The D7100 has better resolving power than the D800

[Geoffc]

I've just realised that I probably owe some of you an apology. Having read a few of the recent posts it's now obvious that some members do not actually understand the basic difference between FX and DX with regards to the mysterious crop factor. This became apparent with the references to my use of the same lens providing different focal lengths on the two formats and a 1.5 crop factors not being considered. In fact it's been suggested that the DX body had the edge because it magnified the image!!

Unfortunately I based my tests on both bodies conforming to the laws of physics which would make 50mm be the focal length and magnification whichever body I attached it to. Admittedly the smaller DX sensor would throw away data around the edge (see Jake's version of the images) but at least the projected "subject" would be the same size when it hit the back of the camera (sensor).

I guess I should have ignored the principle that physics applies equally in FX and DX and factored in some magic that made my 50mm lens pretend it was 75mm long on a DX. Sadly like most things in life, when you claim something is longer than it actually is you eventually get found out which can cause embarrassment.

Again my sincere apologies for not appreciating the mixed ability audience and leaping in with something that was photography fact rather than marketing magic.

Unless someone is going to provide a demonstration that disputes my example (that should be interesting) I will consider this done to death, finished and ended. We have different views and I don't think this will change them.

 

[Nathan Lanni]

Geoffc

For the record, I'm no expert but understood your point, and agree with it to the extent you were willing to take it.

It isn't a matter of the d7100 being better than the d800, but simply within the number of pixels, say within a square mm image sensor area, the d7100 has an edge in its ability to resolve an image due to the fact the d7100's pixels are denser than the d800. This has nothing to do with crop factor because it's a matter of one sensor's ability to resolve an image within that area - not total sensor size. Neither does that example have to do with all those other factors that make the d800 a superior camera, and, ultimately produce better images in most cases.

I think where you ran into resistance is not on the merits of your argument, but some people get nervous when comparing any aspect of the d7100 capabilities to the d800, and in any way suggesting the d7100 may have an edge (but only within those narrowly defined perimeters). You were touching on hollowed ground and obviously collided with their sensibilities.

 

[Geoffc]

Geoffc

For the record, I'm no expert but understood your point, and agree with it to the extent you were willing to take it.

It isn't a matter of the d7100 being better than the d800, but simply within the number of pixels, say within a square mm image sensor area, the d7100 has an edge in its ability to resolve an image due to the fact the d7100's pixels are denser than the d800. This has nothing to do with crop factor because it's a matter of one sensor's ability to resolve an image within that area - not total sensor size. Neither does that example have to do with all those other factors that make the d800 a superior camera, and, ultimately produce better images in most cases.

I think where you ran into resistance is not on the merits of your argument, but some people get nervous when comparing any aspect of the d7100 capabilities to the d800, and in any way suggesting the d7100 may have an edge (but only within those narrowly defined perimeters). You were touching on hollowed ground and obviously collided with their sensibilities.

TeagueAMX

I wasn't going to reply again but you seem to have summarised my various rumblings very succinctly and for that I thank you.

 

[BackdoorArts]

 

[Horoscope Fish]

Facts Schmacts...

Again my sincere apologies for not appreciating the mixed ability audience and leaping in with something that was photography fact rather than marketing magic.

"Facts are meaningless. You can use facts to prove anything that's remotely true."


......

 

[WayneF]

Unfortunately I based my tests on both bodies conforming to the laws of physics which would make 50mm be the focal length and magnification whichever body I attached it to.

I guess it depends on viewpoint. But DX and FX cameras do different things (DX is telephoto due to crop factor), and I assumed for granted that if one were trying for maximum resolution, one would choose to use the gear in optimum ways. If one tries to fill the large D800 FX frame (also mimicking telephoto), one can achieve 36 megapixels (and DX simply cannot, as yet). If one pays no attention to what they are doing, then bets are off.

 

[Silven]

I guess it depends on viewpoint. But DX and FX cameras do different things (DX is telephoto due to crop factor), and I assumed for granted that if one were trying for maximum resolution, one would choose to use the gear in optimum ways. If one tries to fill the large D800 FX frame (also mimicking telephoto), one can achieve 36 megapixels (and DX simply cannot, as yet). If one pays no attention to what they are doing, then bets are off.

Well done WayneF well done. BackdoorHippie I love the image made me laugh picturing Geoffc feeling that way about the "feeling their manhood questioned people" not agreeing with his point of view. Geoffc, great sarcastic reply up above. I'm the Jay Leno to your Johnny Carson!

 

[Geoffc]

Well done WayneF well done. BackdoorHippie I love the image made me laugh picturing Geoffc feeling that way about the "feeling their manhood questioned people" not agreeing with his point of view. Geoffc, great sarcastic reply up above. I'm the Jay Leno to your Johnny Carson!

Silven

According to friends sarcasm has always been one of my strong points, I just need to elevate my photography to the same level now I hoped the reply would be taken in the spirit it was intended and if it made you smile it achieved its aim.

 

[Nathan Lanni]

Backdoor, thanks for that image. It definitely goes into my WTF folder

 

[nmccamy]

I agree with Geoffc. And his point is quite obvious. I want to see if I can explain it differently so more people can understand it. First of all, the argument is more about FX vs DX.

If you were placed in a room where a tripod was bolted to the floor, and the tripod head glued in place facing a flower, and you were given a D800, a D7100, and one 50mm lens, which camera\lens combination would provide better resolution or resolving power?

Let's say when you looked through the D7100, the flower occupied the entire viewfinder (let's assume the viewfinder view is identical in both cameras). This then implies that the flower covers the entire sensor.

Now when you look through the D800, the flower does not fill the viewfinder, it appears smaller. The D800 sensor is larger than the D7100 sensor. What really is going on here is that the flower is occupying the same amount of sensor space on the D800 as it is on the D7100. The extra sensor space around the D800 is completely wasted.

So now you simply add up the number of pixel sensors the flower covers in each sensor. Because the D7100 has more pixel sensors per square inch than the D800, there are more pixels providing detail than in the D800. More pixel sensors ALWAYS means more resolving power, assuming everything else is equal, which is a HUGE assumption. But, the quality of the image relies on a lot more than simply pixel sensor density.

The sticky point is the fact that those pixel sensors are doing a lot more than simply receiving light. And these pixel sensors MUST ALWAYS obey the laws of physics. Packing pixel sensors tighter and tighter may have a profound NEGATIVE effect on resolving power and image quality. If this were not the case, there would be nothing stopping camera makers from manufacturing trillion pixel cameras with astonishing resolution.

The law of diminishing returns applies (at least with our current knowledge). You cannot simply cram more and more pixel sensors together to create a great image. Physics won't allow it. There has to be a certain distance between these pixel sensors to avoid pixel neighbor interference, otherwise your image will quickly deteriorate.

The D7100 has more pixel sensors per square inch than the D800. That is NOT necessarily a good thing. At the same time, the size of those pixel sensors in the D7100 is smaller than the D800, reducing their light capturing capabilities and possibly color rendition capabilities.

Geoffc was ONLY addressing resolving power, not image quality.

If now, you were given a D7100 and a D800 and any lens you wanted, and you had the shoot the exact same scene, then you will start seeing the differences between the two cameras when looking at the resulting images. Some may prefer the "character" of the D7100. It is subjective.

My 50+ years of experience has taught me that you need to find the right camera\lens combinations that fit your style of photography. You cannot count on a single camera and a couple of lenses to do everything. Most professionals have several cameras and lenses and know which camera and lens to use for a particular situation. I've known many who have several different brand cameras and prefer one brand over the other for a specific scenario.

I highly suggest that every serious photographer should set aside money to use toward camera and lens rentals. I have learned so much renting countless times over the years. Don't rely on reviews, word-of-mouth, or anything else. See for yourself! Rent a lens or camera and design your own experiments based on your style of photography. You will discover many surprises along the way! And your opinion offerings will be a truly informed.

 

[joenmina1]

LMAO at "mixed ability audience"!
I have to use that line soon