Bahtinov focus mask

[simmo39]

I have just ordered a Bahtinov mask as Im not convinced Im getting the best focus that i can. My question is: Can you put the mask over your dew shield or do I need to put it directly to the scope? Just trying to save messing about removing and refitting dew shield. ( a bit lazy I know).

[mitchelln]

It should be fine on the dew shield

[simmo39]

Thanks for the quick reply. Will give it a try as soon as I can.

[todd8137]

I do both ,but usally take the dew shield of first but thats just me but on my large frac i usually leave it on

[jnc71106]

if it was me i'd remove the dew shield then use the mask but then i'm fussy

[simmo39]

Well I supose i will have to give it a go both ways then. I will let you know what I find.

[Psychobilly]

I nearly always used mine on the end of the dewshield...

Badly typed on my Galaxay S4 in Tapatalk4

[Spikey]

Never removed the dew shield whenever I've used mine and my focus is always fine.

[todd8137]

I found when use in the dew shield i always forgot to take it of

Pat

[Russe]

It's fine on the dew shield.

[JamesF]

I did wonder this myself when I started using one on my Mak 127.  I reasoned that it works happily for refractors with fixed dew shields, so it shouldn't be a problem if I didn't remove the dew shield on the Mak and just rested the mask on the end of the shield.  As far as I've been able to tell it's worked just fine.

James

[Velvet]

always over dew shield and had no focus problems

[rwilkey]

I always hang mine on the dew shield - does the same job either way.

[glowjet]

And do not worry about the mask being central on the aperture either, it does not matter if it is slightly off, the resulting refraction will always appear on the central axis of your scope

[mitchelln]

And do not worry about the mask being central on the aperture either, it does not matter if it is slightly off, the resulting refraction will always appear on the central axis of your scope

Mine seems to tolerate a surprising degree of error. I once found it had slipped off one of it's pegs leaving a large gap, but still worked fine!

[nightfisher]

On my 180 mak i take dew shield of, but then its a very long dew shield!!

[simmo39]

Well got my mask and gave it a go with dew shield on and off. Dont think it matters, but it does make focusing at higher powers a breeze.