Quote:

---

I find Baader OIII too much dark for visual application.

It looks cutting some quote of useful light from OIII objects. I had possibility to compare it with Lumicon and saw that the last produced brighter and more contrast image over the most OIII nebulae.

OIII from Baader is preferred by my collegue who deal with astronomical photography.

---

Quote:

---

There are many websites that show test results for particular filters, but in the case of your 3 choices, from wide at the top of the list to narrow at the bottom, they are:
Orion (about 15nm, IIRC)
Lumicon (about 12nm)
Baader (about 8.5nm)

The Baader "clips" the 496nm O-III line at about 50% transmission, but since the primary emission in the O-III lines is at 501nm, that doesn't seem to hurt that much.
Frankly, all 3 filters are good, so you won't lose with any of them.
But the Baader will likely give the maximum contrast.

In a small scope, the extremely narrow bandwidth will darken the sky and stars and make the field perhaps unaesthetically dark.
Sometimes there is a reason for a slightly wider bandwidth.
Not only do we want an enhanced nebula image--sometimes the "context" is important, too.

---

Don Pensack is absolutely right.

Cheers,

Post Extras:

Quote:

---

Does anyone know of a site that shows the spectrum (wavelength) in nm that is allowed for the different OIII filters ?
Right now my choice for OIII is either the Baader, Lumicon or Orion 1.25 inch filters.

M97 the Owl Nebula is the target with an Orion XT10i.
Which OIII filter would be best suited for this one?

I figure if it is good for M97, it should be pretty good for the other nebula's ?

Thanks

---

Post Extras:

Quote:

---

Markus,
The Lumicon OIII which normally sells for $140 is on sale for $99.95

---

Quote:

---

The Baader O-III works extremely good on the Veil and other targets. I own the Celestron which is the Baader re-branded. The Lumicon indeed has a wider bandpass as I did a test with a friend in a dark sky situation, and I found the Lumicon slightly better on M-17 and a few other targets. However, I see no point in selling off my Celestron / Baader O-III for a touch wider bandpass.

---

Post Extras:

Quote:

---

Don't forget to look for an Astronomik OIII filter as well.

---

Post Extras:

Quote:

---

Don,

Found a few spectrum diagrams.
OIII Group A, B and Narrow Band


http://www.karmalimbo.com/aro/pics/filters/o3a.jpg

http://www.karmalimbo.com/aro/pics/filters/o3b.jpg

http://www.karmalimbo.com/aro/pics/filters/narrow.jpg

---

Post Extras:

Quote:

---

Another vote for the Astronomik. I've compared it against others, and it is the best in my refractor. A friend has a C9.5. We checked the Astronomik against the Baader in both scopes. We agreed the astronomik was the clear winner.

But of course beware that the performance of such restrictive filters are very affected by aperture and quality of the sky. Regards.

---

Post Extras:

Quote:

---

Quote:

---

Another vote for the Astronomik. I've compared it against others, and it is the best in my refractor. A friend has a C9.5. We checked the Astronomik against the Baader in both scopes. We agreed the astronomik was the clear winner.

But of course beware that the performance of such restrictive filters are very affected by aperture and quality of the sky. Regards.

---

Yet another vote for the Astronomick. I have the narrow band, OIII and H-beta filters all on a filter slide. All work great for me. The OIII might be a little broader than the Lumicon, etc., but the Veil really pops out when I use it in my scope, showing exquisite filamentary detail. Another standout is Thor's Helmet. Just a great filter for planetary nebulae (and the Veil).

Two things I really like about the Astronomick. One, they have very durable coatings, which are essentially scratch-proof and impervious to dew. Two, the view is very aesthetically pleasing, with nice pinpoint stars. In contrast, a couple of the other OIII filters I've seen (the older version of the Lumicon specifically comes to mind) yielded rather funky-looking bloated stars...

---

And I'd like to register another vote for the Astronomik O-III filter. Rob's experiences are very similar to my own. His experiences with the Veil and Thor's Helmet are right on the money. Overall, I'm completely satisfied with my filter purchase.

Post Extras:

Quote:

---

Quote:

---

Another vote for the Astronomik. I've compared it against others, and it is the best in my refractor. A friend has a C9.5. We checked the Astronomik against the Baader in both scopes. We agreed the astronomik was the clear winner.

But of course beware that the performance of such restrictive filters are very affected by aperture and quality of the sky. Regards.

---

Yet another vote for the Astronomick. I have the narrow band, OIII and H-beta filters all on a filter slide. All work great for me. The OIII might be a little broader than the Lumicon, etc., but the Veil really pops out when I use it in my scope, showing exquisite filamentary detail. Another standout is Thor's Helmet. Just a great filter for planetary nebulae (and the Veil).

Two things I really like about the Astronomick. One, they have very durable coatings, which are essentially scratch-proof and impervious to dew. Two, the view is very aesthetically pleasing, with nice pinpoint stars. In contrast, a couple of the other OIII filters I've seen (the older version of the Lumicon specifically comes to mind) yielded rather funky-looking bloated stars...

---

The point to be made here is that a slightly narrower bandwidth would enhance the contrast more, but at the expense of the stars. So which do you use the nebula filter for--nebulae, or views of stars? I'm not being sarcastic because there really is a difference in preference involved.
The TeleVue O-III is a broader one and also of superlative quality. It really does depend on preference.

Post Extras:

Quote:

---

Another vote for the Astronomik. I've compared it against others, and it is the best in my refractor. A friend has a C9.5. We checked the Astronomik against the Baader in both scopes. We agreed the astronomik was the clear winner.

But of course beware that the performance of such restrictive filters are very affected by aperture and quality of the sky. Regards.

---

Post Extras: