smaller lenses.

bogwalrus

came home from work at 2am last night. saw the stars were out and that saturn was in view in my line of sight from my house (for once).

Out comes the dtg and i was blown away by what i saw. The rings and everything.

I used a simple enough 12.5mm lens.

What would be a good recommendation on a smaller lens. maybe 6mm??

Any good makes or links.

thanks

Clif7

bogwalrus wrote: »

came home from work at 2am last night. saw the stars were out and that saturn was in view in my line of sight from my house (for once).

Out comes the dtg and i was blown away by what i saw. The rings and everything.

I used a simple enough 12.5mm lens.

What would be a good recommendation on a smaller lens. maybe 6mm??

Any good makes or links.

thanks

Whats the focal lenght of your scope bogwalrus? Then you can work out the magnification for each eyepiece and narrow down your options.

Formula (if you don't know already) is:

Scope Focal Length divided by Eyepiece Focal Length

The few DTGs i've seen have been around 1300mm focal length, so I'll use that as an example.

1300 divided by your 12.5mm eyepiece will give you 104 X magnification.

The 6mm you mentioned would give nearly 217, which will give awesome images of saturn.

A 4mm would give 325... serious images!!

The only issue I find with high mag eyepieces is the size of the hole. It's not easy looking into a 4mm hole if you are not used to it. 6mm is a lot easier but still takes a bit of getting used to if you are used to something a lot bigger!

Have you considered a barlow lens? A good 2X barlow and your 12.5mm piece will give roughly the same mag as a 6mm piece. Barlows do add an extra piece of glass for the light to travel through though, which will effect your image a bit... pros and cons i guess.

There are loads of good eyepieces out there. I use celestron omni eyepieces and a few x-cels myself but there are tons of great ones. E-bay is great for small items like these (cheap postage too), just make sure you are getting the real deal though and not a sh!t copy.

If you want to buy in person, I know Conns Cameras in town were selling off their telescope stuff at really low prices. WAY cheaper than Astronomy Ireland. But I don't know what they have left. I got a NexImage camera there for 70 quid, AI selling the same thing for 160! They had a box of random eyepieces left that they were selling cheap so maybe give them a ring and see if they have anything left?? Might save you a few quid.

Hope that helps!!

bogwalrus

that was very helpful.

the barlow lens is an added magnification aid for a current lens yeah?

My dtg is 8.75 inch. Would that be 1300mm?

If i can get a deal i would get 2 or 3 lenses as a package but i would want
to have the right lens for the right focal lens.

ebay looks good. might keep my eye out for a good deal.

thanks again.

Clif7

bogwalrus wrote: »

that was very helpful.

the barlow lens is an added magnification aid for a current lens yeah?

My dtg is 8.75 inch. Would that be 1300mm?

If i can get a deal i would get 2 or 3 lenses as a package but i would want
to have the right lens for the right focal lens.

ebay looks good. might keep my eye out for a good deal.

thanks again.

Yeah I've seen an 8.75 before. Focal length was 1295mm i think. Should say it somewhere on the tube if you want to double check. Nice scope

And yeah, barlow lens increases the magnifiation of your eyepiece. So a 10mm eyepiece in a 2 X barlow is the same power as a 5mm eyepiece.

If you wanted to have a good range of magnification you could always get say a 32mm, a 9mm and a 2X barlow lens to go with what you already have.

32mm - 40 X magnification (ideal for wide field of view, galaxies and stuff)

32mm w/ Barlow - 80 X magnification

12.5mm - 104 X magnification

12.5mm w/ Barlow - 208 X magnification

9mm - 144 X magnification

9mm w/ Barlow - 288 X magnification

Thats a nice spread that would definitely keep you going.

bogwalrus

that info was spot on. ill keep my eye on the net for the next week and will then make a purchase.

thanks again