If your theory is sound, then ask yourself why would anyone buy a Ford Fiesta. It's small, cheap and has an underpowered engine. Why aren't people buying the Ford Flex instead? Who needs a Fiesta when you can get a large powerful Flex and go anywhere with it.

See, your question is full of holes. They make different cameras because people don't all have the same budget and some can get by with fewer bells and whistles, smaller sensor, less expensive lenses, etc.

I can tell you one advantage to a DX camera body versus an FX. I have a lot of friends that shoot birds. At least half of them prefer the effect that a DX body gives them versus an FX when using super telephoto lenses. You see when using a 600mm lens on a DX body, it will give you an effective reach of 900mm. Add a 1.4x to that and you've got an effective reach of 1260mm. If using a 600mm on a FX with 1.4x you have 840mm.

twr25 ...

Why would anyone buy a DX camera? Well first of all if you didn't grow up with film, DX is simply another format and nothing more.

Taking this view, DX has smaller camera bodies and lenses, consider the difference between an entry level DSLR and a high end professional one. DX is also cheaper both for the camera and the lenses. DX has an enormous reach compared to FX so when you're after wildlife that's the way to go. And these days in terms of camera features, DX is at least as good technologically against FX. Having said all that I think we should be asking why anyone would buy FX gear instead.

But there is a reason. The larger sensor, for the same resolution with the DX sensor will have physically larger pixels which will result in superior image quality. The other reason is that we, who grew up with film, buy FX because we know what kinds of images we can get And of course those who eventually also discover FX get sold on that too. If you recall in the film days 35 mm was frowned upon in favour of medium format, 610 and 120 film. Medium format always produced better results than 35 mm though the gap was gradually closing. FX today is our medium format though that makes me wonder what we should be calling the hasselblad format now.

If your theory is sound, then ask yourself why would anyone buy a Ford Fiesta. It's small, cheap and has an underpowered engine. Why aren't people buying the Ford Flex instead? Who needs a Fiesta when you can get a large powerful Flex and go anywhere with it.

See, your question is full of holes. They make different cameras because people don't all have the same budget and some can get by with fewer bells and whistles, smaller sensor, less expensive lenses, etc.

I can tell you one advantage to a DX camera body versus an FX. I have a lot of friends that shoot birds. At least half of them prefer the effect that a DX body gives them versus an FX when using super telephoto lenses. You see when using a 600mm lens on a DX body, it will give you an effective reach of 900mm. Add a 1.4x to that and you've got an effective reach of 1260mm. If using a 600mm on a FX with 1.4x you have 840mm.

If your theory is sound, then ask yourself why would anyone buy a Ford Fiesta. It's small, cheap and has an underpowered engine. Why aren't people buying the Ford Flex instead? Who needs a Fiesta when you can get a large powerful Flex and go anywhere with it.

See, your question is full of holes. They make different cameras because people don't all have the same budget and some can get by with fewer bells and whistles, smaller sensor, less expensive lenses, etc.

I can tell you one advantage to a DX camera body versus an FX. I have a lot of friends that shoot birds. At least half of them prefer the effect that a DX body gives them versus an FX when using super telephoto lenses. You see when using a 600mm lens on a DX body, it will give you an effective reach of 900mm. Add a 1.4x to that and you've got an effective reach of 1260mm. If using a 600mm on a FX with 1.4x you have 840mm.