Digital talk

 

The crop factor of digital SLR's

 

by Fred Kamphues

 

 

 

© Mill House

A lot of people ask me about the crop factor of current DSLR's.

 

I will explain this below, using an example of a 35 mm slide of the Gošafoss waterfall in Iceland and a similar Nikon D1X image.

 

Both images were made with a Nikkor AF-S 17-35 mm zoom lens at the same focal length.

 

Nikon F90X

Nikkor AF-S 17-35

at 25 mm focal length

35 mm slide film

 

 

Nikon D1X

Nikkor AF-S 17-35

at 25 mm focal length

23.7 mm CCD sensor

 

The field of view reduction of the digital camera is obvious.

This is also known as the crop factor.

A 25 mm lens on a DSLR camera is no longer a wide angle lens, but corresponds to a 37 mm lens on a 35 mm film body.

 

The D1X has a sensor size of 23.7 x 15.5 mm.

This sensor size is often referred to as APS-C size.

 

As a result the effective field of view is 35/23.7 = 1.5 times smaller.

 

This is indicated in the picture below.

 

Comparison of field of view with a 35 mm film camera and an DSLR camera with APS size sensor

 

If you want to make wide angle pictures with a digital SLR with APS-C size sensor, you need a much shorter focal length than you normally would with a 35 mm camera.

 

This is shown below. The DSLR image is taken at 17 mm focal length, the 35 mm slide was taken at 25 mm focal length. Both images have roughly the same field of view.

 

Nikon D1X

Nikkor AF-S 17-35

at 17 mm focal length

23.7 mm CCD sensor

 

 

Nikon F90X

Nikkor AF-S 17-35

at 25 mm focal length

35 mm slide film

 

 

No crop factor (Full Frame)

The following DSLR cameras have a full frame sensor (appr. 36 x 24 mm) and no crop factor with respect to a 35 mm film camera:

Canon 1Ds, 1Ds MkII, 1Ds MkIII, 1D X, 5D, 5D MkII, 5D MkIII, 6D.

Nikon D3, D3S, D3X, D4, D600, D700, D800, D800E.

Sony Alpha 900, Alpha 850, SLT-A99.

 

Crop factor 1.3 (APS-H)

Canon 1D, 1D MkII, 1D MkIII, 1D MkIV, 1D C.

 

Crop factor 1.5 - 1.7 (APS-C)

The following DSLR cameras have APS size (appr. 23 x 15 mm) sensors:

Canon D30, D60, 300D, 350D, 400D, 450D, 500D, 550D, 600D, 650D, 10D, 20D, 30D, 40D, 50D, 60D, 1000D, 1100D, 7D.

Fuji S1 Pro, S2 Pro, S3 Pro, S5 Pro.

Nikon D1, D1X, D1H, D100, D2H, D2Hs, D2X, D2Xs, D40, D40X, D50, D60, D70, D70s, D80, D90, D200, D300. D300S, D3000, D3100, D3200. D5000, D5100, D5200, D7000.

Pentax *istD, *istDS, *istDL, *istDS2, *istDL2, K110D, K10D, K100D, K100D Super, K200D, K20D, K2000, K-7. K-x, K-r, K-5, K-01, K-30.

Samsung GX-1S, GX-1L, GX-10, GX-20, NX10, NX5.

Sigma SD9, SD10, SD14, SD15, SD1.

Sony Alpha DSLR A100, A200, A230, A290, A300, A330, A350, A380, A390, A450, A500, A550, A560, A580, A700, SLT-A33, SLT-A35, SLT-A37, SLT-A55, SLT-A57, SLT-A65, SLT-A77.

The crop factor of above mentioned DSLR bodies is approximately 1.5.

 

Nikon indicates its full frame cameras with FX and APS-C cameras with DX.

 

Nowadays a large range of ultra wide angle zoom lenses is available, to satisfy the needs of the digital photographer:

 

For Nikon DSLR bodies, the following (ultra) wide zoom Nikkor lenses are available:

Nikkor:

AF-S 14-24 f/2.8G

AF-S 16-35 f/4G VR

AF-S 17-35 f/2.8

AF 18-35 f/3.5-4.5

And with reduced image circle for APS size sensors only:

AF-S 10-24 f/3.5-4.5G DX

AF-S 12-24 f/4.0G DX

AF-S 16-85 f/3.5-5.6 VR DX

AF-S 17-55 f/2.8G DX

AF-S 18-55 f/3.5-5.6G DX

AF-S 18-55 f/3.5-5.6GII DX

AF-S 18-55 f/3.5-5.6G DX VR

AF-S 18-70 f/3.5-4.5G DX

AF-S 18-105 f/3.5-5.6G DX VR 

AF-S 18-135 f/3.5-5.6G DX

AF-S 18-200 f/3.5-5.6G DX VR

AF-S 18-200 f/3.5-5.6G DX VR II

AF-S 18-300 f/3.5-5.6G DX VR

 

For Canon DSLR bodies, the following Canon (ultra) wide zoom lenses are available:

EF 8-15 L USM f/4

EF 16-35 L USM f/2.8

EF 16-35 L II USM f/2.8

EF 17-40 L USM f/4

And with reduced image circle for APS size sensors only:

EF-S 10-22 USM f/3.5-4.5

EF-S 15-85 IS USM f/3.5-5.6

EF-S 17-55 IS USM f/2.8

EF-S 17-85 IS USM f/4.0-5.6

EF-S 18-55 f/3.5-5.6

EF-S 18-135 f/3.5-5.6

EF-S 18-135 f/3.5-5.6 IS STM

EF-S 18-200 f/3.5-5.6 IS

 

For both camera brands the following third party zoom lenses are available:

Sigma:

12-24 f/4.5-5.6 EX DG

15-30 f/4.5-5.6 EX DG

17-35 f/2.8-4.0 EX DG

And with reduced image circle for APS size sensors only:

8-16mm f/4.5-5.6 DC HSM

10-20 f/4-5.6 EX DC

10-20 f3.5 EX DC HSM

17-50 f/2.8 EX DC OS HSM

17-70 f/2.8-4.5 DC Macro

17-70mm F2.8-4 DC Macro OS HSM

18-50 f/2.8 EX DC

18-50 f/3.5-5.6 DC

18-50 f2.8-4.5 DC OS HSM

18-125 f/3.5-5.6 DC

18-125 f/3.5-5.6 DC OS HSM

18-200 f/3.5-6.3 DC

18-200mm F3.5-6.3 II DC OS HSM

18-250 f/3.5-6.3 DC OS HSM

18-250 f/3.5-6.3 DC Macro OS HSM

 

Tamron:

SP AF 17-35 f/2.8-4.0 Di LD

And with reduced image circle for APS size sensors only:

SP AF 10-24 Di-II

SP AF 11-18 f/4.5-5.6 Di-II LD

SP AF 17-50 f/2.8 XR Di-II LD

AF 18-200 f/3.5-6.3 XR Di-II LD

AF 18-250 f/3.5-6.3 IF Di-II LD

AF 18-270 f/3.5-6.3 Di-II VC

 

Tokina:

AF 16-28 f/2.8 AT-X PRO FX

AF 17-35 f/4 AT-X PRO FX

With reduced image circle for APS size sensors only:

AF 10-17 f/3.5-4.5 FishEye DX

AF 11-16 f/2.8 AT XD

AF 12-24 f/4.0 AT-X PRO DX

AF 16-50 f/2.8 DX

 

Digital talk

 

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