*UPDATE 3* Canon PowerShot G1X Revealed

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Jul 21, 2010
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Dave92F1 said:
But given the f/16 spec...

So...here's a question. Even a very low (<6) MP APS-C sensor is diffraction-limited at f/16. Why can EF-S lenses be stopped down to at least f/22 and in many cases to f/38?

Dave92F1 said:
Of course, the press release could simply be fake, or wrong...

Isn't it fun to speculate when we'll find out who is right in a few days?

Absolutely right on both counts! :D
 
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kapanak said:
I am not going to say it will happen, but ruling out the possibility of a 1.5" sensor (24mm diag.) completely is naive. There have been compacts with very similar sensor size in the past. Of note, the Sigma DP1 and DP2 both had a sensor that is just a hair larger than this alleged G-series future sensor (1.7x vs 1.8x). They were also quite compact and took great photos. Also, they both started at $800.

The DP1 and DP2 had pancake primes -- 16.6mm f/4, and 24mm f/2.8. The G series according to the press release has a 4x zoom which is f/2.5 at the wide end.

It's possible to make a big sensor compact, but not with that lens spec.
 
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Richard8971

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Dave92F1 said:
I have to disagree there. The best camera is the one you have with you. IQ and flexibility are great, but they're not worth a thing if you don't have the camera with you.

Touche' I would have to agree with you on that. :) I carry a Powershot A590IS with me at all times for that possibility. I was just suggesting that 800 bucks is A LOT of money to spend on a pocket camera that cannot be "expanded" and more than likey will not have a lens that will bring true justice to a larger sensor. The lens is everything. That being said, there are plenty of less expensive Powershots out there that will fit the need.
 
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Lee Jay

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neuroanatomist said:
Dave92F1 said:
But given the f/16 spec...

So...here's a question. Even a very low (<6) MP APS-C sensor is diffraction-limited at f/16.

No, they aren't.

Why can EF-S lenses be stopped down to at least f/22 and in many cases to f/38?

Because sometimes DOF or correct exposure are more important than preservation of detail.

Note that many planetary astrophotographers use 40D-sized pixels, and shoot at f/30 or so for maximum detail (they get the slow f-numbers by using barlows [teleconverters], not by stopping down - the aperture is always wide open on most telescopes).
 
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Jul 21, 2010
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Lee Jay said:
neuroanatomist said:
Dave92F1 said:
But given the f/16 spec...
So...here's a question. Even a very low (<6) MP APS-C sensor is diffraction-limited at f/16.
No, they aren't.
Why can EF-S lenses be stopped down to at least f/22 and in many cases to f/38?
Because sometimes DOF or correct exposure are more important than preservation of detail.

You're saying images taken using a dSLR with a typical APS-C sensor are not affected by diffraction at f/16? Can you provide some evidence to back up that claim?

BTW, the question about why diffraction-limited apertures are available was rhetorical. Your examples illustrate my point - diffraction resulting in loss of sharpness is not a reason for Canon not to make f/16 available on a 1/1.5" sensor, which was the argument being made to support the idea of an APS-C-sized sensor in the G1x.
 
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Richard8971 said:
Dave92F1 said:
The best camera is the one you have with you.
That being said, there are plenty of less expensive Powershots out there that will fit the need.

+1

If Canon comes up with some clever way to flout the laws of physics and mate a large sensor with the rumored lens, and manages to sidestep the compromises and deliver excellent IQ from the G1x, it will be very interesting. I think it's a pipe dream, but hey...dreams are good!

But for decent IQ in a truly portable package, I like my S100 (had an S95, which my wife now carries in her purse). The S100 fits in my pocket, which is ideal if I can't bring a larger camera. A G series or m4/3? Might as well bring the 5DII and 24-105mm, at least. Fortunately, my wife has grown very tolerant of me carrying lots of gear around on family outings, and also to me shooting frequently at home. The key, for those with wives and kids, is taking great shots of the kids. The proof in the pudding was in early December - my wife was heading out to do some shopping, and said she wanted to take some family portraits for cards later that day. She returned and walked into the living room, to find a 9' backdrop set up, and three light stands with a pair of 24" softboxes (430EX II's in them), and a monolight with a 48" octabox. All I got was a raised eyebrow. ;D
 
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Richard8971

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neuroanatomist said:
I think it's a pipe dream, but hey...dreams are good!

If people didn't dream where would we be? I am sure everyone on here is here because we want some "inside" information on the technology that will be offered in the new cameras! Canon will produce whatever they think will sell and of course, we might get insights because a couple of reps sneek info now and then based on prototypes. Part of the business I suppose. How many rumors have you heard that were 100% accurate? Just about every camera that has been rumored has MOSTLY been true... so think about it.

I welcome a new high-end powershot. $800 bucks? Personally, I will never buy it. Canon... if you are listening. A "point and click" no matter HOW advanced you make it, should NEVER cost as much as a DSLR. Just my opinion guys. :)

It's all in the lens... don't forget that... (Why? Show me a SMALL [point and shoot size] "L" quality lens... Which of course you WILL need for a FF or similar sized sensor!!!) :)

D
 
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Dave92F1

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neuroanatomist said:
You're saying images taken using a dSLR with a typical APS-C sensor are not affected by diffraction at f/16? Can you provide some evidence to back up that claim?

Some quick work with Excel:

The Airy disc at f/16 is about 21 microns across (at 550 nm wavelength; that's greenish-yellow).

The 60D sensor has a pixel pitch of 4.28 microns, so it's definitely diffraction limited at f/16 - the Airy disc is about 5 pixels in diameter. In fact it's diffraction limited starting around f/8 (generously).

A hypothetical Gx 1/1.5" sensor with 14.3 Mpixels (per the press release) would have a pixel pitch of about 1.53 microns (assuming it's a 4:3 aspect ratio sensor, as in all prior PowerShots).

If you assume a sensor is "diffraction limited" when the Airy disc gets to be 2 pixels wide, that sensor would be diffraction limited starting at f/2.3 !!! Which would be a crazy way to design a sensor - if you're diffraction limited even wide-open, why not reduce the number of pixels on the sensor? You wouldn't lose any resolution at all, and you'd improve the low-light sensitivity.

Which makes me think, again, that the sensor is probably bigger than 1/1.5".

neuroanatomist said:
BTW, the question about why diffraction-limited apertures are available was rhetorical. Your examples illustrate my point - diffraction resulting in loss of sharpness is not a reason for Canon not to make f/16 available on a 1/1.5" sensor, which was the argument being made to support the idea of an APS-C-sized sensor in the G1x.

OK, another interpretation is that they figured the best lens they could make for a 1/1.5" sensor is f/2.5 wide open, and they use a definition of diffraction-limited of slightly more than 2 pixels.

If you follow that logic, then they picked 14.3 Mpixels as the most they could fit in and still have them be useful (at least wide-open). And it's true that compacts are used wide-open a lot (small lenses can still be extremely sharp wide-open; unlike DSLR lenses which almost always get sharper a stop or two down from wide-open).

Richard8971 said:
A "point and click" no matter HOW advanced you make it, should NEVER cost as much as a DSLR.

I don't see what the price of a DSLR has to do with it, because a DSLR doesn't compete with a compact - the compact does things a DSLR can't (namely, fit in a small space).

I can imagine Gx cameras that I wouldn't pay $800, or even $500 for.

I can also imagine a (buildable) Gx camera that I'd happily pay $800 for. It would have to have the flippy screen, a viewfinder (any viewfinder; electronic or optical, but not just the screen), faster focus than the G12, and be no larger than the G12. The GPS and high-speed video features of the S100 would be a bonus. If it had all that, I'd happily fork over the $800 even if the sensor is only 1/1.5". I'd like more low-light capability as much as anyone, but in truth the G12's biggest weakness isn't in that department.

Richard8971 said:
It's all in the lens... don't forget that... (Why? Show me a SMALL [point and shoot size] "L" quality lens... Which of course you WILL need for a FF or similar sized sensor!!!) :)

It's not all in the lens once you're diffraction-limited. Once you've resolved all the detail that physics will let you resolve, you're done with resolution. But you can still improve other things (focus speed, light sensitivity, etc.).

And I think the G11/G12 does have a L-quality lens already. It is always much easier to make really sharp lenses for small sensors - the lenses are smaller and you can do things when making small lenses that aren't practical on larger ones.
 
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Anyone else think that the G1X (stupid name considering Panasonic's recently announced GX1) is going to be completely overshadowed by Monday's Fuji X-Pro 1? (http://photorumors.com/2012/01/07/detailed-fuji-x-pro-1-specs-you-must-read-this/).

Perhaps Canon have finally cottoned on to what they're missing, as they are now promising their own compact system camera this year? Presumably they must have already be developing it for some time...

http://photorumors.com/2012/01/07/canon-promises-mirrorless-camera-system-for-2012/
 
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Dave92F1

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traveller said:
Anyone else think that the G1X (stupid name considering Panasonic's recently announced GX1) is going to be completely overshadowed by Monday's Fuji X-Pro 1? (http://photorumors.com/2012/01/07/detailed-fuji-x-pro-1-specs-you-must-read-this/).

I think it's an interesting camera, but too large for the compact segment the G12 competes in. Still, if it had a flippy screen I'd consider buying one. But I think Canon has a patent on that, and few vendors want to risk a fight over that. (Nikon is an exception; I suppose they either made a deal with Canon or have some patent of their own to hold over Canon's head.)

Re the Gx sensor size, on that site there was a post from a year and a half ago that got me thinking:

http://photorumors.com/2010/06/09/canon-aps-h-1-3x-mirrorless/

Obviously that camera didn't happen (if it was ever real), but I think the technical points in the post are valid.

Considering:

  • The f/16 claim in the press release
  • The "shallow DoF" claim (ok, maybe marketing BS)
  • The reduced zoom range compared to the G11/G12 lens
  • The huge price hike from $600 to $800
  • Competitors with sensors of 1/1.0" (Nikon), 4/3, and APS-C (Sony)
  • The fact that full-frame film compacts were no larger than a G12
  • Last, the 14-bit RAW spec. I haven't run the numbers, but I suspect it makes no sense to do 14-bit RAW on a 1.53 micron pitch sensor. 2^14 is 16384, and I'm not sure such a small sensor can even hold that many electrons, so what would be the point of an expensive 14-bit ADC?

I still think the Gx sensor is bigger than 1/1.5" (if the Gx is even real).

I think it's bigger than the Nikon 1 sensor (1/1.0), and probably 1.5x crop, because that would make it a little bigger than Sony's APS-C sensor and all these companies love to bash each other with spec numbers. At $800 they can afford that, and Canon is well aware of how price affects sales - they know very well that a $800 camera with a 1/1.5" sensor will have problems in today's market.

I'll try another prediction - the lens will be very sharp, but will have lots of geometric distortion (barrel, pincushion, etc.). Then they'll correct that in software with the DIGIC 5, so you'll never see it. This will be their way of squaring the circle to get a small, sharp, f/2.5 lens that will cover a larger sensor.
 
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Jul 21, 2010
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It does indeed - but we also see the compromises that were made. It's much thicker than the G12, most of that is the protruding lens. It's not f/2.5, but f/2.8 at the wide end. Where the G12 is f/4.5 at the long end, the G1X is a narrow f/5.8. We'll have to wait and see if other compromises were made in lens design, and how the lens quality holds up to the large sensor.

One more thing occurs to me - I did overemphasize comparisons to EF/-S lenses. Thinking back, the combination of 1/3-stop narrower at the wide end, a very narrow long end make some difference, but importantly, it's a 4:3 sensor, not 3:2, and 4:3 makes more efficient use of the image circle, so all of the lens elements can be smaller than would be inferred from a lens needed for a 3:2 sensor.

Still - the big sensor makes it interesting, and justifies the price tag!
 
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ippikiokami

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neuroanatomist said:
It does indeed - but we also see the compromises that were made. It's much thicker than the G12, most of that is the protruding lens. It's not f/2.5, but f/2.8 at the wide end. Where the G12 is f/4.5 at the long end, the G1X is a narrow f/5.8. We'll have to wait and see if other compromises were made in lens design, and how the lens quality holds up to the large sensor.

One more thing occurs to me - I did overemphasize comparisons to EF/-S lenses. Thinking back, the combination of 1/3-stop narrower at the wide end, a very narrow long end make some difference, but importantly, it's a 4:3 sensor, not 3:2, and 4:3 makes more efficient use of the image circle, so all of the lens elements can be smaller than would be inferred from a lens needed for a 3:2 sensor.

Still - the big sensor makes it interesting, and justifies the price tag!

While it did lose some speed on the lens.

http://www.dpreview.com/previews/canong1x/images/sensorsizes.jpg

Considering how much bigger the sensor is I think we'll be ok. The pic from dpreview gives you a better idea of how giant that thing is. And considering about the amazing amount of detail everyone goes in about how important pixel / sensor size is whenever that subject comes up I think we have a lot to be happy about with Canon in their general direction.
 
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Jul 21, 2010
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Meh said:
neuroanatomist said:
Still - the big sensor makes it interesting, and justifies the price tag!

But will you buy one neuro? You may recall my previously stated gear buying policy.

LOL. No, I don't plan to buy one. For me, it's still too big - larger than truly pocketable (and I don't count cargo pants or coats for that), I'll just bring a dSLR.

There's one thing that might change my mind - if the AF speed and shutter lag approach those of a dSLR, then I'd consider it. That's one of the biggest downsides to a P&S, and one of the reasons I bring a dSLR unless I just can't. I'm sure that someday, contrast-detect AF will get fast enough, but I don't think it's there yet. In that regard, the bigger sensor is a disadvantage - the S100 has a fast burst rate, and because the DoF is deep, the lack of AF between shots isn't a big deal. But with a shallower DoF, a moving subject can more easily move out of the DoF. In fact, I often set my S100 to MF and rely on the deep DoF you get even with a wide aperture to eliminate the need for (and more importantly, the time it takes to) AF.

EDIT: one thing I just noticed - an optional 40m waterproof case. The ISO capabilities of a large sensor might make this a great option for diving. But then again, the combined price of the G1X and the housing will start to approach the cost of an Ikelite dSLR housing, and 28mm isn't really wide enough, and the 'extensive accessories' don't include a WA adapter.
 
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Meh

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neuroanatomist said:
Meh said:
neuroanatomist said:
Still - the big sensor makes it interesting, and justifies the price tag!

But will you buy one neuro? You may recall my previously stated gear buying policy.

LOL. No, I don't plan to buy one. For me, it's still too big - larger than truly pocketable (and I don't count cargo pants or coats for that), I'll just bring a dSLR.

There's one thing that might change my mind - if the AF speed and shutter lag approach those of a dSLR, then I'd consider it. That's one of the biggest downsides to a P&S, and one of the reasons I bring a dSLR unless I just can't. I'm sure that someday, contrast-detect AF will get fast enough, but I don't think it's there yet. In that regard, the bigger sensor is a disadvantage - the S100 has a fast burst rate, and because the DoF is deep, the lack of AF between shots isn't a big deal. But with a shallower DoF, a moving subject can more easily move out of the DoF. In fact, I often set my S100 to MF and rely on the deep DoF you get even with a wide aperture to eliminate the need for (and more importantly, the time it takes to) AF.

EDIT: one thing I just noticed - an optional 40m waterproof case. The ISO capabilities of a large sensor might make this a great option for diving. But then again, the combined price of the G1X and the housing will start to approach the cost of an Ikelite dSLR housing, and 28mm isn't really wide enough, and the 'extensive accessories' don't include a WA adapter.

I agree with the "pocketability" issue. I have a G10 and find it's just big enough to be a burden and once it's a burden I don't mind the greater burden of carrying my small backpack with DSLR. Now, not all of us need to put it into a pocket. Some of us carry purses which makes a huge difference in how large a P&S can be carried without it being inconvenient. And many of the European style shoulder bags for men (a.k.a. "murses") are very fashionable so there's no gender excuses.

Great point about the focus issues. Hadn't thought about it that way before. When out and about with a P&S for emergency photographic opportunities we may not have a lot of time to set up and compose a shot. The large DoF of the P&S means we can be quicker and still be sure the subject will be in focus.
 
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