binned the tal,so which e/p next ?

[rory]

i sold my tal x2 just cant get on with it at all.( i know a few here are after one ,but i believe it's against the rules to sell here at the moment,sorry guys)

so at the moment my current ep's give x 31 and x83 . im going for another bst explorer.

unsure of which will benefit most. i do some planetry observing ,but i spend more time on dso's, which my scope isnt really cut out for .

options 8mm=x125 , 15mm=x66.5 , 18mm=x55. anyone with a simlar size refractor (90mm f/11) have any tips ?

obviously the 5mm is to much and the 25mm is to simlar to my other low mag's.

thanks..

[swamp thing]

unsure of which will benefit most. i do some planetry observing ,but i spend more time on dso's, which my scope isnt really cut out for .

IMO Save your money for a bigger scope then.

This will be of more benefit than any eyepiece.

Regards Steve

[John]

IMO Save your money for a bigger scope then.

This will be of more benefit than any eyepiece.

Regards Steve

Yep - It's a hard message but it's the truth - a 90mm refractor just isn't going to give very satisfying DSO views whatever eyepiece you have in it.

[rory]

right, well your the guys with thr experience, i shall plough everything into saving for the dob. thanks .

[cs1cjc]

I think it is definitely worth getting another eyepiece or two. There are lot of brighter DSOs that will look well in your scope, particularly if you can get to darker skies. The 18mm would be best,. Though the exit pupil of 1.6mm is a bit on the low side, it is about what I use most on my 70mm refractor for DSOs.

For planets the 8mm would be fine.

[dobbie]

i used to use 2" ep,s in my 90mm frac the 24mm was excellent , but aperture wins in the end... even a 6" newtonian will give excellent views of dso and there quite cheap on the s/h market .

[cs1cjc]

Assuming a 7mm dark adapted pupil a 90mm scope gathers 165 times more light than the naked eye - a huge improvement. Ignoring the central obstruction, the 150mm (6") will gather 460 times more light which sounds a lot but is not even a 3 times improvement over the 90mm. This will show slightly brighter images at the same magnification or allow slightly higher magnification but the difference is not huge. In the end you will anyway want to fill the gap between 12mm and 32mm eyepieces and an 18mm would be just fine.

A reflector is not without issues. It will bring longer cool down times and sensitivity to collimation. Last night it was so cold and the air was cooling so quickly that my 200mm did not stabilise in temperature before the clouds rolled after nearly two hours. I would have been better off taking out my 70mm.

I would stick with the 90mm for now, buy the one or two eyepieces you suggest, and use it until you know you have exhausted its performance. It can give good views of many DSOs.

[rwilkey]

I use the PanaView 2" 32mm for DSO's and it is superb in my 100mm f/9, should be OK in yours if you have a 2" focuser.

[rory]

Assuming a 7mm dark adapted pupil a 90mm scope gathers 165 times more light than the naked eye - a huge improvement. Ignoring the central obstruction, the 150mm (6") will gather 460 times more light which sounds a lot but is not even a 3 times improvement over the 90mm. This will show slightly brighter images at the same magnification or allow slightly higher magnification but the difference is not huge. In the end you will anyway want to fill the gap between 12mm and 32mm eyepieces and an 18mm would be just fine.

A reflector is not without issues. It will bring longer cool down times and sensitivity to collimation. Last night it was so cold and the air was cooling so quickly that my 200mm did not stabilise in temperature before the clouds rolled after nearly two hours. I would have been better off taking out my 70mm.

I would stick with the 90mm for now, buy the one or two eyepieces you suggest, and use it until you know you have exhausted its performance. It can give good views of many DSOs.

thats a fair point, i intended to try and bag all the messiers,or at least as many as is possible before moving up a level in apeture.

but as many are so faint from my location ,i m thinking of upping apeture early. but thinking about it, i think i'll stick with the original plan .

be nice to get past 100 messiers( not exlusively , ngc,caldwells too) then compare with a 8"-10" apeture later.

id imagine it will blow me away.

thanks guys.im inspired

i think yhe 18mm will be for me.