7D/60D mRaw (10mp) and 5Dc Raw (12mp)

I own 60D and 5Dc, previously owned a 7D. I don't shoot birds or wild life, so most of my pictures don't require heavy cropping, my observation is based on this apparently.

I noticed that when looking at mRaw from 7D/60D and Raw from 5Dc, at 100% crop, 5Dc seems to have better center sharpness in most cases. I'm not saying that it can't be sharp from 7D/60D, but if I shoot the same lens on both bodies, say tamron 28-75, in general 5D pictures look sharper than 7D/60D.

Is this because of higher pixel density on crop ? Even at 10mp on crop vs 12mp on FF, the actual density on crop is still about twice of that on FF?

I did notice that lenses with weak corner sharpness seem to be better on crop than FF, say my 20mm 1.8, which is terribly soft at corner wide open, it doesn't look that bad on crop.

Depends how you're shooting your comparisons. Are you shooting by framing? Or are you keeping everything else constant, like distance to subject, etc...

If you're comparing by "framing", keep in mind you've moved closer to the subject when shooting w/ the 5D, thus making it easier to get "sharper and more detailed" photos by virtue of being closer to the subject. Another note (due to lower pixel density), the 5D has a much weaker AA filter, so SOOC photos will appear sharper.

Another thing of note is that mRAW isn't doing you any favors when 100% pixel peeping. There's no magical formula when the data's discarded to cut down on file size. My recommendation is to shoot at full resolution, and the resize down in post (which is just a 1 second step) if you want to maximize your detail captured.

Thanks for the answer!

I understand what you mean by framing, essentially the photo taken with 5D is at a shorter distance.

Another case, if I shoot sigma 30 f/1.4 on crop, and sigma 50 f/2.2 on FF, at about the same distance, about the same DOF and FOV. The FF picture probably looks better because the 50 lens provides higher magnification factor optically while 30 on crop is more like digital zooming to achieve the same FOV? Another factor, the sigma 50 at f/2.2 is optically better than sigma 30 at f/1.4, I assume?

thanks again!

genjurok wrote in post #12903906
Thanks for the answer!

I understand what you mean by framing, essentially the photo taken with 5D is at a shorter distance.

Another case, if I shoot sigma 30 f/1.4 on crop, and sigma 50 f/2.2 on FF, at about the same distance, about the same DOF and FOV. The FF picture probably looks better because the 50 lens provides higher magnification factor optically while 30 on crop is more like digital zooming to achieve the same FOV? Another factor, the sigma 50 at f/2.2 is optically better than sigma 30 at f/1.4, I assume?

thanks again!

Yes, you can view the 30 + crop as somewhat of a "digital" zoom in that particular scenario. You're basically asking a smaller sensor to capture as much detail as a larger one does. The quality/amount of light hitting that smaller surface area is a lot less than what would be cast upon the larger FF sensor. Can't bend the law of physics.

Light is light, it doesn't matter how large or how small the sensor is, the same amount of light hits the same surface area? Maybe I am missing the context of the statement though?

Is the comment more around the fact that the more dense a sensor is, the greater the loss of photons being recorded? That is true to an extent, however with gapless microsensors and less deep wells (the 7D design is basically a combination of the 50D sensor and the 5D2 sensor, gapless and less deep wells), this loss is theoretically lessened.

TeamSpeed wrote in post #12904141
Light is light, it doesn't matter how large or how small the sensor is, the same amount of light hits the same surface area? Maybe I am missing the context of the statement though?

Is the comment more around the fact that the more dense a sensor is, the greater the loss of photons being recorded? That is true to an extent, however with gapless microsensors and less deep wells (the 7D design is basically a combination of the 50D sensor and the 5D2 sensor, gapless and less deep wells), this loss is theoretically lessened.

If you're not using the same lens and shooting at the same distance from the subject, then it's not the same.

For example, take a FF and crop camera. Use the same exact lens, we'll say the 85. Keep distance between camera and subject constant, and you'll get the same image circle. The amount/quality of light (if you look at the vectors) is identical within the overall image circle. Naturally, on a crop sensor, much of the image circle is not captured. But whatever amount/quality of light that does hit the crop sensor surface area would be identical to the amount/quality of light that hits the FF sensor.

Now let's alter the setup, keeping distance the same, but slap a 50mm to approximate the same FoV/AoV that is captured on the crop sensor as the 85 would have captured on the FF sensor. You're now expecting the smaller surface area of the crop sensor to provide you with the same light information that was project on a larger image circle on the FF.

But I'm just speculating.

If you only alter the focal length on the two, but kept the shutter and apertures the same, you would expect the same amount of light again to hit each sensor. However since aperture is a ratio, and not all lenses are created equal, or even perhaps the actual aperture iris has some tolerances of error where it doesn't open quite the same exact amount for the new focal length, or if you use a different lens entirely, then there could be a difference.

Yeah, you would expect the same amount of light to be identical to the point it hits the front element of the lens.

After that, the lens will alter the light before it hits the sensor. How much "light" is actually focused onto the resulting image circle is dependent on the FL/lens, and associated aperture.

I think one parameter was not accounted for the lens, it may need to be microadjusted for 7d/60d...so you eliminate that variable. that means a chart shot then compared at pixel to pixel.

but what do i know