# How do I tell if a lens is crop or full frame?



## nickzou (Aug 1, 2011)

Dumb question, I know for Nikkor lenses it says DX for crop lenses but what is the equivalent for Sigma and Tamron?


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## Trever1t (Aug 1, 2011)

I believe they have similar designations.


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## Robin Usagani (Aug 1, 2011)

DC for sigma,
DI II for Tamron  (Dont get mistake with DI which is for both full frame and cropped).


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## Overread (Aug 1, 2011)

Most 3rd party companies will have their own website with sepecific details on their lenses and the cameras they are compatible upon - most also use a part of the lens name to denote if its 35mm or crop sensor targeted - for example here is Sigmas:
Lens Technology - SIGMA CORPORATION
as you can see for sigma 35mm compatible lenses is DG whilst crop sensor is denoted with DC


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## nickzou (Aug 1, 2011)

Tamron AF 70-300mm f/4-5.6 Di LD 1:2 Macro Lens for Nikon NII with Hood DSLR Lenses Full Frame 104A17NII - Vistek Canada Product Detail

So this lens is for both crop and full frame? How does that even work? And why does the note say it is not compatible with the D3 and the D700 then?

Sorry, I was just playing around with my camera this morning when I realized the reason my 50mm feels so cramped all the time is because it's actually not a DX lens. I was checking if this little detail had passed me by with all my other lenses.


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## KmH (Aug 1, 2011)

nickzou said:


> Sorry, I was just playing around with my camera this morning when I realized the reason my 50mm feels so cramped all the time is because it's actually not a DX lens.


I'm afraid you don't understand what is going on.

The field of view (FOV) a 50 mm FX lens delivers on a DX (APS-C image sensor size) camera is exactly the same size a 50 mm DX lens delivers on a DX camera. Both the FX lens, and the DX lens, deliver an FOV equivelent to what a 75 mm (1.5x crop factor) would deliver on an FX camera body.

In other words, the FOV an FX lens delivers on a FX body would be wider (less magnification because the 1.5x crop factor no longer applies) than it can deliver on a DX body.

DX designated lenses are designed to project a image circle that is only larger enough to illumunate a DX (APS-C) image sensor, which reduces the manufacturing cost of the lens.

A DX lens mounted on an FX body will produce a vignetted photo, to one degree or another, because the image circle they project is to small to illumunate the entire FX image sensor.

Nikon FX cameras automatically detect if a DX lens is mounted, and then only use the central APS-C size area of the FX image sensor.


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## nickzou (Aug 1, 2011)

KmH said:


> nickzou said:
> 
> 
> > In other words, the FOV an FX lens delivers on a FX body would be wider (less magnification because the 1.5x crop factor no longer applies) than it can deliver on a DX body.
> ...


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## Robin Usagani (Aug 1, 2011)

You will have the crop maginfication regardless if the lens is made only for crop or for both.


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## Robin Usagani (Aug 1, 2011)

I suggest do a search about crop and full frame sensor and get full understanding what trully is going on.


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## djacobox372 (Aug 1, 2011)

nickzou said:


> Tamron AF 70-300mm f/4-5.6 Di LD 1:2 Macro Lens for Nikon NII with Hood DSLR Lenses Full Frame 104A17NII - Vistek Canada Product DetailSo this lens is for both crop and full frame? How does that even work? And why does the note say it is not compatible with the D3 and the D700 then?Sorry, I was just playing around with my camera this morning when I realized the reason my 50mm feels so cramped all the time is because it's actually not a DX lens. I was checking if this little detail had passed me by with all my other lenses.


 A 50mm dx lens would be just as cramped--the advertised focal length isn't adjusted for crop factor.Since you don't seem to have a full frame camera, then it shouldn't matter--full frame lenses work fine on crop cameras, they just might cost more and be needlessly heavy.


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## kundalini (Aug 1, 2011)

nickzou said:


> So wait, having an FX lens on my D7000 will not result in 1.5 magnification?


You're stuck with a 50mm lens or a 70-300mm lens or whatever lens you buy in the future. End of story.


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