Pre-made Bahtinov mask worth it?

[redneon]

I'm considering buying a pre-made acrylic Bahtinov mask like this one: Pre-made Bahtinov mask. I was just wondering if anyone else had done this and whether they thought they are worth the money?

They seem quite expensive for something I could just make myself, though. The thing is, I don't have easy access to a printer and it seems like a faff to transfer them onto card which are even then susceptible to the elements.

[RikM]

I have two of these starsharp masks http://www.firstlightoptics.com/bahtinov-focus-masks/starsharp-bahtinov-focus-masks.html and they have been some of the best things I purchased for astroimaging. If only for visual use, then I wouldn't bother but for imaging, focus is critical. Most other things you can fix in post-processing, but if you are out of focus, you are stuffed! One of these masks in the right configuration for your scope, together with Bahtinov grabber software, makes getting good focus a breeze.

[nightfisher]

I have a starsharp mask for each of my scopes, they are a superb tool for any kind of imaging, and very handy for visual as well, for what they cost i feel they are very good value

[nephilim]

I must stop reading recommendations for things, been thinking of a mask for a while since it can take forever when im trying to capture the moon/Jupiter etc. One mask ordered from FLO.

[redneon]

Excellent, cheers. Looks like I'm ordering one too

[Bizibilder]

I cut my own from plastic sheet (A4 folders from Tesco at around £1 each - you get at least one and maybe two masks per folder!) and they work a treat and they are waterproof! They only take a few minutes to make with a sharp scalpel and steel ruler.

[Stargazer Jack]

I ordered one from FLO and they are worth the money

[SteveNickolls]

Few things work as well as a Bahtinov mask.

Cheers,

Steve

[ollypenrice]

Another Starsharp fan. I usually do final focus in FWHM but I get within a gnat's crotchet with the mask. Quality is superb.

Olly

[redneon]

Another Starsharp fan. I usually do final focus in FWHM but I get within a gnat's crotchet with the mask. Quality is superb.

Olly

What's FWHM?

[Pete Presland]

What's FWHM?

it's to do with the histogram i think

http://www.detectors.saint-gobain.com/uploadedFiles/SGdetectors/Documents/Technical_Information_Notes/FWHM-Analysis-Arbitrary-Peak-Shape.pdf

[RikM]

FWHM is a measure of the Full Width at Half Maximum hight of the brightnes profile of your focus star. Basically, the software plots the brightness curve and the narrower the width (lower the number) the sharper is your focus. It works very well indeed when the seeing is good but I find with my sky conditions (housing estate in Glos.) that the numbers jump around quite a bit between focus exposures, so I never know quite when I've reach the lowest number. With Bahtinov grabber software you get a clear indication on screen of when you are within the critical focus distance for your specific telescope. So I find it much faster, less stress and I get results at least as good as when I use FWHM.

[springbok]

Another Starsharp fan here, very robust and will last a long time.

[Brent]

Yes, FLO's Starsharp masks all the way for me as well!

It makes focusing a cinch so you can spend your time doing other things

[redneon]

Got mine through the post today so I'm keeping my fingers crossed for some clear skies later...