03 or nebula ?

[omegacrux (David)]

I was thinking of getting an 03 filter, would that be a good choice for visual or would I be better off with a nebula or one of the many others
This will be for a f5 150 doublet
So any input will be most appreciated

David

[Cam (Cam)]

out of all the filters I feel I was "sucked" into buying. The one I use the most is the Celestron UHC/LPR so I say Neb lol

[ausastronomer (John Bambury)]

Hi David,

I would recommend the DGM Optics NPB filter. This is also sold under the brand name of Omega Optical. It is classified as a Narrowband (UHC) filter but it has a very tight band pass and is almost a hybrid UHC/OIII filter so you get the best of both worlds. In addition to this filter I have the Astronomiks UHC and OIII filters and the Lumicon UHC and OIII filters. I have also used all of the OIII and UHC filters from Orion, Celestron, Meade, Thousand Oaks, Televue and Baader. The DGM Optics NPB gets the most use of all my filters. It offers a noticeable gain on a larger number and wider range of targets than any other filter I have ever used, probably because its almost a hybrid.

http://stores.ebay.com/OmegaFiltersE...&submit=Search

You can buy them at a good price on EBay but do not think for one minute they are a cheap inferior product because you are buying from Ebay. There are several other vendors who also sell them.

Cheers,
John B

[omegacrux (David)]

I was looking through the latest Sky at Night and they compare a few filters and o3 hardly makes a difference so I want something that can see the horsehead neb or is that something that 20 hours of camera can see and not our eyes ?

[ausastronomer (John Bambury)]

Originally Posted by omegacrux

I was looking through the latest Sky at Night and they compare a few filters and o3 hardly makes a difference so I want something that can see the horsehead neb or is that something that 20 hours of camera can see and not our eyes ?

Well on a large number of targets and under dark skies in a medium to large aperture telescope an OIII filter will be the best filter to use. An OIII filter knocks out more of the background stars than the other filters but on certain targets, particularly some emission and planetary nebula it is the best filter because it provides the greatest increase in contrast. Magazine reviews can sometimes be very subjective and not give you the full story. What targets did they do the comparison on, what telescope(s) did they use and how dark were the skies? To give you some idea where I am coming from some years agao they did a comparison of 8mm or thereabouts eyepieces. The Vixen LVW came out as the overall winner with a 90% rating ahead of the 7mm Pentax XW with an 87% rating. Now I can guarantee you having used both eyepieces extensively, while the 8mm Vixen LVW is an excellent eyepiece, it is not the equal of the 7mm Pentax XW in just about every performance aspect, yet they rated it on top. What is funny is that Vixen UK is the largest advertiser in The Sky at Night.


No filter will allow you to see the Horsehead (Barnard 33) in your 6" achro refractor. You really need a 14" plus aperture telescope and very dark skies. The DGM NPB helps on this target but is not as effective as a H-Beta filter. The best all round general purpose filter for visual deep sky observing for your scope will be the DGM NPB filter.

Cheers,
John B
Cheers,
John B

[omegacrux (David)]

Thanks John and Cam
Looks like the nbp is short listed thanks for the info
David

[rjbruce (Rob)]

Hi David,

I would agree with the general purpose nebula / UHC style filter, they are a good all round filter and will not dim the image through a six inch as much as a OIII or H-beta as the UHC has a wider band pass that includes the OIII and the H-beta band lines. Some recommend an 8" minimum scope for the smaller bandpass O-III and H-beta filters.

We have seen the horse head through a 12" light bridge at a dark site, but it certainly didn't jump out at you.

Hope that helps.
Rob