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Baader SolarSpectrum 0.7x Telecompressor - 2"
Baader SolarSpectrum 0.7x Telecompressor - 2"
Baader SolarSpectrum 0.7x Telecompressor - 2"
Baader SolarSpectrum 0.7x Telecompressor - 2"

Baader SolarSpectrum 0.7x Telecompressor - 2"

by Baader Planetarium
SKU BAA-2459259
CA$456.00 - CA$456.00
CA$456.00
CA$456.00 - CA$456.00
CA$456.00
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  • 0.7x Focal Reduction Factor
  • Designed for SolarSpectrum H-alpha Filters
  • Corrects for f/30 Telecentric Systems
  • 2" Barrel and Threading
  • Enables Full-Disk Solar Views
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  • Description
  • FAQ
  • Specifications
  • In the Box
  • Downloads
  • Warranty

  • Baader SolarSpectrum 0.7x Telecompressor - 2"

    The Baader SolarSpectrum 0.7x Telecompressor is an essential 2" accessory for any SolarSpectrum H-alpha filter owner, specifically designed to solve the challenge of the required f/30 light cone. This reducer shortens your telescope's effective focal length by a factor of 0.7x, ensuring the full solar disk and its surrounding prominences fit within the field of view of eyepieces in the 30mm to 35mm range.

    The f/30 Requirement: Why SolarSpectrum Filters Need This Compressor

    SolarSpectrum H-alpha filters mandate a parallel light path of at least f/30 to achieve their narrow bandpass. This is typically accomplished using a telecentric system, which dramatically increases the telescope's effective focal length. The consequence is a highly magnified image where the full solar disk no longer fits in the field of view, even with long-focal-length eyepieces of 30mm to 35mm.

    A 0.7x Reduction: Framing the Full Solar Disk and Prominences

    This telecompressor mounts on the eyepiece side of the filter, reducing the elongated focal length by a factor of 0.7x to bring the entire sun back into view. For example, a 6" refractor operating at an effective focal length of 2250mm (at f/30) is reduced to approximately 1700mm, restoring a full-disk perspective. For imagers, this reduction also provides the dual benefit of a wider field for framing and shorter necessary exposure times, helping to freeze atmospheric turbulence.

    Mechanical Mounting: Integrating with the 2" Universal Flange

    Integration into your optical train is straightforward. The telecompressor is designed to thread into the Baader 2" Universal Flange (#2958240, sold separately), which attaches directly to the SolarSpectrum filter housing with four screws. The compressor features a standard 2" male thread and is fully compatible with Baader's T-2 accessory system, allowing for secure, threaded connections to cameras, T-2 prisms, or eyepiece holders.

    Choosing Your Reduction: 0.7x vs. the 0.4x Telecompressor

    Baader offers two options to suit different equipment and goals. The 0.7x Telecompressor provides a moderate reduction that is ideal for most telescope systems to perfectly frame the sun and its prominences. For those with shorter focal length instruments or imagers seeking the widest possible field of view, the more aggressive 0.4x Telecompressor (#2459260) is also available.

  • Why is a telecompressor needed for my Baader SolarSpectrum filter?

    SolarSpectrum H-alpha filters require a very slow, parallel f/30 light cone for optimal performance. This is achieved with a telecentric system, which significantly increases your telescope's effective focal length. The 0.7x Telecompressor reduces this focal length back down, allowing the entire solar disk to fit within a typical eyepiece field of view.

    How does the Baader 0.7x Telecompressor physically attach to the filter?

    It attaches to the eyepiece-side of the SolarSpectrum filter housing. You will need the Baader 2" Universal Flange (sold separately, #2958240), which secures to the filter with four screws. The telecompressor's 2" male thread then screws directly into the flange.

    Can I use the Baader 0.7x Telecompressor for solar imaging?

    Yes, it is highly recommended for imaging. By reducing the effective focal length by a factor of 0.7x, it not only provides a wider field of view to capture the full sun but also significantly reduces the required exposure times, which helps freeze atmospheric seeing.

    When should I choose the Baader 0.7x Telecompressor versus the 0.4x model?

    The 0.7x Telecompressor provides a moderate reduction that is ideal for most telescopes to frame the full sun and prominences. The 0.4x Telecompressor offers a more aggressive reduction for an even wider field of view, which may be preferable for shorter focal length telescopes or for imagers who need to fit the sun into a smaller sensor.

    My refractor has a 2250mm focal length after adding the telecentric. Will the 0.7x Telecompressor let me see the full solar disk?

    Yes, this is the exact scenario it's designed for. The 0.7x telecompressor will reduce that 2250mm effective focal length to approximately 1700mm, which is short enough to frame the entire sun and its prominences when using a wide-field eyepiece around 30-35mm.

    Can I connect my T-2 accessories to the Baader 0.7x Telecompressor?

    Yes. While the telecompressor has a native 2" male thread, it is fully compatible with the Baader T-2 accessory system. You can use various T-2 adapters to change the output to a male or female T-2 thread for securely connecting cameras, prisms, or other components.

  • Net weight (kg) 0.10
    Solar Filter with mount/thread? No
  • Baader Planetarium Warranty