Farpoint astro bahtinov focus mask for celestron 9. This file is licensed under the creative commons attributionshare alike 3. As the focus is adjusted, the center diffraction spike appears to move. 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. Dec 02, 2017 to 3d print the bahtinov mask as shown in the images above, i used opencad a free software and a readymade tweakable template or model called bahtinov mask generator modded which i found on. Three patterns were calculated for each of the masks, one in precise focus, one with 12 microns off focus, and one at 36 microns. When precize focus is achieved the pattern becomes symmetrical. I was playing around with thisonline bahtinov mask generator but when i input the parameters for my camera lens say the sony zeiss 24mm f1. Farpoint fp415 bahtinov focus mask for celestron 9. Two of them form an x shape, and another spike crosses it, forming a shape.
For focusing the image of a telescope, one can use a bahtinov mask. This customizable design generates custom bahtinov masks, which are used to aid focusing telescopes during astrophotography. How to focus at infinity when capturing star fields hasselblad. Farpoint fp410 bahtinov focus mask celestron 8in sct fp410. Bahtinov focus masks are the brainchild of pavel bahtinov, a russian amateur telescope maker and astronomer. I ask as i see they have specific slit patterns for specific telescopes, and i wondered if. The lacerta bahtinov focusing masks are made from a lightweight, sturdy but still flexible plastic material special material. It requires the capability to acquire 640x480 images. This is probably because i dont have a clue how to use it. Farpoint fp410 bahtinov focus mask celestron 8in sct. Farpoint bahtinov telescope focusing mask for celestron 11 sct telescopes larger central opening for when used with hyperstar dropin focusing mask for 11 scts schmidt cassegrain telescopes. The telescope is pointed at a bright star, and a mask is placed in. The spikea bahtinov mask is made from quality light weight aluminum and machined. Diy bahtinov mask diy astronomer stargazers lounge.
Bahtinov focus mask for camera lenses 7579mm od by. Dec 18, 2008 a bahtinov mask is a device used to accurately focus an astronomical telescope. They are named after paul bahtinov, who developed the first designs. How to use a bahtinov mask getting started general help. Bahtinov grabber goes 64 bit and 32 bit update this is the introduction of a 64 bit release of the grabber. Bahtinov mask created by 3d printing astronomy notebook. Some friends of mine recently won a 3d printer in a contest, so i thought id design and print a bahtinov mask for my telescope. How does this mask work, and how did mr bahtinov get the idea to cut such a peculiar shape. The bahtinov mask achieves perfect focus in seconds. The center hole fits well over either the secondary mirror or a hyperstar attachment with a qhy10 camera attached. One thing ive seen with all these focusing methods is the need to get fairly close to focus before they work.
You may do so in any reasonable manner, but not in. May 10, 2011 does a focus mask work for lunar imaging, so you focus on a star then pan across to the moon keeping the same focus. With 85 degree angles, mathematics predicts that the displacement between the central spike and the x intersection should be 6. It consists of a disk made of opaque material fitted over the telescope objective with slots cut out in a specific pattern devised by. The bahtinov mask is a device used to focus small astronomical telescopes accurately.
Im running the 32bit version on a netbook, canon 300d camera and dslrfocus software for image capture. The final image is a wider shot of the backyardeos software best focus in this sequence and placed in the centre of the group. It consists of a disk made of opaque material fitted over the telescope objective with slots cut out in a specific pattern devised by amateur astrophotographer pavel bahtinov. Relativetothehartmannmask,the diffraction pattern created by the bahtinov mask allows for much more precise focus. We have not yet decided if we are going to do this. Bahtinov mask other focusing methods astronomy notebook. The bahtinov mask forms a long cross, composed of two diffraction spikes, centered on the bright object. With adapter it fits lenses smaller than 77mm outer diameter.
Bahtinov focus mask to fit canon efs 1585mm adapter to fit canon ef 100mm f2. How to make bahtinov mask, pdf templates deepsky watch. It will require a dslr to be unmounted to attach the mask and again to remove it, but that is a minor issue. Dec 14, 20 unless its a different scope, ens has one of the bresser messier ar102 f. This distance depends on the focal length of the objective and the distance between the objective and the subject. The following image shows the guider camera in focus, with the center line in a position symmetrical between the diagonals. Continuing the discussion from focusing using bahtinov mask. Unlike autofocus and star measuring software tools, this old school method. The batinov mask consists of three separate grids that produce three angled diffraction spikes when the telescope is pointed at a bright star.
I no longer need to fiddle around and wonder, is this the best i can focus it. Handles height is now customizable if the center hole diameter is 0 then 2 more handles will be added to model for safer fit the handles position relates to the width of ota regarding to my work we sell masks for different telescope types, so i made this slight modifications for a better general usability. Fine focus and bahtinov masks ask craig stark labs. The grids are aligned in such a way that they produce three angled diffraction spikes on the focal plane of the instrument for each bright star or planet. Gosky bahtinov focusing mask for telescopes dew shield diameter from 75mm 114mm 2. I used the patterns from astrojargon and copied the rest from my telescopes normal cap im super impressed with how well it works, and gets the focus way more accurately than i could by eye. I made a simple program that detects the three lines of the bahtinov pattern and tells you how far the central line is from the crossing of the diagonal lines. This mask attaches to the front of the scopes objective lens to show the astronomer how to precisely focus their telescope. The bahtinov mask is a widely used tool that cleverly uses diffraction as a focusing aid. Bahtinov grabber goes 64 bit and 32 bit update niels. Bahtinov mask principle image title illustration of the operation of a bahtinov mask for refracting optics by cmg lee, showing that rotating it by 180 degrees reverses the direction of the pattern. A bahtinov mask can help you achieve a sharp focus for your astrophotography images. Whe i got my first telescope, about a year ago, it came with quite a few extras including one of these masks. Each section of parallel slits is orientated at a slightly different angle, giving three different.
This simple application just grabs an area of your windows screen and finds the focussing accuracy. One mask is a general purpose mask designed to fit refractors and newtonian telescope. Im running the 32bit version on a netbook, canon 300d camera and. The idea is to create a specific diffraction pattern so that you know if you image is in focus. The mask will produce six long angled diffraction spikes on the star. With the help of the resulting diffraction pattern of a star a precise focus can be determined. The device used for recording the image be it traditional photoemulsion or digital sensor should. Bahtinov mask generator modded by botork thingiverse. When the center diffraction spike is symmetrically placed within the cross formed by the other two diffraction spikes. Had access to 3d printer, so i made a bahtinov mask. Farpoint bahtinov telescope focusing mask for celestron 8 sct telescopes dropin focusing mask for 8 scts schmidt cassegrain telescopes. The image projected by the objective gets sharp at a certain distance behind the objective. Aspikeaexample of the nowclassic bahtinov mask is shown in image1.
The bahtinov mask has become the preferred method of focusing a telescope, either visually or when imaging with a ccd camera, dslr or webcam. Unlike a hartmann mask which provides no visual cues on the direction of travel needed for focusing, the spikea mask is a bahtinov mask which clearly shows the direction of travel needed to achieve focus. I have down loaded the software, and a box with set capture area, and donate is all that shows up. I have made a new mask the carey mask, which i think can be even more accurate than the bahtinov. Achieving focus has been a tough challenge since i began with astrophotography, so i decided to do something serious about it, preferably something that does not cost a lot of money. A bahtinov mask can help you achieve a sharp focus for your. In 2008, pavel bahtinov, a russian amateur telescope maker and astronomer, published an ingenious new way to easily focus your dslr camera, webcam or ccd camera for astrophotography. 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. Finding razorsharp focus when shooting astrophotography can be hard stars appear as point light sources, and there are no detailed. Great bahtinov mask for c11 with hyperstar or without. A bahtinov mask is a device used to accurately focus an astronomical telescope. I know some people think these are great and others dont, but when using one, and this might sound like a daft question, does one use it at the end of the dew shield or does the dew shield have to come off. The other mask is designed to fit schmidt cassegrain telescopes. You can use the software bahtinov grabber freeware to help excact focus detection using.
A bahtinov mask is a focusing aid for astronomy in general, and astrophotography in particular. In each panel, im showing the star as viewed with top and without bottom the mask in place. To 3d print the bahtinov mask as shown in the images above, i used opencad a free software and a readymade tweakable template or model called bahtinov mask generator modded which i found on. Bahtinov mask used to help focus a telescope youtube.
Farpoint manufactures this lifesaving astrophotography tool out of virtually indestructable abs plastic and comes in two major types and in a range of sizes. One method that works well is to use a bright star, a bahtinov mask and manual focus with 100% magnification in live view. Each of the fwhm figures are placed under the corresponding bahtinov mask image. What i see in the image when im a long way away from focus is a collection of circles or doughnuts. This indispensable astrophotography tool is constructed from nearly indestruct. The bahtinov mask was invented by pavel bahtinov from russia. Farpoint bahtinov focusing mask for celestron 8 sct.
From beginner telescopes to professional observatories, opt has it all. At times when visually the focus looks correct the one of the overlayed lines shown in the software is way off and can jump between two places. The bahtinov mask is a variation on the hartmann mask which uses three separate grids. Also when the problem occurs the mask angle is also shown incorrectly. Telescope focus aids telescope focus masks high point. Bahtinov masks again, sorry imaging discussion east. Farpoint bahtinov focus mask for astrophotography for skywatcher 150 mak. It was invented by russian amateur astrophotographer pavel bahtinov in 2008. As the instruments focus is changed the central spike appears to move from one side of the star to the other.
After reading many discussions and articles in web pages and forums i decided to build my own bahtinov mask. Jan 02, 2014 to help get an accurate focus with my c11, a bahtinov mask was placed over the corrector lens. Anyone who has ever taken a photograph knows the importance of focusing. Improve your astrophotography focus with a bahtinov mask. In recent years, software has been developed to allow subpixel accuracy when using a bahtinov mask. Comparison of focusing masks gabor toth astrophotography. Jun 23, 2017 the bahtinov mask is a widely used tool that cleverly uses diffraction as a focusing aid. Bahtinov mask baseball software, softball software. For astrophotography, a digital image can be analyzed by software to locate the alignment of the spikes to subpixel resolution. Two programs which offer software based bahtinov assistance are niels noordhoeks bathinov grabber and apt by ivaylo stoynov. The fwhm figures were with the bahtinov mask in place, so are higher than would be the case without, but the method is shown.
If you do not have a bahtinov focus mask, get one, it will ensure you have the best focus possible, regardless of the seeing conditions. Bahtinov grabber for any camera niels noordhoeks weblog. The bahtinov mask was invented by russian amateur astrophotographer pavel bahtinov in 2005. Focusing using bahtinov mask main sequence software. Adjust the telescopes focus so that the central spike appears directly. Focusing tool for serious astrophotographers and those who care about their time and quality of astrophotos. This indispensable astrophotography tool is constructed from nearly indestructible abs plastic. 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. The central spike moves left or right relative to the diagonal x spikes according to focus position. These are not generic masks, each mask is tuned to the telescopes focal ratio for the very best performance. Here, ill show a video of me using both the current version of the fine focus tool and augmenting this with the use of a bahtinov mask. Bahtinov focusing mask for 60mm telescope a printout, generated by tool.
Bahtivov mask the bahtinov mask is a plate with three sections of parallel slits that fits over the end of the telescope and produces diffraction spikes on the focal plane below left photo. Dec 06, 2014 one thing ive seen with all these focusing methods is the need to get fairly close to focus before they work. Its an elaboration on the idea of a hartmann mask something you stick over the front end of your scope to induce a diffraction pattern that makes focusing. Bahtinov mask the easiest way to achieve sharp focus. Bahtinov mask to focus on a star focusing tips youtube. A bahtinov mask is a musthave for every astrophotographer.
The spikea focusing mask astronomy technology today 61 the focus knob, the line will either move towards the center of the v or away from it. Ive read about other methods for people with software and motorized focus, such as fwhm full width half max, but a bahtinov mask is simple to use with. Accurate focusing of telescopes and astrographs is particularly of concern to those involved in astrophotography. The telescope parameters were set to be a 10 at f4. Designing a mask using drawing, design, or cad software can be challenging, as the specifics of the mask change for each telescope based on aperture, focal. Since there was a very bright star in the field alnitak, the leftmost star in orions belt, the diffraction pattern produced by the mask was easy to see in the camera display. A bahtinov mask creates diffraction spikes visible to the viewer, with each direction of slots in the mask corresponding to a spike. Pop the mask in, calibrate the spikes, remove the mask, and there you have it. Farpoint bahtinov focusing mask for celestron 11 sct with. This is a remix of brentbs bahtinov mask generator, thing.
This process is an essential step of any deepsky astrophotography session. The bahtinov mask, invented in 2005 by a russian amateur astronomer, pavel bahtinov in 2005, is a device used to focus using a bright star. From the comments made previously in this thread, it should be sold within two minutes max of this post going live. There are many methods, software and devices on the market but the bahtinov mask is the least. Whilst its of no use to me now, before i used autofocus the bahtinov grabber was so useful to quickly achieve accurate focus so i think it would be a really useful addition to sgp. However, the bahtinov grabber software has no such problems, and can locate the spikes with subpixel accuracy. Oct 24, 2012 bahtinov mask used to help focus a telescope. Farpoint bahtinov masks are by far, the easiest, fastest and most consistent manual focusing aid available to the amateur astrophotographer. Also, a hartmann mask doesnt provide the precision of the spikea. In summary, this mask is much better than a hartmann mask but it is harder to make as it has many openings to be cut accurately.