Messages

16

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 08, 2012, 11:47:25 AM »

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.

17

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 08, 2012, 01:03:59 AM »

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".

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).

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.

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.

18

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 06, 2012, 11:25:19 PM »

Even if the sensor is FF or even close... doesn't make much sence to "give" that much power to a non-lens changable camera... at least in my opinion.

I have to disagree there.  The best camera is the one you have with you.  If all I have room for is a G13, then I wan t the best G13 I can have (within the limits of size, weight, cost, etc.).  Sure, it may be pricey compared to an interchangeable lens camera, but if it's a lot smaller, then it's worthwhile - to some people anyway.

I would buy a T3 before I spent THAT kind of money on a P&S. (and it's cheaper and expandable... IE lenses!!!)

Perhaps you would, but other people (perhaps with bigger budgets) are willing to pay something extra for portability. 

IQ and flexibility are great, but they're not worth a thing if you don't have the camera with you.

19

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 06, 2012, 11:16:41 PM »

Point is, if it really does have an APS-C sized sensor, the relevant comparator lens is the EF-S 15-85mm f/3.5-5.6 (a little wider and longer, but also slower).  Now, who wants to argue that a lens nearly 4" long when retracted and weighing close to 2 lbs. will be seen in a G-series PowerShot?

Excellent point. 

OK, maybe I'm wrong and it's not a 1.5x crop sensor.  Then how do you explain the $800 price (the G12 was $600), the f/16, and the reduced zoom range (compared to the G11/G12)?  (I'll ignore the shallow DOF promise as marketing nonsense.)

The only way that makes sense to me is if the sensor is considerably bigger than the 1/1.7" sensor in the G12.  I don't think 1/1.5" is enough to explain those.

I think 1/1.0" (ala Nikon V1) would, overall, make more sense in a compact than an APS-C sensor, but I don't see how that fits with the "1.5inch" sensor comment in the press release.

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?

20

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 06, 2012, 06:53:11 PM »

Sure, but the problem for the G12 and similar is that they are similar in size to Sony NEX, Micro 4/3 and similar, but in terms of performance it's basically another small sensor compact. What makes the S100 a strong product is that it is a solid performer for its size.

I agree the S100 is a great camera for its size (at least, it will be once they iron out their QC problems), but that's in a different size class than the G-series.

The G11/G12 is actually much smaller than the Sony NEX or 4/3 cameras when you include a similar range zoom lens.  To me, those cameras are nearly as big as a Rebel - not something I'd carry every day, as I do with the G11.

That would be a 17-70mm f/2.5 APS-C lens -- kind of like a big brother to Canon's 17-55mm EF-S lens.

And the 17-55mm EF-S is a huge lens - bigger than the whole G12 camera - despite covering a smaller zoom range than claimed for the Gx.

So either the Gx has a smaller than APS-C sensor, it's huge, or there's a big size advantage from not having to do backfocus past the mirror box...  (I hope the latter.)

21

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 06, 2012, 06:33:26 PM »

But don't get excited - the G1x won't have APS-C, it'll have a 1/1.5" sensor.

We'll see in a few days, but Canon isn't crazy and although the marketing folks do love to exaggerate (like all the vendors), I really don't think Canon's engineers would offer f/16 on a 1/1.5" sensor (because of diffraction, as you implied).

And how will they justify a 1/3 price hike for a tiny increment of sensor size? 

For me, a 1/1.5" sensor would still be OK (I don't think the small sensor is the G12's biggest problem), but I was expecting something closer to the Nikon 1's 1.0 inch sensor. 

But given the f/16 spec, the price hike, and the 4x zoom (instead of 5x on the G12), I think there's a considerably bigger sensor in there.

22

PowerShot Cameras / Re: *UPDATE 3* Canon PowerShot G1X Revealed

« on: January 06, 2012, 04:59:04 PM »

"too big to fit in a normal pocket, too small to be taken seriously" category, at the high end of the usual $350-$700 price range, and with nothing to make it stand out from the crowd.

Some of us carry things like backpacks, briefcases, or computer bags everyday.  If you're one of those, there's a huge difference between carrying a Rebel + lens and something the size of a G12.

It doesn't have to fit in a pocket, but it does have to be a lot smaller than the Rebel.  If it can do that, and come close to DSLR quality, they'll get my $800.

BTW, my theory is that the "1.5inch" sensor is neither 1.5 inch (that would be almost full-frame, unaffordable at $800) nor 1/1.5" (because that's incompatible with f/16 and "shallow depth of field").

I think it's a 1.5x crop sensor.  That would make it a little bigger than APS-C.  Which would be very exciting.

23

PowerShot Cameras / Re: Powershot Gx? [CR1]

« on: December 19, 2011, 11:42:53 AM »

Who would buy this camera at that price point?

I would.  I want a small camera with good IQ & control.  (I have a DSLR but won't carry it around every day.)

I'll miss the OVF, but a good EVF would be OK if it's not too laggy. 

Even just the articulated screen might be OK (but without that, no sale).

With my G11, I mostly shoot with the camera braced against my belly/chest, Hasselblad-style.  Seems just as stable as bracing against the face, and it's less intimidating.  But you need the articulated screen to do that.

24

EOS Bodies / Re: Anyone have a good explanation of "native" vs "expanded" iso?

« on: December 02, 2011, 04:44:37 PM »

As far as I can tell, "native" just means that Canon thinks the resulting noise is acceptable, and "expanded" means it's not really acceptable but you might want to use it.

I don't think there's really any technical difference - it's just that when somebody points at a really noisy image, Canon wants to be able to say "oh, but that that was at an expanded iso".  It's their way of washing their hands about the quality, while still allowing the photographer to crank up the gain really high.

I don't think there would be much (if any) difference between upping the gain in-camera ('expanded' iso) and doing it in post-processing.

25

PowerShot Cameras / Re: PowerShots Next Week [CR2-CR3]

« on: September 11, 2011, 11:12:33 AM »

Another theory is the “S100″ rumors we’re hearing are actually for a G13 and the “S” series isn’t getting an upgrade.

I think not.

If the rumor about the S100 is true - 12 Mpixel bump and no "G13" announcement, I think Canon's strategy is pretty clear.

The "S100" is probably real - it's the best competitor in the really-tiny pocketable category, and a major change like a larger sensor would not be an improvement - it would either end up bigger or with worse optics, so the S95 series will continue with minor tweaks.

But the "G13" absence, together with Nikon's soon-to-be-announced EVIL with a 2.7x crop sensor, is telling.

As far as I know, Nikon doesn't make sensors - they buy them from Sony, same place that Canon buys their small sensors for the PowerShots.   So probably Sony (or, just possibly, Fuji) is making Nikon's 2.7x sensor - either way, surely they offered it to Canon too.

PREDICTION:

So, I'll predict that the G12 replacement will use the same 2.7x crop sensor used the Nikon EVIL.  That means a total redesign, which explains why it won't be ready at the same time as the "S100". 

Personally, I think that's a great decision on Canon's part, provided they do it right. 

The larger sensor will be very welcome for less noise at high ISO.  And I'd _love_ if they could make it focus faster - that's my main complaint with my G11 (more so than the noise). I hope it's not any bigger than the G12, which is already at the upper limit of size for me.  And I really hope they keep the flippy screen - I won't buy it without one (I'd sooner buy a G12). 

But an interchangeable lens on a camera in this size class really isn't important to me.  I see the G-series cameras as high-quality but very portable cameras to be taken along when you're _not_ primarily doing photography  If I need interchangeable lenses, I'm primarily doing photography, and will drag along my 60D and lenses (and tripod) for that.

Cheers,

--Dave