Aperture Mask for 16" f4 dobsonian

[Stu]

Agreed on the 3 to 6 nagler zoom. It's a brilliant ep and it's very nice to be able to just leave one ep in the scope pretty much all night when viewing planets. In my 4" it gives from x115 to x230 which is ideal, and the 50° fov is never an issue on high mag/small targets

Stu

[swamp thing]

Might try this with my 250mm see what the results are like.

This would be the mixed results I mentioned.

I masked down my 16" and found at around 6.5" it deffinitily improved the planetary images on nights where the seeing wasn't the best.

However when I mask my 10" down to around 4" the loss of resolution makes it...well IMO just not worth it. On nights when the seeing makes using the 10" hard work I simply pick low resolution targets.

Be interested to read your findings with your 10":)

Regards Steve

[Adz]

Could I ask your opinion guys on my scope?

I find when viewing Mars atm its surface brightness is too high, even in my 8" dob. I have tried using with the front cap and little removable hole but this cuts way too much light out.

I was considering a baa neo filter instead...

[David Smith]

Love my Baader Neodymium, works really well on Mars at the moment. Not sure how I managed all this time without it!

[swamp thing]

Could I ask your opinion guys on my scope?

I find when viewing Mars atm its surface brightness is too high, even in my 8" dob. I have tried using with the front cap and little removable hole but this cuts way too much light out.

I was considering a baa neo filter instead...

Hi Adam

I have read that some think stopping down an 8" (or even smaller) is worthwhile but I'm far from convinced.

Why not make an aperture stop/s out of cardboard it'll give you an idea of whether you think it's worthwhile or not.

If its worthwhile then make one out of something more permanent.

You may well find the filter of considerably more benefit. I cannot advise on this as I don't use one (not much of a planet observer). Maybe one day.

Regards Steve

[Adz]

I shall do that an experiment Steve

At the moment I want to make the most of Saturns opposition and that effect that makes the rings brighter because of the shadows.

Steve do you use a UHC or OIII with your dobs?

[swamp thing]

You obviously mean for nebulae. I use an O-III, I sold my UHC a while, back wish I hadn't and still had both.

The UHC is a good filter I just needed some cash at the time.

I do prefer the more aggressive O-III though if I had to chose.

Regards Steve