Crop factor magnification impact on Image quality? I was wondering - when a cropped sensor camera crops the center part of an image then magnifies it to fill the frame is there a loss...

inbigd

I was wondering - when a cropped sensor camera crops the center part of an image then magnifies it to fill the frame is there a loss of quality compared to if a full frame camera with a lens of the equivalent greater length (200mm vs 300mm) was used to take the same exact sized image?

If a picture of the moon is taken with a cropped sensor at 200mm and with full frame at 300mm would the images be the same?

And how does a cropped sensor 'upsize' the part of the image it crops so that it 'fills the frame'?

thanks

rwilson1942 Loc: Houston, TX

The sensor is the "frame" there is no magnification or 'upsize' involved. When a FF lens is used on a crop sensor camera, the sensor simply 'sees' less of projected image.

mwsilvers Loc: Central New Jersey

inbigd wrote:

I was wondering - when a cropped sensor camera cro... (show quote)

When you say fill the frame, do you mean the cameras LCD screen or your monitor, or what? There is no magnification, if anything the image is resized smaller to fill your computer screen. Trying viewing at 100%, the actual size of the image. You'll have to pan to see the entire image.

inbigd

mwsilvers wrote:

When you say fill the frame, do you mean the cameras LCD screen or your monitor, or what? There is no magnification, if anything the image is resized smaller to fill your computer screen. Trying viewing at 100%, the actual size of the image. You'll have to pan to see the entire image.

I mean the camera screen

inbigd

What does this mean, from Ken Rockwell's explanation -

"When enlarged to the same print or image size, the photo made from the smaller sensor must be enlarged more. This is done automatically. This is why some people call this a magnification factor.

To get this same crop effect, one would have to use an equivalently longer lens on a 35mm film camera."
-------------------------

Maybe I'm being dense but I thought everything was converted to the same size as film / larger frame.

thanks

Dngallagher Loc: Wilmington De.

inbigd wrote:

I was wondering - when a cropped sensor camera cro... (show quote)

There is no "upsizing" being done, there is no magnification. The crop sensor is changing the "field of view" only.... not making the object bigger/closer.

The reality of the 200 mm on a crop sensor vs a 300 on a Full frame is that the 300 mm will be closer or magnified, where the 200 mm cropped sensor would have a field of view equal to the 300 mm.

http://improvephotography.com/8411/field-of-view-full-frame-crop-sensor-dslr/

Trabor

inbigd wrote:

I was wondering - when a cropped sensor camera cro... (show quote)

Go to
https://photographylife.com/sensor-crop-factors-and-equivalence

and read the article, ignore much of what you will see posted on UHH

" Increased Reach" as used by cropped sensor vendors means "reduced field of View" NOT "ability to go out and grab something"

SharpShooter Loc: NorCal

The term cropped is a little misleading and creates confusion.
I would think the only camera that is not cropped is the biggest camera in the world, what ever that camera would be. EVERYTHING else is cropped by comparison. Yes, even 8x10 view cameras!
Because 35mm FF has become the defacto std. It is the format that most of the common small film sizes are measured to.
Smaller sensor sizes don't crop, they just produce a a smaller piece of the FF equivalent image, hence the term crop!!
And the lenses don't change in focul length either, whether on an 8x10 or a
4/3, but the image view they produce does;-)
SS

mwsilvers Loc: Central New Jersey

inbigd wrote:

I mean the camera screen

It doesn't upsize the image to fit the screen, it shrinks it for both fullframe and crop frame sensors. The native image size at 100% for a 24mp crop image or 24mp FF image is much much bigger than the little 3 or 3.2 inch LCD screen. As I said earlier, try viewing either format at 100% (full resolution, not full screen) on your computer monitor. It will be huge.

inbigd

Thanks everyone. So if you were to make 8" x 10" prints of the same images, let's say of the moon at 200mm with cropped and 300 mm with full frame, both Nikon cameras having 24mp, the images would be the same? I was thinking that the cropped image would have more noise.

mwsilvers Loc: Central New Jersey

inbigd wrote:

Thanks everyone. So if you were to make 8" x 10" prints of the same images, let's say of the moon at 200mm with cropped and 300 mm with full frame, both Nikon cameras having 24mp, the images would be the same? I was thinking that the cropped image would have more noise.

Noise will depend on a number of factors, including the specific sensor, but the images can never be identical because of differences in light transmission, DoF differences between crop and FF, not to mention the lens or lenses being used and each camera's high ISO capabilities, among other things. You're assuming a simple answer to a complex set of parameters.

Capn_Dave

inbigd wrote:

Thanks everyone. So if you were to make 8" x 10" prints of the same images, let's say of the moon at 200mm with cropped and 300 mm with full frame, both Nikon cameras having 24mp, the images would be the same? I was thinking that the cropped image would have more noise.

It probably would as the individual light sensors on a crop sensor are smaller than on a full frame sensor. The larger sensors catch more light.
Imagine a frame with 24 marbles in it. Now make the frame 1/2 the size of the original. to get 24 marbles in that frame, the marbles have to be smaller.
To get the same exposure with the same amount of light, you have to turn up the gain or ISO on the crop sensor. When you turn up the ISO you get more ambient noise

mborn Loc: Massachusetts

Dngallagher wrote:

There is no "upsizing" being done, there is no magnification. The crop sensor is changing the "field of view" only.... not making the object bigger/closer.

The reality of the 200 mm on a crop sensor vs a 300 on a Full frame is that the 300 mm will be closer or magnified, where the 200 mm cropped sensor would have a field of view equal to the 300 mm.

http://improvephotography.com/8411/field-of-view-full-frame-crop-sensor-dslr/

:thumbup: :thumbup: :thumbup:

joer Loc: Colorado/Illinois

inbigd wrote:

I was wondering - when a cropped sensor camera cro... (show quote)

burkphoto Loc: High Point, NC

rwilson1942 wrote:

The sensor is the "frame" there is no magnification or 'upsize' involved. When a FF lens is used on a crop sensor camera, the sensor simply 'sees' less of projected image.

The part of the image circle that the crop sensor sees (crops) has less potential resolution (lower MTF curves or line pairs/mm), but also likely shows less vignetting, barrel distortion, coma, astigmatism, and fewer chromatic aberrations. It's usually more consistent across the frame.

Lenses made SPECIFICALLY for APS-C cameras do not produce a wide image circle that must be cropped. That's why they are potentially sharper (resolve more detail).

If you put a "full frame" lens on a Micro Four-Thirds camera, the reduction in sharpness is more dramatic, unless you use a MetaBones SpeedBooster, which concentrates the light by a stop or more, shrinking the image circle diameter, and improving sharpness.

Note that it is easier to design/build lenses for smaller formats. There is less glass needed, so tighter tolerances are easier to meet.