About this product
Model: tak_tka00598
Part Number: TKA00598
Takahashi Ortho 2x Barlow Lens
Regular Barlow lenses and extenders increase focal length but tend to degrade the image. With this Ortho 2x Barlow lens, Takahashi aims to retain as many properties of the objective with which it is associated as possible.
Combining the Barlow lens with TPL series eyepieces produces a better quality image, whether at the centre of the field or the periphery, than when the Barlow is not used.
At the centre, the Barlow lens even cancels out the very low residual chromatic aberration of the TOA objective.
The photographic performance of the Barlow Ortho 2x lens is greater than the old model, both in terms of chromatism and coma.
In addition to the classical 1.25" (31.75 mm) female barrel, a male T thread (M42x0.75) has been added. This allows direct screwing of cameras or DSLRs (with the addition of a T ring)).
The magnification ratio of the Takahashi Ortho 2x Barlow lens varies as a function of the distance to the lens to the formula m = 2 + 0.0121 x b, where m is the magnification and b is the distance between the end of the T thread and the surface of the sensor (or entrance diaphragm in the case of an eyepiece).
For a ZWO planetary camera with a back-focus length of 17.5 mm, the value of b is 12.5 mm (the T-thread is 5 mm long). So, according to the formula above, the magnification is 2.15.
Specifications
Item number | TKA00598 |
Design | 2 lenses in 1 group |
Magnification | 2x |
Input mechanical interface | 1.25" (31.75 mm) male barrel |
Output mechanical interface | 1.25" (31.75 mm) female barrel + T-thread (M42x0.75) male |
Size | Diameter 46 mm, length 91 mm |
Weight | 130 g |
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