If you're bored, with a bit of time on your hands.......

[Robin Usagani]

My argument was, it depends on what size of print. If you keep it to 300 dpi without interpolating any pixels, then I would say 5D is the winner.

 

[Destin]

My argument was, it depends on what size of print. If you keep it to 300 dpi without interpolating any pixels, then I would say 5D is the winner.

I don't believe that you'd even see a difference with your naked eye. I'd be willing to bet that you couldn't tell one from the other.

 

[Robin Usagani]

Destin, what if it was a photo in a lower light condition?

 

[Garbz]

My argument was, it depends on what size of print. If you keep it to 300 dpi without interpolating any pixels, then I would say 5D is the winner.

That doesn't make sense, the 7D would still win. If you keep the image at 300ppi with no interpolation you end up with a significantly larger print from your 7D than you 5DmkII (19x12 vs 12x8)

 

[RacePhoto]

Another small tidbit to consider. The crop camera uses the center of the lens, the "sweet spot" which should have less flaws than the entire area, to the edges on the full frame. One more reason why a crop camera will be likely to win this experiment. But oh wait, we're cropping that off. Nevermind!

I agree, it's probably not going to be visible to anyone except maybe at 200% on a monitor. :thumbup:

Resulting images:
EOS 5D MkII: 3478 x 2324
EOS 7D: 5184 x 3456


Unless I made some calculation mistake I think this means the 7D results with higher resolution.

Pixel Pitch not resolution, will be the determining factor. And if you crop something to the same size, how is the 5D smaller. I need to re-read, your math. I'll assume you are right and I missed it?

I did it the easy way, .62 x the original 5D image and got 3482 for the 5D to product the same view. Something just doesn't seem right?

 

[Judobreaker]

The pixel pitch is quite easy, its listed in the specs.

Pixels per mm: 156 (5616 / 36 || 3744 / 24) = .006 mm pixel pitch
Pixels per mm: 232 (5284 / 22.3 || 3456 / 14.9) = .004 mm pixel pitch

However, what I calculated is how many pixels cover an equal area.
A crop camera has a smaller sensor than a full frame.
Basically to get the same photo out of a full frame camera you'll need to crop away the areas that a crop sensor wouldn't be able to see (because of its smaller size).
In this case the crop sensor is 22,3 x 14,9 mm and the full frame is 36 x 24 mm.
That means we'd have to crop away 13,7 x 9,1 mm of sensor to get to the same size photo.
Now the amount of pixels on that area will determine the actual pixel-size of the photo.
Because of the smaller pixel pitch the crop sensor will actually get a larger pixel-size than the full frame camera.

 

[Groupcaptainbonzo]

The cheat of course would be to attach a lens to the 5d (or full frame whatever) that is 1.6 x longer focal lenght. then obviously you would have an image where the 5D was even better. But the cost difference between a 300mm f2.8 (VERY expensive) and a 480mm f 2.8 (probably a 500mm) . Well, you are talking the Greek national debt... so maybe a cropped sensor is a good thing.

 

[Destin]

The cheat of course would be to attach a lens to the 5d (or full frame whatever) that is 1.6 x longer focal lenght. then obviously you would have an image where the 5D was even better. But the cost difference between a 300mm f2.8 (VERY expensive) and a 480mm f 2.8 (probably a 500mm) . Well, you are talking the Greek national debt... so maybe a cropped sensor is a good thing.

If you can afford a 300 for $6,000, then the extra $4,000 to get up to the $10,000 400 shouldn't be missed from your bank account too much.

 

[KmH]

The pixel pitch is quite easy, its listed in the specs.

Pixels per mm: 156 (5616 / 36 || 3744 / 24) = .006 mm pixel pitch
Pixels per mm: 232 (5284 / 22.3 || 3456 / 14.9) = .004 mm pixel pitch

However, what I calculated is how many pixels cover an equal area.
A crop camera has a smaller sensor than a full frame.
Basically to get the same photo out of a full frame camera you'll need to crop away the areas that a crop sensor wouldn't be able to see (because of its smaller size).
In this case the crop sensor is 22,3 x 14,9 mm and the full frame is 36 x 24 mm.
That means we'd have to crop away 13,7 x 9,1 mm of sensor to get to the same size photo.
Now the amount of pixels on that area will determine the actual pixel-size of the photo.
Because of the smaller pixel pitch the crop sensor will actually get a larger pixel-size than the full frame camera.

Are you allowing for the microlenses between each pixel?

 

[Judobreaker]

What's up with the micro lenses...?

 

[EchoingWhisper]

I don't think it would be a fair comparison unless the lens are the same in size. A full frame f/2.8 should be equal to a APS-C f/2.0 (around that) to allow fair comparison or else their low light capabilities would be different, because a full frame f/2.8 lens should be about the same size as a APS-C f/2.0 without including AF and VR.

 

[Groupcaptainbonzo]

forgive me if I'm wrong... but.... would there not be some inherent electrical interference with the neighbouring pixels within a sensor chip, that (I think) would be more pronounced , the closer the pixels are together (ie More interference in the 7D chip than in the 5D MkII chip.

Then of course, there is the difference in protocols between the Digic 4 processor (EOS 5D MkII) and the dual Digic 4 processors in the EOS 7D. As the processing will interpret the photon fall on the sensor itself....


This one really needs to be done....

 

[Destin]

I don't think it would be a fair comparison unless the lens are the same in size. A full frame f/2.8 should be equal to a APS-C f/2.0 (around that) to allow fair comparison or else their low light capabilities would be different, because a full frame f/2.8 lens should be about the same size as a APS-C f/2.0 without including AF and VR.

Huh? How do you figure? Their effective aperture doesn't change because of sensor size... I can put an fx lens on my dx camera, and given the same exposure settings, it would produce an exposure equal to that of a dx lens at the same settings.

 

[EchoingWhisper]

I don't think it would be a fair comparison unless the lens are the same in size. A full frame f/2.8 should be equal to a APS-C f/2.0 (around that) to allow fair comparison or else their low light capabilities would be different, because a full frame f/2.8 lens should be about the same size as a APS-C f/2.0 without including AF and VR.

Huh? How do you figure? Their effective aperture doesn't change because of sensor size... I can put an fx lens on my dx camera, and given the same exposure settings, it would produce an exposure equal to that of a dx lens at the same settings.

Yes, that is to simplify exposure. In reality, it's not like that. A f/2.8 FX and f/2.8 DX lens is not the same size. And ISO 100 on FX and DX is different too. A f/2.8 on FX is similar to a f/2.0 DX (total amount of light and depth of field given that both subjects fills the frame) and and a ISO 200 on FX is similar to ISO 100 on DX (noise level and amplification given that the same light enters the sensor and the same sensor technology/design).

 

[Kolia]

Yes, that is to simplify exposure. In reality, it's not like that. A f/2.8 FX and f/2.8 DX lens is not the same size. And ISO 100 on FX and DX is different too. A f/2.8 on FX is similar to a f/2.0 DX (total amount of light and depth of field given that both subjects fills the frame) and and a ISO 200 on FX is similar to ISO 100 on DX (noise level and amplification given that the same light enters the sensor and the same sensor technology/design).

The first part doesn't make sense to me. Shouldn't f2.8 be the same size for a given focal length regardless of lens type ? On a cropped sensor, shouldn't the FX and DX lens yield the same results for a given f stop ? With some light being "wasted" spilling outside of the sensor with the FX.