Buzzer
professor emeritus
Reged: 07/21/07
Posts: 658
Loc: Long Island, NY
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Quote:
Wow, this thread was *waaaay* down on the third page when I went searching for it. 
Farmer Dave, Thank you for your very easy to follow mask generator. I put the numbers in and printed out the mask at 100%, cut out the circle to see if it was right, before I order them from the place in Denver. They both fit like a glove, Thanks again, Andy
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Meade SN-10 Carbon Fiber
TMB 92ss
Mini Borg 50 Guidescope
Celestron CGE Mount
QHY8
Orion Starshoot Autoguider
http://buzzer.zenfolio.com/
"I THINK THE WEATHERMAN NEEDS MORE EXPENSIVE EQUIPMENT"
WANING CRESCENT OBSERVATORY
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snowdragonusa
Pooh-Bah
Reged: 09/04/07
Posts: 1125
Loc: Denver, CO
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Hey Andy,
Be sure to let the folks know at the cutting shop the exact size since sometimes different programs will scale slightly different. They are good people there though and will be sure to get it perfect for you.
Cheers!
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Adam
12" LX200R, AT80LE
Lunt 60mm Ha & CaK solar scopes
DMK41.AS, DSI Pro, DSI-C, LPI
Denver Astronomical Society
Brighton Astronomical Group
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MartyT
professor emeritus
Reged: 09/28/07
Posts: 682
Loc: Kansas City
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While waiting for my laser-cut masks to show up, I needed to make up something to use tonight with my Megrez 90.
This one is made from a thin plastic "For Sale" sign. I cut a strip of sign material about 2" wide and wrapped it around the dew shield of the M90 and marked where it needed to overlap. Then I used some thin CA glue (super glue) along with some special "filler" designed for use with the glue. Then I laid the "ring" I just made onto the mask and glued it in place with more CA and filler. Fits the M90 like a glove...
I cut the Bahtinov factor back to 50 for this mask as I didn't want to spend 2 hours cutting out tiny slits. I think it'll work fine, but the laser-cut mask I designed has more than double the number of slits.
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Celestron CGE / C-11 (CGE-1100)
Megrez 90 FD APO / 0.8x FR/FF vIII
QHY8, 350D, DSI Pro, SPC900NC
KWIQ Guider (QHY5)
ETX-125AT
12" Lightbridge
My Astrophoto Gallery
Astronomical Society of Kansas City
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Ptarmigan
Carpal Tunnel
Reged: 09/23/04
Posts: 2304
Loc: Arctic
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Found it too about this new mask for focusing. I wonder if you make it out of paper or cardboard? Looks like a lot of cutting.
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Ptarmigans=Cute and Cuddly
Meade Starfinder 8
Nikon 10x50
Rebel XT
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Buzzer
professor emeritus
Reged: 07/21/07
Posts: 658
Loc: Long Island, NY
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Marty T gave me the idea to make a mask until I get mine made out of plastic. My daughters had something called card stock laying around. So I printed out my mask onto it and cut it out with the exacto knife. My wife has a glass cutting board, that really made the blade cut good and straight and fast. Don't forget to where your glasses, it really goes quicker,  . Then I took another piece of card stock and msde a tube the same size as the dew shield. I bent 3 places on the mask so I can get tape to hold it all together. Thanks to everyone who helped out with all this, Andy
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Meade SN-10 Carbon Fiber
TMB 92ss
Mini Borg 50 Guidescope
Celestron CGE Mount
QHY8
Orion Starshoot Autoguider
http://buzzer.zenfolio.com/
"I THINK THE WEATHERMAN NEEDS MORE EXPENSIVE EQUIPMENT"
WANING CRESCENT OBSERVATORY
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Buzzer
professor emeritus
Reged: 07/21/07
Posts: 658
Loc: Long Island, NY
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#2
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Meade SN-10 Carbon Fiber
TMB 92ss
Mini Borg 50 Guidescope
Celestron CGE Mount
QHY8
Orion Starshoot Autoguider
http://buzzer.zenfolio.com/
"I THINK THE WEATHERMAN NEEDS MORE EXPENSIVE EQUIPMENT"
WANING CRESCENT OBSERVATORY
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Hermit
member
Reged: 10/26/08
Posts: 34
Loc: Northern California
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Many thanks to all of you who brought about this great tool! I posted some pictures of my version of the focus mask on the binoviewer section of this forum:
Better focus method for individual eye diopter
Best regards,
Rob Crockett
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Meade LX90 LNT 8" Schmidt-Cassegrain
Standard Wedge, LX90 fork, LX200 tripod
Alan Gee II telecompressor f/5.6
Baader short 1.5cm T-adapter/T-ring
Astronomik CLS-CCD clip filter
Self modified Canon XSi with Baader UV/IR filter.
Meade Model 277 60mm refractor with Orion SSAG
Losmandy V-dovetails for balance and guide scope.
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achille66
member
Reged: 08/15/08
Posts: 13
Loc: athens greece
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this is my bahtinov mask for c9.25
its made out of aluminum 1.5mm
mask created through http://astrojargon.net/default.aspx
processed through incscape - great free vector software
laser cut at local athens greece shop - thank you periklis, viky and dimitri
10 minutes work - AMAZING PRECISION in focusing
cost = 20 euros
hartmann masks are funny compared to this
if you intend to make one dont forget to include 3 ears at 270/0/90 degrees (so that the mask stays on the scope and you dont have to hold it)
will post astrophotos with dsi II as soon as the weather clears
great stuff you can find in cloudy nights, i'm excited!
achilleas
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c9.25
eq6 pro synta
etx 125 pe
dsi ii c
hyperion 21/13/08, orion q70 38mm
self made Bahtinov laser cut aluminum mask
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X-Lurker
Underpaid Slacker
Reged: 09/12/06
Posts: 750
Loc: N.W. Ark.
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Hey all,
I'm sure this has been asked already, but there are too many replies to go thru... So here is my question... Which way should I rotate the mask for my newt? Does it matter? Should the angled bars be opposite from the focuser ect..? I just finished my mask 15 min. ago and I would like to try it out tonight. LOOK AT MY SKY CHART!!  All wise please advise. 
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Clear Skies,
Larry
I wasn't sick...I just called in uninterested
Glob
AOAS Member
10" Reflector (Cloud Magnet)
AT66ED
EQ-G (Powered by EQMOD)
Orion SVP 127
DSIc
SPC 900NC
Cloud Filter (On Order)
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John Wunderlin
Vendor - Spike-a Focusing Mask
Reged: 10/01/04
Posts: 655
Loc: Mineral Point, Wi
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Quote:
Which way should I rotate the mask for my newt? Does it matter?
Doesn't matter, unless you have a preference for where the center spike shows up.
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John Wunderlin
Vendor - Spike-a Bahtinov Focusing Mask
Empire Ranch Observatory
Iowa County Astronomers
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X-Lurker
Underpaid Slacker
Reged: 09/12/06
Posts: 750
Loc: N.W. Ark.
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Quote:
Doesn't matter, unless you have a preference for where the center spike shows up.
Thanks for the quick reply! But I'm not sure what you mean? Are talking about wether it's horizontal, diagnal or vertical on the screen? Please explain if you don't mind.
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Clear Skies,
Larry
I wasn't sick...I just called in uninterested
Glob
AOAS Member
10" Reflector (Cloud Magnet)
AT66ED
EQ-G (Powered by EQMOD)
Orion SVP 127
DSIc
SPC 900NC
Cloud Filter (On Order)
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John Wunderlin
Vendor - Spike-a Focusing Mask
Reged: 10/01/04
Posts: 655
Loc: Mineral Point, Wi
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Quote:
Are talking about wether it's horizontal, diagnal or vertical on the screen?
the 'x' pattern will just rotate in your eyepiece or on your laptop screen as you rotate the mask. If the center spike is left of center for example, as you rotate it, it will stay in the same relative position to the outer spikes, but just rotated in the image, as if you write a big X on a piece of paper and then rotate the paper. Does that help?
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John Wunderlin
Vendor - Spike-a Bahtinov Focusing Mask
Empire Ranch Observatory
Iowa County Astronomers
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John Wunderlin
Vendor - Spike-a Focusing Mask
Reged: 10/01/04
Posts: 655
Loc: Mineral Point, Wi
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Also, since you have a newt, you will be able to see the spider vane diffraction spikes as well, but the mask's spikes are much brighter so they basically overwhelm the newt's tiny spikes.
Edit: Here's a link to a picture I took with my mask attached to my XT10i. If you look carefully you can see the spider vane spikes as well as the mask spikes:
http://www.allprosoftware.com/xt10spikes.jpg
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John Wunderlin
Vendor - Spike-a Bahtinov Focusing Mask
Empire Ranch Observatory
Iowa County Astronomers
Edited by John Wunderlin (10/28/08 05:04 PM)
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X-Lurker
Underpaid Slacker
Reged: 09/12/06
Posts: 750
Loc: N.W. Ark.
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Yup, I got it now. Thanks John!
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Clear Skies,
Larry
I wasn't sick...I just called in uninterested
Glob
AOAS Member
10" Reflector (Cloud Magnet)
AT66ED
EQ-G (Powered by EQMOD)
Orion SVP 127
DSIc
SPC 900NC
Cloud Filter (On Order)
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MartyT
professor emeritus
Reged: 09/28/07
Posts: 682
Loc: Kansas City
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Got my Bahtinov masks back from the laser cutter (www.pololu.com) today, a full 2 days earlier than their estimated ship date.
In short, the masks came out beautifully. Every cut was clean and perfect.
Here's a photo of the C-11 sized mask (about 12.5" diameter)
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Celestron CGE / C-11 (CGE-1100)
Megrez 90 FD APO / 0.8x FR/FF vIII
QHY8, 350D, DSI Pro, SPC900NC
KWIQ Guider (QHY5)
ETX-125AT
12" Lightbridge
My Astrophoto Gallery
Astronomical Society of Kansas City
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MartyT
professor emeritus
Reged: 09/28/07
Posts: 682
Loc: Kansas City
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And here's a photo of the Megrez 90 version. The cut-outs on this one are about 2.1 mm wide each - there's no way I could have done this myself. (The mask is brown because it still has the protective paper on the Acrylic)
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Celestron CGE / C-11 (CGE-1100)
Megrez 90 FD APO / 0.8x FR/FF vIII
QHY8, 350D, DSI Pro, SPC900NC
KWIQ Guider (QHY5)
ETX-125AT
12" Lightbridge
My Astrophoto Gallery
Astronomical Society of Kansas City
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swcrawford
member
Reged: 06/15/08
Posts: 29
Loc: Western Tennessee, USA
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Thanks to the earlier poster for the tips on the embroidery hoops. They work really well. They are very light and come in several sizes. Just glue or staple or tack your cut-out to the edge of the rim and slide it right on the scope. And they happen to be 30% off at Hobby Lobby at the moment. I just picked up 5 of them for less than $6.
If you can't find one exactly the right size just get one a little larger and line it with the fuzzy side of a strip of velcro. Or cut a strip of foam from one of those 9x12 craft sheets (also sold at Hobby Lobby - called 'Foamies' I think).
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10" LX200 EMC
ST-80
Atlas EQ-G mount
ETX125PE
Canon EOS Digital Rebel 300D [unmodified]
Phillips SPC900NC [unmodified]
Meade DSI 2 color
Homebuilt Portable Power Supply
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Matthew Ota
scholastic sledgehammer
Reged: 04/30/05
Posts: 967
Loc: New England
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I used to work in the sign industry. "Sintra" is a commercial substrate made from PVC (polyvinyl chloride) I have used it in the past to make solar filter cells and Hartman masks and it works great.
A local sign shop with a plotting table can probably cut your mask faces far less than what a laser shop would do. The sign shops can accept vector formats such as CDR and EPS also.
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Matthew Ota
Meade LX250GPS 10 inch SCT (Frankenscope)
Orion ED 80
ETX-90 OTA
Coronado Helios 1 H-alpha
TheSky 6 Pro
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Darren1968
scholastic sledgehammer
Reged: 02/04/05
Posts: 778
Loc: Ontario, Canada
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I finally got the opportunity to try my Bahtinov mask the other night and what a difference it made.
The top image is when I thought that I had good focus, using my old method, and the bottom image is what I got using the mask.
I want to say thanks to Adam, for originally releasing the vector diagram of his mask. I took your example and resized it for my 80mm scope and then cut it out of foam board. While some of my cuts are not that pretty, I think that the mask worked great.
One question I do have though, is that in looking at others focused star images, with the mask on, you can see a "block" of light near the nucleas of the star for each light ray. This is absent from my start test images. I wonder why 
Darren
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GSO 8" f/4 Newt.
Skywatcher 80ED Pro
Meade ETX-125 5"Mak
Mount: EQ6 Pro
Canon 300D
homepage: http://home.cogeco.ca/~dpursel
ToUcam Pro II
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anat
sage
Reged: 06/03/04
Posts: 235
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My Bahtinov mask is probably the smallest one here 
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Astro-physics 155EDT
Borg 60ED
Losmandy G11 Gemini
Hypermodded Canon 450D
LVI SmartGuider
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