2" or 1.25" lens

[jordanclarke]

hi SGL,

i recently bought an 8" dob (first scope)

i had a great first night with it, and so i want to get a new eye piece obviously! the one's that came with the scope are 1.25" 10mm and 25mm

my scope can take 2" lens's also, so i was wondering whether to invest in 2" or stay with 1.25"??

i know the 1.25" will probably be fine for my scope, but in the future (in many many years) i may want to buy a bigger/better scope where 2" eye pieces are more suitable and it would be nice not to need to re-invest in eye pieces. £$£$£$£

any advice/suggestions would be appreciated!!

[swamp thing]

Hi there

There is no difference in quality between 1.25" and 2". you can get good and bad of both sizes.

It is more to do with the focal lengths and field stops which i will not go into for fear of boring you to death.

Suffice to say that you'll notice it is mainly the mid to lower power eyepieces that are 2"( to keep a nice wide field of view).

There is nothing 2nd rate about good 1.25" oculars so don't be put off by size.

However i would not rush into eyepiece purchase as what mag works on one object wont work as well on another and only experience will tell you which eyepiece you will use the most. Then you can make a more informed purchase.

Congratulations on the scope 8" dobs a great choice.

Clear skies

Steve

[Chris H]

The 25mm ep that came with your scope is not too bad and will easily do the job whilst you get used to using the Dob and what you want to view. The 10mm however is not too good and if you're looking to buy a new ep it would be that one I would look at first. Look for something between 10 and 13mm and it will spend an awful lot of time in your focuser.

[jordanclarke]

thanks for that steve, cleared that up over the 2 and 1.25 so i appreciate it.

hi chris, if i was to replace the 10mm is there a particular brand you'd recommend? i suppose i wouldn't want to spend over 100pounds 2nd hand or new, as i'm a begginer.

also, do you think it would be a good idea to get a barlow, or possibly a powermate (which i hear are better)??

[mikeknowle]

I've been pondering the same think for a while funnily enough. Out of the 10 or so 1.25 ep's I have, I always seem to use the same three. No surprises there...

I've just borrowed a few 2" ep's to do a hot-swap comparison; with a view to just buying one really, really good low-power wide-field ep of whichever dia.

Mike