It's always strikes me as interesting to read the hyperbole that's written when new cameras are launched into the marketplace. If the camera replaces a previous model the makers and reviewers of the new camera try to "place" the performance of the two cameras in a relative way to each other. If the new camera is less noisy than the one it replaces the writers/reviewers and advertisers stumble all over themselves to try and present the differences between the two as "enormous."
One would think that the difference in overall image quality between an Olympus EM-5 and an EM-1 was so obvious that every man off the street would be able to instantly tell the differences between the two. In fact, I would say that the two cameras are more or less equally matched at most settings and that the only time one would see any difference (and it is small) would be when using both cameras at ISO 3200 and above. But even at the extremes it's not as if one camera is noise free and smoothly sharp while the other one gives you a mess of discordant graffiti. In the real world where we work and play the difference is more like a few more speckles and a bit bigger noise profile. Seen on a typical laptop screen even an expert would be hard pressed to divine the "special magic" of one over the other.
And when we venture into the world of video work that's shot with DSLRs, or mirror-free cameras, the same relationship applies. While reviewers gush over tiny differences the reality is that most people viewing the final images flashing by on their screens won't notice, or even be able to tell, that there is a glistening drop of difference between the two.
I'm as gullible as anyone out there but on the other hand I do like to buy stuff and use it in the real world and actually test it under fire. But lately I've been wondering just how much better the "wonder cameras" are than the "detestable" slouchy cameras. For instance, if you ask a lot of people on the web about shooting 1080p video with non-dedicated video cameras (you know, the ones without balanced mic inputs, zebras, and flat profiles, etc. that were designed only to shoot video...) they'll tell you that only certain cameras have the magic joss to be able to make moving images that won't give people headaches or make them nauseated.
In the plus column are cameras like the Canon 5D mk3, the Panasonic GH4 and the Sony A7s. In the blah/crap/soft column is pretty much everything else. Not only do those first three cameras have the magic but in most cases they have bigger, beefier codecs and they are pushing more megabytes per second into the mix which logically should create images of higher quality.
I own a GH4 and I've used it for a number of video projects and I'll tell you this: It's easy to shoot, easy to set up and the files that come from it are very sharp and detailed. More so at 4K but still very sharp and detailed at 2k resolution as well. I also recently acquired a Nikon D610 which is generally described (in regards to its video capabilities) as a "hobbled" camera. The general consensus is that the GH 4 is a "much" better video camera. The Nikon D610 is supposed to have softer files. You must exit video mode to change apertures. There is no focus peaking and certainly no zebras. The maximum information density provided by the camera to the SD card is a compressed 24 megabytes per second. Nothing compared to the 100 or even 200 megabytes per second that the GH4 is capable of providing.
So you would have to be a moron in order to prefer the Nikon D610 video over that of the GH4, right? Well, not so fast. If you only read about the cameras you can be comfortable taking the reviewer's word about the performance but if you pay the bills by doing work with your equipment then sooner or later you'll want to fire up all the cameras you have in stock and start doing some comparison tests. The wet and cold weather, and the general post holiday dormancy of clients, during the first week of the year provided the perfect opportunity for me to take a deeper look at the actual level of differences, in video performance, between four different cameras I've had sitting around. And, as in the book, "Lying with Statistics," it seems that many mountains of varying heights can be made from the substance of molehills.
I'll start with the classic comparison. It's between the GH3 and the GH4. The salivation machine that is the world wide web would have you believe (by consensus) that the GH4 is the new prince of the mirror-free camera video performance world and, amongst the Fuji's and the Olympus cameras on the marketing it's a pretty good thesis. The 1080P files from the GH4 can be very, very sharp and detailed. Much more so than the files from Fuji and Olympus. But is the new camera a "slam dunk" improvement in image quality over the previous model? Not really. Oh yes, it's got more features and more intense codecs to play with but for everyday work, shooting at the 100 mbs (all intra) versus the 72 mbs (all intra) of the GH3 there's very little discernible difference on a new 27 inch iMac screen when comparing moving images directly. Yes, you can go up to 200 mbs (all intra) on the GH4 but the chances of seeing much of a difference is minimal given that in both instances the footage is being shoehorned into basically 2000 x 1000 pixels, and all at 8 bits (maximum) of color. If you need the additional "handling" features of the GH4 or the 4K video image size the GH4 is an easy choice but when you base the differences on comparing 1080p apples to 1080p apples you're just as well off with the older model. At least when it comes to on card performance.
But the more interesting argument that is constantly made is just how bad Nikon's camera are for shooting good video. I'll agree whole heartedly about some depressing handling issues. You should be able to change apertures while shooting video. You should also be able to change sound levels during the production of the video. The Nikon D610 is hobbled in those regards. But I'm going to circle back and talk about the simplest thing: Image-to-image comparisons.
Common belief is that good video can only be produced by the Panasonic GH4 and the Canon 5D mk3. No one has really looked at the Sony DSLRs but if my experience with the a99 is representative then the codecs in those Sony consumer cameras give you a very, very soft file right out of the camera and so I have rejected them for video use ( I have not tested an a6000). Which is kinda crazy given Sony's extremely long experience in making first class, professional video gear. But soft is soft. The most recommended "hybrid" video cameras are the 5D3 ands the GH4. The assumption is that all the other players in the market suffer from some insurmountable stumbling blocks. That list of stumbling blocks includes: soft files (meaning: defocused, poorly down sampled and lacking detail), aliasing, moire, and shadow blocking. The inference is that Pentax, Samsung, the other m4:3 cameras and, of course, Nikons all suffer from some combination of these issues. Whatever the malady in each camera line it is portrayed as being serious enough to prevent the use of these cameras in any truly professional creative video endeavor.
So, of course I dragged out the Nikon D610, the D7100 and the GH family and started rolling video. And that's when the theology of the crossover camera universe started to crumble just a bit for me.
I set the Nikon cameras at their highest quality settings: 25 mbs, 1080p @30 fps. I set the Panasonic cameras at 50 mbs (which I tend to use for most video production aimed for the web or for the desktop) 1080p @30 fps and I started playing around. Here's what I saw. At the defaults the Nikon footage looked very smooth and noise free (all cameras set to ISO 200). At the defaults the GH cameras were both too sharp and too gritty. No real issues here. I can change the presets to make the Nikon's a bit coarser and sharper and I can change the default presets on the GH cameras to be a little softer, a bit more like real life.
But when I put the work up from all the cameras on a screen after ingesting the files into ProRes 4.2.2 files in Final Cut Pro X I found one area of the Panasonic v. Nikon performance in which Nikon (either camera) was the clear winner: Noise handling. Specifically shadow noise. With the GH4, on my middle green sweatshirt, especially in the shadow areas, there was continuous noise that was clearly visible. It won't bother some people who (like me) see the noise as film grain (no big color sparkles) but there are a couple of video pros I know who cringe when they see the footage. You can kill the noise somewhat by "crushing the blacks" but the overall look of the footage changes and it may not be what you had in mind for your production. The Nikons, on the other hand, were nearly noise free, and it was a very, very obvious difference.
While my tests didn't go on for hours and hours I was quickly convinced that the Nikon footage from these two recent models didn't have any of the foibles that the common knowledge community believes are inherent parts of their designs. The Panasonics were sharper (almost too sharp) but the Nikon files were not unsharp or even on the border line. In fact, there was ample detail in the files. Much more than I ever found in footage from the Canon 5D2 I owned and filmed with for a year and a half. In fact, if I had to choose from all of these cameras, in order to do interviews of people where the skin tones were important, I would easily choose the Nikons over the other cameras.
But it appears that we video newbies have been relying on the output directly from our camera's SD and CF slots too slavishly. If you really want to see how close the camera performances actually are (and how much better most consumer video footage can look) you need to start by spending around $400 for an Atomos Ninja Star and a C-Fast memory card. This will allow you to bypass all the compression your in-camera codec is applying to your video files. And most cameras are crunching data down into small, digestible packages that don't show off their real capabilities of their modern sensors very well.
Plug any recent Nikon or Panasonic GH series camera into the Atomos and you can get clean, uncompressed, 10 bit 4.2.2 video recorded directly into a professional editing codec like ProRes HQ. At that point you'll have files that can be banged around, edited, sharpened, saturated and twisted by colorists to make really great looking final footage. And that's because there's no compression and reams and reams of data to play with and change.
I've seen the files Panasonic files from the Atomos Ninja Star right in front of my face on my own monitor and they are packed with information and color that doesn't look like it will fall apart in post processing. The noise though is even stronger than what I was seeing in the compressed footage directly from the camera ( a result of the camera taking a "hands off" approach to the uncompressed files). I have not seen the D7100 or D610 footage from my own camera but I've looked all over the web for uncompressed Nikon footage and have seen some breathtaking stuff.
But getting all the way back to my original premise. If camera "A" is operating at 96.5 percent and camera "B" is operating at 96.8 percent what is the real difference between the two? Yes, it might be a measurable difference but is it a perceptual difference? And more importantly, is it an important difference?
If the efficacy in heart attack prevention with baby aspirin is +2% and the efficacy of another drug is +3% then the difference between the two drugs could be stated as being 33% difference in efficacy. But what of the other side effects?
If the Panasonic is sharper but noisier is that better than a file with less noise but not the same level of bite? If they can both be run through a digital video recorder and both can be profiled to imitate the other what will be the compelling reason to buy or not buy between the two models? What new differentiators will come to the fore?
At a certain point the choices start to narrow down to fixed parameters that can't be changed or modified. Do you need more depth of field in order to keep more of the image in focus at the same angle of view? Then the Panasonics with their smaller sensor geometry and very, very good lenses will be a smarter choice compared with a D610. Conversely, if you need to drop some annoying stuff out of a background and still need your frame just a bit wide you might have more luck with the Nikon.
There are other parameters that seem to be hardwired into the cameras by dint of their sensor designs. The Panasonic is more prone to shadow noise while the bigger Nikon chip (which is a hair away from the absolute state of the art for 35mm sized sensors) is almost noise proof at normal settings (up to 3200, at least). But that doesn't make the choice any bit of a slam-dunk. The handling characteristics of the GH4 are much better for video....and the overall look and color of a file is still subjective.
But how does a cheap camera like the D7100 compare? You can pick up a new one for about $1,000 and what you get is a different array of compromises. A bit more depth of field than the D610 but a bit more noise as well. Clumsier video handling than a GH4 or a GH3 and a fixed screen on the back to boot. But if you look at it in a vacuum you'd be hard pressed to find anything that's an ultimate production killer, beyond the inability to change audio levels and apertures during recording.
Again, put the clean D7100 HDMI signal into an outboard digital audio recorder and you're at par with a Canon 5D mk3, and with a nicer dynamic range into the bargain. And that seems to be the baseline everywhere. Most current DSLR and mirror-free cameras that do video these days seem to have their differences somewhat erased or leveled out when you remove the effects of the in-body compression and the tie to a particular codec. I'm presuming that the Olympus EM-1 can be configured (or will be updated to supply) uncompressed video via its HDMI port as well and we may find that the sensor is perfectly capable of matching the GH4 and coming close to the noise performance of the Nikon D7100 as well.
In fact, just about every camera capable of outputting clean, uncompressed video via an HDMI might all be closer to each other in terms of performance at 1080p video than most would admit. And that would certainly be an eye-opener and a game changer for people who presumed that what they were getting on their in-camera cards represented the best performance capabilities of their cameras.
All of this conjecture brings me right back to my seminal point: That the differences between the cameras is much smaller, generation by generation, than we are led to believe or than we are leading ourselves to believe. When we are in the heat of work we tend to put our heads down and just get our jobs done. Sometimes it is only later when we realize what great tools we had in those past moments. For example (and to answer the question of a VSL reader) let me talk for just a minute about the differences between the full frame D610 and the D7100 APS-C camera.
I am no different from everyone else and I read too much on the web. While I was vaguely happy and somewhat satisfied with the performance of the D7100 for two different jobs I used it for exclusively, I felt compelled, because of the desire construct created by advertising and the echo chamber effect of the web, to grab a full frame, Nikon D610 when the price dropped before Christmas. I was certain that clients would see the difference in quality between the two cameras and that I would certainly see the difference. But the reality is much different. For my commercial work it is very unusual to shoot anything so wide open that DOF is measured in single digit inches. We need some "focus safety" just in case people move around after I've focused on them. That quickly ameliorates one of the key differences.
I shot with both cameras but when I reviewed jobs from the quarter before I got the D610 (reviewed at my leisure during the holidays) I found the images from the 7100 to be exquisite. Some that I shot for a local school may be the best hand held work I have ever done. And that job was done mostly with two inexpensive lenses, the 18-140mm zoom and the 85mm f1.8 (not the more expensive 85mm f1.4!). The skin tones were perfect, the sharpness high and the colors perfect. Would the images have been better from the D610? No. They would have been different-- but not better. The trade off, used the way I would have used both cameras, would have been small, incremental changes in depth of field and nothing else. And there was no fixed metric of better or worse for what is almost entirely an aesthetic choice.
That led me to compare still images I'd done with the D7100 to another job I impulsively did entirely with two D7000 cameras. (This is the model that came out before the D7100, back in 2010. It has a three year older sensor and fewer pixels). In this comparison there was no real, discernible difference in image quality at any size in which I would use the the photographs. None. But on paper the D7100 should be a highly superior camera, technically. But if every job requires a "goodness threshold" of 85% and all your cameras are operating and creating images at over 90% you would logically never see a difference in the final use of the images. If you have a bucket that only holds a gallon does it really matter if you have million gallon tank from which to fill it?
Given how close these three cameras are to each other in making photographs that will be used at 13x19 inches and smaller I am now interested in hooking up the D7000 to an external video recorder and seeing how that sensor would do when freed from the constraints of the slower processing chips of the time and the need, back then, to write data out to slower cards on a slower bus. Of course they needed a higher level of compression then but how would the direct, uncompressed output of the same sensor look today? It would be interesting to find out but I'm not sure if the camera can output clean, uncompressed video via HDMI because that modality really wasn't on people's radar at the time the camera was launched.
That line of thought brings me around to something I've discussed here before and that is the role of raw software and its evolution. Many times I've taken a raw file from an older, six megapixel Kodak DCS 760 camera and reprocessed it in newer and newer raw converters and in every instance the file was improved. Sometimes a lot and sometimes a tiny bit, but in every test there was an improvement. Early on digital camera engineers were battling the speed of the pipeline. There was a need to get the files off the sensor and onto memory in something approaching a short amount of time. One of the things that made the Kodak DCS 760 notable in its time was the ability to shoot 20 or more raw images at a frame rate of 2 fps, continuously. Until then cameras had single digit raw buffers. Files were left uncompressed because compression would have added to the processing time which was more valuable and vulnerable than writing to the memory card. Since we have these totally uncompressed raw files at hand today we're able to see that progress of physical sensors was not nearly as rapid as the development of firmware, and related software functions for image processing, in cameras.
At the end of the test the real parameters that determine whether we pass or fail have to do with how well the video camera or still camera fills the required bucket. All the extras are window dressing without a results advantage. My belief is that all sensors in top flight cameras today can do wonderful things with still photography if the engineers leave the files in as uncompressed a form as possible. Especially important since the uncompressed files give us valuable content that can be reconstructed in better, future software with hardware the performance of which would seem miraculous to current or past camera makers. With the ability to address every pixel in the future raw converters, and associated predictive algorithms of the software, should be able to pull amazing things from our old work.
In the same logic the ability to give us uncompressed video files will give us the same ability to, in the future, bring these legacy files into ever more advanced software and will allow us to create motion pictures of increasingly amazing technical capability. But even more importantly the ability to capture uncompressed files give us a way to level the playing field between a large number of cameras with a wide range of prices and performance characteristics. That allows us to pick the right camera for the art not just the right camera for the best compromise of the day.
Finally, what if it's a given that a $1500 Nikon D610 sensor is able to record files that, when taken uncompressed, are delivering at a level of 95% of the quality of today's best video cameras in the world? And what if the king of the hill, the Arriflex Alexa, is operating at 99.9% of what is technically possible today. For the majority of projects done by the majority of people interested and engaged in video, is that difference of 4.9% worth an extra $50,000??? Will we see the difference when we watch the final product on our phones? On our laptops? On our desktops? Or, in the end will both cameras be equally good enough to fill the bucket?
And when we understand that point, as the best film makers do, we'll be able to move past the silly arguments about how much better one camera is over another and get on with the much harder work of using our imaginations to tell stories we don't know the endings to yet, and in ways that are created by the same imaginations to do things differently than ever before.
Someone will always make a better steak knife. But the steak knife is never as important as the steak.
Dammit. I forgot the advertising again. Oh well.
One would think that the difference in overall image quality between an Olympus EM-5 and an EM-1 was so obvious that every man off the street would be able to instantly tell the differences between the two. In fact, I would say that the two cameras are more or less equally matched at most settings and that the only time one would see any difference (and it is small) would be when using both cameras at ISO 3200 and above. But even at the extremes it's not as if one camera is noise free and smoothly sharp while the other one gives you a mess of discordant graffiti. In the real world where we work and play the difference is more like a few more speckles and a bit bigger noise profile. Seen on a typical laptop screen even an expert would be hard pressed to divine the "special magic" of one over the other.
And when we venture into the world of video work that's shot with DSLRs, or mirror-free cameras, the same relationship applies. While reviewers gush over tiny differences the reality is that most people viewing the final images flashing by on their screens won't notice, or even be able to tell, that there is a glistening drop of difference between the two.
I'm as gullible as anyone out there but on the other hand I do like to buy stuff and use it in the real world and actually test it under fire. But lately I've been wondering just how much better the "wonder cameras" are than the "detestable" slouchy cameras. For instance, if you ask a lot of people on the web about shooting 1080p video with non-dedicated video cameras (you know, the ones without balanced mic inputs, zebras, and flat profiles, etc. that were designed only to shoot video...) they'll tell you that only certain cameras have the magic joss to be able to make moving images that won't give people headaches or make them nauseated.
In the plus column are cameras like the Canon 5D mk3, the Panasonic GH4 and the Sony A7s. In the blah/crap/soft column is pretty much everything else. Not only do those first three cameras have the magic but in most cases they have bigger, beefier codecs and they are pushing more megabytes per second into the mix which logically should create images of higher quality.
I own a GH4 and I've used it for a number of video projects and I'll tell you this: It's easy to shoot, easy to set up and the files that come from it are very sharp and detailed. More so at 4K but still very sharp and detailed at 2k resolution as well. I also recently acquired a Nikon D610 which is generally described (in regards to its video capabilities) as a "hobbled" camera. The general consensus is that the GH 4 is a "much" better video camera. The Nikon D610 is supposed to have softer files. You must exit video mode to change apertures. There is no focus peaking and certainly no zebras. The maximum information density provided by the camera to the SD card is a compressed 24 megabytes per second. Nothing compared to the 100 or even 200 megabytes per second that the GH4 is capable of providing.
So you would have to be a moron in order to prefer the Nikon D610 video over that of the GH4, right? Well, not so fast. If you only read about the cameras you can be comfortable taking the reviewer's word about the performance but if you pay the bills by doing work with your equipment then sooner or later you'll want to fire up all the cameras you have in stock and start doing some comparison tests. The wet and cold weather, and the general post holiday dormancy of clients, during the first week of the year provided the perfect opportunity for me to take a deeper look at the actual level of differences, in video performance, between four different cameras I've had sitting around. And, as in the book, "Lying with Statistics," it seems that many mountains of varying heights can be made from the substance of molehills.
I'll start with the classic comparison. It's between the GH3 and the GH4. The salivation machine that is the world wide web would have you believe (by consensus) that the GH4 is the new prince of the mirror-free camera video performance world and, amongst the Fuji's and the Olympus cameras on the marketing it's a pretty good thesis. The 1080P files from the GH4 can be very, very sharp and detailed. Much more so than the files from Fuji and Olympus. But is the new camera a "slam dunk" improvement in image quality over the previous model? Not really. Oh yes, it's got more features and more intense codecs to play with but for everyday work, shooting at the 100 mbs (all intra) versus the 72 mbs (all intra) of the GH3 there's very little discernible difference on a new 27 inch iMac screen when comparing moving images directly. Yes, you can go up to 200 mbs (all intra) on the GH4 but the chances of seeing much of a difference is minimal given that in both instances the footage is being shoehorned into basically 2000 x 1000 pixels, and all at 8 bits (maximum) of color. If you need the additional "handling" features of the GH4 or the 4K video image size the GH4 is an easy choice but when you base the differences on comparing 1080p apples to 1080p apples you're just as well off with the older model. At least when it comes to on card performance.
But the more interesting argument that is constantly made is just how bad Nikon's camera are for shooting good video. I'll agree whole heartedly about some depressing handling issues. You should be able to change apertures while shooting video. You should also be able to change sound levels during the production of the video. The Nikon D610 is hobbled in those regards. But I'm going to circle back and talk about the simplest thing: Image-to-image comparisons.
Common belief is that good video can only be produced by the Panasonic GH4 and the Canon 5D mk3. No one has really looked at the Sony DSLRs but if my experience with the a99 is representative then the codecs in those Sony consumer cameras give you a very, very soft file right out of the camera and so I have rejected them for video use ( I have not tested an a6000). Which is kinda crazy given Sony's extremely long experience in making first class, professional video gear. But soft is soft. The most recommended "hybrid" video cameras are the 5D3 ands the GH4. The assumption is that all the other players in the market suffer from some insurmountable stumbling blocks. That list of stumbling blocks includes: soft files (meaning: defocused, poorly down sampled and lacking detail), aliasing, moire, and shadow blocking. The inference is that Pentax, Samsung, the other m4:3 cameras and, of course, Nikons all suffer from some combination of these issues. Whatever the malady in each camera line it is portrayed as being serious enough to prevent the use of these cameras in any truly professional creative video endeavor.
So, of course I dragged out the Nikon D610, the D7100 and the GH family and started rolling video. And that's when the theology of the crossover camera universe started to crumble just a bit for me.
I set the Nikon cameras at their highest quality settings: 25 mbs, 1080p @30 fps. I set the Panasonic cameras at 50 mbs (which I tend to use for most video production aimed for the web or for the desktop) 1080p @30 fps and I started playing around. Here's what I saw. At the defaults the Nikon footage looked very smooth and noise free (all cameras set to ISO 200). At the defaults the GH cameras were both too sharp and too gritty. No real issues here. I can change the presets to make the Nikon's a bit coarser and sharper and I can change the default presets on the GH cameras to be a little softer, a bit more like real life.
But when I put the work up from all the cameras on a screen after ingesting the files into ProRes 4.2.2 files in Final Cut Pro X I found one area of the Panasonic v. Nikon performance in which Nikon (either camera) was the clear winner: Noise handling. Specifically shadow noise. With the GH4, on my middle green sweatshirt, especially in the shadow areas, there was continuous noise that was clearly visible. It won't bother some people who (like me) see the noise as film grain (no big color sparkles) but there are a couple of video pros I know who cringe when they see the footage. You can kill the noise somewhat by "crushing the blacks" but the overall look of the footage changes and it may not be what you had in mind for your production. The Nikons, on the other hand, were nearly noise free, and it was a very, very obvious difference.
While my tests didn't go on for hours and hours I was quickly convinced that the Nikon footage from these two recent models didn't have any of the foibles that the common knowledge community believes are inherent parts of their designs. The Panasonics were sharper (almost too sharp) but the Nikon files were not unsharp or even on the border line. In fact, there was ample detail in the files. Much more than I ever found in footage from the Canon 5D2 I owned and filmed with for a year and a half. In fact, if I had to choose from all of these cameras, in order to do interviews of people where the skin tones were important, I would easily choose the Nikons over the other cameras.
But it appears that we video newbies have been relying on the output directly from our camera's SD and CF slots too slavishly. If you really want to see how close the camera performances actually are (and how much better most consumer video footage can look) you need to start by spending around $400 for an Atomos Ninja Star and a C-Fast memory card. This will allow you to bypass all the compression your in-camera codec is applying to your video files. And most cameras are crunching data down into small, digestible packages that don't show off their real capabilities of their modern sensors very well.
Plug any recent Nikon or Panasonic GH series camera into the Atomos and you can get clean, uncompressed, 10 bit 4.2.2 video recorded directly into a professional editing codec like ProRes HQ. At that point you'll have files that can be banged around, edited, sharpened, saturated and twisted by colorists to make really great looking final footage. And that's because there's no compression and reams and reams of data to play with and change.
I've seen the files Panasonic files from the Atomos Ninja Star right in front of my face on my own monitor and they are packed with information and color that doesn't look like it will fall apart in post processing. The noise though is even stronger than what I was seeing in the compressed footage directly from the camera ( a result of the camera taking a "hands off" approach to the uncompressed files). I have not seen the D7100 or D610 footage from my own camera but I've looked all over the web for uncompressed Nikon footage and have seen some breathtaking stuff.
But getting all the way back to my original premise. If camera "A" is operating at 96.5 percent and camera "B" is operating at 96.8 percent what is the real difference between the two? Yes, it might be a measurable difference but is it a perceptual difference? And more importantly, is it an important difference?
If the efficacy in heart attack prevention with baby aspirin is +2% and the efficacy of another drug is +3% then the difference between the two drugs could be stated as being 33% difference in efficacy. But what of the other side effects?
If the Panasonic is sharper but noisier is that better than a file with less noise but not the same level of bite? If they can both be run through a digital video recorder and both can be profiled to imitate the other what will be the compelling reason to buy or not buy between the two models? What new differentiators will come to the fore?
At a certain point the choices start to narrow down to fixed parameters that can't be changed or modified. Do you need more depth of field in order to keep more of the image in focus at the same angle of view? Then the Panasonics with their smaller sensor geometry and very, very good lenses will be a smarter choice compared with a D610. Conversely, if you need to drop some annoying stuff out of a background and still need your frame just a bit wide you might have more luck with the Nikon.
There are other parameters that seem to be hardwired into the cameras by dint of their sensor designs. The Panasonic is more prone to shadow noise while the bigger Nikon chip (which is a hair away from the absolute state of the art for 35mm sized sensors) is almost noise proof at normal settings (up to 3200, at least). But that doesn't make the choice any bit of a slam-dunk. The handling characteristics of the GH4 are much better for video....and the overall look and color of a file is still subjective.
But how does a cheap camera like the D7100 compare? You can pick up a new one for about $1,000 and what you get is a different array of compromises. A bit more depth of field than the D610 but a bit more noise as well. Clumsier video handling than a GH4 or a GH3 and a fixed screen on the back to boot. But if you look at it in a vacuum you'd be hard pressed to find anything that's an ultimate production killer, beyond the inability to change audio levels and apertures during recording.
Again, put the clean D7100 HDMI signal into an outboard digital audio recorder and you're at par with a Canon 5D mk3, and with a nicer dynamic range into the bargain. And that seems to be the baseline everywhere. Most current DSLR and mirror-free cameras that do video these days seem to have their differences somewhat erased or leveled out when you remove the effects of the in-body compression and the tie to a particular codec. I'm presuming that the Olympus EM-1 can be configured (or will be updated to supply) uncompressed video via its HDMI port as well and we may find that the sensor is perfectly capable of matching the GH4 and coming close to the noise performance of the Nikon D7100 as well.
In fact, just about every camera capable of outputting clean, uncompressed video via an HDMI might all be closer to each other in terms of performance at 1080p video than most would admit. And that would certainly be an eye-opener and a game changer for people who presumed that what they were getting on their in-camera cards represented the best performance capabilities of their cameras.
All of this conjecture brings me right back to my seminal point: That the differences between the cameras is much smaller, generation by generation, than we are led to believe or than we are leading ourselves to believe. When we are in the heat of work we tend to put our heads down and just get our jobs done. Sometimes it is only later when we realize what great tools we had in those past moments. For example (and to answer the question of a VSL reader) let me talk for just a minute about the differences between the full frame D610 and the D7100 APS-C camera.
I am no different from everyone else and I read too much on the web. While I was vaguely happy and somewhat satisfied with the performance of the D7100 for two different jobs I used it for exclusively, I felt compelled, because of the desire construct created by advertising and the echo chamber effect of the web, to grab a full frame, Nikon D610 when the price dropped before Christmas. I was certain that clients would see the difference in quality between the two cameras and that I would certainly see the difference. But the reality is much different. For my commercial work it is very unusual to shoot anything so wide open that DOF is measured in single digit inches. We need some "focus safety" just in case people move around after I've focused on them. That quickly ameliorates one of the key differences.
I shot with both cameras but when I reviewed jobs from the quarter before I got the D610 (reviewed at my leisure during the holidays) I found the images from the 7100 to be exquisite. Some that I shot for a local school may be the best hand held work I have ever done. And that job was done mostly with two inexpensive lenses, the 18-140mm zoom and the 85mm f1.8 (not the more expensive 85mm f1.4!). The skin tones were perfect, the sharpness high and the colors perfect. Would the images have been better from the D610? No. They would have been different-- but not better. The trade off, used the way I would have used both cameras, would have been small, incremental changes in depth of field and nothing else. And there was no fixed metric of better or worse for what is almost entirely an aesthetic choice.
That led me to compare still images I'd done with the D7100 to another job I impulsively did entirely with two D7000 cameras. (This is the model that came out before the D7100, back in 2010. It has a three year older sensor and fewer pixels). In this comparison there was no real, discernible difference in image quality at any size in which I would use the the photographs. None. But on paper the D7100 should be a highly superior camera, technically. But if every job requires a "goodness threshold" of 85% and all your cameras are operating and creating images at over 90% you would logically never see a difference in the final use of the images. If you have a bucket that only holds a gallon does it really matter if you have million gallon tank from which to fill it?
Given how close these three cameras are to each other in making photographs that will be used at 13x19 inches and smaller I am now interested in hooking up the D7000 to an external video recorder and seeing how that sensor would do when freed from the constraints of the slower processing chips of the time and the need, back then, to write data out to slower cards on a slower bus. Of course they needed a higher level of compression then but how would the direct, uncompressed output of the same sensor look today? It would be interesting to find out but I'm not sure if the camera can output clean, uncompressed video via HDMI because that modality really wasn't on people's radar at the time the camera was launched.
That line of thought brings me around to something I've discussed here before and that is the role of raw software and its evolution. Many times I've taken a raw file from an older, six megapixel Kodak DCS 760 camera and reprocessed it in newer and newer raw converters and in every instance the file was improved. Sometimes a lot and sometimes a tiny bit, but in every test there was an improvement. Early on digital camera engineers were battling the speed of the pipeline. There was a need to get the files off the sensor and onto memory in something approaching a short amount of time. One of the things that made the Kodak DCS 760 notable in its time was the ability to shoot 20 or more raw images at a frame rate of 2 fps, continuously. Until then cameras had single digit raw buffers. Files were left uncompressed because compression would have added to the processing time which was more valuable and vulnerable than writing to the memory card. Since we have these totally uncompressed raw files at hand today we're able to see that progress of physical sensors was not nearly as rapid as the development of firmware, and related software functions for image processing, in cameras.
At the end of the test the real parameters that determine whether we pass or fail have to do with how well the video camera or still camera fills the required bucket. All the extras are window dressing without a results advantage. My belief is that all sensors in top flight cameras today can do wonderful things with still photography if the engineers leave the files in as uncompressed a form as possible. Especially important since the uncompressed files give us valuable content that can be reconstructed in better, future software with hardware the performance of which would seem miraculous to current or past camera makers. With the ability to address every pixel in the future raw converters, and associated predictive algorithms of the software, should be able to pull amazing things from our old work.
In the same logic the ability to give us uncompressed video files will give us the same ability to, in the future, bring these legacy files into ever more advanced software and will allow us to create motion pictures of increasingly amazing technical capability. But even more importantly the ability to capture uncompressed files give us a way to level the playing field between a large number of cameras with a wide range of prices and performance characteristics. That allows us to pick the right camera for the art not just the right camera for the best compromise of the day.
Finally, what if it's a given that a $1500 Nikon D610 sensor is able to record files that, when taken uncompressed, are delivering at a level of 95% of the quality of today's best video cameras in the world? And what if the king of the hill, the Arriflex Alexa, is operating at 99.9% of what is technically possible today. For the majority of projects done by the majority of people interested and engaged in video, is that difference of 4.9% worth an extra $50,000??? Will we see the difference when we watch the final product on our phones? On our laptops? On our desktops? Or, in the end will both cameras be equally good enough to fill the bucket?
And when we understand that point, as the best film makers do, we'll be able to move past the silly arguments about how much better one camera is over another and get on with the much harder work of using our imaginations to tell stories we don't know the endings to yet, and in ways that are created by the same imaginations to do things differently than ever before.
Someone will always make a better steak knife. But the steak knife is never as important as the steak.
Dammit. I forgot the advertising again. Oh well.
