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Messages - jrista

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1156
Software & Accessories / Re: Adobe Lightroom for iPad Coming Soon
« on: January 18, 2014, 01:40:29 PM »
LR for iPad sounds really good ... if it is anywhere near the feature set of LR5, $99 is a very reasonable price ... where I live right now, that's less then the price of a Big Mac + Coffee ... neither of them are good for my health, so, I'm sure I can forego 1 Big Mac & a Coffee every month to pay for the LR iPad subscription ... even if they double the price I will simply forego 2 Big Macs and 2 cups of coffee every month ... that way I might even be able to extend my life by a few minutes longer, to capture a beautiful sunset or a sexy lady ... then edit it on my iPad with LR, take a good look at my work, be proud of it and then die like a proud peacock ;D

It's not $99. It is $99/year. Big difference. One can buy LR5 and use it and sit on it for a couple years or more, getting more and more value out of the product, all for a single up-front cost of $149 (or $79 for upgraders, which is even better!) This iPad app is a subscription product...so it isn't $99, it is $99/year. It's the "/year" part that pisses people off.

1157
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 18, 2014, 01:34:26 PM »
In Sony cameras with "nigthshot" function, the IR filter can be temporarily displaced from the front of the sensor at the touch of a button to enable night vision. Similar functionality with the AA filter gives the best of both worlds, using AA filter only when necessary. However, a large filter as 24x36mm requires additional space for temporarily be out of the way. A large camera like the Canon 1 series should have enough space for it.

There are patents now for electrically attenuated AA filters. We wouldn't need to "swing" them out of the way, simply reattenuate to effectively turn off AA filtration. With an electrically attenuated AA filter, you could adjust it strong or weak or off depending on the circumstances. Who knows if/when this technology will find it's way into DSLRs, but it would be the best way to deal with the problem, for sure.

1158
I have all the gear I need now. ... Said no photographer (or keen enthusiast) ever.

So long as manufacturers keep manufacturing better cameras, I'll always need. If only they would just stop...I might live in contentment and peace... :P  ;D

1159
EOS Bodies / Re: Will Canon Answer the D4s? [CR2]
« on: January 18, 2014, 03:16:25 AM »
Jrista, without quoting that long post...do you honestly think it's possible for a DSLR to have its sensor cooled to -80 C?  How would that be done in a DSLR?

Active cooling is actually done quite frequently today with high end astrophotography cameras. They use dual stage peltier (TE/TEC, or ThermoElectric) cooling. Peltiers are very thin electronic heat pumps, being simply an array of N and P type silicon sandwiched between two ceramic plates (one "cold" plate and one "hot" plate, heat is pumped from the cold side to the hot side). It would be easy to fit a peltier into existing DSLR bodies without anyone being the wiser (with the exception of increased heat output, as the peltier generates it's own heat along with drawing out heat from whatever is attached to it's cold side.) Now, with most astrophoto cameras, the delta-T they aim for is around 50°C. On an average night, the temperatures drop to somewhere around -10° to -20°, however the really high end ones can cool much more effectively with delta-T over 60°. On a cold night, CCD temp with a really good astrocam can get to below -75°. Most cooled astrocams also employ low noise fans to actively cool a heat sink or heat pipe attached to the hot side of the upper peltier and actively exhaust heat...something similar could be done with a DSLR.

Professional scientific grade CCD cameras used in professional astrophotography, microscopy, etc. use much more significant measures to cool. Professional scientific grade CCD cameras are usually cooled to at least -80°C. In some cases, temperatures are pushed below -125°C, and I've even heard of some scientific grade equipment operating in superconducting conditions at nearly absolute zero (however once you move past -80°C, the cost of maintaining temperature becomes excessively prohibitive.)

In the case of a DSLR, at some point I see some kind of peltier based cooling becoming necessary. At some point, we are going to exhaust the material options, when we've employed things like black silicon, color splitting in favor of color filtration arrays, and maybe even some kind of layered photodiode approach to increase maximum charge capacity per pixel. To continue improving (and at that point, low ISO will be about as good as it can get, so all the improvements will have to occur at the high ISO end), without reducing megapixel count, we will need to reduce dark current noise in the electronics themselves. The most effective way to reduce dark current once CDS is employed is to cool the sensor.

Even for a relatively cheap $2000 astrocam with dual-stage peltier cooling, average dark current drops from around 5e- to 0.02e-, and better ones can be had for $4000 to $10,000 where dark current drops to as little as 0.01e- to 0.008e-. At 0.01e-, you release one electron worth of noise for every 100 electrons released by photons. Today, average read noise at high ISO is around 3e- or so, so cooling could gain us a fair amount of real-world high ISO sensitivity. Even at medium ISO settings, where dark current can still be as high as 5-10e-, could benefit from cooling. Extreme cooling could even be an option to reduce ISO 100 noise as well, albeit at a power cost.

On the notion of power consumption, that would certainly be a hurdle to overcome. Power cells would have to be far more efficient, and certainly hold more capacity, than even the most capable camera batteries of today. I suspect some kind of fuel cell technology would need to be employed to make extreme peltier cooling a reality for high ISO shooters. Fuel cell tech has come a long way recently, and I suspect at some point camera manufacturers will probably switch to them anyway. Thermoelectric cooling could be a user-selectable option as well, and the peltier could be activated automatically on demand if it is enabled so that it does not constantly draw power.

But is this realistic?  How much would it add to the cost?

I've been familiar with cooling used on CCD cameras for astrophotography for a long time.  Which is why I asked if it was realistic or feasible to do it in a DSLR.

Peltiers are super cheap. As for powering them, that's where cost would probably come in...they draw quite a bit of power. I'm not sure what the actual cost might be, but it wouldn't be the most significant cost in the camera, not by a long shot.

1160
if you would like to stick with the price, i would prefer asus.  otherwise, i prefer this:

http://www.dell.com/us/p/xps-15-9530/pd?~ck=mn

as for me, i would wait for dell to low down the price of this and then get it...

below is the image that i did in the past to compare this dell xps laptop with macbook pro (note:  there is a discrepancy in this comparison that you would be found in support.  it should be one year for both... copy cell problem...):




I was looking at the XPS 15 just a few days ago. I find it to be quite an intriguing product. Never been a huge dell fan, but I am very excited that someone is making a retina-level LED display for a laptop, and a Windows 8.1 convertible laptop at that. If I had to choose a laptop right now, it would be the XPS 15 without question. I ended up repairing my old Sony Vaio 18.4" laptop (which only has a 1920x1080 screen of TERRIBLE quality) for only a couple hundred bucks (because that's all I have at the moment)...but the XPS 15 is definitely on my radar.

BTW, onboard memory sounds like memory that has actually been soldered onto the motherboard. That isn't surprising, given how tightly Apple engineers their products to meet extremely tight specifications. I suspect Dell is using a standard form of laptop memory, which would be much more versatile.

1161
Software & Accessories / Re: Adobe Lightroom for iPad Coming Soon
« on: January 18, 2014, 12:34:36 AM »
Sorry to see LR take a cloud model.

Where does it say that???

99 is just the beginning.  Wait until you need that sharpening module only offered as an in-app add-on.

Oh, I get it now.  You're just making stuff up.

Do you pay much attention to the modern world of apps? In-app microtransactions for addons of one kind or another are all the rage. Zynga, for example, is famous for employing microtransactions in their games, to the great financial detriment of the players who become addicted to them. It's how some app developers have raked in hundreds of thousands to millions of dollars for apps that cost a mere few bucks or are even free...and it is certainly no longer limited to just games.

I wouldn't say he is just making stuff up. It's a real-world thing that is becoming far more common, and with Adobe's apparent unquenchable greed as of late, it isn't surprising to hear this brought up as a potential concern. At some point, I fully expect Adobe to figure out that they could make even more money off their already tapped customers by employing microtransactions...and they will probably find an effective way of restructuring their products to take full advantage of the concept. Whether that happens now, with Lightroom for iPad, or at some later date, is yet to be seen...I suspect a later date, but I do expect Adobe to jump on the bandwagon at some point.

1162
EOS Bodies / Re: Will Canon Answer the D4s? [CR2]
« on: January 18, 2014, 12:30:57 AM »
Jrista, without quoting that long post...do you honestly think it's possible for a DSLR to have its sensor cooled to -80 C?  How would that be done in a DSLR?

Active cooling is actually done quite frequently today with high end astrophotography cameras. They use dual stage peltier (TE/TEC, or ThermoElectric) cooling. Peltiers are very thin electronic heat pumps, being simply an array of N and P type silicon sandwiched between two ceramic plates (one "cold" plate and one "hot" plate, heat is pumped from the cold side to the hot side). It would be easy to fit a peltier into existing DSLR bodies without anyone being the wiser (with the exception of increased heat output, as the peltier generates it's own heat along with drawing out heat from whatever is attached to it's cold side.) Now, with most astrophoto cameras, the delta-T they aim for is around 50°C. On an average night, the temperatures drop to somewhere around -10° to -20°, however the really high end ones can cool much more effectively with delta-T over 60°. On a cold night, CCD temp with a really good astrocam can get to below -75°. Most cooled astrocams also employ low noise fans to actively cool a heat sink or heat pipe attached to the hot side of the upper peltier and actively exhaust heat...something similar could be done with a DSLR.

Professional scientific grade CCD cameras used in professional astrophotography, microscopy, etc. use much more significant measures to cool. Professional scientific grade CCD cameras are usually cooled to at least -80°C. In some cases, temperatures are pushed below -125°C, and I've even heard of some scientific grade equipment operating in superconducting conditions at nearly absolute zero (however once you move past -80°C, the cost of maintaining temperature becomes excessively prohibitive.)

In the case of a DSLR, at some point I see some kind of peltier based cooling becoming necessary. At some point, we are going to exhaust the material options, when we've employed things like black silicon, color splitting in favor of color filtration arrays, and maybe even some kind of layered photodiode approach to increase maximum charge capacity per pixel. To continue improving (and at that point, low ISO will be about as good as it can get, so all the improvements will have to occur at the high ISO end), without reducing megapixel count, we will need to reduce dark current noise in the electronics themselves. The most effective way to reduce dark current once CDS is employed is to cool the sensor.

Even for a relatively cheap $2000 astrocam with dual-stage peltier cooling, average dark current drops from around 5e- to 0.02e-, and better ones can be had for $4000 to $10,000 where dark current drops to as little as 0.01e- to 0.008e-. At 0.01e-, you release one electron worth of noise for every 100 electrons released by photons. Today, average read noise at high ISO is around 3e- or so, so cooling could gain us a fair amount of real-world high ISO sensitivity. Even at medium ISO settings, where dark current can still be as high as 5-10e-, could benefit from cooling. Extreme cooling could even be an option to reduce ISO 100 noise as well, albeit at a power cost.

On the notion of power consumption, that would certainly be a hurdle to overcome. Power cells would have to be far more efficient, and certainly hold more capacity, than even the most capable camera batteries of today. I suspect some kind of fuel cell technology would need to be employed to make extreme peltier cooling a reality for high ISO shooters. Fuel cell tech has come a long way recently, and I suspect at some point camera manufacturers will probably switch to them anyway. Thermoelectric cooling could be a user-selectable option as well, and the peltier could be activated automatically on demand if it is enabled so that it does not constantly draw power.

1163
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 18, 2014, 12:04:41 AM »

Same thing goes for the feathers of a bird. Each barb is a wave crest, and the space between them is a trough. Overlay multiple feathers on top of each other, and you have a complex moire pattern.



And this very often is responsible for the various colors we perceive the feathers to be...but sometimes also the feathers have pigment...and sometimes it's both...correct?


Color would be different. I'm not talking about light waves, I'm talking about spatial waves. Color is determined by the ratio of energy absorption vs. energy reflection at the photon-electron interaction level in an atom. An object is red because it absorbs more of all other frequencies except red, and reflects more red than all other frequencies. ALL frequencies are absorbed, and ALL frequencies are reflected, the color of an object is ultimately determined by the amount of the spectrum reflected vs. not. A white object reflects all frequencies equally and absorbs all of them minimally, a black object also reflects all frequencies equally yet absorbs all of them significantly. This is also why darker objects tend to get hotter faster in the presence of electromagnetic energy, where as lighter objects get hotter slower.

Anyway, color is the result of an entirely different phenomena. When I say wave, I mean spatial frequency, not light wave.


But color in feathers is often determined by refracted light, not directly reflected light.  Sorry you were not discussing color, in any case, but either way, this is what causes us to see various colors of feathers.


Yes, LIGHT is what determines color. But I am not talking about light. I'm talking about spatial frequencies. Spatial frequencies have nothing to do with light. Spatial frequencies are waves (two dimensional waves, to be precise), but not light.

Reflection, refraction, absorption...that is all a phenomena of photon-electron interaction at the atomic level. You can also include diffraction in that list as well...in some cases, some of the color patterns produced by bird feathers when illuminated by more direct light is the result of diffraction, as well as refraction and reflection. But again...that's light. I'm not talking about light, though. I am simply talking about shape and form and how those things can interfere...spatial structure.


How did you arrive at something so basic, from a discussion of AA filters?  The nature of "resolution" has nothing to do with "spatial structure", because "detail resolution" exists on a much smaller scale...unless of course you're talking about cropping an image down to a few pixels square.


Sorry, not really sure what your asking here. This discussion ultimately came out of an earlier discussion about moire, and the cause of moire in photography is interference of spatial frequencies. I posted some bird photos on the demand of another member, and he noted seeing moire in them...however that moire was the result of bird feathers creating an interference pattern, not the sensor, and thus, the discussion at hand...about how moire can exist in reality without cameras at all, because it's all about spatial frequencies and how they interfere with each other.

I mean, what is the answer to this thread's question, in your mind?  Will Canon ditch the AA filter completely, yes or no?  If so, when?


No, I don't think Canon will ditch the AA filter at all. In all honesty, I find it ironic that the lack of an AA filter is considered a "high end" or "desirable" feature, just because Leica ditched them years ago (as did some MF cameras) and because now the schizophrenic Nikon has latched themselves and their success onto the removal of AA filters. It is even more ironic that those very same medium format cameras are frequently used to photograph people in studios, where fabrics of every variety are endemic. I have also read more than enough forum threads where MF users, including Leica users, complain about not having an AA filter because it produces so much moire.

Removal of an AA filter is far from a high end feature. It is a gimmick for all but a very few niche photographer types who's work primarily involves photographing things with entirely random data that could not produce much aliasing regardless. For the vast majority of photographers, use of an AA filter is quite essential to producing BETTER image quality. Aliasing produces nonsense, noise, useless detail. ANTI-Aliasing restores that useless nonsense noise to a more accurate form.

From a technical standpoint, an optical low pass filter is quite literally the best way to achieve this as well. X-Trans is a great example of this. While X-Trans doesn't experience aliasing, I've never seen any full size image that looked anywhere as sharp as the average full size DSLR image. X-Trans does basically the same thing as an optical low pass filter, however it is LESS discerning. A low pass filter is quite discerning in that it is designed only to blur certain spatial frequencies. Explicitly, optical low pass filters blur frequencies right in the range of the sensor's nyquist limit, the barrier between spatial frequencies that can be fully resolved without detrimental aliasing, and spatial frequencies that cannot be resolved properly at all, and are guaranteed to produce tons of nonsensical output that just increases noise. OLPFs blur exactly the right amount of high frequency detail so as to produce the least amount of impact on the photograph at large. There are some variations...some AA filters are slightly "strong" in that they blur a little bit of resolvable frequencies, other AA filters are a little "weak" in that they don't blur enough, resulting in some moire and aliasing occuring anyway. The X-Trans will blur all detail up to whatever radii is involved in their 6x6 grid overlap (which is pretty much guaranteed to be a larger radius than a low pass filter), so X-Trans will be blurring a lot more detail on a much more consistent basis.

It should also be noted that the kind of high frequency softening performed by an OLPF is easy to reverse. They produce a generally predictable form of blurring in a uniform manner across the entire area of the frame. As such, the application of a light unsharp mask filter can easily reverse the apparent softening, and restore the vast majority of "lost" detail (it's not really lost, most of it is there, especially if the AA filter isn't too strong.) Moire, on the other hand, is unpredictable, and can be extremely difficult to impossible to correct in post.

This, as it so happens, is also the case with lens diffraction. Many people mistakenly opt for using a wider aperture to avoid diffraction when what they really need is a deep DOF, however it is FAR more difficult to correct a depth of field that isn't deep enough. Diffraction blur is uniform across the entire area of the frame, and is predictable, and as such, it is easy to reverse with some sharpening. It is better to stop down more and deal with diffraction, than shoot wider and deal with a non-linear blur throughout the depth of field.

You gotta pick your battles, and it's best to pick the ones you can win. Combating softening due to an AA filter is easy. Super easy! The only people who complain about having an AA filter are those who don't quite understand it, how it works, or why we use them instead of some other alternative. Were more than a decade into the age of digital photography. It isn't like other options haven't been explored. Modern AA filters employ the best technique based on very sound theory, and are quite effective at the task. Removal of moire via post-processing tools? That is an area that has very little theory at all, has minimally effective tools at best, is impossible to correct at worst, and assuming there is a solution out there somewhere, will likely require many years or decades yet to discover a solution, effectively describe the process, and for some software developer to figure out how to convert the theory into an effective algorithm with a useful set of UI tools.

Personally, I hope Canon doesn't change a thing about their AA filters. IMO, they are already generally on the "slightly weak" side, and already allow too much moire through. I find the 7D AA filter to be quite effective at combating moire, and it is easy to sharpen the results to look as good as the competitors that don't have AA filters. I'm reposting an image from an old debate with Mikael on this very same subject, where I made the same arguments:



To the left is a 7D image taken from DPR, compared to one of Nikon's new AA-less cameras (D5100 or D7100, I forget which). I've applied a very light unsharp masking filter to the 7D to combat the softening caused by the AA filter. You will be very hard pressed to find any significant differences between these two images, with the exception that the image WITHOUT the AA filter clearly has problems with moire, where as the 7D does not. There is very little if any difference in sharpness, but the IQ of the 7D is higher...it's more accurate (and, it's also slightly over-exposed relative to the Nikon sample...I left that uncorrected, but that's why some of the fine detail doesn't look as "crisp"...it simply isn't as dark.)

1164
Software & Accessories / Re: Adobe Lightroom for iPad Coming Soon
« on: January 17, 2014, 11:28:59 PM »
I would point out, for those of you who want Lightroom on the go, that you can already have it. Not only that, you can have the full Lightroom. Just get a Windows 8 Pro tablet (not Windows 8 RT, you need the full Windows 8). I currently use a Surface Pro, and I have both Lightroom and Photoshop installed on it. I can use it out in the field for countless hours so long as I don't forget to bring along my charging block and my AC converter for my car. The Surface Pro includes a stylus, which is actually a very intuitive way of working with these apps small controls on the high density screen...and I actually find it is a bit more productive stylusing my way through LR than mousing my way through it on the desktop. You have all the simultaneous multi-input capabilities as well, so you can switch between using stylus, touch, and kb/touchpad at will, so you can always use your most productive device to perform commands, move through the UI, etc.

Anyway...for those who don't want to drop $100 a year on an iPad app that is sure to be a shadow of the full LR, especially if you already own an LR license, just pick up a Windows 8 tablet. Dell now has one that has a screen resolution with a higher density than the iMac laptop retina displays, and it's competitively priced, for those who want a really nice device to do their photography work with. The Surface Pro 2 should also be a pretty nice device, with its improved battery life, as it also included the stylus.

1165
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 17, 2014, 11:23:06 PM »

Same thing goes for the feathers of a bird. Each barb is a wave crest, and the space between them is a trough. Overlay multiple feathers on top of each other, and you have a complex moire pattern.


And this very often is responsible for the various colors we perceive the feathers to be...but sometimes also the feathers have pigment...and sometimes it's both...correct?

Color would be different. I'm not talking about light waves, I'm talking about spatial waves. Color is determined by the ratio of energy absorption vs. energy reflection at the photon-electron interaction level in an atom. An object is red because it absorbs more of all other frequencies except red, and reflects more red than all other frequencies. ALL frequencies are absorbed, and ALL frequencies are reflected, the color of an object is ultimately determined by the amount of the spectrum reflected vs. not. A white object reflects all frequencies equally and absorbs all of them minimally, a black object also reflects all frequencies equally yet absorbs all of them significantly. This is also why darker objects tend to get hotter faster in the presence of electromagnetic energy, where as lighter objects get hotter slower.

Anyway, color is the result of an entirely different phenomena. When I say wave, I mean spatial frequency, not light wave.

But color in feathers is often determined by refracted light, not directly reflected light.  Sorry you were not discussing color, in any case, but either way, this is what causes us to see various colors of feathers.

Yes, LIGHT is what determines color. But I am not talking about light. I'm talking about spatial frequencies. Spatial frequencies have nothing to do with light. Spatial frequencies are waves (two dimensional waves, to be precise), but not light.

Reflection, refraction, absorption...that is all a phenomena of photon-electron interaction at the atomic level. You can also include diffraction in that list as well...in some cases, some of the color patterns produced by bird feathers when illuminated by more direct light is the result of diffraction, as well as refraction and reflection. But again...that's light. I'm not talking about light, though. I am simply talking about shape and form and how those things can interfere...spatial structure.

1166
Software & Accessories / Re: Adobe Lightroom for iPad Coming Soon
« on: January 17, 2014, 11:17:42 PM »
Sorry to see LR take a cloud model.

Where does it say that???

99 is just the beginning.  Wait until you need that sharpening module only offered as an in-app add-on.

An in-app microtransaction that costs $9.99 itself.

1167
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 17, 2014, 11:16:59 PM »

Same thing goes for the feathers of a bird. Each barb is a wave crest, and the space between them is a trough. Overlay multiple feathers on top of each other, and you have a complex moire pattern.


And this very often is responsible for the various colors we perceive the feathers to be...but sometimes also the feathers have pigment...and sometimes it's both...correct?

Color would be different. I'm not talking about light waves, I'm talking about spatial waves. Color is determined by the ratio of energy absorption vs. energy reflection at the photon-electron interaction level in an atom. An object is red because it absorbs more of all other frequencies except red, and reflects more red than all other frequencies. ALL frequencies are absorbed, and ALL frequencies are reflected, the color of an object is ultimately determined by the amount of the spectrum reflected vs. not. A white object reflects all frequencies equally and absorbs all of them minimally, a black object also reflects all frequencies equally yet absorbs all of them significantly. This is also why darker objects tend to get hotter faster in the presence of electromagnetic energy, where as lighter objects get hotter slower.

Anyway, color is the result of an entirely different phenomena. When I say wave, I mean spatial frequency, not light wave.

1168
EOS Bodies / Re: The Next DSLR Will Be Entry Level [CR3]
« on: January 17, 2014, 11:13:15 PM »
When you consider that the vast bulk of Canon's camera sales are entry level, plus there are at least one new model per year, it would be far more surprising if they did not introduce an introductory model....

Canon, introducing the beginners introductory entry level DSLR model....can we multiply the notion that it is an "entry level" camera any further?  ::)

1169
EOS Bodies / Re: Will Canon ditch the AA Filter?
« on: January 17, 2014, 10:49:04 PM »
Your problem is that your thinking in terms of sky and frond, rather than waveform A and waveform B. If you decide to think of the problem as sky and fronds, then yes, you just have sky and fronds. You have to change your mode of thinking. It isn't sky and fronds interacting to produce...sky and fronds. It is waveform A and waveform B interacting to produce waveform AB' (which, yes, if you "imaged" waveform AB' you would have sky and fronds...but it would be sky and fronds in an entirely different and unique pattern that did not represent A or B distinctly...it would only represent aliases of A sky and fronds and B sky and fronds....does that make sense?)

I'm talking in terms of a general concept. As I said before, it depends on how you think about the problem. You can think of it as real-world objects, or you can think of it as something else...as discrete waveforms that interact. Generally speaking, of course...I am talking about moire in the abstract, not necessarily the specific. I was trying to demonstrate the concept at large.


Strictly speaking though those frond type and lines overlayed over lines moire patterns are not interfering waveforms though so the moire there really is not wave interference even in a general sense and it's something different (although there are direct similarities to what you'd get from a matched set of wave interferences, but it's different and you don't get the fringing and stuff and so on, you could 1:1 match the center point of the black parts and white parts or centers of the overlapped fronds and centers of the 'overlapped' sky parts to the very peaks and very troughs of matched interfering waveforms though).


They are a waveform, when "observed" as an image.You don't need a camera to think of things in different conceptual models...everything you see could be considered as represented in spatial waveform space. Technically speaking, rather than strictly speaking, everything in the universe exists with different representations in different conceptual models, and each one is valid. Anyway, this discussion has gone way off topic, so....


But the moire pattern isn't strictly a waveform interference pattern. I mean just go to the even simpler thick parallel black lines of slightly different spacing on transparencies and overlay them in various ways and look at the moire.  That's not classical waveform interference. The moire can be directly related in ways to waveform interference but a true waveform interference pattern of closest relation isn't the same.


The lines of your transparencies are part of a wave. The lines themselves, say black, are the "trough" of a wavelength, where as the transparency next to it is the crest. Moire occurs because you are overlaying two waveforms. Just because they are lines on a paper does not mean they cannot be modeled as a spatial frequency...a spatial frequency is exactly what they are. Thick black lines separated by thick bands of transparency is a wave of lower frequency, while thin black lines separated by thin bands of transparency are of higher frequency. This image from Norman Koren's site demonstrates:



Just a bunch of black and white lines, right? No, it's not...depending on how you model or observe the information, it is both lines, AND it is a wave. AND it's also a pattern. The red plot at the bottom models those lines differently than how we classically see them. ALL THREE representations (cage, wave, pattern) are correct and valid...simultaneously. Here is a visual example of moire in reality, caused by the interference of two parts of a monkey cage at a zoo (this moire has nothing to do with the sensor, as the patterns are all clearly much larger than sensor pixel size):



The monkey cage is no different than Norman's diagram...it simply exists in more dimensions rather than one. It all depends on how you decide to mentally and conceptually observe the information your eyes are seeing. Yes, it's just a monkey cage. But that cage's structure can be represented by a wave, as can the moire pattern produced by overlapping parts of the cage.

The nice thing about reducing all this stuff (despite the fact that it is very different real-world things like lines on transparency, monkey cages, pixels on a sensor, etc.) to waves is that you then have a single conceptual mental model with which to work with. ALL interference, therefor, is ultimately the same thing, can be modeled the same way, processed with the same mathematics, etc.

1170
Software & Accessories / Re: Adobe Lightroom for iPad Coming Soon
« on: January 17, 2014, 08:40:58 PM »
A yearly cost of $99 is WAY too much. Adobe has their pricing model jacked way up to 11, and they don't seem to realize it. The average cost of owning Adobe products in the past was a fraction of what it costs today for the average photographer and freelancer. While it maybe as cost effective for monstrous corporations, Adobe is seriously alienating their long term loyal individual customers with this inane pricing model. The per-app prices should be $3 - $5 per month, with maybe a few key apps like Photoshop at around $10 per month (simply because of the sheer volume of functionality they provide, which is indeed rather extensive).

If Adobe sticks with these ludicrous prices, someone is going to realize there is a massive and growing population of potential consumers for high quality products in the photographic editing segment, and they are going to deliver the goods at a reasonable price, at a rather massive long term cost to Adobe's bottom line. There is no way Adobe makes enough off of the big corporate users to support their business model if they lose the majority of their individual customers...which really begs the question:

Why are they trying to suck us dry like this?

It really doesn't make sense...

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