What do you experts think of this?

[blinky]

3X Barlow lens on Ebay. It says it is Achromatic, should I only buy an Apochromatic one? It is mainly to use with my TuCam for imaging the Planets. I have an 8" Newt that is F5 so this would get it to F15, is this enough for imaging or do I need to get something stonger?

http://tinyurl.com/y5w5gl

EDIT: Tiny'd the URL Daz

[GordonCopestake]

APO is better, especially for imaging. I would hold off on that one to be honest. If it was for visual then it would probably be ok, but imaging no

IMO

[blinky]

You reckon I should save my pocket money for this then?

http://www.firstlightoptics.com/proddetail.php?prod=ae4ximagemate

[GordonCopestake]

If you are skint buy the Tal 3x one for £35, a much better barlow IMO, if you can afford to go up to £70 get the meade APO one, if you can afford to go to £100 get the televue powermate second hand

[Ambermile]

Seems pointless getting an apo one for an achro scope, but the less false colour you introduce the better. There *may* be a 2x 2" Powermate around here soon for about £120...

Arthur

[GordonCopestake]

I might be interested in that Arthur...

[Ambermile]

Not mine I hasten to add. Friend was going to buy it for use with his 16" Dob but he has the balance so fine that if a mouse farts 50 yards away it carousels The PM weighs maybe 22 oz and it would mean "weight on, PM in, EP in, look, EP out, PM out, weight out..." all night. I'll see if it's still around tomorrow evening at Seething for you.

Arthur

[blinky]

So is 2X or 3X enough or do I really need 4X? Sure I also saw a 5X somewhere as well. If 2X is enough there seems to be loads at good prices on ebay etc

[GordonCopestake]

Seems pointless getting an apo one for an achro scope

Not much colour in a newt?

[GordonCopestake]

Not mine I hasten to add. Friend was going to buy it for use with his 16" Dob but he has the balance so fine that if a mouse farts 50 yards away it carousels The PM weighs maybe 22 oz and it would mean "weight on, PM in, EP in, look, EP out, PM out, weight out..." all night. I'll see if it's still around tomorrow evening at Seething for you.

Arthur

The wonders of dobs. Not hurry on the sale, i have to sell a few bits myself to be able to afford anything. Im afraid the aztech is on the market too as i've sold all my refractors seems pointless keeping it

[Ambermile]

What scope do you have? If refractor and you use a diagonal then with a 2x barlow you will get 2x with the EP in the barlow in the diagonal in the focuser, and 3x with the EP in the diagonal in the barlow in the focuser.

With a 4x barlow it would be 4x and 6x respectively.

Arthur

Seems pointless getting an apo one for an achro scope

Not much colour in a newt?

Well nobody told me that...

Which makes the previous staement pointless as well then...

Arthur

PS "Well nobody told me that... " OK, so they did...

[GordonCopestake]

[Ambermile]

:binky: