Dodgy Barlow?

[WinchesterAstro]

I've always been a bit dissatisfied with my scope's performance at higher magnifications (it's a 100mm SkyWatcher Heritage mini-dob). Yesterday, when in daylight I was incidentally checking the alignment of the finderscope, I noticed that adding in the Barlow made views much, much worse. Darker, mushier, softer... just yuk, and tweaking the focus only helped a little. The barlow itself has a fair few small spots of muck on it, but otherwise looked fine.

To me this explains why the higher-magnification views have always been unsatisfying with this scope. The Barlow is the stock barlow that came with it. Would I see a significant improvement in quality if by buying a new Barlow?

Thanks in advance.

[Cosmic Geoff]

19 minutes ago, WinchesterAstro said:

Would I see a significant improvement in quality if by buying a new Barlow?

Not necessarily. If you were using a kit eyepiece of 9 or 10mm focal length for the higher-magnification views, this would explain the poor performance, as these eyepieces are not much good and should be replaed by something better. 

I bought a Celestron Omni barlow lens to replace a kit Sky-watcher Barlow and found there was no difference at all.

A daylight view would inevitably be darker at higher magnifications, and the 'seeing' would also affect the view.

[AstroKeith]

That scope is an f4. That is fast and will a) require excellent collimation, and b) good eyepieces.

The EPs provided wont be very good (it really is a budget scope) and I'm not sure it would be worth spending much more on better ones?

Main thing is to check your collimation is spot on.