TeleVue Mars Type A and Type B Filters

By: Vlad Fedosov
02/01/2025

Mars is an elusive planet to observe. Firstly it only comes around opposition(close to the Earth) only once about every two years. Even then many times it is still quite small compared to the apparent size to the other planets. So what to do to increase the chances of seeing the most on this elusive target? Well, this is where the TeleVue Mars Type A and Type B filters come in, and try to increase your chances of seeing the hidden gems of the red planet!

The TeleVue Mars Type A and Type B filters are specifically designed to enhance the visibility of Martian surface features. They were available in 1.25” size. I tested the filters during the 2024/2025 Mars opposition Mars reached a relatively small apparent size of 14.6 arcseconds. The scope used was my excellent Meade 12” ACF f/10 SCT.

Televue Mars Type A Filter:

  • Dual-band: This filter transmits green and red light while blocking other colors. I noted that the color visually was a light orange, and certainly not a green tint.
  • Enhanced detail: It aims to bring out details on the Martian surface while preserving the natural color of the polar caps and other features. Overall I noted that the filter makes the polar ice cap very vivid! Albedo was not as vivid even compared to a nonfiltered view. The overall feel that I got from the filter is that besides making the polar ice cap pop there was really no other improvement though was a pleasant view overall.

Televue Mars Type B Filter:

  • Color filter: This is a more traditional colored filter that emphasizes the red color of Mars. I noted the color of the image produced was VERY orange.
  • Contrast enhancement: It helps to increase the contrast between light and dark areas on the Martian surface. This filter certainly did increase the contrast of the albedo surface details. The polar ice cap was not as obvious.

Conclusion:

The overall feel that I get from these filters is that they are nice and do provide some mild increases in the detail that you can see. Are these filters a game changer in observing Mars? Absolutely not! If you’re an avid Mars observer I do feel that these are still a good addition to your arsenal with a nod to the Type B filter for surface detail increase. Happy Mars observing!!!