Improving a 6" refractor

[slippo74 (Cristiano)]

Hi all, hope you guys are having a wonderful 2010!

I got a new scope...I know, it is not an APO triplet but I'm very happy and it is delivering very nice view, in specific cases even better than my main scope. Let's get to the point of my post.

Question 1:
As it is an achromatic refractor I'm dealing with colour fringing on bright objects, not really that much but it still an issue.
Have you guys any personal experience with Chromacor or V-Block filters? Are they really good as per their are promising?

Question 2:
Also, I absolutely need to change the focuser.
Any recommendation beside the expensive MoonLite and similar?

The model that I got is the Skywatcher 150x1200 pictured below:



Always thanks for any input

Cheer, Cristiano.

[TheDecepticon]

Wow, picture 1 is a happy boy with his new toy!! What a monster!
There are some other filters around, I think Baader doone that seems ok, but I have never come across a review.
This isn't the one I was thinking of, but there is one review for it, which I've not included.

http://www.optcorp.com/product.aspx?...-1155-859-8917

[Omaroo (Chris Malikoff)]

Hi Cristiano - and congratulations of your new acquisition

V-block or "minus violet" filter (various brands) do work to a degree in canceling out the purplies, but at a cost. Any filter will restrict light transmission, and in this case the image can be noticeably dimmer with one in place. Given that - they do work.

[miki63au]

G'day Cristiano, nice collection of goodies!

I think Baader "semi-apo" filter is the best bet, however I don't have experience with that. At CN refractor forum people saying this is the filter which has the minimum colour shift effect.
Regard of chromacor, I think the economy of the achro diminish rapidly
because of the expense of the corrector. On top of that you really need to evaluate the spherical aberration to get the correct conjugate.
If you find your achro has a zonal error, the chromacor is not correcting for that.
If you want to make it sharper, and you brave enough to thinker,
the Fraunhofer doublet can be optimised by changing the gap between the elements. This is the most crucial for spherical aberration, and if you optimise it with the green filter the reward is well worth it. Again it must have a smooth figure!! If it has a zonal error or astigmatism just live it as it is, and use it for low power wide field.

Cheers,
Mick.

[lacad01 (Adam)]

Hi Cristiano, nice equipment for sure
With regards to focuser have you looked at the GSO Crayfords? Have a look at Bintel or Andrews under their ATM or accessories sections.

[bobson (Bob)]

Hi Cristiano

I was planing to get something like that for a while. Could you please give more details on this part:

I'm very happy and it is delivering very nice view, in specific cases even better than my main scope.

Thanks mate

[Satchmo]

Originally Posted by slippo74

Question 2:
Also, I absolutely need to change the focuser.
Any recommendation beside the expensive MoonLite and similar?

The 96mm ID GSO Crayford focusser suits ( $199 )
I have an Orion V Block but find the views more satisfying without it ( I like to see the stars looking white even if the brighter ones have a bit of violet fringe).

[slippo74 (Cristiano)]

Hi guys... you are wonderful as usual!!!
Thanks a lot for your advices, very informative.
I believe I'm going to try one of the V-block filter for now (saw something cheap from Orion or so). In regarding the focuser, well I need to check again with Bintel or Andrews and see if I can get something locally without order overseas.

Originally Posted by bobson

Hi Cristiano

I was planing to get something like that for a while. Could you please give more details on this part: "I'm very happy and it is delivering very nice view, in specific cases even better than my main scope. "

Thanks mate

Hi Bob, look... I always wanted to get a large chinese refractor even considering the attractive price. My expectations were of course not such great but I have to say that this scope is fantastic! Images are really sharp and the contrast is very very good. Planets like Jupiter or Mars are a pleasure when in the eyepiece and large objects as some of the extend nebulas can be seen without issues... double stars are great, with Moon I've pushed till 340X with no problem. Of course it is not perfect (focuser and included diagonal are not great quaility and needs to be replaced) and you will be a bit disappointed with colours fringing if you already own an APO.

However those kind of scopes are really generous in performances, easy to set and their huge aperture it is a strong vantage.

Hope this helps (sorry my english sucks)

[DavidU (Dave)]

I loved my 150mm x 1200 Achro. I think the Baader Neodynium filter is good.
I actually don't mind the violet fringes. Also, these scopes when collimated and centred well give great pin point stars, a real bargain these days.

[bobson (Bob)]

Thanks Cristiano, thats the info I was looking for. On the picture you posted is that 10" or 8" Meade? Looks like 10 but its hard to say. So this refractor would give better views on the planets and moon than that Meade? I am asking because I remember one member from here has 12" Dob like mine and he said his refractor 150 mm Skywatcher beats 12" Dob any time on planets and Moon.


cheers

[slippo74 (Cristiano)]

Originally Posted by bobson

Thanks Cristiano, thats the info I was looking for. On the picture you posted is that 10" or 8" Meade? Looks like 10 but its hard to say. So this refractor would give better views on the planets and moon than that Meade? I am asking because I remember one member from here has 12" Dob like mine and he said his refractor 150 mm Skywatcher beats 12" Dob any time on planets and Moon.


cheers

You are welcome Bob... in the pic you can see an 8" Meade LX90. I can ensure you that on Moon and planets the 6" refractor is performing far better. Of course I'm talking about what you see in the eyepiece with no references to imaging.

Cheers

[duncan]

Hi All,

So how does the 6" Refractor stack up against the 8" Meade for Photo's of the planets,Moon, and Deep sky?

This will be an interesting one.

Cheers,
Duncan

[strongmanmike (Michael)]

Hi Cristiano

A few years ago some friends and I had one of these scopes of yours side by side with my Astrophysics Starfire 6" APO and after observing several objects and comparing side by side those present all agreed that the views through the AP were indeed slightly superior but we were all surprised at how close it was considering the vast difference in price.

I think for deep sky astrophotography it may have some slight limitations but for visual I think you have a winner

Mike

[M_Lewis (Mark)]

I own the 150mm ST version (750mm focal length) of your scope, and have the V-block filter. You can see noticable difference in the halo by using it, to the point where in some cases it is not noticeable, and with the moon for eg, I see no purple at all.

I agree with the comments on deepsky, some things are definately a challenge, but like all things considered, it's about how dark and unpolluted light you can find which will be the biggest influence on the performance.

The focuser whilst course is solid, I found after a few outings it was a simple case of getting used to, as it's nothing like my Mak, rather a different beast.

Cheers

Mark

[slippo74 (Cristiano)]

Hi guys

Ok, well... after all your great advises and comments I decided to give a try to a V-block filter and moved on a not expensive solution from Orion.
Instead and in regarding the focuser it was a bit more challenging situation.
Quite hard to find something that I really like it. Most of the focuser available in the local stores are not having the finderscope dovetail attached to the top part like the focuser that comes originally with the scope. So I had no choice (such good excuse) than to order the Moonlite CF ...



Cheers, Cristiano

[DavidU (Dave)]

Mate ! Awesome bit of kit !

Originally Posted by slippo74

Hi guys

Ok, well... after all your great advises and comments I decided to give a try to a V-block filter and moved on a not expensive solution from Orion.
Instead and in regarding the focuser it was a bit more challenging situation.
Quite hard to find something that I really like it. Most of the focuser available in the local stores are not having the finderscope dovetail attached to the top part like the focuser that comes originally with the scope. So I had no choice (such good excuse) than to order the Moonlite CF ...

Attachment 70975

Cheers, Cristiano

[bobson (Bob)]

Wow that looks good man!

bob

[dcalleja]

He sure looks happy!