Eyepieces for DSO's

[ApOpLeXiA]

Hey

i have dobson scope

at the moment i only have the standard eyepieces and 3*barlow(which is uselss for dso?)

also i have 2 standard maede eyepieces they came with a etx80

all eyepieces are 1.25'', i am wondring if 2'' will be better for DSO?

I have seen nice 2'' eyepiece : Skywatcher PanaView, they come in 26mm, 32mm and 38mm, it says the FOV is 70 degrees

I am wondering if they would be any good for DSO?, if they are not could one of you maybe advice me on a eyepiece that i should get and would you also need a specific filter?

also wondering if the light shroud is essential since skywatcher doesnt make it...,

thanks in advance

[Ags]

You need to give more information - what sort of dob do you have, and what are the focal lengths of you eyepieces? Are you observing from a site with bad light pollution or from a dark site.

For example 2 inch EPs can show a large section of the sky but typically at a low magnification, which means the sky background would look gray and washed out if you are observing from a light-polluted location.

[Orion_the_Hunter]

Hi, what size & focal length/ratio is your Dob?

I have just ordered a Panaview 32mm as I believe this is a great wide angle ep/'finder' ep.

Other Dob users on SGL also recommend something with magnification of 70x-110x for looking at smaller, dainter DSO. For my 8" F5.9 Dob, this would mean an ep in the region of 11mm-16mm. PerSonally, I think I might get a 14mm Meade 5000 Meade - Meade Series 5000 Super Plossl

With a 1.6x Barlow I would also have ep focal lengths of 20mm and 8.75mm.

Then my wife will confiscate the credit card.

[NGC 1502]

It depends on what sort of DSOs you are observing as to what is the

best magnification to use.

Something like the Pleiades or the Beehive large open clusters can only

be seen in entirety with low power wide field of view. You can also use

this for finding other DSOs that will benefit from a higher power - for

instance, M51 and its companion galaxy can be seen at low power, but

looks better at medium power (80 - 120x) as this darkens the background

sky, increasing the contrast between object and sky.

And some DSOs look best at high power, the Eskimo planetary neb in Gemini

looks best (to me) at about 150x. Globular clusters look good at higher power

as well.

With my 10" Dob, I use 44x, 85x and 150x most of the time for DSOs.

I've found the most usefull filter for DSOs to be a UHC, but it only helps

for some objects, planetary nebs for example. But galaxies, open and

globular clusters are not helped with a filter, so I wouldn't rush to get

one, I think I'd get some nice eyepieces first.

Hope this is of some help, Ed.

[ApOpLeXiA]

i have a skywatcher 300p flextube

the eyepieces are 10mm , 25mm, 26mm and 9.6mm or so i believe....

i intend to observe in an area which isn't very light poluted, but where im located atm there is severe light polution

I have a moon filter and a light pollution filter purchased with it , but im afraid that they are a bit ''crappy' since the moon filter costed 12 euros:P and the light polution 24 euros ( i just see its recommended to use for telescopes up to 114 mm diameter , oops hopefully i can return it!)

[Ags]

That's an impressive dob! It is very fast (I think F4.7). I've heard that SkyWatcher Aero EPs work better in very fast scopes like yours.

You must also consider exit pupil - this is the tube of light leaving the scope and entering your eye. Obviously this should not be bigger tjhan your eye pupil! To calculate exit pupil, divide theEP focal length by the scope focal ratio. I'd guess you should not get an EP much above 25mm for an exit pupil of around 5mm

[ApOpLeXiA]

yes i saw that in the manual!!!, im still quite young (22) so im guessing i have more then 5mm(but not sure how to measure;)

i think it it f5.. but not sure , and the Aero EP would be better then the Panaview:P?

it's a bit more expensive but i rather get a good eyepiece right away instead of having to buy a new one next month

[Ags]

I have seen a number of reviews of Aeros on SGL - the consensus seems to be that the Aero wins out against the Panaview in a fast scope. Disclaimer: I don't own any 2" EPs - I'm just repeating what I've read.

Pupil size: start with 7 when you're 20, and subtract 1mm for every decade after that.

[ApOpLeXiA]

decided to take the panaview (since its a bit less expensive, 100 euro agianst he 150 for the aero), just got it and wow its big and heavy compared to a 1.25 inch

[m.tweedy]

Pupil size: start with 7 when you're 20, and subtract 1mm for every decade after that.

Looks like I am going to have to sell my gear when I reach 90:evil6:

[ApOpLeXiA]

lol!

[Ags]

Let us know how the panaview works out in your scope.

[ApOpLeXiA]

yes i will, im still novice so not much to compare it 2 (except the standard ep's)

and am also waiting for a clear night...