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Dyptorden

Nebula Filter comparison IDAS/DGM (for the beginning)

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Hello,

Any of you guys had the chance to hold both the IDAS D1 and the DGM NPB filters? Soon I might buy my first "nebula" filter and due to lack of cash... I can't afford to make any mistake.Also anti-LP is a quality I'm looking for. In my research I found many advocates for each of them, but I didn't find a clear comparison between these two, only that both seem to be better than the aggressive Lumicon UHC.

Can you give me an advice or ... suggest some other filter from other companies?

As usual, I thank you for your patience with the newbees :D

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I've not used either I'm afraid however I'm aware that the filter guru David Knisely on the "Cloudynights" forum thinks very highly indeed of the DGM NPB filter ranking it (slightly) over the Lumicon UHC. Personally I'd put some weight on his views on that filter.

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The IDAS filter is generally considered a Light Polution Suppression filter whereas the DGM filter is a nebula filter.

The DGM removes in effect everything between 520nm and 620nm - one sort of trough is removed all else is passed.

Whereas the IDAS hsa a series of narrow cut off's at 3 or 4  narrow bits of the spectrum where I assume the main LP occurs.

The IDAS cuts at 435 (Hg), 550 (Hg), 590 (Na) and 630 (??)nm in narrow sections of say 20nm. 630nm may be Oxygen?.

Both pass the Ha and the IDAS P2 passes the SII whereas the IDAS D1 seems to block most of it.

The DGM one is as said is a single big cut off from 520 to 620nm, so whatever is removed at 435 and 630 by the IDAS is passed by the DGM, there are also bits passed by the IDAS that blocked by the DGM.

As 435nm is Hg LP then this could be relevant, I suspect that the 630 removal is less relevant.

Bit concerned that the comparison is between 2 filters that are not specifically designed for the same purpose.

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