larryepage Loc: North Texas area

The other side of this is that when considering upgrades or "moving forward," it is a fundamental engineering principle not to allow money already spent..."sunk cost"...to affect your decision. Doing so can improperly lock you into your current situation when that may or may not be the best choice for you. It may also push you into a suboptimal decision. Rather, I would encourage you to consider that the ability to use your DX lenses on a new FX camera body in fact allows you to move forward with the body upgrade, continue taking photographs, and gracefully move to new lenses as your experience leads you. The net is that you have the new camera, begin learning to use it, and can then acquire more appropriate lenses as you go. Any temporary plateauing of quality (you can only compare to the camera you are replacing, not the D7200 or D7500 that you didn't buy) will be resolved as you later acquire new lenses. And...in the meantime, you will still be enjoying the additional features and functions of the new camera. Be careful here, and make certain that you are thinking down the road, not just about tomorrow.

Chris T Loc: from England across the pond to New England

Paul - your dimensions for an APS-C (Nikon, Sony, Pentax, Fuji) are slightly off - it's actually closer to 370.

And Canon square millimeter areas are even lower - about 329-330mm.

So, based on the Canon dimension (yours) - it's actually a whole lot less = 2.62 … or .38

Glenn Harve

If you have an old Nikon 35mm, put your DX lenses on and see. You might suprised. If you crop the full frame closer to square, even better. Software can help with fall-off.

acreutz

Very good and thoughtful additional replies!

PHRubin Loc: Nashville TN USA

I was responding to the OP who uses Nikon.
The dimensions seem to depend on the source. Here are 2 that don't agree (I used the first):
https://www.ephotozine.com/article/sensor-size-and-crop-factor-explained-with-sample-photos-17813
https://newatlas.com/camera-sensor-size-guide/26684/#p206324 (you have to multiply out to get mm²)

zug55 Loc: Naivasha, Kenya, and Austin, Texas

Many in this thread pointed out that you do not use the full potential of your FX body if you use DX lenses, and I concur. Unless you are willing to buy FX lenses it is not worth it. So one choice is to upgrade within the DX environment--say with the D500.

If you upgrade to a full-frame system you are looking at buying at a set of full-frame lenses to make the move worthwhile. No matter what system you go with, full-frame lenses are substantially more expensive, and also heavier.

If you go full-frame (and you should have a good reason for wanting to do that) I would go mirrorless. See what Nikon has to offer--perhaps wait until the next generation comes out. Or you may decide to go with a different system.

I think that most people who consider switching to a full-frame camera do not realize how much money they will have to spend to get the most out of that camera and to make that initial investment worthwhile.

Chris T Loc: from England across the pond to New England

Not only THAT, Zug … but many DX/APS-C users are not aware of the weight difference until they go there - not only for lenses, but, in the bodies, themselves. If you regularly carry a kit bag - holding one or two bodies - with an assortment of 3-5 lenses … and you make the upgrade to FF - you're in for a shock!

sv3noKin51E

acreutz, regardless who perceives one way is the correct way, we use both DX and FX. We now have a sufficient number of full frame lenses for FX, we still exchange, using certain DX lenses on FX bodes and vice versa. There are a wealth of fine older lenses that work extremely well on DX and FX bodies, including many over 20 years old. They may not have VR, some don't have AF or some other state of the art feature, but some of Nikon's old glass is still much better in some cases than what many can afford to purchase new. Whatever gets the shot that you're happy with is what matters, regardless of the pixel count. Happy shooting, sv

Chris T Loc: from England across the pond to New England

Trying to bring that up, now, Paul …

I used a chart with ALL sensor sizes - currently rounding the Net … it shows all areas in sq. mm. plus all the linear dimensions - of practically every digital sensor and film size - known to Man!!!!!

larryepage Loc: North Texas area

That is a choice, though, and it can be largely mitigated. The truth is that most DX lenses (at least the ones that I am aware of) are consumer grade lenses. One of the only counter examples that I am aware of is the 17-55mm f2.8 DX Nikkor Gold Ring zoom that I don't think is still made. And my copy of that lens is a bit heavier than the 24-70mm f2.8 FX lens (non-VR) that is its full frame functional equivalent.

The difference in weight between DX and FX lenses of similar focal lengths and apertures and build quality by the same manufacturer are miniscule. What I see happening is that people compare the weight of variable aperture DX zooms (which is just about all I see available now) to constant aperture FX zooms. Of course the constant aperture zoom is going to be larger and heavier. I don't care if it is for FX or DX.

I have two DX lenses. The 18-200mm variable aperture zoom is a lot lighter than the pro-level 17-55 f2.8. Yet both are DX lenses. FX vs. DX has nothing to do with it.

It is possible to realize much of the same weight and size savings on FX cameras by simply buying lower grade lensed, like you are forced to do if you buy DX lenses...that's all that is available.

I do not care what choices other folks make, but let's keep our apples and oranges straight here and make better informed decisions.

zug55 Loc: Naivasha, Kenya, and Austin, Texas

Perhaps this is a choice that can be mitigated. (Buying an FX camera is choice that can be mitigated as well.) I would agree that most DX lenses are consumer-grade lenses. However, if you are going to upgrade to FX you also want to buy better-quality lenses. And they are larger, heavier, and more expensive. If you don't want better quality stay with the DX format.

You write: "It is possible to realize much of the same weight and size savings on FX cameras by simply buying lower grade lenses, like you are forced to do if you buy DX lenses." First of all, I doubt that. FX lenses have to provide for a wider field of view, hence their heftier size. But let's assume that your statement is correct: why bother putting the same type mediocre consumer-grade lens on an FX body? Why buy a Ferrari and then only drive it in first gear?

larryepage Loc: North Texas area

Many here already choose to use heavier, higher grade lenses on their DX cameras. For them, the weight impact of moving to a DX body will be negligible. My point here is that a need or desire to move to full frame can be reasonably done in phases, and those phases can reasonably start either with lenses or the body. It baffles me completely that so many folks here are so fixated that they cannot conceive of starting with the body.

Glenn Harve

BINGO

Thomas902 Loc: Washington DC

too funny... like no one mentions that the lion's share of sport and BIF shooters mate full frame telephoto optics to DX bodies... Instead the lion's share of UHH responding to this thread quote vendor hype about either throwing away part of the optics image circle or loss of DOF when using a crop sensor...

There is a compelling reason for migrating to FX for those working commercially... That being if the majority of your clients need architectural interiors... Here there is virtually no substitute for full frame...

acreutz I shoot both DX and FX bodies and find both are stellar at what they do best... the key here is identifying your target audience and choose accordingly...

All the best on your photographic journey acreutz

Thomas902 Loc: Washington DC

"... If you don't want better quality stay with the DX format..." Really? So Sigma's offerings for Nikon DX format i.e. the 18-35mm f/1.8 isn't a quality optic? What about their 50-100mm f/1.8? I have and shoot the 17-50mm f/2.8 and find it to be vastly superior to my FX zoom optics (on a FX body) of the same FX focal range at a fraction of the price...

Oh well... what ever...