MAK127 to 150pd-s - the right move?

[BargeGazer]

I am currently using a Starmax 127 Mak which has a lot going for it as a compact travel scope. But it has a horrible focuser and a slow F-number.

I am thinking of moving up to the Skywatcher 150pd-s

Will the extra 25mm or so diameter give me a boost in visibility and usability (cool down time, focussing) as well as being a bit more astroimaging-friendly (speed)?

I shall use it on an HEQ-5 so I think this should not be worried by the weight of the OTA even in imaging mode.

David

Opinion seems to be divided on the compatibility between this mount Ang the larger 200pd-s. Is this correct?

[pete_l]

1 hour ago, BargeGazer said:

Will the extra 25mm or so diameter give me a boost in visibility and usability (cool down time, focussing) as well as being a bit more astroimaging-friendly (speed)?

The size difference will be unnoticable - both for eyeballing and imaging. However the change from a (what?) F12 to an F5 will make targets such as galaxies and nebulae much smaller but brighter. Planets will be a lot, lot, smaller but stars will be the same. Sky backgrounds appear darker with longer F-value scopes.

Focussing will have to be more precise with a lower F-value and your field of view will be larger. Though, as mentioned that means the actual objects you wish to view will be smaller.

[Wpit]

14 hours ago, BargeGazer said:

I am currently using a Starmax 127 Mak which has a lot going for it as a compact travel scope. But it has a horrible focuser and a slow F-number.

I am thinking of moving up to the Skywatcher 150pd-s

Will the extra 25mm or so diameter give me a boost in visibility and usability (cool down time, focussing) as well as being a bit more astroimaging-friendly (speed)?

I shall use it on an HEQ-5 so I think this should not be worried by the weight of the OTA even in imaging mode.

David

Opinion seems to be divided on the compatibility between this mount Ang the larger 200pd-s. Is this correct?

I agree the focuser is pretty bad. I had to add a piece of pipe insulation to make a larger easier to control focus knob. The inner hole for the pipe is a perfect snug fit for the existing knob and no need for glue. Give that a try but it sounds like you need to look for more than 150 to make a difference and go for a more precise 2 speed engineered focuser. I think the scope manufacuturers have this in mind when they sell the scopes with poor standard focusers.

Edited July 10, 2017 by Wpit
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