D850 vs D500 Pixel Density

I have a question about pixel density. But first let me explain my eventual question. I shoot ocassional wildlife, mostly birds with a D850 and a 200-500mm lens. My brother shoots with a D500 and the same lens. I shoot raw entirely and edit with LR. He shoots jpeg only and edits only with the photo editor on his IPad. His photos literally blow me away in detail, sharpness, and lack of noise. I have recently learned that the pixel density of the D500 is 5.68 compared to the D850 at 5.32, a 7% difference. I understand that there all kinds of variables (shooting technique, tripod vs handheld, etc...) that can affect picture quality. I also understand that even though the pixel density of a small frame camera may be higher, the FF will have the advantage of lower noise since the pixels are larger. My question, finally. Is there a way to determine the pixel density of the D850 when switched to crop mode? Since the size of of the pixels certainly doesn’t change, does shooting in the D850 crop mode significantly reduce pixel density?

Is there a way to determine the pixel density of the D850 when switched to crop mode? Since the size of of the pixels certainly doesn’t change, does shooting in the D850 crop mode significantly reduce pixel density?

How could the physical arrangement of the pixels (and thus the pixel density) on the sensor possibly change by simply not recording to some portion of the sensor?

Pixel density doesn't change whether you crop or not. The D850 and D500 has about the same pixel density so I would say if you don't like your pictures then your brother is doing something right and you are doing something wrong.

It makes little sense to shoot a larger format if magnification is the name of the game - wildlife, field sports, macro, etc.

 

Full-frame comes into its own for wide-angle and studio work, where a low ISO can be guaranteed. Because you can only realise the full image-quality potential of full-frame under controlled conditions, or when natural conditions happen to be just right. For example; any atmospheric heat turbulence is going to impair the definition of full-frame and DX to an equal degree.

 

The smaller format also offers greater depth-of-field for a given aperture and angle-of-view. For instance, your brother might only need to zoom in to 350mm to fill the frame with the subject, whereas you'll have to zoom fully to 500mm and still not get the frame filled. And with a variable aperture zoom that's also going to impact on the aperture and maybe slow the AF speed down.

 

So for wildlife, full-frame just isn't the best tool for the job. This is an instance where 'digital zooming', AKA cropping, shows an advantage.

 

If you really want to show your bro what your camera can do, then you need to challenge him to a still-life or portrait shoot out!

 

BTW, Dieter and BeBu are correct in saying that pixel density stays the same whatever portion of the frame you use.

 

And FWIW, the D500 shows only about a 3% improvement in absolute resolving power compared to your D850. Using pixel area as a comparator is a completely misleading parameter, except as a very rough guide to noise performance. For all practical purposes the cameras are equal on a pixel-for-pixel basis.

Edited November 10, 2018 by rodeo_joe|1

Like the previous posters, I doubt if the difference has anything to do with pixel density. It is likely that other variables are at work. My guess is that the difference lies in post processing.

 

For starters, both you and your brother would need to use the same in camera settings that apply to Jpegs like sharpening, active D lighting, etc. These are in Pictures Controls. When you take your pictures in your D 850, take both RAW and Jpeg. Then open them in Nikon View Nx-i as that program will show what the camera has captured. Then compare these unprocessed pictures to your brother's unprocessed images on his ipad if that is possible.(Just importing the images to the ipad might "process" them somehow.) . And before he processes them look at his images on Nikon View NX-i too. If the images taken with both cameras look the same using the same Nikon software then my bet is that his processing software on the ipad is what is causing the images to look different. You then would need to experiment wth the editing settings you use in LR to see if you can make your images look like his images. .

As I understand it a small frame camera is able to capture more detail than a FF because the pixels are much smaller. A FF performs better at higher ISOs because the pixels are larger. Pixel density is determined by the width and height of the sensor and the total number of pixels. When shooting in crop mode on a FF camera, it would seem that the number of pixels available in the resulting area of sensor would be much less than the same number of pixels in the same area of a small frame camera, thus reducing the pixel density.

As I understand it a small frame camera is able to capture more detail than a FF because the pixels are much smaller.

 

Change the "because" to "if" to make this a true sentence. In your and your brother's case, the pixels are about the same size. Pixel density is a measurement of number of pixels per unit of linear distance or area, so it is directly proportional to pixel size.

Edited November 10, 2018 by chulster

Chulkim, if the pixels of a small frame camera and FF are the same size then you basically answered my original question. However, again as I understand it, the pixels of a small frame camera have to be smaller then a FF pixels in order to fit al of the pixels on the small frame sensor. This is what led me to my original question. The sensor on D500 contains 20mp. How can the cropped area of a D850 contain the same number of pixels, since the pixels are larger? What am I missing?

pcassity

 

The D850 sensor size is 35.9mm x 23.9mm, which is an area of 858 square mm. It has 45.7 megapixels, so the pixel density is 5.32 megapixels per square cm.

The D500 sensor size is 23.5mm x 15.7mm, which is an area of 369 square mm. It has 20.9 megapixels, so the pixel density is 5.68 megapixels per square cm.

 

When the D850 is in crop mode, you are using only the middle 23.5 x 15.7 part of the sensor and everything outside that is ignored. So the D850 in crop mode has about (369/858) x 45.7 megapixels, which is 19.6 megapixels, which is only slightly less than the D500. You just can't see the difference between 19.6 and 20.7 meegapixels with the naked eye - it is only a 5% difference.

 

Your assumption "the pixels of a small frame camera have to be smaller then a FF pixels in order to fit al of the pixels on the small frame sensor" is wrong. For a small frame sensor you simply use fewer pixels. What may have confused you is that each different Nikon Dslr has different size pixels. The pixel size on a D3 was much, much larger than the pixel size on a D850, for example.

NetR

Thank you. So, if the pixels size for both of these cameras are basically the same, the effective pixel density is (almost) the same for the D850 in crop mode as the D500?

As I understand it a small frame camera is able to capture more detail than a FF because the pixels are much smaller. A FF performs better at higher ISOs because the pixels are larger. Pixel density is determined by the width and height of the sensor and the total number of pixels. When shooting in crop mode on a FF camera, it would seem that the number of pixels available in the resulting area of sensor would be much less than the same number of pixels in the same area of a small frame camera, thus reducing the pixel density.

 

- If you were comparing a 24 megapixel DX sensor camera with, say, a 36 megapixel FF camera, then that would be true.

But you're not!

 

The difference in photosite pitch (not strictly pixels, because they don't exist until the photosite data have been processed) between a 20.87 megapixel D500 and your 45.75 megapixel D850, is only about 0.12 microns, or 3%. With the D500 having the marginally tighter 'pixel' pitch.

 

That's nothing in real terms.

 

So if you switch your D850 to DX mode, or fit it with a DX lens, then to all intents and purposes you have the equivalent of a D500 sensor in your camera.

 

In old fashioned terms, both cameras are theoretically capable of resolving close to 116 line-pairs per millimetre. The real life limit being closer to 100 lppmm - a figure that I doubt any telephoto zoom lens is capable of delivering.

Edited November 10, 2018 by rodeo_joe|1

P.S. Forget pixel density!

That involves area and exaggerates any linear difference by a power of two.

 

Any sensible comparison between image parameters is purely linear and one dimensional. Resolution, magnification, pixels per inch etc. All linear.

I started a response this morning that vanished while I was working on it, but what I was going to say has been said repeatedly: There effectively is no practical difference in pixel density between your D850 and your brother's D500. The difference between 19.6mp(D850 in DX crop mode) and 20.9mp(D500) is so miniscule that you are unlikely to see ANY real world difference.

 

Like others, I would attribute any difference to technique. If the two of you swapped cameras, it would take this variable out of the equation and might be very telling.

 

A secondary consideration would be to eliminate other possible variables. Since your brother shoots SOOC JPEG, you COULD be seeing the result of aggressive in-camera sharpening and interpreting that as more detail. Similarly, less aggressive in-camera noise reduction could mean that his camera "blurs" less detail than yours. It might be worth setting your camera to the EXACT SAME settings in terms of color, sharpening, noise reduction, and lens correction to make sure of this, and going straight to JPEG(or otherwise using the Nikon software to process your RAW files using the camera supplied settings) These high resolution sensors are EXTREMELY sensitive to focus inaccuracy, and it could be that the focus is a tiny bit off on your camera. This is grasping at the straws, but sample variation certainly exists in lenses and perhaps your brother has an exceptionally good 200-500, yours is exceptionally bad, or some combination of the two(swap lenses and see if things change).

 

Whatever it comes down to, the sensors in your respective cameras likely aren't the problem.

Thanks all! I probably shouldn't have included the information about my brother's photography. As I mentioned and has been emphasized in the responses, there can be numerous reasons why there is a difference in detail, noise, sharpness, etc.. between my shots and his. My main interest was about pixel density and how the 850 compared to the 500. I appreciate your thoughts and explanations and now have a much better understanding!

Thanks all! I probably shouldn't have included the information about my brother's photography. As I mentioned and has been emphasized in the responses, there can be numerous reasons why there is a difference in detail, noise, sharpness, etc.. between my shots and his. My main interest was about pixel density and how the 850 compared to the 500. I appreciate your thoughts and explanations and now have a much better understanding!

And as we all said they are about the same for the D850 and D500. If you compare something like the D7200 to my FX camera Nikon Df then the difference is very big.

If you compare something like the D7200 to my FX camera Nikon Df then the difference is very big.

To make the comparison perhaps a bit more even, reach back in history and look at a D2X vs. a D3. Both are 12mp, but the D2X is DX and the D3 is FX(Nikon's first).

 

The D2X definitely has its weaknesses, but it holds a lot more detail in the center of the frame than does the D3. The pixel density on the D2X is similar to what one would see on a 28mp FX camera, which in fact is higher than even the(somewhat uncommon and hideously expensive when new) D3X. Of course, resolution is certainly not everything. A year and a few months ago, my D2X was my main camera but not mostly gather dust, while my D3s is a recent addition that has a home in my bag next to higher resolution cameras(D600 and D800).

 

I think it's also somewhat interesting to note that, for a while, Nikon's "go to" sensor for DX(aside from the D500) was 24.2mp. The D7500 has replaced this with the 20.9mp sensor from the D500. If I were in the market for a new(er) DX camera, I'd likely pass on the D7500 in favor of a D7200 for a couple of reasons, although admittedly the lower resolution is NOT one of those reasons(the lack of an AI follower tab and the presence of only a single card slot would be my reasons).

If I were in the market for a new(er) DX camera, I'd likely pass on the D7500 in favor of a D7200 for a couple of reasons, although admittedly the lower resolution is NOT one of those reasons(the lack of an AI follower tab and the presence of only a single card slot would be my reasons).

Yup, the D7200's are keeping their prices quite well!

 

I guess they had to downgrade (cripple) the D7500's features to make it below the D500 in 'PRO'ness.

 

IIRC, the pixel density leader is still the J5, so if pixels on target is the aim for slow wildlife, something like the J5 + 400mm 2.8 VRII would work out OK. (Approx 1100mm f2.8 reach EQ)

I was always slightly surprised they did the '9fps-with-the-grip-and-big-battery' thing with the D850, which was, I assumed, the ultimate STUDIO camera.

 

If it moves fast in the dark, you need a D5.

 

It almost (!) puts the D850 in DX crop mode in parallel with the D500 pixel and speed wise...;)

 

Although I suspect the shutter isn't really built for long full-auto bursts...?

IIRC, the pixel density leader is still the J5, so if pixels on target is the aim for slow wildlife, something like the J5 + 400mm 2.8 VRII would work out OK. (Approx 1100mm f2.8 reach EQ)

 

- Reach ain't everything. As I touched on before; the more air you put between lens and subject, the more you're reliant on perfect 'seeing' conditions, and the more any such arial disturbance will degrade the image.

 

You're almost certainly better off honing your stalking skills and patience, and spending a fraction of the big bucks a mega-lens would cost you on a hide, or camo clothing.

I guess if you're trying to fill the frame with a hummingbird, an FX 800mm , a 500mm on DX or a 300mm on CX would all work OK.

 

... from the same shooting position.;)

- Reach ain't everything. As I touched on before; the more air you put between lens and subject, the more you're reliant on perfect 'seeing' conditions, and the more any such arial disturbance will degrade the image.

 

You're almost certainly better off honing your stalking skills and patience, and spending a fraction of the big bucks a mega-lens would cost you on a hide, or camo clothing.

 

And the perspective you get with the ultra long lens may not be what you want. You do that because you can't get close to your subject. I guess if I am into birds I would learn to get their consent to take their pictures.

PCassity,

Its not the camera but the settings and or your shooting style.

If your comparing raw to jpegs you will always be disappointed with raw until you do your own editing.

JPEG files are edited in the camera so you get sharpened, color and contrast "corrected" and noise reduced images right out of the box. I have always felt that Canon's default jpegs were better than Nikon's but I know that I can get the same if I edit in PS.

Again its not the camera. Stay frosty.

The Nikon D850 and D500 appear to have the same nominal pixel spacing (density?). If you divide 45.7 MP by 2.25 (the nominal cropping factor, squared) you get 20.3 MP, which is essentially the same as 20.7 MP advertised for the D500. Not all pixels are the same. Back-illuminated sensors have much less space between cells, so the cells cover about 90% of the available area, compared to as little as 60% for conventional sensors. Larger cells have better light gathering capability and lower noise, but sensor resolution depends only on how many cells per inch there are.

 

Camera shake at a shutter speed of 1/F will reduce the effective resolution to about 6 MP, regardless of the sensor. That improves inversely proportional to the shutter speed, but at 3x speed (1/1500 for a 500 mm lens), you're still only realizing 18 MP. Image stabilization helps a lot, but not as well as a solid tripod and head. Neither helps much if the subject is moving.

PCassity,

Swap systems and settings with your brother and see if you get the same results as you did before.

If there is no appreciable difference then look at your brothers technique and the shooting style to see what you two are doing differently. Good hunting.

I guess if I am into birds I would learn to get their consent to take their pictures.

 

- Effectively, that's what using a hide or camouflage does!