Crop Factor sizes- I'm confused ?

I've recently got my first Canon, a G 12. Really like it, great little, versatile camera.

Got some questions about sensor size:

1) I know the sensor size on my G12 is smaller than any DSLR...but is it bigger than a typical P+S camera ?

I understand that there are different sensor sizes for DSLR cameras.

2) The confusing part is that Canon I understand has three different sensor sizes for different Canon DSLR's.

3) One is the Full frame....which has a sensor the same size as a 35mm film exposure. I think the Canon 1D and the Canon 5D Mk. 11 use this sensor as they are both full frame DSLR's ? Is this correct ?

4) There is also a Canon DSLR APS-H sensor which is smaller than the full frame, but bigger than the the APS-C sensor size, which is used by Nikon, Pentax and Sony. Which Canon DSLR's use this sensor ?

5) But then Canon has yet another DSLR sensor size, that is used only by Canon and it is an ASP-C sensor, yet I understand it is smaller in size than the aforementioned APS-C sensor used by Nikon, Pentax and Sony DSLR's

Which Canon DSLR uses this sensor ?

6) How can it be the same classification (an ASP-C sensor like the other makes) but be smaller in sensor size than the other makes ?

I'm also not sure if this question fits in Canon EOS Digital cameras section, or another section in the Canon Forum ?

Don't have the sensor size for the G12 right here. You can probably find it at the-digital-picture or dpreview.

It's true that Canon has three different sensor sizes in their current DSLR (EOS) lineup. They are used in many older models too. I only list the most recent introductions.
The 1Ds Mark III and 5D Mark II both uses a 24*36mm sensor, same as the format used on 35mm film. Also called full frame.
Then the 1D Mark IV uses an APS-H, which is 1.3 times smaller along the side of the sensor, compared to full frame.
Finally, the 7D, 60D, 600D and 1100D uses an APS-C sensor, which is 1.6 times shorter along the sides than the full frame sensor. The reason both this and Nikon's smaller sensor is called APS-C is that the difference is small. Nikon's reduction factor is 1.5.

Canon's three flavors of sensor are:
- FF .. you're correct on this one. Same size as 35mm film and used in the 1Ds bodies and 5Ds
- APS-H .. you'll find this in the 1D series of bodies and the "crop" factor is 1.3X
- APS-C .. the smallest size and found in the 60D, 7D and Rebels with a "crop" factor of 1.6X

As for why Canon's sizes differ from the competition, well, you'll have to ask Canon Engineering.

Your G12 has a bigger sensor than many P&S, but not as large as a APS-C sensor (as you stated)

Here is a nice image showing size relationships between camera sensors... The G12 has a sensor size of 1/1.7" - Many of Canon's more budget camera used a sensor of about 1/2.3-inch, which is inbetween the 1/1.8 and 1/2.5" listed below.

HOSTED PHOTO
please log in to view hosted photos in full size.

apersson850 wrote in post #11901597
Don't have the sensor size for the G12 right here. You can probably find it at the-digital-picture or dpreview.

It's true that Canon has three different sensor sizes in their current DSLR (EOS) lineup. They are used in many older models too. I only list the most recent introductions.
The 1Ds Mark III and 5D Mark II both uses a 24*36mm sensor, same as the format used on 35mm film. Also called full frame.
Then the 1D Mark IV uses an APS-H, which is 1.3 times smaller along the side of the sensor, compared to full frame.

Finally, the 7D, 60D, 600D and 1100D uses an APS-C sensor, which is 1.6 times shorter along the sides than the full frame sensor. The reason both this and Nikon's smaller sensor is called APS-C is that the difference is small. Nikon's reduction factor is 1.5.

Why would the 1D Mark 1V's sensor be smaller than the two full frame cameras (5D Mk 11 and older 1D), considering (if I'm right) that the 1D Mk 1V is the top of the line Pro Camera that Canon makes ?

Thanks for all the information from everyone. My G 12's pictures aren't as clear, detailed, good, etc...as my DSLR bodies and I expected that, as it has a small sensor. Thanks to the poster who posted the comparison chart showing the different sizes of digital cameras....in some ways I'm amazed at how good the pictures produced by the G12 are, considering how small the sensor is...I suppose it to do with the quality of the G12's lens and other features, it has over a typical P+S.

Another question. Is the Canon G series, such as my G12 considered a P+S....or because of it's more advanced features...is it in a different class ? Thanks for the answers...I'm not new to photography, but I am new to Canon...4 weeks.

It's an "Advanced" P&S

Canon makes two different top line cameras.

The 1Ds Mark III (s presumably for Studio) is aimed at the highest possible image quality. Hence the largest sensor.
The 1D Mark IV is aimed at action and sports, for photo journalists. Thus the emphasis is on high continuous drive speed, something which benefits from smaller moving parts (when the sensor size is reduced, so can the flipping mirror be) and lower resolution (less data to handle for each image).

Another reason is that when Canon started making the first 1D camera (not 1Ds), the APS-H size sensor was the largest chip their production technology allowed them to do in one step in their machines. Thus the production process was significantly simplified compared to the full format sensor manufacturing, something which could help keeping the cost down.

Lesmore wrote in post #11901734
Why would the 1D Mark 1V's sensor be smaller than the two full frame cameras (5D Mk 11 and older 1D), considering (if I'm right) that the 1D Mk 1V is the top of the line Pro Camera that Canon makes ?

The 1Ds MK IV has not been released, it would be the fullframe version. So the highest spec fullframe camera is the 1Ds MK III.

The G12 does have a larger sensor. It's a 1/1.7", if I remember correctly, whereas most P&S are 1/2.33"

Lesmore wrote in post #11901734
Why would the 1D Mark 1V's sensor be smaller than the two full frame cameras (5D Mk 11 and older 1D), considering (if I'm right) that the 1D Mk 1V is the top of the line Pro Camera that Canon makes ?

Back when dSLR's were new to the consumer market, Canon had four lines in three sensor sizes:

1Ds - Full frame professional. Slow frame rate and lots of pixels.
1D - 1.3X format professional. Much faster frame rate and less pixels. The less pixels is what allowed the higher speed and the smaller format was a good compromise to allow less pixels.
10D and Rebel - 1.6X in the 'entry' and middle markets.

The split at Canon between the full frame 1Ds line (1Ds Mark II...1Ds Mark III) and the 1D line (1D Mark II, 1D Mark III and 1D Mark IV) has continued.

Along the way Canon released the lower cost (~$3000) full frame option of the 5D. The 5D has the large sensor of the 1Ds cameras but is featured like a slow version of the 10D, 20D, 30D, 40D, 50D line. It's kind of a compromise in costing way the heck more than the XXD bodies but way less than a 1Ds Mark III.

They are visualized in post #4.

Powershot G12 sensor - CCD sensor, 1/1.7 " (7.60 x 5.70 mm, 0.43 cm²) -9.2mm diagonal (4:3 aspect) 10mp

The Canon A495 point & shoot - CCD sensor, 1/2.3 " (6.16 x 4.62 mm, 0.28 cm²) 10mp
The Canon S90 point & shoot - CCD sensor, 1/1.7 " (7.60 x 5.70 mm, 0.43 cm²) 10mp

Sensor seems to be the same size with the S90 point and shoot. It comes down to the rest of the camera and built in features... digic processor and software inside that increase the cameras image quality with better iso ratings and so on.

http://www.neocamera.c​om/camera.php?id=238
http://www.dpreview.co​m …specs/Canon/can​on_g12.asp

apersson850 wrote in post #11901771
Thus the emphasis is on high continuous drive speed, something which benefits from smaller moving parts (when the sensor size is reduced, so can the flipping mirror be) and lower resolution (less data to handle for each image).

This is almost all correct but for one thing. The speed difference between the 1Ds and 1D (same generations) is always purely the data processing rate.

If you look, at almost every generation the 1Ds has twice as many pixels and can shoot at half the rate.

The mirror boxes in the 1D and 1Ds cameras are the same. Flipping the mirror is not the limit on the 1Ds speed.

apersson850 wrote in post #11901771
Canon makes two different top line cameras.

The 1Ds Mark III (s presumably for Studio) is aimed at the highest possible image quality. Hence the largest sensor.
The 1D Mark IV is aimed at action and sports, for photo journalists. Thus the emphasis is on high continuous drive speed, something which benefits from smaller moving parts (when the sensor size is reduced, so can the flipping mirror be) and lower resolution (less data to handle for each image).

Another reason is that when Canon started making the first 1D camera (not 1Ds), the APS-H size sensor was the largest chip their production technology allowed them to do in one step in their machines. Thus the production process was significantly simplified compared to the full format sensor manufacturing, something which could help keeping the cost down.

I get it now, thanks to the last two posters for explaining. Where does the Canon 5D Mk 11 fit in ? I think it is a full frame , pro level camera at a reduced cost.
But because of the price differential I'm assuming it must not be at quite the same level as the the other two....but still robust enough to be considered a pro camera ?

Have I got that right ?
The 5D Mk 11 has always had a lot of appeal to me.

The 7D is also an excellent camera, but with a smaller sensor, but is considered to be a pro level camera...or not ?

I find that Canon has so many choices in DSLR's that I have difficulty keeping it all straight.

Appreciate the information from all.

Both the 7D and 5D2 are professional level.

The 7D has a crop sensor, yes, but many wildlife and sport shooters want this. Gives them increased reach on their lenses (field of view changes, multiplies by 1.6x).

5D2 is professional as well, just lacks better build, high end AF and some other features the 1D series will have.

They are all great cameras.