September 02, 2014, 04:42:46 PM

Show Posts

This section allows you to view all posts made by this member. Note that you can only see posts made in areas you currently have access to.


Messages - jrista

Pages: 1 ... 77 78 [79] 80 81 ... 277
1171
EOS Bodies - For Stills / Re: 7D vs. 70D: Which has better image quality?
« on: February 26, 2014, 02:57:45 PM »
Do you think that keeping my Sigma back a little at the 400mm level and increasing the ISO ( like 400-800) and aperture to f8 or narrower will offer me better clarity on the 70D body?

Nope, the lens is already outresolved esp. on crop, the tiny sensor difference will be lost. You'll get 2mp more of blur though :-p ... face it - there are no good and inexpensive 400-500mm tele zooms, it's better to crop a good 300mm. Btw all I can look at are the charts, and I don't see any reasons why the conclusion shouldn't be valid.

Sigh. The message just doesn't seem to sink in.

There is no such thing as sensors outresolving lenses or lenses outresolving sensors. Output resolution, the measurable resolution of your images, is the RMS of the resolutions of the components involved in producing the  image. Lenses, additionally, are non-linear. At some apertures their intrinsic resolving power may be less than the sensor, and at other apertures, it may be more (sometimes MUCH more) than the sensor. By increasing sensor or lens resolution, regardless of which one is doing better, will still increase output resolution. (And we are still quite far away from diminishing returns yet, so increasing sensor resolution is still the cheapest way to increase output resolution.)

As for the comment about there not being any good inexpensive 400-500mm zooms, I beg to differ. The Tamron 150-600mm has been tested and demonstrated to be quite good for it's class. It's no EF 600mm f/4 L II, but it is the closest thing your going to get, and there is really no alternative for good optical reach. Even at f/8, a 600mm lens is going to increase subject area by 2.25x relative to a 400mm lens. It would increase subject area by a full factor of 4x relative to a 300mm lens. The fact that the lens is diffraction limited at that point is irrelevant. There is absolutely no way that an upsampled 300mm crop is ever going to compare to an uncropped, unscaled 600mm image. Simply not going to happen. You can't overcome four times as many pixels on subject.

Thanks for the comments guys, I like the Digital Picture comparison charts, but they just don’t drum in “real life” comparisons that I can draw from.
Do you think that keeping my Sigma back a little at the 400mm level and increasing the ISO ( like 400-800) and aperture to f8 or narrower will offer me better clarity on the 70D body?  Just a thought as I think I’ll be able to get away with those settings in most cases as it’s full on sunshine here 365 days a year!  8)  Ultimately I’d love to own a 300mmL prime with a 1.4X and a 2X convertor, but that’ll be next years challenge.  I think you’ve answered my question regarding the 70D's IQ, I’ve set my heart on it and will be buying one next month, hopefully before I go to Berlin!!  I’ve also managed to bag myself a mint condition 24-105L so I’ll be in a good place in a couple of months ;)

If you have the 300mm f/2.8 L, then you already have a superb lens. Using a 2x TC is easy, and at 600mm you have four times the detail on your subject. Regarding aperture, use the aperture you need to get the necessary DOF. Don't worry too much about ISO, especially at ISO 400-800. The 70D should do quite well up to ISO 1600. It is only when you get beyond ISO 1600 that your IQ may start to degrade enough that you might need to be concerned, however the 70D is sharper than the 7D, and sharpness eats noise for breakfast. (Background blur, on the otherhand, tends to be eaten by noise for breakfast, lunch, and dinner, but blurry backgrounds are super easy to clean up, so it really doesn't matter much.)

If you need reach (i.e. you shoot birds or wildlife), then there is really no substitute for optical magnification. Raw focal length is your best friend. Backing off your focal length from longer to shorter is actually a bad idea. Instead of thinking about upsampling a crop from a shorter lens, think about downsampling the full image from a longer lens. No matter how you slice it, a downsampled image from a longer focal length will have more detail and less or equivalent noise to any image shot at a shorter focal length.

1172
PowerShot / Re: Canon to Leave the Entry Level Point & Shoot Market?
« on: February 26, 2014, 02:45:31 PM »
Smartphones are integrated into the internets and social media.  That's what killed P&S cameras.  Quality means nothing in this segment.
True, I think convenience beat out quality here ... I shoot more with my smart phone than any other camera. of course none of them are for artistic reasons, I use my smartphone to take pictures of newspaper adverts, take photos of important documents (and use it as a scanned copy), restaurant menus, screen shots and whatnot. I suppose for those who are not "into" photography, a smartphone is far more better and convenient/useful than any high end camera or camcorder.

I think its not just convenience...its the whole "the camera in the hand" argument. I mean, it's convenient having a camera on your phone...but the big issue is that, everyone has their phone. It's ALWAYS on their person. No matter how good a dedicated camera device may be, the only camera that really matters is the one you have on your person, the one you can put in your hand at a moment's notice. There is really no competing with a universal device that is always on and always in hand. Phone camera controls are often very inconvenient. Even Lumia's new Nokia Camera software, while better, is still not convenient. It's tedious. But it's the camera I have in hand all the time.

1173
EOS Bodies / Re: Will the next xD cameras do 4k?
« on: February 26, 2014, 02:42:53 PM »
So do you believe Canon is willing to cannibilize their cinema line with xD bodies RIGHT NOW?

Two of the 3 mirrorless cinema cameras only do 1080p video, while with the recent release of the 1200D all EOS DSLRs can also record 1080p video.This partial overlap of features has existed from the start, I don't see why extending it to 2160p video recording would suddenly be a problem. You invented the "RIGHT NOW" yourself, the earliest xD release we can expect is in 6 months - end of march is more likely to be the release of a 750D and/or a 100D successor.

My apologies for applying the same line of argument towards you as with previous posters. The reasoning behind the mentions of right now or in the very near future were because some in here believe that the GH4 is somehow going to have such a significant impact on the market that it will force Canon's hand into xD level 4k soon.

In a nutshell, I am merely saying that I don't believe anything that Panasonic is doing right now is going to push Canon to do anything it wasn't already planning to do or change their timeline for doing it. They may very well put 4k in something in 12 months. But it doesn't mean Panasonic was any part of the conversation that led to that decision.

The comment about the GH4 being the fire that would spur Canon into action and put 4k in all their cameras is what originally spurred the debate. There is no question that 4k is around the corner. How far off that corner is is up for debate...some seem to think were right on top of it, but from a consumer consumption standpoint, it's still a few years off...sometime 2016 at the earliest is when I think people will begin to regularly buy 4k TVs and might start getting 4k computer screens and would then actually be able to utilize the 4k video they are taking with their phones (assuming they ARE taking 4k video...I suspect 1080 and 720 will remain the video choices of consumers for a while yet, due to smaller files, quicker upload times.)

The GH4 is not going to spur Canon into action. That's been the debate in this thread for some time, and I completely agree with John here. Canon just isn't threatened by Panasonic. They aren't even really threatened by Nikon, who is their largest competitor by market share! Canon will do what Canon does on Canon's timetable. For those who don't like that, you might as well pick up a 4k "camera" from some other manufacturer, because Canon won't make a broad move into 4k until they are sure to make a boatload off of the feature.

As far as high end DSLRs go, Canon may bring 4k to the 1D X an 5D III via firmware. Their sensors are high enough resolution, and for standard cinematic frame rates, they have enough bandwidth for compressed 4k. When it comes to RAW 4k, I really do not expect to see that from any lower end Canon DSLR that currently exists, and I suspect it will end up being relegated to Cinema EOS and Magic Lantern. But as others have already mentioned, to handle RAW 4k, you need significantly greater storage throughput, so that is unlikely to happen until the next generation of high end DSLRs. I figure there is a 50/50 chance the 7D II will get it...depends on whether the rumor about it being more video-heavy are true or not.

1174
PowerShot / Re: Canon to Leave the Entry Level Point & Shoot Market?
« on: February 24, 2014, 11:25:49 PM »
Also, the article was japanese...who knows if it really has anything to do with the sales of these models in western countries. If they are still making money on them here (I kind of doubt they are making all that much still, especially with the likes of the iPhone and Lumia 1020 on the market), they may still sell them here.

FWIW, the Americas and Europe each accounted for ~30% of fixed-lens cameras in 2013, so 'western countries' are buying the majority of P&S cameras (although the distribution of high end vs. low end could vary by geography).

So, is that 60% of a market that shrunk by 40% over the last three years, or a broader market? I mean, if the market is shrinking, and western countries were the bulk of the sales in that market, then that would seem to mean that the bulk of the shrink in market share came from us as well.

So even if we are the major buyers of "fixed-lens cameras" (that's pretty broad right there...it encompasses  more than the sub $200 camera market), then I am not really surprised by the article or the claim that Canon is going to ease out of the ultra low end of that market. I know a LOT more people these days have the Lumia 1020 here in Colorado. I see them everywhere now (I have the Lumia 920, and the large lens on the back of everyone else' Lumia is always telling me I need to upgrade! :P) Everyone else has an iPhone...I rarely ever see anyone taking pictures with a cheap P&S anymore...everyone does their photography with their phones (and there are of course the few nitwits who take photos with their giant iPads as well.)

1175
EOS Bodies / Re: Will the next xD cameras do 4k?
« on: February 24, 2014, 09:19:22 PM »
But where are the 4k computer screens and 4k TVs that people need to view those videos on?

In the shops would be my guess ... http://en.wikipedia.org/wiki/4K_resolution#List_of_4K_monitors.2C_TVs_and_projectors ...  :D

LOL!

Sure, at $40,000 a TV and $3000 a computer screen. That isn't consumer-level pricing. When TV's get down to $2000 and screens get down to $200, then were talking broad consumer consumption. We aren't even close to that yet.

http://www.amazon.com/Seiki-Digital-SE39UY04-39-Inch-Ultra/dp/B00DOPGO2G/ref=sr_1_1?ie=UTF8&qid=1393293262&sr=8-1&keywords=4k+ultra+hdtv

Ah. Well, I'm happy to admit that's a game changer. I don't generally look at unknown off brands, but this is definitely consumer grade pricing.

1176
PowerShot / Re: Canon to Leave the Entry Level Point & Shoot Market?
« on: February 24, 2014, 09:15:35 PM »
Fixed lens cameras accounted for ~46% of the total revenue from digital cameras last year.  In general, the cheaper models of a given product line outsell the high end models.  Seems like a lot of ¥ to throw away.

Based on the actual article (translated from japanese), it doesn't sound like they are exiting immediately. The chart does show some fairly significant declines in the market (by about 40%) since 2010. The article also says they will be halving their market participation every couple of years...so they aren't going to be exiting over night. They will be diminishing their presence in the ultra low end range of that market, and shifting the excess resources to other cameras at the higher end of the range of that market. It doesn't even sound like they are going to be shifting the resources to DSLRs...just more lucrative compact camera models and accessories.

It really doesn't sound like they are throwing away money, it sounds like they are shifting their resources to maximizing the potential of that market where there is still potential to be had.

Also, the article was japanese...who knows if it really has anything to do with the sales of these models in western countries. If they are still making money on them here (I kind of doubt they are making all that much still, especially with the likes of the iPhone and Lumia 1020 on the market), they may still sell them here.

1177
Second, microlenses are used on ALL sensors nowadays. The advantage of microlenses is not solely given to APS-C sensors, therefor there is no advantage at all.

That's not the point. The point is that with microlenses in place there is little difference between a sensor with 18m physical pixels (60D) and one with 40m physical pixels (70D). The light is directed toward one pixel or another, so pixel size does not have a significant impact on total image noise.

The 7D does not have 40 million physical pixels. It has 20.2 million physical pixels, who's photodiodes are split in half. There is a BIG difference there!! HUGE DIFFERENCE. From a light gathering standpoint, the 70D has 20.2mp, vs. the 60D 18mp. That is only a 2.2mp difference, not a 22.4mp difference. Please don't exaggerate this, because your being exceptionally misleading about how the 70D sensor is designed. It is NOT 40.4 million pixels...it's 20.2 million pixels. PIXELS. Not independently read or binnable photodiodes, but pixels. There is ALWAYS two photodiodes binned and read per output pixel when it comes to doing an image read (image read, in contrast to an AF read, which is entirely different and not valid in the context of discussing IQ.)

Quote
Microlenses only serve to increase the incident light on the photodiode. That does not change the photodiodes capacity.

True. But that's about DR, not image noise. People...like the guy who started this thread...honestly think if Canon gave them an 8 MP sensor with modern circuitry that it would be some kind of super high ISO performer. It wouldn't do any better then a 70D on noise, though it should have better DR.

Sorry, but wrong. The more light on you get to the photodiode, the more charge you are  going to accumulate in less time. That means you can get away with a lower gain for each ISO setting. That is SPECIFICALLY about noise, not DR. I mean image signal noise. Read noise is an entirely different beast, and does not really apply here.

Quote
I'd also point out that even with microlenses today, we aren't even close to 100% capture.

Source? Also: if it's not 100%, it seems to at least be sufficient to make pixel density irrelevant (again, 70D vs. 60D, or any modern high density sensor with microlenses vs. a lower density sensor before microlenses.)

The source would be dozens of patents. Go read ImageSensorsWorld or find where Chipworks breaks down sensors, then dig up the patents mentioned. You'll learn a lot about Q.E. and total light percentage incident on the photodiode. And that's really what matters here, the light incident on the photodiode itself. A "pixel" is more than just a photodiode...but only the photodiode is actually sensitive to light.

Here is one link: http://image-sensors-world.blogspot.com/2014/02/sharp-explains-ishccd-improvements.html

This is Sharps improved microlens (and it also talks about deep photodiodes, however this is for an IR camera, so the deeper photodiode doesn't apply the same way to visible light photography.) Sony, Samsung, and others also have similar patents for improved mirolenses, although I think Sharp's is a bit more advanced as it's newer (although there is still going to be off-axis light incident on the microlens that is still going to be lost, hence the reason Sony employs a double-layered microlens design, and I believe Canon may ultimately employ a double-layer approach in the future for their compact cameras as well.)

Even with improved microlenses, your still not getting 100% focus nor 100% conversion. The silicon of the photodiode itself has a specific Q.E. These days, at room temperature, about the highest Q.E. your going to get is about 65%, and most sensors are between 40-55% Q.E. So, assuming you did somehow accurately focus 100% of the light incident on the microlens directly onto the photodiode (a logical fallacy, it is impossible to get 100% efficiency out of ANYTHING), your still going to be losing 40-60% of that light simply because not every photon that strikes the photodiode is going to actually free an electron. Some are simply absorbed and converted into heat, and a small amount will even reflect off the photodiode itself.

Advancements in nano-scale silicon manufacture have given rise to things like nano-spikes and black silicon. Both of these work to produce a gradient transition between the well and the photodiode. Somewhat like a nanocoating works on a lens...by eliminating any abrupt transitions in index of refraction, you dramatically reduce the chance of a photon reflecting in the first place. Such advancements, if they make their way into still photography sensors, might increase Q.E. into the 70% range or so at room temperatures.

Quote
Third, the 70D is not a 40.4mp sensor. It is a 20.2mp sensor.

I would say at the hardware level you guys are talking about, it is a 40.4 MP sensor. The pixels are physically separated and basically half the normal size.

No, the photodiodes are split in half, but every pixel has two binned photodiodes. As I already said above, the pixels are what matter, because when you bin the charge in both photodiodes, the outcome is identical to having one single photodiode per pixel.

But who cares? Feel free to compare other sensors. Direct observations do not support the idea that a lower density sensor would automatically yield superior high ISO. And if this were the case, someone would be doing it.

Density is a matter of perspective here. You don't seem to have read the rest of my answer about wildlife photography. Assuming identical framing and identical aperture, the 5D III is technically a DENSER sensor than the 7D or 70D. With identical framing and aperture, you end up with MORE pixels on your subject...AND those pixels are bigger. This does not contradict equivalence, as a matter of fact it is entirely in line with it. The only difference is that equivalence assumes the aperture is stopped down and the ISO is increased in order to reach equilibrium.

My point is that in real live, we don't always do that. As a matter of fact, in real life, I would RARELY do that. In real life, the chances that I would be using a longer focal length with a faster aperture is very real, and highly probable, in which case no APS-C camera could ever possibly compare to any FF camera. Pixel size doesn't even matter here...all that matters is total sensor area, really. For any given aperture, at identical framing, the larger sensor is gathering more light in total.

Quote
Outside of that...it's all just theory, theory that otherwise indicates that the FF sensor will always have the advantage at the same or faster aperture than the APS-C sensor is used at

Unless you happen to want more DoF and not less  ;)

If you want more DOF, you can always have more DOF. But again, the FF camera is better, because you have more options there. You can have much thinner DOF with FF than with APS-C at any given focal length, without requiring more complicated retrofocal designs that eat away at IQ to get those ultra wide focal lengths and still have nice boke.

As I said, the one single use case where cropped sensor is better is when you are literally reach-limited. You cannot get closer, you only have one focal length. In that case, smaller pixels are better. Don't get me wrong, here. I've argued that use case a lot! I'm usually on your side, because that advantage for cropped sensors isn't given enough credit. (People mostly only credit APS-C with being cheaper.) For a lot of people, especially people who ARE on a budget, the reach advantage of a high performance cropped sensor camera like the 7D (or 7D II, as the case may be) is well and truly valuable. I most certainly don't deny the value of having a cropped sensor. It is valueable, and it can allow a LOT of aspiring bird and wildlife photographers the option to frame tightly without having to get closer than their skill may allow. That was and is my argument for getting the 7D in the first place.

I just have to point out that in every other circumstance, where you are not reach limited, FF sensors will do better. Bigger pixels, more pixels, and the ability to get more total light AND more pixels on your subject. You are basically trying to use the theory of equivalence for the exact opposite of what it actually says, which is that for any given quantity of light, a FF sensor is gathering more light in total...not the other way around.

Pixels on subject is really at the heart of the matter here. With a 5D III, I always have the option (although maybe not necessarily the ability in fringe cases) to get more pixels on my subject, and because the 5D III pixels are bigger...well, there is just no contest. No APS-C sensor could ever compare. Even assuming I did stop down...all that serves to do is reduce the IQ of the 5D III to the level of an APS-C sensor...it does nothing to lift the IQ of the APS-C sensor up.

1178
Has it ever been rumored for their to be prototypes in testing of what would essentially be a physical 1.6x crop of a FF sensor, allowing the ISO capabilities of the 6D/5D3 in, say, an EOS M or xxD body?

I'd love me an EOS M with 6-9 megapixels of low light goodness!

Thoughts?

Would this be stupid-expensive to develop? I can imagine the right advertising campaign could sell the concept of fewer pixels for low light, arty, shallow DoF shooting with the 22mm f/2 with results that're still 2-4x larger than necessary for Facebook ;)

Your post shows a fundamental misunderstanding of how cameras work.

There is no difference between low light performance when adding more pixels in the range of pixels that DSLR's typically have. The issue with more pixels = more noise is only relevant to ultra compact sensors, like smartphones.

There USED to be an issue with more pixels adding more noise BEFORE micro lenses were invented.



Let's just do the math.

According to DXO Mark's sensor tests. The Canon 70D which has 40.4 megapixels which are binned into 20.2 mp in files and has ISO performance that is equal at 2.5 times it's ISO rating compared to the 5D Mark III, which has 22.3 megapixels. The 5DIII has around 5 times less pixel density than the 70D.

So ISO 1000 on the 70D = same noise as ISO 2500 on the 5D Mark III.

The 70D has a sensor area that is 1/2.5 times that of the 5D Mark III. Wait a second... isn't that the exact difference between the 70D and the 5D Mark III's ISO? Yes it is!

Because the sensor is 2.5 times smaller the GAIN on the smaller sensor has to be 2.5 times higher for a given illumination to get the same exposure. Meaning if you cropped the 5D Mark III's sensor to APS-C ISO 2500 would now be called ISO 1000, even though the sensor gain is identical.

With current sensor technology there is no meaningful difference between the noise sensitivity of larger pixels to smaller pixels in DSLRs. That's why Canon can go from an 18 megapixel sensor in the 60D to a 40.4 megapixel sensor and actually improve noise performance in the 70D. That's why the 36 megapixel D800 and the 22.3 megapixel 5D3 have the same noise performance.

The reason why full frames are better than APS-C sensors is aperture and sharpness.

An APS-C camera has the exact same depth of field at equivalent focal lengths to a full frame camera when the APS-C camera is at f/1.75 and the full frame is at f/2.8. Or when the APS-C is at f/2.5 and the full frame is at f/4.0.

That's why the Sigma 18-35mm f/1.8 on crop gives you the same look as a 24-70mm f/2.8 lens on full frame.

What this means is that if you put an f/1.4 lens on a full frame you are shooting at f/0.85 on crop, and there are very few f/0.85 lenses. That's why full frame is better in low light, because on crop you are shooting at way lower equivalent aperture and the lenses available for full frame tend to have faster apertures.

Even though you can design faster lenses for crop than you can for full frame (f/0.85 40mm lenses for example exist for crop but not full frame) full frame is better than crop because it is much easier to design a lens with a given equivalent aperture and equivalent focal length for full frame. A f/1.2 50mm lens on crop will look much worse than a 85mm f/2 lens on full frame. The net result is that you have better availability of faster lenses, and at equivalent settings full frame typically has at least twice the resolution and way less aberrations.

For example if you compare a 70-200mm f/2.8 IS II on a 70D @ 70mm f/2.8 vs a 70-200mm f/4.0 IS L on a 5D Mark III @112mm f/4.5, the lens on the full frame has 3.3 TIMES the spacial resolution and detail.

Your talking equivalence. In a sense, your right, when it comes to aperture equivalence vs. total sensor area, an f/4 400mm lens used on a 70D is effectively equivalent to an f/8 800mm lens used on a 5D III. That does, however, assume that you actually use cameras that way. I'd like to present a real-world scenario that demonstrates why this isn't actually necessarily the case.

First off, smaller pixels don't "add" noise. That's a misnomer. Noise is present in the image signal, it is a NATURAL phenomena derived from the physical nature of light. Smaller pixels divide up an image signal into smaller parts, thus the intrinsic noise in the discretized result is higher. That REQUIRES more gain. Equivalently, that may not be an issue, however again...in a real-world situation, things can be and are frequently not equivalent.

Second, microlenses are used on ALL sensors nowadays. The advantage of microlenses is not solely given to APS-C sensors, therefor there is no advantage at all. Microlenses only serve to increase the incident light on the photodiode. That does not change the photodiodes capacity. I'd also point out that even with microlenses today, we aren't even close to 100% capture. Even with double layered microlenses, both above and below the CFA, there isn't 100% capture. Microlens power, something difficult to control but critical, is usually wrong for the given photodiode pitch. The photodiode is also not level with the readout wiring, the wiring creates a literal "well", deep inside of which the photodiode sits. Microlenses direct more light into the photowell, however with smaller pixels, a greater percentage of that light is lost as incident strikes on the wiring wall itself. Some even reflects back out of the photowell. An area of research right now in CIS manufacture is the production of more accurately curved microlenses that focus more light onto the photodiode itself. Other avenues of research, such as lightpiping, fills the photowells with a high-K refracting substance that picks up where the photodiodes leave off, channeling more light onto the photodiode. However in NONE of these cases is light capture ~100%. You still have losses.

Third, the 70D is not a 40.4mp sensor. It is a 20.2mp sensor. Plain and simple. When you bin, you bin, there isn't 40 million much smaller pixels...there are 20 million slightly smaller pixels. The charge of both halves of a DPAF pixels are read out and combined ON THE SENSOR. There is effectively ZERO difference between that and having one full sized pixel. The 70D is a 20.2mp sensor, always has been a 20.2mp sensor, always will be a 20.2mp sensor. The 32 million pixels (80%) that are used for DPAF are only read out individually for AF purposes. Gain will be twice as high, noise will be twice as high (at least), but this kind of readout does not produce images. It is only used for AF. It is an invisible factor that never affects IQ. From a photography standpoint, the 70D is a 20.2mp camera with a 26726e- FWC. Plain and simple.

Finally, there is aperture in-equivalence. In absolutely no way are the smaller pixels of a sensor like the 70D equivalent to the larger pixels of a 5D III when you consider identical aperture at identical framing. Let me take my wildlife photography as an example. I LOVE blurry backgrounds! For blurry backgrounds, I use the fastest aperture I can get away with. I spent $13000 on a 600mm f/4 lens to help me get blurrier backgrounds (and to get more reach once I moved to FF.) I currently use a 7D. It's a great camera, it has served me well for over two years now. But it's just not cutting it when it comes to helping me achieve all of my goals. So I'll be switching up to a 5D III soon.

Now, here are the facts of how the 5D III will affect my shooting. First, it will lose the reach advantage...and the FPS advantage. At least, theoretically. I can always attach a TC or get closer to my subject...getting closer is not much of a problem especially with wildlife, and when it is, the TC will do quite fine (I've never needed to use a TC with my wildlife photography...in fact I always feel I should be able to get closer, but the 7D crop factor is the limiting factor here). I do not need to stop down, the entire point is to reduce the depth of field, so aperture equivalence (ironically) doesn't apply here...instead of stopping down from f/4 to f/8, I simply leave the aperture at f/4. As for the FPS difference, the 7D has an inherent AF jitter...so it loses about 2-3 fps anyway, so there is really no difference there (the edge might even lean in the 5D III's favor.) That leaves all the other differences. The 7D has a smaller sensor, so I have to be back farther to frame, meaning less boke. It has smaller pixels, so more noise (because of higher gain). It has fewer pixels.

The 5D III has the advantage in every respect. Its larger FoV allows me to get closer, which is exactly what I want. Once I'm closer, I frame the subject the same way. That means I'm not only using larger pixels (so less gain), but putting MORE of those larger pixels on my subject! There is no way around it here. Even in my previously reach-limited scenario, with a 600mm lens, reach is not nearly the issue it used to be at 400mm (a subject area difference of 2.25x relative to the frame, so if the difference between a 7D/70D and 5D III is 2.5x, moving to the longer lens left me with a mere potential 0.25x reach loss...however given the 7D's AA filter, we can call it even.)

The simple fact of the matter is that, while a FF sensor at f/8 gathers roughly the same total light as an APS-C sensor at f/4.5, that isn't how people shoot. We aren't even forced to shoot like that by any real-world conditions most of the time. The crop-sensor advantage really only presents in literal reach-limited scenarios, where you are photographing small birds at a distance, and cannot get closer. The 70D or 7D would then have the advantage...you could use a 400mm f/5.6 lens on a cropped sensor, or an 800mm f/8 lens on a FF sensor...and you would then indeed finally experience the one case where equivalence directly applies. Outside of that...it's all just theory, theory that otherwise indicates that the FF sensor will always have the advantage at the same or faster aperture than the APS-C sensor is used at (i.e. 5D III + 600/4 vs. 70D + 400/5.6...5D III wins hands down every time no contest; beyond that, my 600mm f/4 with a 1.4x TC is 840mm f/5.6, so even when I am limited by reach, once I add the TC I am still not at an "equivalent" aperture...I'm at the same aperture, so the 5D III + 840mm lens STILL wins, hands down, every time, no contest).

I'd also offer that photographer skill plays a significant role in combating the direct application of equivalence. Even as a bird photographer, the more you hone your skill, the less you will actually NEED a physical reach advantage. Professional bird photographers are much more skilled at getting close enough to frame fully with a FF camera without using a teleconverter than your average novice with a 7D and 400mm lens. Spend five years or more photographing small birds on a regular basis, and you'll ultimately find that you end up having too much reach, and actually need the FF sensor to give you back some FoV. (This is basically where I am now...I'm able to get far closer to the small birds in my back yard than I used to, and I certainly need less reach with the wildlife, and the 7D with my 600mm lens is actually more of a problem than not.)

The theory is sound, but there is more to equivalence than simply always reducing camera equipment to equal use cases. The real-world case is that use cases are NOT equal, therefor lending the advantage to FF.

1179
I'm really not convinced that pixel size has as much to do with image noise as some say it does. Over the years as sensor resolution has continued to rise, high ISO noise has also gone down.

I actually suspect that the high ISO capabilities of current full frame cameras have as much to do with the processor as any aspect of the sensor. There are also many things that can be improved irrespective of pixel size, maybe Canon saves their best designs, materials and components for high end models. They cripple other things commonly enough, why not specifically produce worse low light on low end models?
Lower resolution means you can do more processing per image. If it is mostly processing power making the difference then a 40MP camera with the same processor as the 1Dx should have the same ISO quality at half the burst speed. I'm looking forward to seeing the results from Canon's first big MP full frame.

The readout rate is only going to affect read noise levels. Slower frequency components will introduce less noise of their own into the signal. If you look into astrophotography CCD cameras, they have very low readout rates, often reading fewer megapixels per second than there are in-total in the sensor. This, along with cooling by TEC, aims to reduce read noise (both dark current by reducing temperature, and high frequency noise by reducing readout rate (i.e. using slower frequency ADC units and the like.))

Read noise only affects the shadows, however. Overall noise is the result of the randomness with which photons strike photodiodes and free an electron. Photon shot noise, the primary source of high ISO noise, follows a Poisson distribution. The only link this has with the electronics of the sensor is via quantum efficiency. Increase Q.E., and you increase the ratio of incident photons to an increase in charge by one electron. Beyond that, photon shot noise is not an electrical phenomena, it is a physical and natural phenomena. Q.E. is already relatively high in sensors...most have around 50% give or take 5% or so. To reduce high ISO noise (at any ISO) by a factor of two, one must double Q.E. That means we can only half high ISO noise once (at best), but that would require 100% Q.E. (and not even astro cams with low frequency readout (i.e. 0.3 frames per second) and three-stage water-cooled TEC with a 70°C delta-T can achieve that!)

That leaves only one other option for reducing noise at high ISO: pixel size. Photon shot noise is the result of the randomness with which photons strike pixels. An increase in pixel size is effectively the same thing as an analog averaging algorithm...larger area, more incident photons per pixel, less total variation across pixels. There is absolutely no question that larger pixels result in less noise (especially at high ISO, where read noise is already a minimal contribution of total noise, far, far less than it is at lower ISO...for example, the 1D X has 2.2e- read noise at ISO 3200, but 38.2e- at ISO 100! The 5D III has 3.1e- at ISO 3200, and 33.1e- at ISO 100. Read noise is a negligible amount at high ISO.

However, contrast the charge saturation point of larger pixels of FF with the smaller pixels of APS-C, and there is a very clear benefit to FF sensors. The 1D X has 3069e- and 10.5 stops DR at ISO 3200. The 5D III has 2179e- and 9.5 stops DR at ISO 3200, where as the 7D has 1067e- and 8.5 stops DR at ISO 3200. The 7D has 2.9e- read noise at ISO 3200, approximately the same negligible amount as the 1D X and 5D III. The 1D X has a three-fold noise advantage AND a two-stops dynamic range advantage at the same ISO, and that is all thanks to the larger physical photodiode area. The 5D III has a clear two-fold noise advantage over the 7D.

The logical next step is to say the 70D has better pixels. The 70D has better pixels at LOW ISO (a good thing, certainly for Canon) thanks to a higher FWC (26726e- vs. 20187e-), however it's smaller pixel area than the 7D still results in a lower saturation point at higher ISO. The 70D gets a mere 999e- charge saturation at ISO 3200. It has a slight 0.2 stop DR advantage thanks to ever so slightly less read noise, but that difference is within the margin of error of Canon's metering sensor.

When it comes to high ISO image quality, there is absolutely no substitute for total photodiode area. One either increases pixel size, or one could, as I mentioned before, possibly layer photodiodes in each pixel. Three times the photodiodes in depth, and one could potentially double the sensitivity of APS-C pixels. Combined with BSI, and one could make APS-C pixels pretty small and still have the IQ be acceptable, even quite good. But, one could also always employ the same technology in FF sensor pixels...so APS-C will never have the IQ advantage. Except in the case of very reach-limited scenarios...no amount of pixel processing can really overcome the benefit of 4x more pixels. ;)

1180
How good do you think the IS is at 600mm? It doesn't seem like 4 stops to me.

depends.

how do you calculate that it is not 4 stops?
you shoot handheld with and without VC and look how many stops you need to see no blur from your tremors? ;)

or you just say you should be able to handhold it at ~1/30s. @600mm. ;)
http://www.ephotozine.com/article/tamron-sp-150-600mm-f-5-6-3-di-vc-usd-lens-review-23866
It is claimed in this review that 50% of his shots at 1/40 s are sharp.  Most of mine are blurred at that speed.

Sharpness at such speeds is entirely subjective. Given the kind of use cases this lens will most likely be used for (birds, wildlife and other action with cropped sensor cameras), at 1/40s, your likely going to get considerable blur, even if you have steady hands. Your subjects will be moving, and even a small amount of movement (ESPECIALLY for birds) at anything under about 1/800s results in blur.

I used to try to keep my shutter speed slower with the 7D to keep noise levels lower (and avoid having to go over ISO 1600), however for passerines, they are so jittery and constantly on the move that anything under about 1/800s (and in the case of the really small, super hyper birds like chickadees or bushtits and the like, even shutter speeds of 1/1250s and slower) results in subject blur. This was even the case with the EF 600mm f/4 II on a heavy duty tripod and gimbal (GT3532LS + Jobu Pro 2).

The only time your going to get stable 1/40s shots hand-held is if there is no motion in the scene. I had the luck of getting a 1/6s handheld shot ONCE in my entire time photographing:



Night Heron at Night
Canon EOS 7D + EF 600mm f/4 L II
1/6s @ f/4 ISO 3200


The only reason I was able to get the shot is because the bird was literally motionless for the entire time it took me to uncap the lens, stabilize myself so that I was motionless, configure the right camera settings, and take the shot. This was about a half hour or so after sunset, during the last minutes of civil twilight/first minutes of astronomical twilight. It was truly "night". Unless you intend to go around photographing night herons at night, I don't expect many nature photographers who get the Tammy 150-600 will be getting many sharp handheld shots at such low shutter speeds. ;)

1181
Has it ever been rumored for their to be prototypes in testing of what would essentially be a physical 1.6x crop of a FF sensor, allowing the ISO capabilities of the 6D/5D3 in, say, an EOS M or xxD body?
I'd love me an EOS M with 6-9 megapixels of low light goodness!
Thoughts?
Would this be stupid-expensive to develop? I can imagine the right advertising campaign could sell the concept of fewer pixels for low light, arty, shallow DoF shooting with the 22mm f/2 with results that're still 2-4x larger than necessary for Facebook ;)
Why not just shoot with your 6D and crop to the middle of the image?
Maybe because 6D is relatively large, heavy and expensive, compared to APS-C. It may also be because all zoom lenses for it are large, heavy and expensive, compared with EF-S lenses.
The point is, in the general consumer marketplace, where megapixels sell, you will not see a low megapixel camera because it will not sell. If there ever was to be a specialized low megapixel camera, it would be a FF camera where the pixels will have 2 1/2 times the area of an APSC camera with the same number of megapixels, and thereby, out perform it in low light or high ISO..... and it would not be inexpensive....

Indeed! And, it a'int! It's called the 1D X...and it's about, oh, $6800 bucks. :D

Humor aside, I'd go for a lower mp APS-C camera with greater SNR, if someone made one. Personally, though, I'd really prefer someone do something more interesting with APS-C. Instead of larger pixels, I really think that layered photodiodes would be very interesting. It's been hypothesized and theorized and even patented in a few ways. Foveon is based on the concept...it has a blue, green, and red set of photodiodes layered vertically in each pixel. The colors are somewhat "natural" in that is how light penetrates silicon...blue is filtered out first, then green, then red. I don't see why the concept couldn't be applied to a bayer-type sensor, however. Blue in a bayer sensor tends to include some green as well, so having say two layers of charge-holding photodiodes could theoretically double the FWC. Green could possibly have two or three layers of photodiodes, and red could certainly have three, if not four. I've read about such patents a couple times on ImageSensorsWorld, although it seems all for the video segment so far. Would really be intriguing to see how such a design might improve the sensitivity and dynamic range of sensors overall, but particularly smaller ones like APS-C.

1182
Reviews / Re: Why the DxO bashing?
« on: February 22, 2014, 04:04:59 AM »
[..keep on blaming your tools, if it makes you feel better about your inability to use them properly.

If 20+ other Canon bodies (let's not even consider the Exmor sensored bodies), often used the same way, did not produce objectionable FPN when pushed then how can you conclude that's a user fault? The 7D is KNOWN to have stripey shadows with only a small push that you can even do in DPP.  Too bad you don't have yours yet so you could provide a lens cap shot so we could see if it had stripes or not.

e.g.
7D non-pushed
www.canonrumors.com/forum/index.php?topic=9299.msg169599

and crop from same slightly pushed file in DPP
www.canonrumors.com/forum/index.php?topic=9770.msg176368#msg176368

The 7D is by far at it's weakest at ISO 100. I think Neuro is more like myself in that more often than not, he's shooting at a higher ISO. Past ISO 400, banding is pretty much non-existent, meaning all of the ISO settings between 400 and 3200 are pretty usable. By ISO 3200 itself and again the camera isn't all that usable.

I don't think anyone denies that the 7D has a banding problem at low ISO. That's well known. At ISO 400 sometimes you don't even need to push anything at all, and banding can be a slight problem in the midtones.

The 7D isn't really a landscape or studio camera, though. It's an action camera. It's an ok one, but lacking the very high ISO capabilities of a FF camera, it's limited in it's usable scope in that arena. The 70D has demonstrated some clear improvements in the area that the 7D used to dominate. It definitely has less noise, it's sharper, more usable at ISO 400 and 3200 (even though it actually has slightly more noise, it's less revolting noise). Not by a huge margin, but by enough of a margin.

I think in the long run, between the improvements made in the 70D and even more so the improvements made in the 6D, the next DSLRs from canon should be pretty good on the noise front. If there was ever a "biggest complaint" against the 7D, it would be it's poor handling of noise, in general. Second to that would be the perceived softness due to the AA filter. (Ironically, I personally love the 7D's AA filter, as it's a godsend for bird photography...no moire at all, especially with a big white...but most people are limited to smaller/cheaper lenses, so I understand the outcry for a weaker AA filter.)

1183
EOS Bodies / Re: EOS 7D Mark II Coming in March? [CR1]
« on: February 21, 2014, 10:48:26 PM »
... my only fear is what most CR headlines will be about once it's actually released, maybe the rumored 5d4?

Maybe the main page headlines.  The forum topics will mostly be about how bad the IQ of the 7DII will be, due to poor DR at low ISO, FPN, etc...all before its even released.  Once it hits store shelves, Aglet will take one shot with the lens cap on, push the exposure four stops, and declare the 7DII to be DOA, which will lead to the inevitable proliferation of predictions of Canon's imminent demise.   

On a serious note, if the 7DII is Nessie, what does that make the 100-400 II?  A Sasquatch-Yeti-Martian hybrid living in Area 51?
Now that I have a long lens, I need a new body for my quest to take a picture of Bigfoot. Since the naysayers will undoubtably pronounce the af and iq as garbage, this will be the perfect camera. After all, who wants a picture of Bigfoot that isn't out of focus?

LOL.

+1 and +1, one for each! :P


1184
Reviews / Re: Why the DxO bashing?
« on: February 21, 2014, 10:47:27 PM »
My impression through the CR forum is that DPReview is the lesser of the two evils, but honestly don't know why when they are so similar to DxO.

Any opinions/comments comparing methodology and results between DxO and DPReview?

The big difference is that DPR's % score attempts to rank the camera (build, ergonomics, IQ, AF, etc.), whereas DxOMark's score is for the sensor and only the sensor.  Pair a great sensor with poor autofocus, you get great DR and low noise...and a blurry image.  DxO doesn't care, to them it's still great.  DPR would mark down the overall score due to the poor AF.

Since people buy cameras, and not bare silicon sensors, DPR's single number score is a bit less useless than DxOMark's sensor score.

It's also a lot clearer that DPRs ratings (which are conveniently percentages, something everyone fully understands) are subjective, based on the reviewers experiences as well as technical tests with the camera.

This is in contrast to some arbitrary number that requires you to go investigating HOW that number is derived, something the very vast majority of DXO viewers DO NOT do. That scalar number is a black box output that does not factor in enough information in order to be truly accurate, and yet it is boldly claimed to be "scientific". It may well indeed be produced via a scientific process, but the number is otherwise utterly meaningless, yet given all to much precedence, by the unwary general public.

That's the danger of DXO...their bold claim to science and yet black box effect.

1185
EOS Bodies / Re: Will the next xD cameras do 4k?
« on: February 21, 2014, 10:43:57 PM »
There isn't enough bandwidth to support 4k streaming such that it looks significantly better than 2k. I am an avid fan of NetFlix, for example, and their Super HD is good, but not great. But when you get right down to it, even 2k (1080p) is only rightly done off of a BluRay disc. You get the full uncompressed audio and exceptionally crisp, sharp picture. You don't get anything even remotely resembling that with streaming, even some of the higher quality streaming thats showing up online now.

Netflix claims their UHD streams are 15.6Mbps HEVC/H.265 while the 1080p streams max out at 5.8Mbps AVC/H.264. Sure bluray video will likely look better in 2015 but those streams probably don't look so bad, depending on whether h.265 delivers on its promise of doubling the compression ratio at the same quality level as h.264. Anyway you don't get to decide for other people what is valid "4k" or UHD video and what isn't.

I'm not "deciding" anything. It's the type of market. When LCD screens came on the scenes so many years ago, I remember it took about four years for the dominant flatscreen tech, plasma and projection screens, to phase out. I'm expecting about two years for 4k, a 200% increase in adoption rate. It may indeed be less than that, but my point is that it hasn't happened already, which is what would drive a company like Canon to start putting full 4k recording technology in all of their DSLRs. The money that fuels the growth for a new technology like this comes from those few people who demand the absolute best quality possible. Not everyone spends $40k or $20k or even $10k on a TV. It's the videophiles and audiophiles who want true 4k video (not some extensively compressed stream that diminishes quality, but TRUE full resolution 4k, and for a full 2hr video, that can take as much as 200Gb or so).

Anyway, I certainly don't dictate anything. Neither do any of you. It's Canon who will decide, and I am simply betting that they don't jump on the 4k bandwagon for consumer-grade devices yet. They probably won't until next year at the earliest (and then only in the higher end models, likely as a firmware update for existing cameras), and I don't suspect we'll see 4k recording in "all" of their devices until some time after 2016.

Pages: 1 ... 77 78 [79] 80 81 ... 277