This is my Toucam, this is my Scope

[AstroTiger]

Hi guys

me again, i bet ur getting tired of hearing about my new toucam, sorry

But i have a question to ask.

My telescope i bought from ebay, its a strange one, with mods now.

I added brass screws for easiler collimation.

The thing is there is a lense at the end of the draw tube. Someone told me its cos of the focal length, a means of extending it. The focal ratio is 6 so its a fast focus telescope.

The question i have is, will i need to stack barlows to make this work with the toucam?

Thanks for advise

Al

[The Warthog]

Some short-tube scopes have a barlow at the end of the drawtube. this is to make them behave like a longer focal length scope. You can add a Barlow to this system, and double or triple it again. You can always stack Barlows. I wonder what would happen if you took the lens off the bottom of the drawtube in these scopes. Would you have a rich-field scope with a very short f/l?

[Naz]

Speaking from experience, I don't think that the barlow will do much for you on that scope, i have a similiar scope, and using a barlow even with a 20mm ep, the image is Rubbish.

The way that i understand these scopes to work, is with a spherical mirror, and to use a barlow to correct the light path.

You would be trying to put another barlow in the system, and unfortunately planetry imageing would be an no no. You should be ok on wide field images, if the camera can be focused, only trial and error will tell.

What is the make of your scope? Did it come with any paper work / manual?

nabban

[AstroTiger]

oddly enough no

I bought it from ebay as it was cheap, only intending to use it for the time being.

It is a six inche newtonian

Has the lense at the end of the drawtube, i need to take it out to collimate though. Bit of a pain.

It is ok for the planets, have had some decent views from it.

I need to get to know it better really.

As Bob Marriott was saying last night over a pint, its as imprtant to know ur scope as it is to know ur car.

I am graudally buying more for it, the toucam being the latest investment. See how it goes

She does need a motor though, but then i will have to look at polar alignment for that ;-(

We'll see how it goes i guess. I personally though don't think it wil be long before i get rid in favour of another instrument

Al

[MartinB]

If that lens is acting like a x2 barlow that will give you F12. You could increase to F24 with a x2 barlow. This will probably give better results than F12 but you will need good seeing I guess. Trial and error I suppose.

Martin

[AstroTiger]

i think warthog is right about the lense at the end being a barlow,

Yes i have tried removing it but i am then unable to focus properly. So the lense is def needed.

I have had some decent images out of the telescope, and am particualy looking forward to imaging the moon as well.

I will keep you posted as to my results.

Al

[Naz]

I think you will have to experiment with your set up, I would suggest just useing it visually at first to see what the effects of the barlow. You should try this on a good night on fairly bright objects at first, before trying the fainter DSO's

All equipment has limits, it's just finding those.

Is there a local Astro Club in your area? They would be worth talking too, someone there would be able to look at your set up and advise.

But please keep asking here as well.

nabban

[lunator]

Al

This scope needs the corrector as part of the opitcal path.

You can use a barlow with the scope.

My main issue with scopes like this is that there is an additional element in the optical path that absorbs light and can be an additional source of aberations etc.

Us the scope for now but to get the best from your ToUcam I would get another scope that does not have a corrector.

Regards

Ian

[AstroTiger]

thanks for that lunator,

I did wonder if it was a build in barlow, obv not. As i say i cannot focus on anything without that lense being there.

TB honest i am prob going to get what i can from it with the webcam. I cannot collimate the scope easily without removing the lens first.

To assist with this issue i also purchased a site tube.

We'll see what else can be achieved.

Though looking at prices of other instruments it won't be long before i upgrade :-)

Al