SW150PD

[A320Flyer]

Hi folks

I own a SW150P which I use with a ZWO183MM Pro/Filter Wheel/ Baader MPCC. With the correct 55mm spacing to the CC, I need to rack in the focus tube to get focus. This means I get horrible little “nibbles” taken out of my stars where the focus tube interferes with the light path. I’m thinking of “upgrading”to the 150PDS as I understand that the primary mirror is set nearer the focus tube to avoid this. Can anyone confirm? Will I still get the “nibbles” with this combination?

Thanks

Bill

[Ronclarke]

You won't, you are right with saying the PDS model has the mirror nearer so no 'racking' in needed..

Good luck

Ron

[alacant]

29 minutes ago, A320Flyer said:

nibbles

Hi. Same on my 130pds. Easiest way is to saw off 10mm of the inner focuser barrel where it enters the light path.

HTH.

[R26 oldtimer]

I went with a bresser 150/750 newtonian, after reading about focuser protruding issues in the 130pds. It seems to me that is better built than the pds series with it's massive 2.5" r&p focuser. Used with a DSLR the focuser protrudes about half a centimetre in the telescope tube without entering the light path. I am also under the impression (not sure though), that it comes with a slightly bigger secondary than the 150pds.

Overall, I would say it's a very nice alternative to investigate.

[A320Flyer]

Hi guys. Thanks for all the responses. In the end, I simply removed the collar on my mpcc which allows it to be pushed further down the draw tube. To now get focus I have to rack the draw tube out a bit which has cured the nibbles. 

Bill