oiii filter

[Paul73]

I agree with John. Haven't looked at the Owl nebula with a filter for ages. Mostly because, together with M108, it makes such a great sight. M27/57 are similar, they just look great with their associated star fields. Why lose the backdrop for a marginal gain in detail.

The Viel is a very different proposition......

Paul

[swamp thing]

I don't normally use a filter to observe the owl as I find the "eye" features are easier seen without one.

This however seems to go against the grain as usually dark features are improved with the extra contrast of an O-III filter. Maybe the 'eye' features are similar to the central part of the ring nebula that once a filter is used seems to glow faintly with gas and can actually take away from the "ring" effect.

[alan potts]

Going back to amount of use these get. We had a thread running over two years back, it must be, I got an Astronomik's Olll wholey on the back of John's report of being able to see more background stars, which I consider important in the overall effect. I then bought this 2 inch in England when I was over for the Coroners hearing after my Brother died, I then placed it in my cabinet and forgot it for almost a year. When I used it i was stunned just what it does to the Viel in my smaller scopes, I was not so impressed with it in the LX where I can only get a .91 of a degree FOV and X74, must give it another try though.

In the 115mm APO with the 31mm Nagler it comes into its own though as one of the best Summer views. If the clouds and rain ever let me i will try the Owl.  Looking through the Deep Sky Atlas it shows lots of targets where a Olll filter has its uses and targets where UHC and HBeta excel.

Sometimes I consider buying one of these sliding draws for filters so you can push them in and out of view with one hole empty, that may well be a useful device, but with these larger filters now at over 200 quid a time the device needs to be well made.

Alan.

[Piero]

For planetary nebulae an OIII filter helps a lot to me. I would not use a UHC filter on these targets though as in my opinion PN can benefit from an increase in contrast rather than in extension. This is what I have found so far for Ring, Eskimo, Ghost of Jupiter and Owl nebulae. Images were quite blurry or even not visible (Owl) when using an UHC (at my available magnifications), whereas they showed a bit more than just a blob using an OIII filter.

On extended nebulae, it is another story and it is a matter of taste I think. If you prefer to maximise extension, I would go for an UHC; if you want to maximise contrast an OIII. Both these filters work very well on M42 to me. Of course, you can avoid using a filter on this target if you have enough aperture. In my case it made a substantial difference and I the view through these filters gave me two nice images that I will not forget. 

This said, I am looking forward to trying my filters on the Cygnus. I speculate that the UHC will not reveal the Veil and NGC7000 whereas the OIII might make the difference. I suspect this because this is what happened when I looked for the Rosette Nebula. 

All this with a small telescope and under a sufficiently dark sky (6-7 UMi stars). With bigger telescopes things can be different of course as more light is collected and this whole game is about collecting light eventually! 

[swamp thing]

In the 115mm APO with the 31mm Nagler it comes into its own though as one of the best Summer views.

Alan.

You've obviously not seen it through the 18" yet then? 

Select your 21mm Ethos and your O-III and get ready to pick yourself off the floor.  

The detail is just astonishing. My larger scope nearly caused me to have my jaw wired up after I saw this last year. Absolutely incredible view.  The intricate wisps of delicately glowing gas enter-twinning with one another as they twist and dance across the eyepiece is just breathtaking. 

Believe you me the veil comes alive with aperture in a way that is simply mind blowing.

[estwing]

I'll second that ....I was there!...Alan your about to find out why I rave about john's mirrors..

[Stu]

You've obviously not seen it through the 18" yet then?

Select your 21mm Ethos and your O-III and get ready to pick yourself off the floor.

The detail is just astonishing. My larger scope nearly caused me to have my jaw wired up after I saw this last year. Absolutely incredible view. The intricate wisps of delicately glowing gas enter-twinning with one another as they twist and dance across the eyepiece is just breathtaking.

Believe you me the veil comes alive with aperture in a way that is simply mind blowing.

Crickey Steve, you are getting all poetic on us

Must admit, I'm looking forward to a decent view of it. SGLX was ok but not stunning.

I repeated your 31 Nag vs 21 Ethos comparison on the Veil last night in the 150ED.

I hate to say that I agree with you on that target. Much dark sky background, better contrast and more detail.

I shall hang onto the 31 because I love it in my other scopes but the 21 really is cracking

[niallk]

Sometimes I consider buying one of these sliding draws for filters so you can push them in and out of view with one hole empty, that may well be a useful device, but with these larger filters now at over 200 quid a time the device needs to be well made.

Alan.

Sorry to hear about your brother.

I was just so amazed by liddle 1.25" astronomik O-III filter, that I bought a cheapo filter wheel so that I could flick in a sec from no filter/O-III/UHC/Neutral density/Green Filter. It works a treat in my 250px, giving great freedom and ease.

Sadly I can't focus with the wheel in place in my 15", and I'm a little reticent to start trimming poles . I've seen pics of those sliders and they look the job, though the cost of going to 2" filters is a biggie. Argo Navis + aperture helps here though - I can pop in high mag ep for planetary neb, and AN will locate accurately the target within fov of 7mm - so don't need to changing filter in the dark from a finder ep to a high mag ep etc.

[Dom1961]

Talking about astronomik OIII, is it any good? I was just looking at that online

[Piero]

Talking about astronomik OIII, is it any good? I was just looking at that online

I love mine! A genial invention!

[John]

I found the Astronomik O-III a really excellent and effective filter in all my scopes from 4" to 12" in aperture.

[swamp thing]

I'd say;

I couldn't tell it apart from my Lumicon when I tried one on the veil complex with my 10" 

Impressive  

[Dom1961]

Can the same be said for their UHC?

[niallk]

Talking about astronomik OIII, is it any good? I was just looking at that online

One look at the veil... - worth it!

[alan potts]

I think it is a toss up as to which is better, people seem to say Lumicon is best but then people also say you can't tell the difference. I bought the Olll Astronomk's first because of a trusted report of being able to see more background stars, important in smaller scopes I would have thought. The results of the Astronomk's in all my scope apart from the big Dob has been very good.

If these things were not so costly I would get a Lumicon just to see, I have to hold my hand up and admit to buying all my 2 inch filters secondhand, I have a Lumicon 2 inch deep sky which works nicely on on some targets, though this I understand it their version of the CLS/LP filter which I don't have, oddly I have seen written that it works better in a dark sky. I think it was the one reason why I would find the filter wheel a useful tool as I could load all of the 2 inch ones into it and chop and change, I only ordered a 1.25 H Beta though as it was for me a one horse race with it going on the 24mm Panoptic in the big scope aimed purely at exit pupil for the HH.

I have not seen the Viel yet through the 18 inch as it has been awful here and still looks like no change, I must stop buying things, it's my own fault.

Alan

[Stu]

I have the Lumicon which I do think is excellent. I don't find the stars are dimmed too much, but then I haven't looked through an Astronomik in comparison.

My view is that it shows me the nebulae beautifully, and the stars well enough to put the nebulae in context so I am happy.

It worked very well in the 6" the other night, showing me the Veil from site just a few miles south of Heathrow so not too bad! It's great in the 4" too.

[Piero]

Can the same be said for their UHC?

In terms of quality, to me it is an excellent filter, but I guess you are more interested in knowing whether you might need this as well or not. 

It serves different purposes to me. It works very well if you are interested in viewing the full extension of a nebula (therefore using a low power eyepiece). OIII, UHC and H-beta work better on a dark sky, and in my opinion this is particularly true for the UHC and H-beta filters (although I don't own a H-beta). 

I enjoy my UHC filter, but if I had to chose between a UHC and OIII, I would go for the OIII. On this aspect I changed my mind after trying them both on a few targets and then joined the thoughts of many folks here.

Whereas a UHC filter allows you to improve the image of a nebula, an OIII filter allows you to see nebulae that you cannot see. For nebulae that you can see without filter, an OIII improves the contrast noticeably.

I believe that if you live/watch under (very) dark skies, an UHC might be sufficient though. 

[Dom1961]

Unfortunately I'm not lucky enough to have dark skies:(

[alan potts]

Maybe that is one thing you can't can't get from STL, the sky being the limit.

Alam

[alro]

Even though i live in a relatively dark sky area, i was really imoressed with the difference my uhc filter made, it was jaw dropping. And this is with a lower price end brand, it works really well for me though.

incase anyone is interested ive still not initiated my oiii. Hopefully it will be the equal to his brother (uhc)

Al

[alro]

Hello, do you get data sheets provided with lumicon and astronomik oiii filters, and if so, how does my stl oiii filter compare?

thanks

al

[alan potts]

Well as said, I have 2 Astronomk's filters both 2 inch and there seems to be nothing at all with them, though both bought S/H.

However on the box of the Lumicon is a label with handwriting on for % numbers, As follow:-

H beta, 486nm 94%:

Olll 496nm 93%:

Olll 501nm 93%:

and H Alpha 656 nm 92%.

It is a Lumicon Deep Sky Filter which I believe is their take on CLS, they say however these work better from a dark site, anything to sell things. I really liked it on the Orion Nebula, it was just massive in the 18 inch. I tried it on a few galaxies as well and it maybe did make them a little clearer, though not much.

[John]

Hello, do you get data sheets provided with lumicon and astronomik oiii filters, and if so, how does my stl oiii filter compare?

thanks

al

If you google the filters by name the band pass charts will be found. It's difficult to do a precise comparison by just looking at the charts to be honest with you because the scales various brands use are not the same so the data is difficult to compare. Comparing the actual views through them is the best way, as ever

One other benefit of the Lumicon and Astronomik filters that I've found is that stars are more sharply defined, perhaps due to the optical glass used and the quality of coatings.

[jetstream]

I have both and they are a bit different and both excellent. The Astronomik's optical quality was evident the other night when splitting the Double Double using the VX10 @ 96x- the filter view was as good as the unfiltered view on this split. The Lumicon is a bit darker giving more contrast on some objects ie Veil, NA neb. In my scope the Astronomik bettered the Lumicon on the Owl neb, Crescent neb etc. You can't go wrong with either one and if obs from LP skies mostly I would choose the Lumicon.

[Paul73]

Interesting. I would never have thought of using an OIII to split doubles.

Nice to get an opinion from someone who has both Lumicon and Astronomik.

Paul