Bahtinov Mask

[theghettostylus]

Hello! Saw a Bahtinov Mask on Amazon today o e which is for use with a 150-200mm scope would one of these work on a 150p? Or should I get one designed for my scope? Being a skywatcher 150p.

Thanks.

Jason

[Steve Ward]

You can get the mask specific for the 150P from FLO ... (http://www.firstlightoptics.com/bahtinov-focus-masks/starsharp-bahtinov-focus-masks.html) 

Or direct from Keith at Starsharp ... (http://www.morris-engraving.co.uk/bahtinov.htm)

Extremely well made laser-cut masks worth every penny ... 

[theghettostylus]

They are about the same price as the ones on Amazon so may as well go for the one tuned for the scope.

Thanks!

Using live view to focus on stars is not an easy task.

[Steve Ward]

They work better when cut to exact specifications of diameter and focal length rather than the 'one size fits many' approach ... 

[theghettostylus]

I went for the 150p f5 mask! Will just have to use the old liveview focus till it arrives.

Thanks for the advice.

Jason

[Steve Ward]

You're welcome ... 

[piprees]

I reckon it'll be the best thing you'll get, for the price.

People will say that guiding makes the biggest difference, even me, but pound for pound, getting the mask made the greatest difference to my imaging.

Best of luck,

P.

[theghettostylus]

I am very glad I got the mask, focusing is done within a few seconds. Knowing it is more accurate than just by eye is so much better. Definitely money well spent.

[StargeezerTim]

I reckon it'll be the best thing you'll get, for the price.

People will say that guiding makes the biggest difference, even me, but pound for pound, getting the mask made the greatest difference to my imaging.

Best of luck,

P.

Before I got a mask, I would go the the object via synscan, look with eyepiece, then put the DSLR on and spend ages trying to focus with liveview. Moving the magnifying box on the screen right and left, up and down, whilst moving the focuser in and out in an often vain attempt to find a star bright enough to focus on... (also put iso to max and often forgot to change back when imaging...)

Since getting the mask, I do a two star alignment, and after aligning the second, put the mask on, eyepiece out, camera in, focus on the alignment star (Vega and Arcturus are great!) then slew to my object in perfect focus. Do one exposure just to check the the synscan worked (it nearly always does!) then start my series of exposures with confidence...

I know that I could have used an alignment star to focus the camera with before I got the mask but for some strange reason (Dense and daft!), it never occurred to me...

So my £12 mask from Tring Astronomy has been a really useful buy and led to a much more streamlined and sensible setting up process...

[theghettostylus]

I gave mine a test last night and it was fantastic, didn't take any pictures as I forgot to charge the batter on my camera :0 plus it was cloudy anyway but why don't they make small ones to fit on a camera lens? Or would that just not work?

[Steve Ward]

If you give Keith the lens details he'll cut one to the required spec , no lens too small - no 'scope too big ...