Will my D40 lenses fit the D5100 or D7000

More fun on NikonUSA

> Will my D40 lenses fit the D5100 or D7000?
> Subject says it all–will my D40 lenses fit the D5100 or D7000? And how, in general, can one tell which lenses will fit which cameras?

The short answer is: Yes, all lenses that “fit” your D40 will fit the D5100 D7000 and later Nikon dSLRs with an F-mount (that’s currently all Nikons dSLRs).

The only Nikon F mount lenses that will not fit on these cameras are some that were designed to operate with the mirror up and had different box dimensions. These mounts would crash the reflex mirror. Fortunately there are very few of these lenses around and most are collectors items so you won’t run into it. A quick google will warn you if this is the case.

But what you are really asking is do they mount and work the same? The answer is still: Yes, but with one exception. Nikon lenses with a “G” designation but not an “AF-S” one will not auto-focus on the D5100 or D7000, but will on the D40. Fortunately, there are very few lenses that qualify for that, and those that do are low-end lenses that have since been replaced by better/cheaper models—the only time you have to worry is when someone is trying to pawn off a dud second-hand.

Note that any old AF lenses you purchase for the D40 will now auto-focus on the D7000. Whereas before they didn’t at all because the latter has an in-body motor while the former does not. You do lose matrix metering capability vs. the D40, but most people will take AF over the matrix meter.

As for understanding the smorgasbord of compatibility, [Nikonians has a friendly chart](http://www.nikonians.org/nikon/slr-lens.html). (There may be a slight error. I don’t believe the D5100 has an AF motor in it.)

Another thing to note is that where the Nikonians chart has a big “No!” for pre-AI lenses, you can use a [John White’s conversion service](http://www.aiconversions.com/) to “upgrade” the pre-1977 lenses to an AI lens so that the aperture functions correctly when the shutter is pressed. (These lenses, with the exception mentioned above will mount, but they the aperture controls won’t be automatic.)

This is one of the strengths and pitfalls of the Nikon system. Nikon has decided to ensure mount compatibility for the F mount since its inception (it predates Pentax and Canon). But advances in technology need to be incorporated into the lenses also. Other companies either break backward compatibility across the line or are slow to implement new features to ensure body/lens compatibility at the right price. Nikon splits this difference with deciding how much of the old lens suite to build in the camera based on the price point/budget and usage scenario (size/weight) of its typical shooters.

Monitor cover for Nikon D5000/D5100?

Sometimes I get bored and answer questions on the Nikon USA forum:

> Is there a monitor cover which will work with the D5100? I am thinking of a cover similar to the BM-8 that came with my D70.

The 5100 has a flip out LCD, so there is no need for a monitor cover. Instead, just flip out the LCD, rotate it, and flip it back in.

There are third party sites that make “[screen protectors][google screen protector]” which are thin films designed to protect the LCD from scratching. I don’t know how effective or useful they are since the glass or plastic used to protect the Nikon LCDs has improved over the years and quality varies from model-to-model. Plus, it is simply not very likely that a dSLR camera LCD will get scratched—dSLRs just aren’t often found in your pocket along with your keys a la iPhone 😉

For instance, my Nikon D3 with a glass screen and no plastic protector doesn’t have a scratch even though I’m and outdoor shooter and have tens of thousands of shutter clicks. Similarly, my GF’s Nikon D5000 doesn’t have a scratch because it is easy to rotate the display to a safe position for storage and transportation.

BTW, avoid most “anti-glare” thin film protectors unless you are sure you know what you are doing. They work by frosting the film to scatter the reflection. However the material used in the frosting may be too close to the size of the pixels in the high-density monitors of a camera LCD. When that happens you end up being able to see the individual red, green and blue pixels in the display making it annoying. 🙂

[google screen protector]: http://www.google.com/search?q=lcd+screen+protector+nikon&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a#sclient=psy-ab&hl=en&client=firefox-a&hs=PzF&rls=org.mozilla:en-US%3Aofficial&source=hp&q=lcd+screen+protector+nikon+5100