larryepage Loc: North Texas area

The real answer here is that "it depends." I moved to digital photography about 14 years ago with a Nikon D200 and a 18-70mm DX zoom lens after shooting film with the Olympus OM system for 30 years, and Minolta before that. The camera was great (especially for the time), but the lens was pathetic. Poor construction leading to "wiggly" operation, and a general lack of sharpness and color rendition led me to save to buy a 17-55mm f2.8 DX zoom. Still a DX lens, but day and night in performance. It was Nikon's only "professional" grade DX lens at the time. It delivered outstanding stability, durability, sharpness, and image rendition. I still use it on my D500, but gave the 18-70 away...couldn't rationalize taking any money for it.

Shortly after, I bought the Nikkor 70-200mm f2.8 VR, which is a full frame lens. Similar performance, and absolutely no drawbacks. It has performed flawlessly for over 12 years. The only other DX lens I ever bought was a used Nikkor 18-200mm VR DX zoom, just for those all-day, non-critical snapshot applications when I wanted to avoid carrying a lot of weight. It's OK, but not great, and today I'm more likely to use a full frame Nikkor 24-120mm f4 VR on those days.

Other good full frame lenses were added over the years. When I got a D810 for a specific application, I was already set with excellent lenses for it. Other than a little extra weight stemming from the more durable construction, I have never experienced any negative from using an FX lens on a DX body.

rehess Loc: South Bend, Indiana, USA

I switched from film to digital in 2007. I was using a Canon film camera at the time, so I stayed with Canon. At first, I used my film lenses - what a Nikon user would recognize as "FX" - unless I needed wide angle, when I used the lens that had come with the camera - what a Nikon user would recognize as "DX" - and I noticed no difference.

Don, the 2nd son Loc: Crowded Florida

Because you own em!

SteveR Loc: Michigan

I'm not sure what you're trying to say, Ron. An 18mm lens is an 18mm lens. Both will project the same image onto the sensor, whether they be dx or fx.

rehess Loc: South Bend, Indiana, USA

I think he was saying that you have to go with a 'wider' lens to get the same effect with"APS-C" that you got with "FF".

PHRubin Loc: Nashville TN USA

How many can't resist the temptation to say an 18mm lens is 18mm no matter if on an FX or DX camera?

Soul Dr. Loc: Beautiful Shenandoah Valley

I'm not saying anything, other than the lens is what it is.

will

DeanS Loc: Capital City area of North Carolina

An 18mm Nikon fx lens on a dx body produces an image equivalent to a 27mm lens on a ff body. Not aware of a 27mm lens however. On a Canon, the image would be equiv to a 28.8 mm lens on ff body. Crop factors are: Nikon, 1.5; Canon, 1.6.

Rongnongno Loc: FL

Right and a wider lens that either does not exist or is very expensive.

This is issue concerns only the wide angle lenses.

SuperflyTNT Loc: Manassas VA

The question was about using an FX lens instead of a DX lens on a DX body. An 18mm FX lens will give you an rquivalent image to a DX lens on a DX body. It’s in comparison to an FX body that it will speak like a 27mm.

SteveR Loc: Michigan

I understand what he's saying, but as I replied, an 18mm lens is an 18mm lens. The center portion of a FF 18mm lens will project the exact same image onto a dx sensor as a dx lens will. Exactly. Don't let the crop factor confuse you. The 18mm dx lens on a dx camera will still provide the field of view of 27mm.

I can see that the crop factor is still a confusing subject.

camerapapi Loc: Miami, Fl.

An FX lens will only use part of the sensor with a DX body. It is fine but using DX lenses the whole sensor is covered. Photographers use the term full frame to indicate that a sensor has the size of a 35mm film negative, which is correct and cropped sensor to indicate a sensor of smaller size when using a dSLR camera. If a DX lens is used with a cropped sensor the whole sensor is covered and the same goes with the M43 system that when the 4:3 ratio is selected the whole sensor is used.

An advantage as you surely know of using long lenses with a DX body is that because of the "digital factor" the lens is made longer, most convenient for wildlife photography.

rehess Loc: South Bend, Indiana, USA

I am not confused by crop factor. I have a Sigma 10-20mm lens for my "APS-C" Pentax KP. If I were to move to a "FF" Pentax K-1ii, I would need a 15-30mm lens to get the same range of views.

rehess Loc: South Bend, Indiana, USA

On an "APS-C", a lens acts longer. On my Pentax KP, a 300mm lens gives me the same views that would require a 450mm lens on a "FF" K-1ii. However, the lens does not change - it is 300mm in either case.

Rongnongno Loc: FL

Some of you folks are really confused.

A FX lens on DX body, as is a case has it focal length multiplied by a coefficient that is dependent on the manufacturer (Multiplying factor - MF).

When it comes to a FX lens on a DX body (I have not mentioned at anytime anything else) wide angle cannot be 'replaced' by a FX lens due to the MF.

A 18mm DX is similar to a FX lense (note similar, not the same) if mounted on DX and a FX respectively. To have a similar match on an DX using a FX lens, the lens will need to be FX 10mm which is expensive. Anything lower than that just does not exist but at a really high cost.

There is another glaring issue: The lens built.