please do a search on the forum!!!! it was discussed many times before

timmytimer said:....
Maybe the D90 is something you like and plan to continue using as a spare/second body ....

I agree , BUT once you have upgrade to somthing like a D700 you will another want another D700 as a spare

I am afraid you will not be content with a D90 even as a spare
beware a D700 is going to spoil you

I disagree slightly with the notion that an FX lens is a waste of money if there's a DX equivalent. It's all in the eye of the beholder. Someone like me who's teetering on the decision of FX vs. DX won't be buying new DX lenses. Ever. If I buy good DX glass then decide to go FX I've just wasted money. I'm faced with having to replace the lens or buy a second one to work fully with the FX body. Therefore, it may be advantageous for me personally to spend a little more on the FX version in turn reducing the long term risk of the purchase. The next body may turn out to be DX but when it's time to upgrade again it may not be true. Especially since this decision is taking so long to make this time around.

The other possible scenario I see relates to a spare camera body (or future upgrades). Maybe the D90 is something you like and plan to continue using as a spare/second body but are looking to upgrade to FX in the future. The D90 is a decent quality body. By sticking with FX lenses they are fully compatible with either body. IMHO the DX lenses are simply less versatile and have less resale value due their limitations.

Hi,

how do you identify witch lens is for FX or DX camera? If isn't any DX abrev. in the lens type is it for FX body??

The important thing to remember, while you can put FX lens on a DX body, if you put a DX lens on a FX or 35mm body, it will fit, but the image will not cover the FX sensor. A DX lens is designed for a DX body only
A FX lens is likely to be a waste of money if there is DX equivalent

I will answer in short. You can almost any Nikon lens you want on your D90. FX or DX, both work.

The sensor on a DX camera is 16x24mm so a DX lens only has to cover the diagonal of that size (I am not doing any maths here). An FX sensor is 24x36mm so an FX lens has to produce a bigger sized circle falling on the sensor.

Now imagine the FX size compared to a DX and and you can see it is 1.5 times larger, so the DX sensor is in effect only showing the central portion of the circle that would fall on an FX sensor. Because DX lenses only accommodate that portion they can be built smaller.

So any FX lens is fine on a DX camera, but DX lenses cannot be used on FX because they would be black outside the DX circle area, or to put it mildly they would vignette really bad. However the area at some point would be OK, so on say a 12-24mm DX lens it would be OK to use from 18-24mm.

If you can pick up classic lenses at the right price, do so, because although Nikon does produce better glass now the sensors in Cameras haven't yet reached the point where the lens show it's flaws, although in the very near future that will no longer be true. I am not sure at how many mega pixels it would take, perhaps someone else on here would be able to answer that.

markogts said:
However, in terms of depth of field, hyperfocal distance and diffraction, things get pretty complicated, and at the end, the FX format has some advantages.

Not to be pedantic, but two of the three "advantages" you list for FX are results of it being first, and thus the basis for comparison.

Shallower vs deeper DoF @ small f-stops for any given Field of View is an aesthetic preference.
Hyperfocal distance issue is really the same issue looked at from a different perspective.

A lens is a lens, no matter what is attached behind it. If you take a FX lens on a FX body and then you crop the image by a factor of 1.5, you get less field, as if the lens was longer. A DX sensor crops *every* image, so every lens has a narrower field of view and so behaves as if it was longer. So, in terms of perspective, a 100mm on a DX will appear identical to a 150mm on a FX. However, in terms of depth of field, hyperfocal distance and diffraction, things get pretty complicated, and at the end, the FX format has some advantages.

Google is your friend, ask it nicely and it will tell you everything you want, well, almost everything lol... mansurovs.com/nikon-dx-vs-fx

First of all, yes lenses designed for 35mm cameras will work on DX bodies. Secondly, the crop sensor bodies do not magnify anything, it is just a smaller frame, so it has less capturing area than an FX/35mm frame, it is not like using a teleconverter.

Sorry for being naive but need clarification on DX vs. FX lenses. I know a DX camera has the magnification property from the sensor. What's up with an FX lens? Can I still put it on a D90? Will the FX lens still benefit from the DX sensor magnification? Totally lost, please clarify. Thank you