barlow lense

[jamest47]

could someone give me some advice on the best barlow lense for my scope. Im looking for a good lense to view jupiter.

[John]

Is your scope the 90mm maksutov type or the refractor ?

Google seems to show me both types with that model

It will affect the answer to your question you see !

[littlebeagle]

I've been using this one Revelation Astro 2.5x Barlow Lens

Found the views when combined with my 25mm eyepiece better than using my 10mm eyepiece alone.

I'm using a skywatcher 200p and the standard eyepieces that came with it.

[jamest47]

thanks for the reply

its a refractor type. Do i need to buy the Meade barlow or is there better quality ones to obtain?

[John]

OK, the refractor has a focal length of 800mm. A good power for viewing Jupiter would be something around 150x which will need an eyepiece of around 5mm focal length. Your 6mm eyepiece gives you 133x which should be giving decent views of the giant planet. I you got a 2x barlow and used it with a 10mm eyepiece then that would be 160x which would be OK. You can use any brand of barlow you like but the best one in the "affordable" category is the TAL 2x which costs £35.00. There is no point in using too much power on Jupiter as you will just get a large but fuzzy image.

[jamest47]

thanks john

i seen x2 barlow lenses for around £15, am i better buying a good quality one around £35 ?

[John]

thanks john

i seen x2 barlow lenses for around £15, am i better buying a good quality one around £35 ?

To be honest, yes. Optical quality is what it's all about and the Russians (who make the TAL equipment) offer it at good prices. The next step up is around £80 for the Celestron Ultima 2x Barlow.

[jamest47]

ok cheers will get myself a TAL lense

[John]

ok cheers will get myself a TAL lense

My advice assumed that you also have a 10mm eyepiece ?

If not then the 2x barlow lens will be too powerful if used with the 6mm eyepiece.

[jamest47]

just checked i dont have a 10mm, have a 6mm & 12mm

what should i do?

thanks

[glowjet]

If I recall the Meade DS-2090 has quite reasonable optics, if you want a planetary eye piece you could go down the route of purchasing an Orthoscopic 5mm which will give you 160x and although they have a narrow FOV they are an excellent ep, something in the Japanese Circle T range you should be able to buy s/h for £25 to £30 or even better by a small margin, the Baader MC range of Orthoscopics. This could be a less costly solution than a Barlow and 10mm ep combined , just a suggestion as another way round your problem

[jamest47]

thanks, will these lenses give me a better view of jupiter compared to the 6mm alone?

[glowjet]

the 6mm and 12mm supplied with your scope will be of the Plossl design, multi element wide angle, the Orthoscopic is a 4 element unit which although having a narrower field of view gives extra light transmission and high contrast, which makes them popular for planetary work and star study