canon G1X: big sensor fixed lens camera

[ElFenix]

Anyone watching the emergence of mirrorless interchangeable lens cameras will have spent much of the last year patiently waiting for Canon and Nikon to show their hands. Nikon clearly decided such cameras didn't need large sensors, and now it appears Canon has concluded they don't need interchangeable lenses. Both these moves make sense for companies wanting dedicated photographers to keep buying DSLRs, but Canon's approach is likely to be of more interest to those enthusiasts.

http://www.dpreview.com/previews/canong1x/

the hot:

• 14 MP 1.5" sensor is the same height as APS-C, but slightly narrower (4:3 aspect rather than 3:2). that gives it a similar pixel site size as a 7D, so sheer IQ from the sensor perspective could be quite good.
  
• lots of controls
  
• not that much larger than a G12 or a u4/3 (though obviously the latter can be taken apart for carrying)

the not so hot:

• 28-112 f/2.8-5.8 lens is not quite as wide as people are used to in the premium camera market, and is definitely not very bright on the tele end (which gives back quite a bit of the large sensor advantage compared to, say, an f/2-2.8 lens with similar range).
  
• OVF is meh

bitching has already commenced on the many forums where you would expect it

 

[gar655]

the not so hot:

• 28-112 f/2.8-5.8 lens is not quite as wide as people are used to in the premium camera market, and is definitely not very bright on the tele end (which gives back quite a bit of the large sensor advantage compared to, say, an f/2-2.8 lens with similar range).
  
• OVF is meh

Well, a 2-2.8 lens of similar range would've been much, much larger. For its target audience the lens is better than any of the kit lenses on the APS, micro 4/3s or Nikon 1 series. In fact none offer quite the range and none are faster.

Being built on and for the body "should" result in corner to corner sharpness at all FLs and Avs. The IS "should" be more affective.

Size wise it's not much bigger than the smallest mirrorless with kit lens.

My only "not so hot" is I wish it started at 24 or 25 and went a tad longer, or even the same tele end but wider.

Overall I think it's the best of this type of camera. After all once you have to start carrying multiple lenses the "portability" issue takes a big hit.

 

[CuriousMike]

That's damn near the perfect camera for my wife.

Make it 20&#37; smaller and < $400 and we're talking.

 

[randomlinh]

That's damn near the perfect camera for my wife.

Make it 20% smaller and < $400 and we're talking.

heh, a 50% price cut is asking quite a bit =)

 

[gar655]

It's only $100 more MSRP than the small sensor Fuji X10 (or something like that), has better IS (Canon's is great) will offer better resolution and dynamic range at all ISOs and far less noise at high ISOs without resorting to the resolution and detail crushing pixel binning method of the Fuji.

 

[Gooberlx2]

Make it 20&#37; smaller and < $400 and we're talking.

I kinda wonder if we'll manage to see a Canon S1?? with something like a u4/3 size sensor, while maintaining the same size. I'd love to see at least u4/3 quality in a truly pocketable form factor.

 

[foghorn67]

I know Canon has gone on record about EVIL cameras. But I'm sure they have one in the works. They have to at this point.

 

[vbuggy]

http://www.dpreview.com/previews/canong1x/

the hot:

• 14 MP 1.5" sensor is the same height as APS-C, but slightly narrower (4:3 aspect rather than 3:2). that gives it a similar pixel site size as a 7D, so sheer IQ from the sensor perspective could be quite good.
• lots of controls
• not that much larger than a G12 or a u4/3 (though obviously the latter can be taken apart for carrying)

the not so hot:

• 28-112 f/2.8-5.8 lens is not quite as wide as people are used to in the premium camera market, and is definitely not very bright on the tele end (which gives back quite a bit of the large sensor advantage compared to, say, an f/2-2.8 lens with similar range).
• OVF is meh

bitching has already commenced on the many forums where you would expect it

Given the size of the sensor I don't think even the F5.8 vs F2.2 will actually be inferior in use - as big as the gap appears to be - certainly if we're talking about lining it up with e.g. the Fuji with the 2/3 EXR sensor.

I'm looking forward to it. Seems on the face of it like the DSLR backup I've been wanting.

 

[JohnnyRebel]

Very appealing...

 

[ElFenix]

Given the size of the sensor I don't think even the F5.8 vs F2.2 will actually be inferior in use - as big as the gap appears to be - certainly if we're talking about lining it up with e.g. the Fuji with the 2/3 EXR sensor.

I'm looking forward to it. Seems on the face of it like the DSLR backup I've been wanting.

i didn't say inferior, i said you're giving up some of the advantage.

if your sensor is 3 stops larger, and your lens is 2 stops slower, you've still improved by a stop.

 

[JohnnyRebel]

i didn't say inferior, i said you're giving up some of the advantage.

if your sensor is 3 stops larger, and your lens is 2 stops slower, you've still improved by a stop.

Please expain "stops" on sensor size.

JR

 

[RobDickinson]

If the efficiency per area is the same then 3 stops on the sensor means a sensor 8 times bigger..

 

[JohnnyRebel]

If the efficiency per area is the same then 3 stops on the sensor means a sensor 8 times bigger..

I guess my real question is whether a size stop of a lens is exactly equivalent to a lens f-stop, as implied by ElFinix. I am only familiar with ISO/Aperture/Shutter speed stops.
JR

 

[Throckmorton]

The sensor pixels are bigger but the lens isn't any bigger than other cameras so it's not gathering any more light... how does that affect things?

 

[ElFenix]

I guess my real question is whether a size stop of a lens is exactly equivalent to a lens f-stop, as implied by ElFinix. I am only familiar with ISO/Aperture/Shutter speed stops.
JR

exposure is all about light gathering, and a bigger sensor gathers more light.

most people don't think of sensor formats in terms of stops, but for describing the noise performance of the same apparent exposure over different formats it really helps you understand why the 4/3 35-70 f/2 is only the equivalent of the 7-200 f/4 on a 5D.

basically, f-stops for lenses aren't an absolute amount of light, they are a light intensity. same intensity over a larger area results in more total light. 2 stops more open results in 4x the light over the same area. so a sensor 1/4 the size with a lens 2 stops faster is still the same total light. or, a sensor with 4x the area with a lens 2 stops slower is, again, the same total light.

The sensor pixels are bigger but the lens isn't any bigger than other cameras so it's not gathering any more light... how does that affect things?

but it is gathering more light.

remember that f-stops are relative figures. on a longer focal length lens the absolute aperture at any given stop is larger. while a 50/2 is a 50/2 is a 50/2, it's a long focal on 4/3, normal on 35mm, and wide on 48x36 medium format. and that medium format sensor is gathering 8x the total light than that 4/3 sensor is. but, it's also using a much wider field of view.

if we use the same field of view, and the same f-stop, we get a 25/2 on 4/3, 50/2 on 35mm, and 100/2 on the medium format. the aperture diameters for each are 12.5mm, 25mm, and 50mm.

note that these settings do not result in equivalent images because the larger absolute aperture on the larger cameras results in a shorter dof.

 

[vbuggy]

i didn't say inferior, i said you're giving up some of the advantage.

if your sensor is 3 stops larger, and your lens is 2 stops slower, you've still improved by a stop.

Some, sure.

But I think - correct me if I'm wrong here - you're also still going to get shallower DOF with the Canon vs the Fuji at the tele end. It's maybe not a total walkover at that end, but you're still going to get your relative money's worth. At the wide-to-mid end - there's very likely going to be no contest, if not a total shredding.

 

[ElFenix]

Some, sure.

But I think - correct me if I'm wrong here - you're also still going to get shallower DOF with the Canon vs the Fuji at the tele end. It's maybe not a total walkover at that end, but you're still going to get your relative money's worth. At the wide-to-mid end - there's very likely going to be no contest, if not a total shredding.

should be, yes.

there's also the question of whether digital sensors can actually take full advantage of super fast apertures due to the shallow angle of incidence of light coming from the other side of the lens. which results in more-than-film light fall off and also more dof. one of the benefits of a mirrorless camera is that you can use a lens element to attempt to correct some incidence issues that wouldn't fit behind an SLR lens.

 

[JohnnyRebel]

exposure is all about light gathering, and a bigger sensor gathers more light.

most people don't think of sensor formats in terms of stops, but for describing the noise performance of the same apparent exposure over different formats it really helps you understand why the 4/3 35-70 f/2 is only the equivalent of the 7-200 f/4 on a 5D.

basically, f-stops for lenses aren't an absolute amount of light, they are a light intensity. same intensity over a larger area results in more total light. 2 stops more open results in 4x the light over the same area. so a sensor 1/4 the size with a lens 2 stops faster is still the same total light. or, a sensor with 4x the area with a lens 2 stops slower is, again, the same total light.

Maybe you can point me to a more detailed source for sensor stops. I am not getting it.

If the f-stop for a lens is the focal length divided by the apparent diameter of the lens aperture (apparent because the aperture blades are not located with the front element), how does this vary due to the size if the sensor on which the light falls. For example, my FX lenses are the same f-stop on my DX camera as they are on an FX camera. There is a field of view change, and pixle density differences, but the brightness of illumination remains the same. f/4 is f/4. This is why handheld light meters work for setting exposure.

What am I missing?

JR

 

[Throckmorton]

exposure is all about light gathering, and a bigger sensor gathers more light.

most people don't think of sensor formats in terms of stops, but for describing the noise performance of the same apparent exposure over different formats it really helps you understand why the 4/3 35-70 f/2 is only the equivalent of the 7-200 f/4 on a 5D.

basically, f-stops for lenses aren't an absolute amount of light, they are a light intensity. same intensity over a larger area results in more total light. 2 stops more open results in 4x the light over the same area. so a sensor 1/4 the size with a lens 2 stops faster is still the same total light. or, a sensor with 4x the area with a lens 2 stops slower is, again, the same total light.





but it is gathering more light.

remember that f-stops are relative figures. on a longer focal length lens the absolute aperture at any given stop is larger. while a 50/2 is a 50/2 is a 50/2, it's a long focal on 4/3, normal on 35mm, and wide on 48x36 medium format. and that medium format sensor is gathering 8x the total light than that 4/3 sensor is. but, it's also using a much wider field of view.

if we use the same field of view, and the same f-stop, we get a 25/2 on 4/3, 50/2 on 35mm, and 100/2 on the medium format. the aperture diameters for each are 12.5mm, 25mm, and 50mm.

note that these settings do not result in equivalent images because the larger absolute aperture on the larger cameras results in a shorter dof.

Forget the f-stops. If the lens diameter is the same and the view angle is the same, the amount of light entering the lens that is directed to the sensor is the same.

 

[JohnnyRebel]

Forget the f-stops. If the lens diameter is the same and the view angle is the same, the amount of light entering the lens that is directed to the sensor is the same.

EDIT: Nevermind

JR

 

[vbuggy]

I believe he said lens diameter. Not focal length.

 

[ElFenix]

Forget the f-stops. If the lens diameter is the same and the view angle is the same, the amount of light entering the lens that is directed to the sensor is the same.

well, yes. but that's not what you stated.

at the long end the canon is at 10.4mm across and the fuji at 10.1mm, so the canon gives back most of its advantage there.

but at the short end the canon is still at 10mm while the fuji is at 3.55mm. that's a hole 8x larger. 3 stops.

 

[Throckmorton]

well, yes. but that's not what you stated.

at the long end the canon is at 10.4mm across and the fuji at 10.1mm, so the canon gives back most of its advantage there.

but at the short end the canon is still at 10mm while the fuji is at 3.55mm. that's a hole 8x larger. 3 stops.

What did you think I meant when I said the lens isn't gathering more light?

Are you talking about apertures? Forget all this camera-specific terminology and think about the actual physics. The same amount of light being focused on a smaller sensor is just that... the same amount of light being focused on a smaller sensor.

 

[ElFenix]

What did you think I meant when I said the lens isn't gathering more light?

Are you talking about apertures? Forget all this camera-specific terminology and think about the actual physics. The same amount of light being focused on a smaller sensor is just that... the same amount of light being focused on a smaller sensor.

but it is gathering more light. negligibly more at the long end, yes, but 8x more at the short end.

 

[Throckmorton]

but it is gathering more light. negligibly more at the long end, yes, but 8x more at the short end.

What do you mean?

Lenses same diameter

Both set to 1x zoom

Same view angle = same light