UHC and OIII on Nebulas with extreme light pollution...

[AlexxxAA]

Hi guys.

So i did my 2nd light with my new 12" lightbridge last night. Unfortunately the only times that I'm able to observe is between 9-11pm and the she sky still isn't as dark as it could be. I guess ideally would be to stay out until midnight or 2am the sky is at its darkest.

Because of where i live i have to stick to bright objects. Galaxies are non-existent here. I tried looking at M51 and all i saw were 2 extremely dim cores.

So I swung to M57 and tried comparing views with and w/out filters. I went to 100x with the filters and didn't notice much. Without the filters the star field around is much richer and nicer, and M57 is a dim little halo. I found that the view with the filters only made the ring a little more noticeable. Almost all the stars were washed out, and only the brightest star next to it remained. No detail on nebula though...

NGC 6543 (The Cat's Eye Nebula) is a different story for me. I inspected the nebula at 305x. The view through the Nagler by itself was very pleasing. The central star shined very prominently and seemed to give the nebula a very nice effect due to it being there. The asymmetric shape that it has was very apparent. Switching to the filters washed out the stars again. The only star left was the 10th magnitude star right next to it. The filters made the nebula much brighter, but the central star was no longer visible. And the detail of the nebula was gone. It just seemed like a bright oval. I enjoyed the plain view much more. This nebula handles magnification very well.

Next was M27. I had a little harder time starhopping to this one, but i eventually found it. I had completely forgotten how large this nebula was compared to the rest of the planetaries! Even with the 24mm at 64x, the nebula was about 1/4 or 1/5 of the diameter of the view. However, the nebula was very dim . I actually almost missed it while starhopping. The light pollution almost washed out the nebula completely. I switched to the UHC and saw an improvement on the nebula. Now it was a little more noticeable from the background, but still looked like a round, dim, blob. But switching to the OIII really made a difference here! The nebula really popped out from the dark background now. And since it was a wide view, there were plenty of bright stars still visible around. The nebula still seemed round, but with averted vision, the dumbbell shape was very apparent. Not any detail though. And the central star was never visible. Im not sure if the central star is something that i should be able to see?

Due to the light pollution here, many beautiful objects are stripped of their beauty. Even bright globulars seem dim. I think that I'm going to stick to bright, compact planetaries for the time being. I will most likely start sketching all that i find. That way i pay more attention to detail as well on what I'm viewing.

[Carbon]

Nice report Alex. You're right about galaxies, just dim cores, as you say.

I was out observing last night as well. My dob is still out of commission due to the mods I'm currently making on it so I used my C11.

I concentrated on Saturn for a little while, testing my new 8.8mm ES eyepiece on that but seeing conditions at the time did not allow for any worthwhile evaluation, so I used a 14mm @ 200X and a variety of other EP's to just absorb the nice crisp views for a few minutes.

I also concentrated on the blinking planetary nebula.....always a fun object to look at. The ring nebula looked wonderful as well.

By this time M13 was straight up near zenith and the views were most pleasing at 140x and 200x, 20mm and 14mm respectively.

I will have my Lightbridge all finished and put together this week and hopefully try it out this weekend with the new mods. I posted some new photos of the mod just this morning in the Mother Of All degree circle threads over at CN.

George

[Double Kick Drum]

Great report. Thanks for sharing.

[michael.h.f.wilkinson]

Nice report. I found that UHC does not help with the Ring, but does with many other planetaries, including M27. Haven't got an OIII yet.

[AlexxxAA]

Nice report Alex. You're right about galaxies, just dim cores, as you say.

I was out observing last night as well. My dob is still out of commission due to the mods I'm currently making on it so I used my C11.

I concentrated on Saturn for a little while, testing my new 8.8mm ES eyepiece on that but seeing conditions at the time did not allow for any worthwhile evaluation, so I used a 14mm @ 200X and a variety of other EP's to just absorb the nice crisp views for a few minutes.

I also concentrated on the blinking planetary nebula.....always a fun object to look at. The ring nebula looked wonderful as well.

By this time M13 was straight up near zenith and the views were most pleasing at 140x and 200x, 20mm and 14mm respectively.

I will have my Lightbridge all finished and put together this week and hopefully try it out this weekend with the new mods. I posted some new photos of the mod just this morning in the Mother Of All degree circle threads over at CN.

George

Thanks george. Ill try and see if i can sign up over there at CN as well so i can see those mods. Gonna start thinking about mods myself for balancing.

[AlexxxAA]

Great report. Thanks for sharing.

Thanks Martin. I think i might start counting down my observations like on your signature. Thats pretty darn cool!

[AlexxxAA]

Nice report. I found that UHC does not help with the Ring, but does with many other planetaries, including M27. Haven't got an OIII yet.

Thanks Michael. From what i have noticed, at least for the planetaries, the OIII brightens the nubula much more than the UHC. I might try to find something fainter tonight and see how the UHC and OIII help with something like that. Something like a 10-12th mag planetary nebula and see how the filters fare with that!

[Carbon]

Thanks george. Ill try and see if i can sign up over there at CN as well so i can see those mods. Gonna start thinking about mods myself for balancing.

You can achieve good balance by attaching a couple of speaker magnets. You can also purchase counterweights specifically made for the Lightbridge for a more elegant solution. They all work pretty good.

George

[AlexxxAA]

I will have my Lightbridge all finished and put together this week and hopefully try it out this weekend with the new mods. I posted some new photos of the mod just this morning in the Mother Of All degree circle threads over at CN.

George

In which forum or thread is this on??? I cant seem to find it

[Carbon]

In which forum or thread is this on??? I cant seem to find it

I post under a different user name over there. This link below should take you directly to my post with photos I posted this morning. It's a huge thread titled 'Degree Circles', about 50 pages long.

http://www.cloudynights.com/ubbthreads/showflat.php/Cat/0/Number/5309699/Main/937949#Post5309699

[swamp thing]

Nice report.

Your findings with the filters don't surprise me.

Filters cannot make any objects brighter. That isn't possible, what they do is filter out unwanted light thus improving contrast between nebulae and sky.

The more aggressive the filter the darker the sky background and also any stars within. No filter will help with central stars in PN they can't. For this you need to remove the filter.

One thing when using nebula filters of special importance is your own dark adaption, this must be good. This is also not easy to achieve when observing from an urban environment, but if you can get fully dark adapted when using filters the effect they can have is more dramatic.

One method is the old head under a cloth ploy (you look an utter tool but it does work ). Anything to block extraneous light from entering the eye.

Once fully dark adapted you will find the filtered view of much more benefit.

Clear skies

[AlexxxAA]

I post under a different user name over there. This link below should take you directly to my post with photos I posted this morning. It's a huge thread titled 'Degree Circles', about 50 pages long.

http://www.cloudynig...949#Post5309699

I just checked it out. Thats pretty cool! Awesome work

[AlexxxAA]

Nice report.

Your findings with the filters don't surprise me.

Filters cannot make any objects brighter. That isn't possible, what they do is filter out unwanted light thus improving contrast between nebulae and sky.

The more aggressive the filter the darker the sky background and also any stars within. No filter will help with central stars in PN they can't. For this you need to remove the filter.

One thing when using nebula filters of special importance is your own dark adaption, this must be good. This is also not easy to achieve when observing from an urban environment, but if you can get fully dark adapted when using filters the effect they can have is more dramatic.

One method is the old head under a cloth ploy (you look an utter tool but it does work ). Anything to block extraneous light from entering the eye.

Once fully dark adapted you will find the filtered view of much more benefit.

Clear skies

Thanks Steve. You are right about the effects of the filters. I was just so excited that the appearance of the nebula brightening was what stuck in my head for the report.

And i will definitly try different methods for dark adaptation. Living in such a bright city is hard, since even the sky itself has a bright pinkish glow.

[swamp thing]

And i will definitly try different methods for dark adaptation. Living in such a bright city is hard, since even the sky itself has a bright pinkish glow.

I know buddy I live in south London not quite LA but 6 or 7 million people, so pretty big.. Gotta love that glow..........not.