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Messages - dilbert

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1456
EOS Bodies / Re: Canon Dual Pixel Liveview Autofocus
« on: July 02, 2013, 11:41:28 AM »
I'm also hoping that the pixels aren't all split in a left/right horizontal pattern, as the video shows, but that half of them are split vertically, because no one would want the AF system to be sensitive to horizontal contrast only.

Based on what I've read, including a statement from Chuck Westfall who was asked for clarification on the matter, they are all split in the same direction.  That means the Dual Pixel CMOS phase AF system is a giant vertical line sensor, responsive only to horizontally-oriented details.

Any guess as to whether the next generation will have a quad split (2x2) to do both vertical and horizontal or would it be better to use the next neighboring pixel of of the same color instead?

What they might be able to do is to have a pattern on the sensor of PDAF cells rather than just straight up and down.

So maybe the new bayer sensor looks like this:

R.I.G.I
I.G.I.B

I = vertical AF sensor and one for horizontal might look like this:

R.-.G.I.R.-
|.G.|.B.|.G
- = horizontally sensitive AF sensor.

Or they might do:

R.-.G.|.R.-
G.|.B.-.G.|

or

R.-.G.|.R.-
G.-.B.|.G.-

but to subdivide all of the pixels again would really cut into the ability of a pixel to capture light for recording the image with.

1457
EOS Bodies / Re: Canon Dual Pixel Liveview Autofocus
« on: July 02, 2013, 11:30:25 AM »
The best explanation I've seen thus far is on dpreview's website here:
http://www.dpreview.com/previews/canon-eos-70d/3

Each and every of those 20.2 million active pixels that makes up the picture (whether red, green or blue) is divided into two pixels. One for the left phase, and the other for the right phase. They both hide behind one micro lens, and are positioned next to each other (hopefully without any appreciable gap, as that might cause a strange bokeh effect) to receive the phases. Combined, they theoretically cover pretty much the same area as a conventional photodiode, and should give the same light gathering capability. Its no more than pixel binning to recreate a normal image from this sensor, with normal light gathering capabilities.

So in theory this dual pixel configuration should have no detrimental effects on SNR over a conventional 20.2MP APS-C sensor. Let's hope they've used a new sensor fabrication process to manufacture this sensor, to bring along the much anticipated (and reported) improvements in SNR - I'm guessing that was is in effect a 40.4 MP APS-C sensor would be next to impossible to make with the old sensor fabrication process.

You don't get something for nothing.

If space on the sensor is taken up for PDAF sensors next to pixels, then space on the sensor that could be given to the pixel (allowing it to store more photos, for example) is lost.

Even if the half used for autofocus was somehow fed back into the colour, space has to be lost for the boundary between the two.

Or to put it another way, the noise characteristics of the 70D should be about that for a 40MP APS-C sensor using the same sensor technology without the PDAF split.

1458
EOS Bodies / Re: Canon Dual Pixel Liveview Autofocus
« on: July 02, 2013, 04:40:04 AM »
Interesting development.

For some number of pixels, it is going to reduce (halve?) the amount of light that is received by the photo diode.

If this is the green pixels, as suggested by some diagrams, then it may make little/no overall difference as there are already twice as many green receptors as there are red/blue.

Additionally, this means that there will be some pixels that do not record the same level of light as others. This will need a bit of new fancy footwork for raw converters to properly evaluate what it means to have a pixel that is not and will never have the same luminosity as all of the others around it.

This has potential to have an adverse impact on noise simply due to there being less signal available.

Will be interesting to see the outcome!

1459
Lenses / Re: Kit for California trip
« on: July 01, 2013, 10:52:50 AM »
...
I plan to take my 6D and S100 as a pocketable backup.  My lens choices are:

Wedding:

24-70 2.8 II (just purchased yesterday) - maybe...
50 1.4
85 1.8
430EXII speedlight

Hiking:
24-105 L
70-300 L (offered as a loan by a friend)
... you may even wish to buy the Tamron 70-300 VC, as it isn't far off in terms of IQ but it is 1/3 the price and about half the weight (consider both hiking weight and checkin weight if you're flying.)

You may even want to consider just going with the three zooms - 24-70, 24-105 and 70-300. At a wedding, you don't want to be swapping your lens around too much otherwise you'll be missing photo ops.

For hiking in Sequoia, I'd recommend finding a tripod that weighs in at about 2.5lbs or less. Depending on which part of it you're in, you really don't want to be hauling around heavy gear as that'll mean less food/water.

1460
EOS Bodies / Re: Canon 70D Reaction
« on: July 01, 2013, 10:07:55 AM »
He's been watching Canon bring out "new" cameras and is realising that Canon just deliver warmed up vomit each time a new camera is announced.

For being 'warmed up vomit' the 1D X and 5DIII take pretty good pictures.

Wow, so you really don't like the 1DX/5DIII that much?

1461
EOS Bodies / Re: Canon 70D Reaction
« on: June 30, 2013, 10:25:15 AM »
I might have learned something from watching that... is it true that wifi won't work in a Magnesium alloy frame?

Correct, same with GPS. If you put a battery powered radio in a metal box and close it up, the radio will have a lot of trouble playing the local radio stations. Depending on the metalwork, the radio waves are either reflected or absorbed by the metal.

So it becomes very challenging to build a small, complete metal/alloy body that supports sending and receiving radio waves.

1462
EOS Bodies / Re: Canon 70D Reaction
« on: June 30, 2013, 10:20:36 AM »
There's a little bit o' hate in the video, but nearly everything he says is accurate or likely so.  There seems to be  a lot more hate right here in the posts.  Fanboys, stop coming to Canon's defense.  It needs to innovate by getting rid of the color vomit and crappy noise performance of its APS-C sensors.  It needs to do better.

Exactly.

1463
EOS Bodies / Re: Canon 70D Reaction
« on: June 30, 2013, 10:18:56 AM »
My Problems with the Canon 70D

What's wrong with you?

He's been watching Canon bring out "new" cameras and is realising that Canon just deliver warmed up vomit each time a new camera is announced.

1464
EOS Bodies / Re: Canon EOS 70D Spec List
« on: June 29, 2013, 03:16:53 AM »

Of course for DR it's pretty certain that D7100 will be a clear winner.

I don't think Canon cares about DR vis-a-vis the Nikons ... that could only be so because the most of the users of the cameras also don't care about DR ... I'm no longer sure if I should care either.  ;)

More DR in canon cameras is certainly welcome, but it isn't all that matters.

Right.

The 70D needs to be compelling and different enough to get lots of 1xxxD, xxxD and xxD users to upgrade to it. The 60D was very underwhelming in that regard.

1465
EOS Bodies / Re: Canon EOS 70D Spec List
« on: June 29, 2013, 03:14:04 AM »
I can think of no technical reason why Canon could not mount its GPS and Wi-Fi antennas inside the display bezel like Apple does with the Wi-Fi antennas on the MacBook Pro.  It's not like the screen will ever be made of metal.  And if they find that the signal isn't good enough for some reason, there are lots of interesting tricks they could do to get around it, like adding a couple of tiny bands of metal somewhere on the front, separated by rubber seals from the rest of the body.

Do you mean the display bezel at the back or the LCD one on top?

The one at the back has a user-replaceable plastic cover to protect it, so it may be that putting an antenna there will disrupt that design.

1466
Pricewatch Deals / Re: Deal: Canon EF 24-105 f/4L IS $699
« on: June 29, 2013, 03:10:07 AM »
yeah starting to smell like either EOL or being replaced.

1467
EOS Bodies / Re: Canon EOS 70D Spec List [CR3]
« on: June 28, 2013, 10:51:58 AM »
btw, I bet there are a huge number of "camera news websites" (ie. dpreview) that are really pissed with Canon right now for allowing this kind of leak. The last leak of this kind was the 20D(?) where essentially a pre-press brief on the camera was leaked. It was not long after that when a bunch of websites put together a call to vendors to stop the leaks in order for them to actually have a worthwhile business. I wonder if we've gone back to the ol' days of web leaks...

... the pictures are just too significant to be "accidental."

1468
EOS Bodies / Re: Canon EOS 70D Spec List
« on: June 28, 2013, 10:45:46 AM »
I suppose the only thing MORE worthless than DxOmark's sensor scores, are their lens scores.  Absolutely worthless.
How can you say that? DXO scores the 50f1.8 higher than the 600f4.0 so it MUST be a better lens........ (Huge sarcasm tag inserted here)

DxO measures the ability of a lens to deliver a quality image. To whit, the 50/1.8 can deliver a higher quality image for than the 600/4.0. Both lenses can be good lenses and deliver exceptional IQ but it is perfectly ok for one lens (even a cheaper lens) to be better than the other for a given purpose.

Just because something is cheap doesn't mean it is bad or low quality, similarly, just because something is expensive doesn't make it high quality.

1469
EOS Bodies / Re: Canon EOS 70D Spec List
« on: June 28, 2013, 04:02:23 AM »
I really don't see all the hassle regarding GPS. I think it's useless. GPS is useful in cars and mobile phones if you're lost, but geo-tagging? Couldn't care less and certainly will not be a deal maker or breaker.

When you've been on holiday, come home and upload geo-tagged photos into Lightroom 4 or similar, then you will understand.

1470
EOS Bodies / Re: Canon EOS 70D Spec List
« on: June 28, 2013, 12:59:14 AM »
where is the pic?

DMCA/copyright/takedown notice?

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