2,199 Zeiss to resolve 100% of a 36MP 135 format sensor. DXO just did it again, they threw any "scientific" credibility they had out the window, not that they had much left anyway.

What is the basis for your knowledge here?

My earlier linked law of physics.

You're assuming that the imperfections in the lens are noticable/detectable with that camera.

As has been quite eloquently shown by many DSLRs, lenses for SLRs that were thought perfect in film days are been found lacking in the digital era.

Or to put it differently, that Zeiss lens outresolves the sensor.

There is no such thing as lens outresolves sensor or sensor outresolves lens. That's a misnomer. I've proven that, PBD has proven that, many people have proven that over the years on these forums. Image resolution is the result of a CONVOLUTION, of the lens, sensor, even air, all functioning to assert their impact on what's being resolved. That results in lens resolving power (if it has a higher power), when convolved with sensor resolving power, having an asymptotic relationship with the sensors resolving limit. (Similarly, if it's the other way around, the sensor has an asymptotic relationship with the lenses resolving limit.) There is no "outresolving"...it just doesn't happen.

The math is simple: (1/SQRT(LensSpot^2 + SensorSpot^2))/2. That's how you determine the theoretical optimal resolution of a lens combined with a sensor in line pairs per millimeter. It doesn't matter if the resolving power of the lens is higher than the resolving power of the sensor, it is physically impossible for ANY lens to resolve enough that the output resolution was 100% of the D800's sensor. PHYSICALLY IMPOSSIBLE. To do it, you would REQUIRE a lens with infinite resolving power at an infinite aperture. To even get close, you need MASSIVE resolving power in the lens...resolving power that is only possible if the lens is ideal at apertures like f/1, maybe f/1.2, at MTF50.

Every single lens test should result in an output resolution (measurable resolution actually recorded in the image itself) that is LESS than both the lens and the sensor, and certainly less than the element with the lowest resolving power. For any lens test to "resolve 100% of the sensor", it would literally have to be a "perfect" lens...in every single way, at every single aperture. Just as with the relationship between lens and sensor, our attempts to achieve perfection have an asymptotic relationship with perfection itself...we can never actually attain it.

60
Third Party Manufacturers / Re: Nikon's D800E 30% sharper than D800
« on: July 09, 2014, 12:28:44 PM »
Most definitely. I'd love to see a chart of total resolving power versus dollars. Gotta pay to play.

What I know is you need more than a $2,199 Zeiss to resolve 100% of a 36MP 135 format sensor. DXO just did it again, they threw any "scientific" credibility they had out the window, not that they had much left anyway.

What is the basis for your knowledge here?

Science. Physics. Reality. You might want to look those up some time and give them a visit!  ::)

Quote
Quote
A result made all the more comical when you look at the $4,000 Otus results on the D800E, down to 33MP, a drop of over 8% for what is regarded as one of the finest photography camera lenses ever made. I think DXO have two teams of testers and the Canon team, who clearly multiply all their results by 0.9, mistakenly did the Nikon Otus when they did the Canon Otus as well. No that's not true, I believe the Canon testers are OK, it is the Nikon test team that multiply all their results by 1.15.

As for not being able to have 99% of perfection or it being a strange way to look at it, I understand that, I was just trying to illustrate that anybody claiming perfect anything is farcical and it isn't as simple as the lens being capable of resolving more than the sensor. Like the >14 stops of DR in a 14 bit file, extrapolate to ridiculous figures all you want (DXO) but if I can't actually realise that shadow lifting capability it is of no practical use.

Totally agree with everything here. DXO has some really wacko shite goin on with their lens tests. They have the weirdest lens test results I've ever seen...anywhere.

But that wacko S___ produces arguably the best RAW conversion results when they feed it into DxO Optics.

Have you ever used anything other than DXOOptics? I spent six months with that program. It is HORRIBLE compared to Lightroom, Photoshop, even RawThearapy (I haven't used DarkTable in a while, but I'd put money on even it being better than DXO). DXOOptics produces some of the worst quality output I've ever seen in a RAW editor, especially with Canon files. So, sorry, but "arguably" doesn't belong in your sentence above...because it is NOT "arguably" the best RAW conversion. It's arguably among the worst. I have several wildlifer friends who use DXOOptics, and after my initial recommendation that they move to Lightroom, which was immediately dismissed, I've not had the heart to tell them their RAW conversion looks terrible. Even to this day, every time I see these photographers photos, I cringe at the blotchy noise or the scratchy detail.

Arguably...hardly!!  :P

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