Terry in Indiana Loc: rural Indiana

After my Nikon d7100 rolled off the bed onto the carpeted floor (YIKES!) about a month ago, it has been slow to focus and not as sharp. So I finally broke down and took it to be repaired and rented the closest thing I could find, a Nikon D700. After I got home, I read online comparisons between the 7100 and 700 and on most specs they are very similar, with the huge exception that the D700 is full frame (as opposed to the 7100 being cropped) and the sensor size is twice as big. But the pixel count is close and most reviews say the 7100 IQ is nearly as good if not equal. So apart from the wider view that the full-frame provides (which, frankly, is not an advantage often especially since I usually like to get closer to my subjects), what's the big deal about the sensor size? I don't understand why a bigger sensor is better...and makes the camera model cost twice as much. All other things being comparable, I don't understand why bigger sensor is better? I know there are lots of technical experts on this forum...can you please explain it to me?

Rongnongno Loc: FL

It is not the sensor that is better...
It is the pixel sensor (4 sensels) that make the difference.
The larger the sensor the more space so in theory bigger pixels so more sensitive to light. This is what the FF cameras do and quite well at that.

Now, with miniaturization something else is going on. Cameras like the Nikon D800 (and D810) the pixels have been made smaller and more better but at the price of luminosity. Yet this camera offers an incredible dynamic range.

Mr PC Loc: Austin, TX

I'm far from an expert, but from what I've read and absorbed around here, the problem with your D7100 and my D5200 with their cropped sensors is vignetting near the edges of the image. I usually shoot a little wider than what I think I'll need and crop in Lightroom. Problem solved. I've gotten some images lately that I don't think could be much better. I think after a certain point in sensor quality and pixel density, higher quality glass makes more difference. Unless you are going to print huge posters at very high quality, I'm not sure you could tell the difference. My 2 cents. I'm sure we'll hear about it if I'm wrong...

boberic Loc: Quiet Corner, Connecticut. Ex long Islander

Generally the FF cameras have better low light performance and can make larger prints with less noise. Or tighter crops. If you are almost never going to agressively crop or enlarger bigger than 11 by 14. and don't shoot in low light they are essentially the same

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

You are confused . . .

joer Loc: Colorado/Illinois

FF are obviously better if you compare same size sensors.

The D700 has 1/2 the pixel count of the D7100. It will provide images at higher ISOs with less noise. Although they are several years apart in sensor technology and you can't crop to the same degree.

The camera functions are much better on the D700 but not everyone appreciates that. It depends on your shooting preferences.

Larger photo sites are better than smaller ones for images quality.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

:thumbup: :thumbup: :thumbup:

f8lee Loc: New Mexico

I believe what @Rongnongno meant to say in his reply is that the individual photo sites are larger in the larger FX sensor (when the pixel count is the same) - each individual photo site is thus more sensitive to photons and less prone to take false readings of heat photons (which is what constitutes noise in images as you raise the ISO sensitivity). So that is why, all things being equal, larger sensors perform better in low light.

Of course, as technological advances are made, this aspect of sensitivity will keep improving, so the smaller sensor camera of today might outperform the FX body of a few years back in low light conditions.

As for cost differentials, this has much to do with the manufacturing process of chips - yields for smaller chips are higher since for a given master wafer of chips a flaw that makes a single chip unusable is less impactful on the production run. As an example imagine that the wafer size is such that either 5 FX chips or 10 DX chips can be etched on that wafer (I'm making up the numbers - the point is the general concept here). Imagine further that there is are two flaws in the wafer such that two spots end up becoming unusable. This means that 2 of the 5 potential FX chips are lost, while only 2 of the 10 DX chips are lost. This translates into a higher cost of manufacturing for larger chips - simple as that. It's also why making the 48x36MM "medium format" chips found in the larger cameras costs yet more.

The other thing the larger sensor offers is shallower depth of field for a given aperture, which may or may not be important to your style of shooting.

SharpShooter Loc: NorCal

Terry, I probably know less technically about size than you do.
But the difference between 31A and 34C.
What would YOU rather unwrap!! :lol: :lol:
Did I make my point!!
SS
PS, Terry, what is your camera doing on the bed, anyway??! :lol:

mongoose777 Loc: Frisco Texas

I always been told the bigger the sensor the better and cleaner the images will become.
Bigger allows for more Microns and the more you have the better overall performance and quality.

Gene51 Loc: Yonkers, NY, now in LSD (LowerSlowerDelaware)

uh, what's a micron?

Rongnongno Loc: FL

:lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol: :lol:

Rongnongno Loc: FL

Poorly phrased here.

mongoose777 Loc: Frisco Texas

Its a term to measure Pixel Pitch
Example the Hasselblad H4D40 has 6 microns vs Nikon D800E 4.7 microns.

Visible light is found in the wavelengths between a 400-750nm (.4 to .75 micron). Obviously, an individual pixel (photo site) can't be anywhere near this small and still record photons. Today's smaller digicams feature sensors down to about 2.2 microns in size, and as we all know can be quite noisy. At this small size they simply can't capture enough photons as compared with their inherent noise level. DSLRs offering 8-12 Megapixel on APS sized sensors seem, therefore, to have settled in the 5-6 micron level and offer an optimum combination of resolution, low noise and moderate cost.

In summary, if you try for ever higher resolution in a small chip – something's gotta give. The smaller the pixels, the lower the quality as compared to a similar sensor with larger pixels. Very small pixels (sub 5 micron) start to run into the laws of physics, where signal to noise ratio, and the simple ability to capture enough photons limits their ability to sustain significant improvements given known technologies.

This is why you will see a lot of small black specs when zoomed in from a high 18MP plus in the much smaller sensors found in the lower end cameras and point and shoots.
But when compared to a much larger sensor with the exact same MP count the larger sensor wins out.

mongoose777 Loc: Frisco Texas

So this is what you do?
You make fun of people just because you've never heard of a micron?
If I didn't explain it well enough, then why not just chime in on a professional expert opinion instead of just being an asshole!
We try to offer opinions here on this forum as they are our own, but if another has a different angle or a challenge, then its always wise to hear both sides and will become better educated.
But, when one pokes at another with countless childish LOL's and cares to not offer a reasonable alternative or explanation is nothing more than arrogant or perhaps just ignorant.