DIY solar filter for 150mm newt advice

[palebluedot]

I am about to embark on creating a a filter for my 150P. I have been reading about various designs and have not been able to work out what would be best for my scope.

I have been a bit confused about the optimum aperture. I read that 80-100mm is best. My off axis (built into the tube cap) would be too small in this case and and the whole 150mm too big. Should I make something in between if so should it be off axis or centred? I read small is better so I am reluctant to go for the full aperture especially as I would like a go at imaging.

Any advice, or pointers to threads that I have missed would be appreciated.

[Merlin66]

I'd make the filter aperture as big as the clearance between the spider/secondary/ mirror will allow. - measure the distance from the edge of the secondary to the edge of the main mirror - the maximum off-axis size would be what you measure....probably around 60mm (150-35)/2 =55mm or so

[palebluedot]

Thanks Merlin.

[palebluedot]

I think I'll combine Merlin's advice with Ash's paint kettle design:

http://stargazerslounge.com/diy-astronomer/137388-praise-paint-kettle.html#post1768289

[palebluedot]

Seeing as it was a relatively sunny day, I thought I should do with what I had to hand.

Heath Robinson, eat your heart out!

I got some nice views, tried the webcam but the magnification was far to high, is there any way to widen the FOV?

SLR (20D) was a nightmare to focus, I think I NEED a new cropped sensor camera with live view. However, the wife prolly would disagree.