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IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
IMPORTANT: Our store is located in Canada. All orders that include products manufactured outside of Canada or USA will be subject to tariffs and duties, regardless of the order value. US customers are responsible for all applicable duties and tariffs, and those will be billed by the carrier, except for the Lacerta upgrade kit, for which we collect them at checkout.
Shelyak Spacer for Star Analyser

Shelyak Spacer for Star Analyser

by Shelyak
SKU SHK-BA0014
$34.00 - $34.00
$34.00
$34.00 - $34.00
$34.00
Price Match Policy!
  • Increases Grating-to-Sensor Distance
  • Adjusts Spectrum Dispersion for Optimal Scale
  • Stackable Design for Custom Spacing
  • Matches Spectrum Length to Sensor and Pixel Size
  • Maintains the Star Analyser's Intrinsic Resolution
1 in stock
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  • Description
  • FAQ
  • Downloads
  • Warranty

  • Shelyak Spacer for Star Analyser

    The Shelyak Spacer for Star Analyser is a fundamental accessory for tuning the dispersion of your spectra. By physically increasing the distance between the Star Analyser diffraction grating and your camera's sensor, this spacer spreads the spectrum over more pixels, optimizing the image scale for your specific instrument setup.

    Adjusting Dispersion: Match Your Star Analyser to Your Sensor

    In the simple optical path of the Star Analyser, the spectral dispersion is directly proportional to the grating's distance from the sensor. This spacer provides a simple, mechanical way to increase that distance, physically lengthening the spectrum captured on your camera's chip. This is essential when using a camera with small pixels or a short focal length telescope, where the spectrum might otherwise be too compressed.

    It is critical to understand that while this spacer increases dispersion, it does not increase resolution. The spectrograph's ability to resolve fine spectral details is an intrinsic property of the grating itself. This spacer simply spreads the existing detail over a larger area, it does not create new detail. For maximum flexibility, these spacers can be stacked to achieve even greater separation.

  • What is the primary function of the Shelyak Spacer for Star Analyser?

    Its primary function is to increase the physical distance between the Star Analyser's diffraction grating and your camera sensor. This action spreads the star's spectrum out over a larger area of the sensor, a property known as increasing the dispersion.

    Does adding the Shelyak Spacer improve the resolution of my spectra?

    No, it is very important to note that it does not. The spacer increases dispersion (the physical length of the spectrum on the sensor) but does not change the resolution (the ability to distinguish fine details). Resolution is an intrinsic characteristic of the Star Analyser grating itself.

    How does the Shelyak Spacer help when imaging the spectrum of a star like Vega (Alpha Lyrae) with a large-format camera?

    On a camera with a large sensor or with a short focal length instrument, a star's spectrum can appear very small and compressed. By using the Shelyak Spacer, you can increase the dispersion to spread the spectrum of Vega across more pixels, making its characteristic absorption lines easier to sample, see, and measure.

    Is the Shelyak Spacer useful for a planetary camera with small pixels?

    Yes, it is particularly useful in this scenario. Cameras with small pixels require a more spread-out spectrum to avoid undersampling the spectral details. Using a spacer ensures that the resolved details from the grating are projected over enough pixels to be properly recorded by the camera.

    Can I use more than one Shelyak Spacer for my Star Analyser?

    Yes, the spacers are designed to be stackable. You can thread multiple spacers together to achieve a greater distance between the grating and sensor, which will further increase the dispersion of the resulting spectrum.

    Is there any downside to using the Shelyak Spacer?

    The main trade-off is surface brightness. As you increase the dispersion, the light from the star is spread over more pixels. This reduces the brightness of the spectrum at any given point, which may require longer exposure times to achieve the same signal-to-noise ratio, especially for fainter targets.

  • Shelyak 1-Year Warranty