I'll check them out also, Jim KK ---- Jim Waters <james.t.waters@xxxxxxx> wrote: ============= What about the IDAS LPS D1 or P2 filters? http://starizona.com/acb/IDAS-Light-Pollution-Suppression-LPS-D1-Filter---2-48mm-P2806C737.aspx Jim -----Original Message----- From: az-observing-bounce@xxxxxxxxxxxxx [mailto:az-observing-bounce@xxxxxxxxxxxxx] On Behalf Of kevin.kozel@xxxxxxx Sent: Thursday, November 06, 2014 5:21 PM To: az-observing@xxxxxxxxxxxxx Cc: Tom Polakis Subject: [Norton AntiSpam][AZ-Observing] Re: The best single nebula filter Thanks, Tom. I'll keep looking and do some more research also. DGM also has other filters too KK ---- Tom Polakis <tpolakis@xxxxxxx> wrote: ============= The spectral curve of the NPB filter looks like it's set up to let the OIII doublet and H-Beta lines through, much like the Lumicon UHC. So it's probably a good general-purpose filter for visual observing of emission objects. Since you mentioned photography, it's not likely to do very well due to the significant "red "leak" that these filters often have. The transmission curve is shown at this site: http://www.horiba.com/uk/scientific/products/optical-filters/product-line/amateur-astronomy-filters/npb-filters/details/npb-2-00-14149/ Since your dark-adapted eyes are so poor at seeing long ward of 6000 angstroms, that transmission in the red doesn't harm its visual performance. For imaging, however, the filter is likely to be ineffective. Tom ---- Eric Steinberg <eric@xxxxxxxxxx> wrote: > DGM Optics NPB filter - best all around. You can also buy a "second" from > him that is optically perfect at a discount. > Eric > > -----Original Message----- Kevin Kozel wrote: > Hi folks. > If one were to shop for the single best filter for visual and photographic > nebula use, what would that one filter be? -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list. -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list. -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list. -- See message header for info on list archives or unsubscribing, and please send personal replies to the author, not the list.