It’s an acrylic Bahtinov mask that uses a clear optical material for improved light transmission. The diffraction spikes Bahtinov mask from William Optics is a patented design, and it works exceptionally well. The latest version of this focusing tool is the best I’ve ever used, because the improved design allows more light to pass through the mask. Diffraction Spikes Bahtinov Mask by William Optics But if your shooting with a DSLR camera or dedicated astronomy camera and you just want quickly confirm your focus is on – using a Bahtinov mask is one of the easiest ways to do this. (Such as the FWHM measurement in BackyardEOS or APT).
BACKYARDEOS NO FRAME AND FOCUS MANUAL
In this post, however, I’ll be describing tips that are most useful to those shooting with a refractor telescope, that are using a manual focus routine.Īutomatic and motorized focuser users have the ability to use software that tells them when a star is as sharp as possible. These patterns can be dissected and tweaked to diagnose issues with collimation and find a sharper focus for astrophotography. For example, a Newtonian reflector creates its own star diffraction spikes by nature of its design. Refractor telescope owners expect razor-sharp details in their photography, so mastering the art of focusing stars is a must.Īn image of the Eastern Veil Nebula with sharp, pin-point starsĭifferent types of telescopes have better ways of achieving a sharp focus than others. However, this pleasing characteristic is only present when your focus is spot-on. One of the reasons I love apochromatic refractors, is their ability to capture colorful, pinpoint stars. In general, the smaller the stars are in your image, the better. Why Focus is Critical for Astrophotography Other types of focusing masks include the Hartmann mask and Scheiner Disk.
The mask helps visual observers and digital astrophotographers to achieve a razor-sharp focus in seconds. The design itself was created by Russian astronomer, Paul Bahtinov. The process involves placing the focusing tool on the objective lens of your telescope or camera lens, and observing a bright star. Unlike autofocus and star measuring software tools, this “old school” method can be done without the use of an external computer, and only takes a minute. No matter which type of camera you use, a Bahtinov mask can help you achieve a higher level of accuracy when focusing your telescope or a camera lens. Related Post: Practical Focusing Tips for Astrophotography Use a Bahtinov mask for better focus You can avoid this unfortunate circumstance by using a simple tool that effectively confirms that your focus is as sharp as can be, a Bahtinov mask. In many cases, I did not realize how bad the focus of my image was until I attempted to process the final image. Over the years, I’ve had my fair share of deep-sky astrophotography focus mishaps. With so much time and effort put into your polar alignment and autoguiding accuracy, it would be a shame to spoil a photo due to poor focus. This process is an essential step of any deep-sky astrophotography session. A Bahtinov mask can help you achieve a sharp focus for your astrophotography images.