Compact Barlow lens with eyepiece adapter extension (M28.5×0.75mm thread). 2.5x magnification and 1.25″ fitting diameter




This compact Barlow lens can be fitted to the end of a standard 1.25″ eyepiece to increase the overall image magnification by 2.5 times. It consists of two parts, a compact Barlow lens (with M30x0.75mm thread) and an eyepiece adapter tube (with M28.5×0.75mm thread). This enables the compact lens to be compatible with 1.25″ eyepieces with either M30x0.75mm or M28.5×0.75mm inner barrel threads.

This compact Barlow lens ensures perfect alignment between the centre of the Barlow lens and the eyepiece.


  • Increase the overall image magnification by 2.5 times.
  • Compact design. It can fit 1.25″ (31.75mm) eyepiece barrel with either M30x1mm female threads, or with M28.5×0.75mm threads. These thread features are among the most commonly used eyepiece barrel threads currently found in the market.
  • This compact Barlow lens enables a perfect alignment between the central axis of the eyepiece and the Barlow lens.
  • Built with quality optical glass and with multiple broadband anti-reflection green coatings to reduce light reflection and to limit the effect of chromatic aberration.
  • Built with metal frame and metal eyepiece adapter tube.
  • Size: overall length – 21mm; eyepiece adapter tube diameter: 31.5mm
  • This Barlow lens can fit into PL16, PL20, PL26 and PL32 eyepieces which are available from this shop.



1. The image is for illustration purpose only and the telescope eyepiece is not included in this listing. This Barlow lens has been designed to fit most 1.25″ eyepieces. However, it is still possible that the thread may not fit some eyepiece brands due to thread difference. In this case, you can still use this Barlow by inserting it into the telescope’s eyepiece holder, then put the eyepiece on top. This can achieve a similar result.

2. Sometimes when a DSLR camera is connected to a telescope with the camera lens being removed, or an image diagonal lens is added to the telescope (to convert the upside down image to right side up), the image cannot be focused on the camera’s viewfinder (or seen through the eyepiece). This is often because the image focus point is shifted beyond the focus adjustment range of the telescope.

This compact lens and extension barrel can also be attached to the 1.25″ T-adapter set. This enables correct image focus on cameras when the cameras are attached to telescopes.

This compact lens also serves the purpose of adjusting the image focal point and enables the camera to get a focused image through a wide range of telescopes.

Additional information

Weight 0.01 kg


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