Barlows

[Ryohei]

Hi. I'm a newcomer to the forum, and more or less a newbie at serious astronomy.

I recently bought a Skywatcher 150PL, which comes with a couple of lenses and a 2x Barlow. The strongest lens is 120mm, which with the Barlow gives a mag of 240x. Now, from what I've read , there seems to be a maximum mag (giving good results) of equal to twice the width of the mirror in mm. As my mirror is 150mm, I take that to mean the maximum mag would be 300x.

My question is this: would I get away with using a stronger Barlow? I see there are 3x and even 5x lenses available, which would give a maximum mag of 600x, i.e. about twice the suggested "best" level. I'm quite happy with the mag I have for lunar observation, but when I viewed Saturn a few weeks back it was quite small and no surface detail was apparent, although I was able to see the rings clearly.

Would the 5x produce an unacceptably fuzzy image? If so, could I still get adecent enough result with the weaker 3x?

I hope you will be able to give me some advice, before I commit to buying one or the other.

Thanks

[swamp thing]

Hi

IMO the 240X that you have is probably as much as you'll need for the Planets.

It's very seldom that seeing allows any higher power to be used.

I hardly ever use much over 300X even in my 16" scope.

I think the 5x Barlow is mainly aimed at the imaging market.

The 3x although usable with some of the longer focal length eyepieces is not as versatile as the 2x.

Seeing detail on the Planets takes patience and practice not high power.

The brilliant sketches of fine planetary detail that you see on this forum are the result of hours spent at the eyepiece learning to see fine detail.

The only way to see fine detail is to keep looking.

I would stay with the powers you have and just keep observing, you will be surprised how much detail you can pick out after a bit of practice.

Good hunting and clear skies.

Regards Steve

[John]

Have to agree with Steve on this - I doubt you will usefully use 300x very often so 600x would be a bit of a waste of time.

I find I've been using 180x for the most satisfying views of Saturn lately with my 6" mak-newtonain.

[mag10]

I can vouch for seeing getting better with practice.

I know its counterintuitive: Same equipment, same conditions (say), same eyes.

How could my eyes get better just by looking?

I don't know why or how, but its absolutely true.

[tony69]

Hi. I'm a newcomer to the forum, and more or less a newbie at serious astronomy.

I recently bought a Skywatcher 150PL, which comes with a couple of lenses and a 2x Barlow. The strongest lens is 120mm, which with the Barlow gives a mag of 240x. Now, from what I've read , there seems to be a maximum mag (giving good results) of equal to twice the width of the mirror in mm. As my mirror is 150mm, I take that to mean the maximum mag would be 300x.

My question is this: would I get away with using a stronger Barlow? I see there are 3x and even 5x lenses available, which would give a maximum mag of 600x, i.e. about twice the suggested "best" level. I'm quite happy with the mag I have for lunar observation, but when I viewed Saturn a few weeks back it was quite small and no surface detail was apparent, although I was able to see the rings clearly.

Would the 5x produce an unacceptably fuzzy image? If so, could I still get adecent enough result with the weaker 3x?

I hope you will be able to give me some advice, before I commit to buying one or the other.

Thanks

hi and welcome have you used you scope yet if so what have you seen ?.

[Ryohei]

Hi

Thanks for all the helpful advice & suggestions. I reckon you've saved me from making a potentially expensive mistake or two!

@tony69 - not all that much, given the generally **** weather recently (and the lightness of the sky when it is actually clear). I did manage to get a look at Saturn a couple of times though before it drifted a bit too far west. The Moon was also nicely visible against a darkening sky, around 5-6 days into the current cycle, and I actually got a photo or two, by the crude method of holding my SLR to the eyepiece and clicking. Might have to convince my other half I need adapters now....

[Adamski]

Hi. I have the same scope as you and after some practice i am able to see some surface features on saturn and jupiter along with some of their moons. I soon learnt that checking collimation helps, although it takes a while at first, but once performed on the whole scope it takes only a minute to check periodically. Averted vision is another trick of the trade which can help, especially on dso's. Enjoy.