Another Barlow question (sorry)

[DaBozUK]

I didn't want to post a barlow question, as there have been so many already, but I read through many posts with Barlow in the title, and I am left confused.

I see that 250x to 300x mag is probably the limit of what is useful in typicaly viewing conditions. So for my Konusky 200mm newt reflector (1000mm tube f/5) with the supplied 10mm and 26mm eyepieces, I guess a 2x barlow is what I should aim for.

But, should it be a 2" or 1.25"? does it need threaded lens? because I have a fast scope, how much should I spend...?

Added to which, I'm not happy with my 26mm eyepiece, as it seems to distort objects as you position your eye around the eyepiece (saturn is almost impossible to see as a single crisp object).

And so I'm confused. Any guidance to an appropriate barlow for my setup would be much appreciated.

Boz

[kniclander]

I would say you are better off buying one better e/p than barlowing the probably not grat supplied e/ps.

just MHO

[DaBozUK]

Ok, in that case I have absolutely no idea where to begin now. I look at websites with eyepieces on and I have no idea if they are suitable or not. I read the sticky and seem to be the only one who found it confusing. I think I want something between 5mm and 35mm, and with wide FOV but not too wide as my pupils don't dilate very well.

Feels like I've hit a brick wall with my new hobby. I'll put up with what I've got until some revelation occurs, or it puts me off entirely.

[swamp thing]

Hi Boz

IMO you should buy the best 2" Barlow you can afford. There are two reasons for this:

1. You may swap and change eyepieces throughout your hobby but a good 2" Barlow will be in your eyepiece case for life.

2. You cannot use a 2" eyepiece in a 1.25" Barlow and the 2" low power eyepieces are the ones you'll want to Barlow to keep that comfortable viewing that they give.

You can however use 1.25" eyepieces in a 2" Barlow.

Buy cheap and you'll be buying again!!

Regards Steve

[Andrew*]

I'm sorry you found the guide confusing. It's quite a complex subject, so don't worry if it takes a while to understand.

The supplied eyepieces are not be so good as you have found out. Upgrading these in conjunction with buying a barlow would be a good idea and set you up nicely for observing.

As you have also worked out, 5mm would give a good maximum power of 200x and around 35mm a sensible minimum of around 30x.

If you want to stay on a budget, I think a good quality 1.25" 32mm plossl eyepiece for 31x (and 63x with a 2x barlow), and a 10mm plossl for 100x (and 200x) would give you a good spread. As for brand, the Meade 4000s might be a good place to start.

For barlows, the Tal 2x is very good for its low cost.

I hope that helps you a bit. If you could be more specific about your budget, we can try and suggest good brands.

Andrew

[DaBozUK]

Great advice guys, thanks. I also found another sticky in the primers forum which explains eyepieces in a more consistent way and that's helping.

I can probably afford £60 on eyepieces for now, so will try and find something that fits above in that range. Is that achievable for an f/5?

[brantuk]

As mentioned above the Tal 2x is a great vfm buy. In the price range you're thinking of a Celestron Ultima (or Orion Shorty) 2x are around £85 and most popular - I got one s/h for just over half the retail in prime condition and very pleased with it. Not seen anything better under £100. Hope that helps

[DaBozUK]

How annoying, the TAL barlows are sold out everywhere and not in stock until late summer.

At £30 to £40, the were within budget. Is there any other make that is comparable for similar price? The celestron ultima is too expensive at £80.