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Author Topic: 26.4mp 5D Mark III Mid-year? [CR1]  (Read 39715 times)

kirillica

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #60 on: April 19, 2011, 02:23:12 AM »
Sorry, but you are wrong. My calculation is correct. I'm not talking about quality of the pixel. I'm talking about resolution of the final picture with same field of view.
Just compare current models. A 18MP 7D picture will easily outresolve a 8MP 5D2 picture with same field of view.
Since, as I wrote, there are only advantages and no real drawback with higher pixel density (within current manufacturing possibilities) there is no reason to increase density as much as possible.
Am not talking about incorrect numbers, but the logics you're using it. Number of pixels doesn't show anything in DSLR world: picture quality in battle 5DmII vs 7D is fatal (while mp diff is not so huge). Quality matters, and please stop counting megapixels ;)

Just take a picture of an object that fills a smaller part of 5D2 frame. Then take a picture of the same object with same lens at the same distance using a 7D. Look at wich image will give best resolution to the object. Then you will have learned that is was your logic that were incorrect.
Please correct if I'm wrong: do you take a crop-factor as an advantage of DSLR? If "yes", then you should be more than happy using mobile devices for shooting :)
I'm talking about the same size object on photo using both cameras. I was tried both and, to be honest, it's very difficult to find advantages shooting 7D when you don't need high speed and this new-fancy AF (for example, in studios)

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #60 on: April 19, 2011, 02:23:12 AM »

NotABunny

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #61 on: April 19, 2011, 05:33:56 AM »
Quote
5DII high ISO performance is much better than the 7D

Tuggen didn't say that the 5D2's high ISO performance is the same as the 7D's. He said that the 5D2's high ISO performance is the same as the 7D's per UNIT AREA of sensor.

The reason why there are DSLRs, crop factors, medium frame format, is because the SENSOR SIZE DIFFERS, not because there are more or less pixels.

Of course the 5D2 outputs cleaner images than 7D since it has a 1.6 ^ 2 times bigger sensor, but each square millimeter has the same noise level (I haven't checked this, the cameras' technologies may have differences since they are separated by quite some time, but it verifies for 1D4 and D3s).
« Last Edit: April 19, 2011, 05:41:28 AM by NotABunny »

fernando

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #62 on: April 19, 2011, 06:19:45 AM »
Dunno if this is relevant or not but the the site that posted this rumor says that they've talked to the source before.

Quote
I feel better about our Canon EOS 5D Mark III tip than this one because I’ve conversed with that source before -CGG

At least it's not from a random/new/unknown source. Cheers for a 5DMKIII by mid-year ;)

neuroanatomist

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #63 on: April 19, 2011, 01:22:15 PM »
Quote
5DII high ISO performance is much better than the 7D
Tuggen didn't say that the 5D2's high ISO performance is the same as the 7D's. He said that the 5D2's high ISO performance is the same as the 7D's per UNIT AREA of sensor.

Of course the 5D2 outputs cleaner images than 7D since it has a 1.6 ^ 2 times bigger sensor, but each square millimeter has the same noise level

Ok, fine, but s/he is still wrong.  There are two main factors that affect noise - sensor size and pixel size.  Some will argue that pixel size alone determines noise, which is also incorrect.  The total light-gathering capability (i.e. size) of the sensor is the primary factor, but smaller pixels do collect fewer photons per pixel, meaning less signal and a lower SNR. With a strong signal (i.e. good light), photon noise dominates and there is effectively no difference in noise from different size pixels.  But as light levels drop and gain is applied, read noise has a greater contribution.  In that scenario, the smaller pixels of the 7D are going to produce more noise per unit area than the larger pixels of the 5DII.
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kirillica

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #64 on: April 19, 2011, 02:41:44 PM »
Ok, fine, but s/he is still wrong.  There are two main factors that affect noise - sensor size and pixel size.  Some will argue that pixel size alone determines noise, which is also incorrect.  The total light-gathering capability (i.e. size) of the sensor is the primary factor, but smaller pixels do collect fewer photons per pixel, meaning less signal and a lower SNR. With a strong signal (i.e. good light), photon noise dominates and there is effectively no difference in noise from different size pixels.  But as light levels drop and gain is applied, read noise has a greater contribution.  In that scenario, the smaller pixels of the 7D are going to produce more noise per unit area than the larger pixels of the 5DII.
Huh, at least someone got I've meant. Nr of pixels means nothing when we compare FF and crop, but they still insists: if we have 18Mp on crop, then Canon should show us 46Mp on FF with all other fancy stuff. ;D

transpo1

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #65 on: April 19, 2011, 02:56:03 PM »
Still don't see how Canon could produce a 5DIII by mid-year with the current supply issues...and why would they announce one mid-year if it wasn't shipping until the Fall? Wouldn't that drastically cut down on existing 5DII sales?

davidpeter

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #66 on: April 19, 2011, 05:26:44 PM »
Dudes. The price of the AA filter and the chip itself grows exponential with both size and pixel density. Sooner or later, you have to choose. Haven't you recognised that the bigger sensors always had wider pixel pitch?

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #66 on: April 19, 2011, 05:26:44 PM »

gmrza

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #67 on: April 19, 2011, 07:46:28 PM »
If these specifications are true, I can see the D800 selling well.

Uh, perhaps you haven't been paying attention, but the factory where Nikon makes all of its pro-level DSLRs was seriously impacted by the earthquake earlier in the year. If that factory is responsible for the D800 then there could be a significant delay to it and other D? series cameras.

I wouldn't be surprised if this is the case and Canon knows it and is pouncing early because of it.

Canon has also been hit badly - I'm not sure how badly.  The company I work for also owns a distribution business, which includes Canon.  When I checked yesterday, there was one (1) lens in stock.  There have not been any xD cameras in stock for a while as well.
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CJRodgers

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #68 on: April 20, 2011, 03:10:50 AM »
If the 5d mkiii had noise improvement would it make using f2.8 better for low light as you can use higher ISO?

torger

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #69 on: April 20, 2011, 03:36:40 AM »
If the 5d mkiii had noise improvement would it make using f2.8 better for low light as you can use higher ISO?

Yes, but at some point there's a limit. There are two parts of noise, the camera's own ("read noise") and noise in light itself (photon shot noise). Most people forget about shot noise and assume that noise at high ISO is just contributed from the camera electronics. Actually, the shot noise is often dominating (I have not found out where the line goes, but perhaps some other reader of this forum knows).

The signal-to-noise ratio of the shot noise reduces the more light you gather, that is lower shutter speeds, larger apertures, larger sensor size. That is you always want to gather as much light as possible, to be able to use as low ISO as possible.

One other factor to know about is that not all f2.8 are the same concerning light transmission, and it is not only about vignetting. There can be quite large differences between lenses, some lenses can transmit a half stop less light than others at the same aperture. For example the 24-70 f/2.8 has a transmission corresponding to ~f/3.4 while a large aperture prime lens set at f/2.8 typically has much better transmission (did not find an example measurement unfortunately, but it can easily be observed in testing).

NotABunny

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #70 on: April 20, 2011, 03:39:09 AM »
Quote
5DII high ISO performance is much better than the 7D
Tuggen didn't say that the 5D2's high ISO performance is the same as the 7D's. He said that the 5D2's high ISO performance is the same as the 7D's per UNIT AREA of sensor.

Of course the 5D2 outputs cleaner images than 7D since it has a 1.6 ^ 2 times bigger sensor, but each square millimeter has the same noise level

Ok, fine, but s/he is still wrong.  There are two main factors that affect noise - sensor size and pixel size.  Some will argue that pixel size alone determines noise, which is also incorrect.  The total light-gathering capability (i.e. size) of the sensor is the primary factor, but smaller pixels do collect fewer photons per pixel, meaning less signal and a lower SNR. With a strong signal (i.e. good light), photon noise dominates and there is effectively no difference in noise from different size pixels.  But as light levels drop and gain is applied, read noise has a greater contribution.  In that scenario, the smaller pixels of the 7D are going to produce more noise per unit area than the larger pixels of the 5DII.

Okay, but this multitude of factors which affect the noise level is just theory. However, if you have physical evidence that the pixel size alters the noise level of photos, I really want to see it. I mean, physical evidence which meets scientific comparison criteria, not photos like those from IR ( http://www.imaging-resource.com ) where even the photos taken with a D3x and a D3s are not taken in the same light (the RAW images have different brightnesses: about 0.5 stops of difference).

Here is a simple way to do it: rent say a 1D4 and a D3s (or a D3x and a D3s, though they are separated by several years of technological advancements), take photos of the same subject, in the same light, with the same shutter speed, same F-number, and with the same output for the brightness of the photos. The only thing which may vary is the ISO (if the cameras do indeed have different ISO sensibilities); if any other parameter varies then that's like comparing apples and oranges. (Of course, this ignores the difference in the transmissivity of the lenses.)

Here is physical evidence that the pixel size does NOT alter (in practice, not in theory) the noise level of photos even at ISO 12800: http://www.canonrumors.com/forum/index.php/topic,255.msg3911.html#msg3911

Of course, one must really understand that sensor size normalization is necessary because we want to scientifically compare noise per UNIT AREA (not per photo since the sensors have different sizes). Since the 2 cameras have a pixel density per UNIT AREA whose ratio is 2.5, one can just see that pixel density doesn't affect noise per UNIT AREA. Consequently, pixel density is irrelevant in the current technological context.
« Last Edit: April 20, 2011, 04:08:16 AM by NotABunny »

CJRodgers

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #71 on: April 20, 2011, 04:35:16 AM »
If the 5d mkiii had noise improvement would it make using f2.8 better for low light as you can use higher ISO?

Yes, but at some point there's a limit. There are two parts of noise, the camera's own ("read noise") and noise in light itself (photon shot noise). Most people forget about shot noise and assume that noise at high ISO is just contributed from the camera electronics. Actually, the shot noise is often dominating (I have not found out where the line goes, but perhaps some other reader of this forum knows).

The signal-to-noise ratio of the shot noise reduces the more light you gather, that is lower shutter speeds, larger apertures, larger sensor size. That is you always want to gather as much light as possible, to be able to use as low ISO as possible.

One other factor to know about is that not all f2.8 are the same concerning light transmission, and it is not only about vignetting. There can be quite large differences between lenses, some lenses can transmit a half stop less light than others at the same aperture. For example the 24-70 f/2.8 has a transmission corresponding to ~f/3.4 while a large aperture prime lens set at f/2.8 typically has much better transmission (did not find an example measurement unfortunately, but it can easily be observed in testing).

Yea i would love to know what the theortical best the 24-70L could be. This would be an ideal lens if it could handle low light just a bit better. So do you think no matter how good the noise handling in the camera, this lens could never be fast enough for really low light.

torger

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #72 on: April 20, 2011, 07:43:28 AM »
Yea i would love to know what the theortical best the 24-70L could be. This would be an ideal lens if it could handle low light just a bit better. So do you think no matter how good the noise handling in the camera, this lens could never be fast enough for really low light.

It depends on what quality you want. For me personally, I often find f/2.8 a bit dark for indoor shooting. On the other hand, when going below f/2, the depth of field gets so short that it often becomes a problem (tricky to get focus right). Being able to go down to f/2 and sometimes below I think is often valuable indoors. If I know I'm going to shoot indoors I prefer a prime 35 or 50mm over a f/2.8 zoom - the wider aperture range gives me more flexibility than the zoom. The 50mm f/1.4 is a real good price/performance option, a bit narrow on APS-C though for being indoors.

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #72 on: April 20, 2011, 07:43:28 AM »

neuroanatomist

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #73 on: April 20, 2011, 10:53:57 AM »
Here is physical evidence that the pixel size does NOT alter (in practice, not in theory) the noise level of photos even at ISO 12800: http://www.canonrumors.com/forum/index.php/topic,255.msg3911.html#msg3911

Do you mean the links to the photos on Juza's website?  Those are 'fact'?  In the long list of websites that purport to provide factual information, the last place I'd go is Ken Rockwell's.  But the second to last place I'd go is Juza's.  He does capture great images - but technical information?  No.  His reviews, at least, are filled with technical inaccuracies.

Here is a simple way to do it: rent say a 1D4 and a D3s (or a D3x and a D3s, though they are separated by several years of technological advancements), take photos of the same subject, in the same light, with the same shutter speed, same F-number, and with the same output for the brightness of the photos. The only thing which may vary is the ISO (if the cameras do indeed have different ISO sensibilities); if any other parameter varies then that's like comparing apples and oranges. (Of course, this ignores the difference in the transmissivity of the lenses.)

Your simple way sounds like exactly what Juza did in your link in the other post:

At http://www.juzaphoto.com/eng/articles/canon_1d_mark4_review_comparisons.htm there are 2 images (JPEGs converted from RAW) of a scene, taken in the SAME light, one with Canon 1D4, one with Nikon D3s, at ISO 12800....At the end, you'll have two images whose quality is indistinguishable.

That's a simple way to make a practical comparison - but if you're looking for 'physical evidence which meets scientific comparison criteria' then comparing a 1D4 and a D3s is a simple way to make a flawed and meaningless comparison. 

First off, those are JPGs converted from RAW.  Converted how?  Different RAW converters handle different files differently.  Even if the same RAW converter was used (e.g. ACR), different amounts of NR are applied to files from different cameras, and NR is applied even if the NR setting is turned off in the software.  A real analysis would involve starting with the RAW files themselves (Juza doesn't make those available, just the JPGs), and analyzing the raw data itself using IRIS, Rawnalyze, or dcraw. 

Even that's a flawed comparison - are you aware that RAW images are not really the raw data coming off the sensor following some sort of standard ADC?  There is processing that occurs in-camera prior to the RAW file being written.  On att least some Nikon models (D3, D300), a portion of the low-level signal is truncated during ADC, which obvoiusly occurs prior to the RAW file write.  Astrophotographers using Nikons employ a 'mode 3 workaround' (modes 1 and 2 being Off and On) - mode 3 means powering off the camera during the dark frame exposure that follows the long exposure.  Why?  Because in addition to subtracting the dark frame prior to writing the RAW file, the camera also applies a median blur function to the image - something you might not want, but is baked into the RAW file creation in-camera.  It's pretty likely that Canon also applies some processing of the image data in-camera prior to writing the RAW file.  So comparing Canon vs. Nikon for noise in RAW files is really comparing apples and oranges.

Okay, but this multitude of factors which affect the noise level is just theory. However, if you have physical evidence that the pixel size alters the noise level of photos, I really want to see it. I mean, physical evidence which meets scientific comparison criteria...

If you'd like a reasonably cogent, scientifically-based discussion of image sensor noise, try the link below, in particular section 3c.

http://theory.uchicago.edu/~ejm/pix/20d/tests/noise/index.html
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NotABunny

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #74 on: April 20, 2011, 11:33:34 AM »
First off, those are A real analysis would involve starting with the RAW files themselves (Juza doesn't make those available, just the JPGs), and analyzing the raw data itself using IRIS, Rawnalyze, or dcraw. Even that's a flawed comparison

Yes, those images are not ideal, but they're far better than anything else I've seen (and by the way, his interpretation of the photos is opposite - he's comparing noise at pixel level). It would be really great if you could show a better comparison.

But you're ignoring the practical point. Those images are taken at a very high ISO, where one sensor has 2.5 times the pixel density of the other. So, what does it take for all the factors that you list to cause a visible noise difference? ISO 1 million or a sensor with 100 MP? Does that make any practical difference today?

Even the RAW photos from IR taken with the D3x and the D3s, at ISO 12800, show very little noise differences (and only in the shadows, in favor of the newer one, of course), and one has twice the pixel density of the other. So, what does it take for the noise differences to be more than barely visible?

I'm not sure if we are even debating the same subject?! It makes no difference to me (or to anyone who screams at Canon to put only 10 MP on a FF sensor) if the noise differences can only be quantified with statistical means and aren't visible to the naked eye.


Later edit:
Actually, to make this simpler, I admit that a higher pixel density generates nosier images, but I want the people who want Canon to put only 10 MP on a FF sensor, to see what difference that would make: invisible to the human eye (unless you're looking for it).
« Last Edit: April 20, 2011, 11:44:53 AM by NotABunny »

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Re: 26.4mp 5D Mark III Mid-year? [CR1]
« Reply #74 on: April 20, 2011, 11:33:34 AM »