high power e.p.

[faulksy]

just after some advise. i have a cpc 9.25 and my high power e.p. is a 9mm bgo which gives me 261x so now im looking for more power ready for those dark cold clear nights do you remmember them lol.another question to go with my high power e.p. is i have never been to a truly dark site which will change this season as i have found a few within a hours drive, so my question is will i be able to use higher power due to less light pollution which should equal less thermal heat from the lights, houses e.t.c. so what e.p. do you reccomend with similar performance to the 9mm bgo thanks guys and gals should maybe add that i have tried the 8mm bst which was good but seemed less power full than my bgo 9mm do you think the 7mm bgo would be to much ?

[E621Keith]

The skies in UK usually limits magnification to around 250x due to atmospheric turbulence. I think this has to do with the jet stream flowing right on top of us. To be honest, I rarely use more than a 12mm on my c925. 8mm (294x) is the highest I ever used successfully and only in nights of exceptional seeing.

May be you can consider the 8.5mm XF as an upgrade to your BST.

[faulksy]

hi keith, have sold the 8mm bst as there was no gain at all over my 9mm so was thinking 7mm bgo maybe or st hr 8mm for those rare nights of good seeing should also add i use the 9mm bgo most times that i get to use it but would i use another e.p giving 70x more than mt 9mm bgo

[RoloFanatic]

I would not get an eyepiece more powerful than about an 8mm because I bought a 4mm eyepiece when i got my first telescope because i was hungry for power, but the eyepiece was completely wasted, the seeing conditions are NEVER good enough to see anything. For example, Jupiter is just a fuzzy blob

[faulksy]

hi rolo, i have tried a 8mm but not much in it realy compared to my 9mm, so was thinking 7mm for the odd night. were abouts in north wales you from ?

[Spec-Chum]

Why not barlow your 12.5mm BGO for when viewing is exceptionally good? Or even, your 15mm TS planetary, 7.5 could be doable on some nights?

[crazyjedi]

I have a 5.5mm EP that is rarely used. I usually use my 12mm Radian for solar system stuff. I am looking into buying a 9mm Nagler or 10mm XW for planetary viewing. I think anything shorter is not going to get much use. The above mentioned idea of getting a barlow is a good one

[faulksy]

my scope always seems to handle the 9mm most nights which is around 260x so think i will go with the 7mm bgo,for those nights coming up

[Naemeth]

Contrary to others, you may be able to get a little more out of the atmosphere, be warned, only on the Moon! I've tried 325x on the Moon and things were darn good (that's a 4mm barlowed for me), but on most nights and for most objects, I wouldn't even recommend going to 260x, if I were you, I'd get a 10mm if you don't have one, as you will probably get more focused results.

Your choice at the end of the day .

[Spec-Chum]

I'd still have to recommend a quality 1.25" barlow to be honest. That'll give you an extra 6.25mm, and 8mm (Nirvana) in one fell swoop and for around the same price (if not cheaper, as in a TAL) as the BGO...

but as they say...the choice is yours!

[farunj]

Yup, the barlow recommendation is really good!! I too would suggest getting a Barlow!

[faulksy]

I'd still have to recommend a quality 1.25" barlow to be honest. That'll give you an extra 6.25mm, and 8mm (Nirvana) in one fell swoop and for around the same price (if not cheaper, as in a TAL) as the BGO...

but as they say...the choice is yours!

true mate, not easy is it lol

[Moonshane]

my longest focal length scope is 1840mm (16") and I have a 1600mm (6") scope also - both dobs. I have eyepieces as follows:

32mm, 26mm, 15mm, 13mm, 12.5mm, 10mm, 9mm, 8mm, 7mm and a 6-3mm Nagler zoom and use all of them on both scopes.

The 6-3mm Nagler zoom gives 267x-533x on my 6" scope and I use it frequently on double stars and the moon. It's also useful occasionally on Mars and Saturn (mainly 'for fun' on the latter though). It gives about 300-600x on my 16" which when masked to 170mm gives superb images of Mars sometimes at 300x. I live in light pollution and on a housing estate so there's every likelihood that you'll be able to use higher powers but only on certain objects.

my most useful eyepieces for DSOs (other than doubles) on my big scope are my 26mm (71x) and my 13mm (140x) and often just these two stay in the focuser. With my 'planetary' 6" I tend to swap as the seeing changes hence the bunching of focal lengths at the higher end.

[Naemeth]

my longest focal length scope is 1840mm (16") and I have a 1600mm (6") scope also - both dobs. I have eyepieces as follows:

32mm, 26mm, 15mm, 13mm, 12.5mm, 10mm, 9mm, 8mm, 7mm and a 6-3mm Nagler zoom and use all of them on both scopes.

The 6-3mm Nagler zoom gives 267x-533x on my 6" scope and I use it frequently on double stars and the moon. It's also useful occasionally on Mars and Saturn (mainly 'for fun' on the latter though). It gives about 300-600x on my 16" which when masked to 170mm gives superb images of Mars sometimes at 300x. I live in light pollution and on a housing estate so there's every likelihood that you'll be able to use higher powers but only on certain objects.

my most useful eyepieces for DSOs (other than doubles) on my big scope are my 26mm (71x) and my 13mm (140x) and often just these two stay in the focuser. With my 'planetary' 6" I tend to swap as the seeing changes hence the bunching of focal lengths at the higher end.

Out of interest, have you tried 500-600x on the Moon?

[Grotemobile]

Hi, i have got a C11,& the best thing i bought was a

Celestron Zoom EP .This goes from 8mm to 24.

Sometimes you need less mag, for a better view.

I find a mag of around 250 is about right for these

scopes.On the moon you can push a bit more.

That is just what i have found.

Steve

[LukeSkywatcher]

I rarely use anything below an 8mm EP with any of my scopes (see my signature). I have a 4mm Celestron Omni, but since i bought i have used it once only and that was to observe the Moon. That was on a night of exceptional clarity and seeing.

Regarding barlows......................why not just buy a single EP that gives the same magnification?. So for example, instead of using a 20mm+2x barlow...................buy a single 10mm EP.

Or in this case, instead of a 15mm+2x, buy a 7.5mm (if you can). You should be able to use 7.5mm quite often as its not much of a push from 8mm.

[farunj]

I rarely use anything below an 8mm EP with any of my scopes (see my signature). I have a 4mm Celestron Omni, but since i bought i have used it once only and that was to observe the Moon. That was on a night of exceptional clarity and seeing.

Regarding barlows......................why not just buy a single EP that gives the same magnification?. So for example, instead of using a 20mm+2x barlow...................buy a single 10mm EP.

Or in this case, instead of a 15mm+2x, buy a 7.5mm (if you can). You should be able to use 7.5mm quite often as its not much of a push from 8mm.

Yup true. But instead of getting 1 EP you get 2 EPs with the Barlow!! For eg. 20mm with a 2x Barlow will give 10mm. So you effectively have 2 EPs, a 20mm and a 10mm!!

[brantuk]

Hi Mike - A dark site will be good and you may be able to push the mag a bit - but you also need good transparency. I was looking at Jupiter in a 925 one year at Kelling which was pitch black - but the atmosphere made it look extremely wobbly and it appeared to "boil" constantly only freezing dead still for a second or two now and then.

That's when I realised how good a webcam would be for capturing the odd perfect image in a continual series of frames. So whilst a dark site will be better - don't expect perfection or you may feel let down. Like most of the above I find 8mm-12mm generally give good results - but the 5mm only comes out on very rare occassions.

[glowjet]

I have some Explore Scientific 82° and my 6.7 is really good, this would give your scope some 350X and an FOV of somewhere around 0.23° no doubt be very good for star work and on the occasions of good seeing, who knows. TH has them but Christopher's ( Astronomics ) in the States has them at a discount price of $99 at the moment, if you have someone to bring one over the water.

John.

[Mr Spock]

For deep sky I use my 22mm and 17mm T4 Naglers, and 42mm LVW on clusters. The 13mm comes in handy for globulars and small planetaries.

For planets and the moon I go with the conditions. That's why I have 13mm, 12mm, 10mm, 9mm, 8mm, 7mm and 6mm - whatever fits the seeing conditions really.

[scarp15]

I would have thought that something around 11mm at 214x will get the most use at the high power end.

[Moonshane]

Out of interest, have you tried 500-600x on the Moon?

I have used it at that sort of magnification on the moon and doubles (and as mentioned for fun on Saturn). in truth the image is larger but more mushy at that sort of magnification with no more detail visible - possibly less detail visible.I find that 400x often gives the best views of doubles and sometimes the moon but there's the odd night when the seeing is very good that the image remains stable even at about 500x - to my eyes anyway. I could probably use more power on my big dob then but I prefer the tracking of my EQP at high mags mentioned.

[Naemeth]

I have used it at that sort of magnification on the moon and doubles (and as mentioned for fun on Saturn). in truth the image is larger but more mushy at that sort of magnification with no more detail visible - possibly less detail visible.I find that 400x often gives the best views of doubles and sometimes the moon but there's the odd night when the seeing is very good that the image remains stable even at about 500x - to my eyes anyway. I could probably use more power on my big dob then but I prefer the tracking of my EQP at high mags mentioned.

I had the same kind of feeling when I barlowed my 4mm giving me 325x effectively, I didn't think there was more detail really, it was just bigger and more difficult to track. I also noticed dirt on my mirror so probably won't be doing it again at least until my mirror is clean. The Moon perhaps has the ability to be magnified so much because it's the brightest thing in the night sky.

[Moonshane]

if you can see dirt when in focus, it's more likely to be in your eyepiece or barlow as you'd be unlikely to see dirt on the mirror at the eyepiece.

[Naemeth]

if you can see dirt when in focus, it's more likely to be in your eyepiece or barlow as you'd be unlikely to see dirt on the mirror at the eyepiece.

Strangely, this was right after I'd cleaned my Barlow and Eyepiece, so it was the mirror. Collimation was slightly off though (Secondary and Primary), and still is until I get it sorted, much better now though.