Tube lens MT
Aberration correction range
MT-1 , 2 , 40 : Visible wavelength range (435.8 – 656.3 nm) MT-L : Near-ultraviolet (355 nm) to near-infrared (1800 nm) MT-L4 : Ultraviolet (266 nm) to visible (620 nm)
Dimensions
MT-1
MT-2
MT-40
MT-L
MT-L4
Intermediate image position
Intermediate image position
Intermediate image position
Intermediate image position
Intermediate image position
ø21
ø35
ø35
ø33g 6 −0.009 −0.025
ø33g 6 −0.009 −0.025
ø34
ø30 -0.01 -0.05
-0.01 -0.05
ø30
Half-reflecting mirror (for epi-illumination)
Half-reflecting mirror (for epi-illumination)
ø35
ø35
Objective mounting position (see below)
Objective mounting position (see below)
Objective mounting position (see below)
Objective mounting position (see below)
Workpiece’s side focal position
Workpiece surface
Workpiece surface
Workpiece surface
Workpiece surface
Workpiece surface
Workpiece’s side focal position
Workpiece’s side focal position
Workpiece’s side focal position
Workpiece’s side focal position
Specifications Code No.
Focal length (mm)
Magnification (tube lens)
Image field (mm)
Effective lens dia. (mm)
Dimensions (mm)
Mass (g)
970208 970209 378-010 378-008
200 400 200 200
1X 2X 1X 1X
ø30 ø30 ø24 ø24
ø24.0 ø18.0 ø11.2 ø22.0
ø40×32.5 ø40×32.0 ø34×27.5 ø35×32.0
43 42 45 30
378-009 30 Note: A distance of 76.5mm in 970208 and 970209 drawings is for an image field of ø30 (without vignetting). For an image field of ø24 or ø11 (the latter is the image field of a 2/3-inch camera), use the formula (1) and (2) below to calculate the distance. 200 1X ø24 ø23.0 ø35×30.6
Reference: Placement of Objective and Tube Lens VMU and WIDE VMU and FS70 employs an infinity-corrected optical system in which the image is created by an objective lens and an imaging (tube) lens. Mitutoyo’s long working-distance objective lenses are designed to cover a field of view of up to ø30 mm (when the tube lens 970208 or 970209 is placed) and up to ø24 mm (when the tube lens 378-008 , 378-009 or 378-010 is placed) at the specified distance from the objective . However, use the following formula to calculate the approximate distance, when a different distance other than that as specified is required in order to insert your own optical system or other optical elements:
ø 1 : Objective exit pupil diameter (mm) ø 2 : Effective diameter of tube lens (mm) f 2 : Focal length of tube lens (mm) ø : Image field diameter (mm)
ø
= ( ø 2 –ø 1 ) • f 2 /ø [ mm ]· ······················ (1) ø 1 = 2 • f • N.A. [ mm ]· ··························· ( 2 )
Image field
Example: What is the distance ( ), when using M Plan Apo 10X * and tube lens ** ( 970208 ) to cover an image field of ø24? *f= 20 mm, N.A .= 0.28 (Refer to page 16 .) * *ø 2 = 24 mm, f 2 = 200 mm (Refer to the above chart.)
Tube lens
ø2
From formula (2 ): ø 1 =2x20x0.28 =11.2 (mm)
From formula (1 ): = (24−11.2 ) x200/24 =106.6 (mm)
ø1
Objective
f1
Therefore a distance ( ) up to 106 mm can cover an image field of ø24 without shading.
In other words a distance ( ) smaller than the specification does not affect optical performance . Contact Mitutoyo for detailed information.
NA
Workpiece surface
36
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