Bahtinov mask - worth while?

[idlelimey]

Hi All,

Would a Bahtinov mask be worth while if I'm not imaging? I saw one on eBay for £15 and wondered if I'd see any use of it for just visual observing?

Many thanks!

[beamer3.6m]

FLO sell these for about the same price (if not the same) as on Ebay just to ensure quality.

[Stephen]

FLO sell these for about the same price (if not the same) as on Ebay just to ensure quality.

If you are talking about the star sharp ones, they are the same thing - made by Keith Morris IIRC

I own two and use them all the time, but not for visual

[idlelimey]

Actually, just found this while looking in to other mask types:

Hatmann Mask

Might give it a go making my own one first. If it gets used I'll buy a manufactured one.

Does anyone have any experience with different types of focus mask? Bahtinov, Carey, Hartmann - any others?

[cgarry]

I have a Bahtinov for each of my scopes, they are fantastic. I would not bother for visual observing though.

Personally I would order direct from Keith via his eBay shop, he usually gets in touch to make sure you are getting the correct one for your scope. Fantastic service and it saved me from getting the wrong mask for my WO Z80FD.

Cheers,

Chris

[Photosbykev]

For imaging they are worth their weight in gold, for observing I can't see any worthwhile benefit in using them.

[idlelimey]

Thank you all, I think I'll go ahead and build one anyway (just for the laughs) and when the time comes that I get around to imaging I can buy one.

Thanks for your help, everyone here is always so quick off the mark!

[ollypenrice]

I never found the Hartmann useful but for imaging the Starsharp ones are tip top.

Olly

[Demonperformer]

I just use homemade Y-masks for focussing - simple and cheap to make and they let in more light so the image is brighter and easier to focus.

[beamer3.6m]

Can I ask a stupid question:

Do you have to use a star to focus with these or can you use a planet, such as Saturn. I just want to check that the shape of saturn (i.e the rings) will not cause problems.

If not I will bet getting one of these today.

[cgarry]

I has to be a star, a planet is not a point source and does not work.

Chris

[beamer3.6m]

So can these be useful for planetary imaging with webcams and if so how would you go about focusing?

[FLO]

FLO sell these for about the same price (if not the same) as on Ebay just to ensure quality.

If you are talking about the star sharp ones, they are the same thing - made by Keith Morris IIRC

I own two and use them all the time, but not for visual

Yes, Keith makes the StarSharp Bahtinov masks offered here at FLO. He has appointed FLO his only UK retailer. It is an arrangement that is working very well for us both

Keith's Ebay store is still open, there is no difference in price.

Steve

[WWPierre]

So can these be useful for planetary imaging with webcams and if so how would you go about focusing?

You would focus first on a bright star, then move to the planet.

With high magnifications, the focus sweet spot gets very small. I use my Bahtinov to attain best focus sometimes when observing.

[PRG]

I used this website to print out a Bahtinov mask. You have to enter the focal length and aperture of your scope and it generates a pattern to print out. I tried this yesterday, glued it onto some card and then spent ages cutting out the slots. had a go with it last night and was amazed that it really does work, really useful for imaging. If I use it alot I'll probably invest in the FLO/Kieth Morris one.

You definitely can't use it on Saturn, I tried, just to see, and you get multiple images of Saturn.

[ollypenrice]

If I focus on a star and then go to a planet I can refine the focus. I have never understood why since they should both be at infinity. I haven't tried using a star at just the same altitude and must do so. Anyone?

Olly

[Macavity]

With video imaging, I use the non-integrating (instant) mode and a bright star. Fine tuning on a faint star, with the inevitable delay of integration, is less fun. I want to try out the GRADUATED scale of my small helical focuser though... I sense it might be used to profit.

[Mister-t]

I used this website to print out a Bahtinov mask. You have to enter the focal length and aperture of your scope and it generates a pattern to print out. I tried this yesterday, glued it onto some card and then spent ages cutting out the slots. had a go with it last night and was amazed that it really does work, really useful for imaging. If I use it alot I'll probably invest in the FLO/Kieth Morris one.

You definitely can't use it on Saturn, I tried, just to see, and you get multiple images of Saturn.

If you know anyone seriously into card making they may have a cutting machine. A work colleague done mine from a tiff image file. the results were impressive. see photo.