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JOC

Baader aspheric 31mm 2" -> 1.25" or Omni Plossl 32mm

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It has been suggested that my Baader aspheric modular 31mm might be useful to view the veil in the summer.  However, to do this I'll need an O-III filter and my O-III is 1.25mm.  The Aspheric is a 2" EP, but has a 1.25mm cone to allow it's installation in both sizes of focussers (my own focusser is 2" or 1.25 with an adapter).  Hence I can put my O-III filter on the Aspheric, but only with the 1.25mm adapter.   With the adapter in place I guess I loose a significant part of wide field of view of this EP.  If this is so then I have a different possible EP I could use a Celestron Omni Plossl 1.25" 32mm which will obviously take the O-III filter directly.

So which will I get the best view with?

The Baader aspheric 31mm with 1.25 adapter or

The Celestron Omni plossl 32mm

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Ive not used the 31mm aspheric but i have used the 32mm Omni and didnt rate it much to be honest. I think i gave it to my grandson for use in his 70mm refractor. Its an ok eyepiece but not what id call good. You might consider a 35mm Baader Eudiascopic, which is just a bit special with its 'jump out of the eyepiece star fields effect.'

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If you use the 1.25 inch barrel adapter on the 31mm Aspheric you do loose light from the outer parts of the field of view. The 32mm 1.25 inch plossl will probably be showing you as much sky. The Baader Aspherics are not that well corrected in the outer part of the field either so maybe not worth the investment for use in your F/6 dob.

Your Omni 32mm plossl is an average lower cost plossl but might be worth a try. With a decent O-III filter it should show you either the east or west segments of the Veil Nebula but you won't be able to fit both in the same field - you need a really wide field for that, more than your scope can deliver.

So to summarise I would probably stick with the Omni 32mm and use the 1.25 O-III filter with that.

 

 

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3 hours ago, JOC said:

So which will I get the best view with?

Just a heads up... if you have serious trouble seeing the Veil with either set up your filter might not be up to par. I had an Orion Ultrablock that was a very poor sample, it turned me off UHC type filters for a couple of years.

Bottom line- the filter needs to be good.

How dark is your location? For perspective, the Veil is easily seen with no filter in truly dark skies as is Pickerings Wisp.

JOC, your pursuit will be well worth the while on this object.

How many stars can you see around the 4 stars of the Little Dipper bowl? Any?

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Low cost UHC and O-IIIs simply dont work as effectively as better quality ones. I've found that to my cost over the years.

Lumicon and Astronomik are the names that I look for now.

 

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I have a 2” Lumicon OIII visual filter, and both the 31mm and 36mm Baader Aspheric eyepieces, and either one in my 16” dob work fantastically well for the Veil.

This doesn’t help for those with a 1.25” filter though 😆

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6 hours ago, jetstream said:

Just a heads up... if you have serious trouble seeing the Veil with either set up your filter might not be up to par. I had an Orion Ultrablock that was a very poor sample, it turned me off UHC type filters for a couple of years.

Bottom line- the filter needs to be good.

How dark is your location? For perspective, the Veil is easily seen with no filter in truly dark skies as is Pickerings Wisp.

JOC, your pursuit will be well worth the while on this object.

How many stars can you see around the 4 stars of the Little Dipper bowl? Any?

I'll have wait until the clouds clear to count, but on this web site https://www.nightblight.cpre.org.uk/maps/ I am literally on the cusp of 0.5-1 and 0.25-0.5 Nanowatts/cm2/sr I am not entirely certain what the scale means, but I guess it is fairly good, though I could have real words with the numbskull that put up 4 flood lights about 1/4 mile down the road recently which are now all I can see at eye level and in through my bathroom skylight window.  O-III Filter wise I have one of these Optics ones https://www.firstlightoptics.com/uhc-oiii-visual-filters/oiii-filter.html However, I have no idea how good it is vs. more expensive ones.

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I think that you might be best to travel and join with some astro observers if you can. Being a Northerner, might not be the best placed to advise, but dependent upon where you are in Essex, could you plan on traveling North into Norfolk for instance? Here you could hook up with what sounds like a very good visual astro group that includes @Littleguy80. You will then for certain bag the Veil.

Edited by scarp15
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1 hour ago, John said:

Low cost UHC and O-IIIs simply dont work as effectively as better quality ones. I've found that to my cost over the years.

Lumicon and Astronomik are the names that I look for now.

 

I didn't want to come right out and say this.:happy7: but we share the same thoughts on this.

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2 hours ago, JOC said:

I'll have wait until the clouds clear to count, but on this web site https://www.nightblight.cpre.org.uk/maps/ I am literally on the cusp of 0.5-1 and 0.25-0.5 Nanowatts/cm2/sr I am not entirely certain what the scale means, but I guess it is fairly good, though I could have real words with the numbskull that put up 4 flood lights about 1/4 mile down the road recently which are now all I can see at eye level and in through my bathroom skylight window.  O-III Filter wise I have one of these Optics ones https://www.firstlightoptics.com/uhc-oiii-visual-filters/oiii-filter.html However, I have no idea how good it is vs. more expensive ones.

For me astronomy has been a process and still is as I venture into different areas to observe. Extended objects vs points sources...when does an extended object act like a point source? look at Hickson 55 for example. I have recently learned about some of this with help from others.

The Veil is an extended object with much light in OIII. In order for our eyes to work well with the OIII we should have an exit pupil between 4mm-5mm (or more), but under less than dark skies the 4mm gets the nod.

So the 31mm gives about 5mm exit pupil. Your 26mm plossl gives about 4.3mm.

We know have a plan- try them both. No need for expensive eyepieces to view the Veil ie the 25mm SW Super plossl works very well.

However, filter choice can make a huge difference. The only one I would buy now is the Astronomik OIII (or TV, same thing). Lumicon had big issues that I'm not sure theyve overcome.

So a plan overview might include:

Practise observing 52 Cygni naked eye

View the Veil when high in the sky

Try your current OIII with both the 26mm and 31mm

Purchase an Astronomik OIII, try again

If no luck, its off to darker skies.

JOC you will see the Veil, but it is a process. Out of curiosity what are your favorite objects to observe?

 

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54 minutes ago, jetstream said:

Out of curiosity what are your favorite objects to observe?

Don't laugh, but still as a novice observer the answer is 'ones that I can find!'

Seriously I haven't observed too many objects yet, but I think my favourites so far have been the ring nebula - just the coolest thing in the sky, the blue snowball (something I can actually see colour in, Alberio coloured double star and Lyra - the double double and I have split it as far as 4 stars clearly.  I've also got a soft spot for the trapezium in the Orion nebula, but I still can't see more than about 4 stars in it.  Oh and it goes without saying the planets - Saturn and Jupiter are obviously cool and the moon and sun.  I think this qualifies as all the easy to find/easy to see objects LOL

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4 hours ago, scarp15 said:

I think that you might be best to travel and join with some astro observers if you can. Being a Northerner, might not be the best placed to advise, but dependent upon where you are in Essex, could you plan on traveling North into Norfolk for instance? Here you could hook up with what sounds like a very good visual astro group that includes @Littleguy80. You will then for certain bag the Veil.

You’re more than welcome to join us at Norwich Astro Society. The skies are certainly dark enough, people of all abilities and everyone helping each other out. Breckland Astro society have a nice site and are also a helpful bunch. I think they might be a bit closer to you. Drop me  a PM if you’d like to visit either of these societies’ sites. 

With regards the 32mm Celestron Plossl, I had one of these and used it to see the Veil with my 130mm reflector and a good quality Astronomik OIII filter. This was from my back garden in the suburbs of Norwich so probably a bit worse than your skies. Based on that, I’d say your filter is the only question mark.

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40 minutes ago, JOC said:

Don't laugh, but still as a novice observer the answer is 'ones that I can find!'

Seriously I haven't observed too many objects yet, but I think my favourites so far have been the ring nebula - just the coolest thing in the sky, the blue snowball (something I can actually see colour in, Alberio coloured double star and Lyra - the double double and I have split it as far as 4 stars clearly.  I've also got a soft spot for the trapezium in the Orion nebula, but I still can't see more than about 4 stars in it.  Oh and it goes without saying the planets - Saturn and Jupiter are obviously cool and the moon and sun.  I think this qualifies as all the easy to find/easy to see objects LOL

No laughing, you have a very good start JOC!

Being able to split the double double tells much about your optics, cooling and collimation- its all good. Excellent.

I must also point out that it was @John who helped me first find the Veil, again many thanks to him.

I still like to observe objects near constellations for ease of finding and when the DSC froze up the other night I was driving the 24" @ .7deg TFOV around manually, a challenge indeed, but the basics carried me through. Your goto should work well if you have a stable base and use very tight FOV (high mag) to align, my SynScan is like this on the AZEQ6.

Right now M81/M82 are VG, M108 is so easy to find and is a nice taste of things to come for you.

One last and important thing to our observing plan:dark adaptation- you need 30mins in darkness to fully adapt for the Veil,galxies etc. Vogel is an expert on this.

http://www.reinervogel.net/index_e.html

Edited by jetstream
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