Recommended 82 degree eyepiece for skywatcher 200p f/6 dob.

[woodmeister]

 I am unsure if I have astigmatism in my eye or not. I will find out this week if I get an appointment at the opticians and will ask them.

I do not view with my glasses on as they have a lot of scratches and marks that cause the images to look worse than they do with my glasses off.

Hopefully this weekend it will clear up and I can have another observing session and check out how well it preforms.

[jetstream]

Well I just spent an hour with the 23mm Luminos from home.Starting with a 18.6 mag sky,90mm frac and the 23mm Luminos, star shape was checked.All good except the extreme far edge,just visible, some astigmatism-not much at all and you had to work to see it.

The 90mm picked up one of the Leo triplet,m81,m82,m57,m13 and M97(18.6 mag).at 20.0 mag it picked up another of the triplet and m108.The 10" dob took the whole triplet,m97,m108 and all the rest,much more visible,plus more objects.

In the 10" aberrations are visible in the outer FOV-20%?,mix of astigmatism and coma.One thing of note with these widefields (Ethos too) is that head/eye alignment to the eyepiece can either minimze or aggravate the aberrations.The 23mm Luminos finished off the evening giving me my first look at the Veil,very low in the sky,maybe NELM 4.3 down there-even through the soup both east and west were visible with the OIII.

Woodmeister,the 23mm Luminos is a capable EP that makes things easy to see with its great FOV and I am looking forward to your further reports and thoughts about it.

[woodmeister]

Jetstream, sounds like you had a good time with the luminous and helped you see a lot of objects.

To be honest I have not delved much into faint fuzzies much as my viewing location is not the must ideal place. However it still does not always stop me form looking though without dark adaped eyes averted vision still does not pick up much par grey fuzz.

I hope somehow the weather clears up this weekend so I can get back out there and use the thing some more.

[mdstuart]

I had astigmatism. If you rotate your eye and the astigmatism rotates then its your eye.

Next rotate the eyepiece to rule that out..

Then try rotating the primary 45 dregs to rule that out.

Finally it could be the secondary...check its not pinched in any way..

My issue was with the way my primary mirror was mounted...

Good luck..

Mark

[neil groves]

I recently bought an Orion Q70 32mm wide field ( 70 degree ) FOV for my 120ED OMG.........took a little getting used to after my 20mm plossel that came with the scope but once I rolled the rubber eye cap back and got my eyeball closer to the glass, the view is huge, I use it for hunting faint stuff like Galaxies and it covers such a wide FOV that it saves a lot of time, I was using my 20mm and hunted for 10 mins or more for M101 and nothing, I switched to my Q70 and within 1-2 mins had a galaxy in my FOV and started to image..........ok it wasn't M101, (I still havn't found that) but my point is the wide view is great for covering larger swaths of sky at one time to find stuff (I won't use GoTo) and looking through it gives you the sense you are wayyy out in space looking around.

Neil.

[woodmeister]

Since the weather has played nice for once I decided to get the scope out and have another session with my new eyepiece.

I went and found m13 just to start off with, after that I went and found the m93 I think (one between Hercules and draco I think it was) added another messier to my rather small list thus far

[jetstream]

woodmeister,do you have an OIII or UHC filter?If so try the 23mm Luminos on the Veil nebula,when high in the sky and clear,its great and greater from dark skies.I have also picked up the elusive Monkey head nebula with this EP and OIII-very good view.If you get to dark skies,the North American Nebula(part of it) will be visible in your scope with this eyepiece.One of the best investments purchased has been an OIII filter,which experienced SGL members recommended.I can see the Veil in my 90mm with it even in my LP home.

Congrats for finding M13 and M93

[woodmeister]

I tried testing how the eyepiece preformed toward the edges of the field in my f/6 scope. when I positioned my eye in the right place stars where sharp to roughly 80-85% of the field, then both astigmatism and coma kicked in which makes for some quite interesting shapes. I will note that since my eye positioning is not always perfect I might have aggravated the astigmatism a bit when looking at the outer edges of the field for the aberration.

There was also a blue colour fringe that appeared on acturus as I moved it toward to edge of the field, but I would have expected that anyway on a bright object and did not bother me. I believed I did notice minor edge brightening in the eyepiece. However I think that was most likely the streetlight nearby that was causing that when they was not swamping me with light it would be unfair to speculate.

I looked around sadr in Cygnus and the view was amazing as they are loads of stars around there, I know there are a few open clusters around there but I do not know which open clusters I was looking at, but the wide field really shines on these objects.

I have enjoyed using this eyepiece, wide FOV rules. I do find having to position my eye on its big flat top rather annoying but that Is just down to personal preference. For the $193 dollars I paid for it I find it to be a bargain for what you get from the eyepiece. I would LOVE to try this from a dark sky site.

[woodmeister]

woodmeister,do you have an OIII or UHC filter?If so try the 23mm Luminos on the Veil nebula,when high in the sky and clear,its great and greater from dark skies.I have also picked up the elusive Monkey head nebula with this EP and OIII-very good view.If you get to dark skies,the North American Nebula(part of it) will be visible in your scope with this eyepiece.One of the best investments purchased has been an OIII filter,which experienced SGL members recommended.I can see the Veil in my 90mm with it even in my LP home.

Congrats for finding M13 and M93

Why ty, I do own a UHC filter. However I got the UHC filter when I only owned 1.25 eyepieces and have no 2 inch filter which is a bummer. Wonder if I should get a 2 inch OIII filter just so I have both. Would like to go hunting DSO in dark skies with one but I bet that I would get so lost at a dark sky site.

[jetstream]

Yes the 2" filter is worth it,for sure,it should(?) fit the focuser adapter you have so you can use 1.25 EP too.The OIII I purchased is expensive,but John the mod recommended it as I use it in the 90mm frac as well.It is the Astronomik OIII,but with the good 8" aperture you have most would work I think.It is worth asking which OIII in a thread,lots of great experience here.Honestly,since getting the OIII I don't use the UHC.

Have you seen the Ring neb -m57-yet?Use the UHC in your 1.25" for now and give it a go.Find Vega and go from there,down and over to the right between two nice stars.At a dark site I set up early,when the bright stars are visible in the constellations to use as a guide,but sometimes I just stare up in amazement as the sky darkens....

The blue "ring" is typical of a lot of eyepieces at the edge,my ES18mm,16mmNagler and others do this.Oh yeah,the Luminos don't fog up easily either,which is nice.One more thing,the edge of field brightening happens to me with my prism diagonal in the 90mm,but not in my 10"dob,this may be caused by the wide field stop of this EP when used in some adapters etc

[woodmeister]

I had astigmatism. If you rotate your eye and the astigmatism rotates then its your eye.

Next rotate the eyepiece to rule that out..

Then try rotating the primary 45 dregs to rule that out.

Finally it could be the secondary...check its not pinched in any way..

My issue was with the way my primary mirror was mounted...

Good luck..

Mark

Thx Mark for the reply. I am unable to rotate my primary as there is a fold inside the scope from when the metal was folded in on itself. The primary mirror holder on my dob has a small grove to show where to insert it so it does not hit this fold and can only rotate it. As for the secondary I have never unmounted it and I am a bit apprehensive about that.

I guess it is just my eye positioning that is causing the astigmatism. I have -0.5 astigmatism in my left and -1.0 in my right which is not that much.

[woodmeister]

Yes the 2" filter is worth it,for sure,it should(?) fit the focuser adapter you have so you can use 1.25 EP too.The OIII I purchased is expensive,but John the mod recommended it as I use it in the 90mm frac as well.It is the Astronomik OIII,but with the good 8" aperture you have most would work I think.It is worth asking which OIII in a thread,lots of great experience here.Honestly,since getting the OIII I don't use the UHC.

Have you seen the Ring neb -m57-yet?Use the UHC in your 1.25" for now and give it a go.Find Vega and go from there,down and over to the right between two nice stars.At a dark site I set up early,when the bright stars are visible in the constellations to use as a guide,but sometimes I just stare up in amazement as the sky darkens....

The blue "ring" is typical of a lot of eyepieces at the edge,my ES18mm,16mmNagler and others do this.Oh yeah,the Luminos don't fog up easily either,which is nice.One more thing,the edge of field brightening happens to me with my prism diagonal in the 90mm,but not in my 10"dob,this may be caused by the wide field stop of this EP when used in some adapters etc

Hi I tried m57 last night took me longer than I thought to find it as I went over the same patch of sky a few times before I noticed it. I tried the uhc filter and to be honest it either stayed the same or made it slightly harder to see. I tried both my stock 25mm and the 7mm. It seemed like I got the brightest view when using the 23mm luminous unfiltered.

 At least I have seen another messier object.

My 2 inch adaptor has thread on the inside at the bottom of it so I guess I could shove a filter there. However the adaptor that fits onto the 1.25 eyepiece adaptor has no thread so I can't put a  2 inch filter on the bottom to use with 1.25 eyepieces which sucks

I wonder if it would be better investing in a 2-1.25 adaptor that is threaded and then just buying 2 inch filters.

[John]

....I wonder if it would be better investing in a 2-1.25 adaptor that is threaded and then just buying 2 inch filters.

This works fine as long as you don't have 1.25" eyepieces with slightly longer barrels (some have) in which case they will contact the filter and damage it. A neat trick is to get such an adapter and then add a 14mm Baader Fine Tuning Ring onto the bottom of it. The other side of the Baader FT Ring is threaded for 2" filters so you can safely put one on knowing that no 1.25" eyepiece barrel is going to get anywhere near it.

[jetstream]

I also use a "adapter extension ring",mine from Agena astro,Johns advice is good again.

I'm not surprised at all that your best view came from that Luminos,it works very well,competing on nebula with my 21mm Ethos.I was also using the 23mm and my 21mm,with my UHC and OIII on the Ring,under very challenging conditions.I actually quit when the northern lights came out -the last straw.

So I'll be blunt about my Orion Ultrablock(UHC),its junk,a very poor example of this kind of filter.The Lumicons,Astronomik etc are very highly regarded and must work better.My Ultrablock made my view worse with all EP tried (on the Ring),its below avg on the Veil and is only acceptable on M42,from LP skies.

Now the good news...the Astronomik OIII gave a very nice,bright,clean image of the Ring,this filter works very well on nebula,M42 included.It even pulled out the Veil with the moon flying about and with the northern lights draping across my sky-Veil not bright but there.Then I went in the house.

From very dark,transparent skies I find no filter on certain nebula is better,M57,M27,M42 etc,but the 2" OIII  is a must have.The Ring can take a lot of mag unfiltered(or filtered with the right exit pupil range).

Wait till you see the Veil in the 2" OIII ....

[John]

......I actually quit when the northern lights came out -the last straw.....

I'd sacrifice nice views of M57 for the Aurora Borealis on a few nights of the year I reckon 

I found the Ultrablock quite a nice UHC type filter. I was certainly able to show the Veil Nebula quite well in a 4" scope with one. The Astronomik O-III is a definite step up though - as well as improved nebulae contrast the surrounding stars are better defined too.

M27, the Dumbell Nebula, is another fine planetary nebula not too far from M57. Much larger than "the Ring" and with an intriguing structure that a good UHC or O-III filter helps explore further   

[woodmeister]

This works fine as long as you don't have 1.25" eyepieces with slightly longer barrels (some have) in which case they will contact the filter and damage it. A neat trick is to get such an adapter and then add a 14mm Baader Fine Tuning Ring onto the bottom of it. The other side of the Baader FT Ring is threaded for 2" filters so you can safely put one on knowing that no 1.25" eyepiece barrel is going to get anywhere near it.

I also use a "adapter extension ring",mine from Agena astro,Johns advice is good again.

I'm not surprised at all that your best view came from that Luminos,it works very well,competing on nebula with my 21mm Ethos.I was also using the 23mm and my 21mm,with my UHC and OIII on the Ring,under very challenging conditions.I actually quit when the northern lights came out -the last straw.

So I'll be blunt about my Orion Ultrablock(UHC),its junk,a very poor example of this kind of filter.The Lumicons,Astronomik etc are very highly regarded and must work better.My Ultrablock made my view worse with all EP tried (on the Ring),its below avg on the Veil and is only acceptable on M42,from LP skies.

Now the good news...the Astronomik OIII gave a very nice,bright,clean image of the Ring,this filter works very well on nebula,M42 included.It even pulled out the Veil with the moon flying about and with the northern lights draping across my sky-Veil not bright but there.Then I went in the house.

From very dark,transparent skies I find no filter on certain nebula is better,M57,M27,M42 etc,but the 2" OIII  is a must have.The Ring can take a lot of mag unfiltered(or filtered with the right exit pupil range).

Wait till you see the Veil in the 2" OIII ....

Thank you for the advice, appreciate it.

I have to agree with John about the aurora borealis though would love to be able to see that a few times a year.

I own the skywatcher uhc filter which for me does not really seem to improve contrast much and I don't notice it. However it must work a bit since my Mother could not see the orion nebula until I put the filter on.

I am taking to my new luminos and the pleasing views that it gives though it does not seem the most user friendly with the large flat top. But the views and the increase in contrast versus the stock eyepiece is a vast improvement and money well spent.

Is there any difference in brands when using 2-1.25 adaptors?

Cheers

[jetstream]

My longest 2"-1.25" adapter is from Stellarvue,works great,but for use in my white light wedge,a filter screwed on the bottom will hit the prism-hence the ring John was talking about to create mid sized length from a shorter adapter.The SV adapter is 45mm overall length,with 35mm under the shoulder-it will work even with the very long-40mm(barrel)- Nagler zoom.

Others here can help you with which one or FLO too

[neil groves]

Since the weather has played nice for once I decided to get the scope out and have another session with my new eyepiece.

I went and found m13 just to start off with, after that I went and found the m93 I think (one between Hercules and draco I think it was) added another messier to my rather small list thus far

I went out to find M13 and found a faint fuzzy patch, I thought oh great, got it.....turned out to be M93, so a couple nightslater did aother scan and got M13 so now I have aso those M's off my list.

Neil.

[woodmeister]

Nice one Neil. Always makes me happy when I find a messier object.

I remember looking for m10 and m12 but I could not find them. I blame it on the street light that sits up the road giving me grief. So I moved onto them 2 instead.

I guess my next 2 targets are the dumbbell nebula and the veil. I hope I can bag the veil with my UHC. I might increase my chances if I climb up the streetlight right outside my house and put a black bag over it ( the light sits right under Cygnus  ).

Good luck with the hunt.

[woodmeister]

I am guessing that having a long 2-1.25 adaptor will not affect the view if I need to rack the focuser all the way in to focus.

what would be the minimum length ideally that I should be looking. For example would the orion precision centering adaptor and others like that work fine with the baader FT ring.

If I ever get round to buying these two items I best get looking for a pre owned lumicon or astronomic are they are quite pricey. Or just buy a cheaper make and hope it is one of the good ones.

Thx again.

[jetstream]

Woodmeister,when Iwas pursueing an OIII,I had a refractor of 90mm to use it with.There a lot of filters that work,some spec 8"-10" aperture as minimum,but through Johns vast experience he has found a very high quality and forgiving filter-the Astronomik gives excellent,excellent views and is compatible with small apertures too.

Do you know the implications of exit pupil on filters and DSO?With your 23mm you have a 3.8 mm exit pupil @ f6,which is in the lower end of the specs for the OIII.But because the Astonomik is forgiving,it will work great

If your interested members will help you

ps any adapter will work just get the rings to adjust length so EP barrel can't hit filter

[woodmeister]

Jetstream, cheers for the advice you have given me. Now I just need to get me an adaptor and FT ring.

I am aware of exit pupil and its implications but I could always do with a refresher so I will give that another read over.

thx again to you, John and everybody else for your sound advice.