> Message du 26/08/15 21:33 > De : "Jean-Luc CECCOLI" > A : "RomanoGiannetti" , darktable-users@lists.sourceforge.net > Copie à : > Objet : Re: [Darktable-users] milky way picture post processing > > > With my old D700 whose iso range is (100) 200 - 6400 (25600), I found the > upper limit for well contrasted > low-noised pictures to be 800-1200. > From 1600 up, the noise becomes more and more visible. > Ary's being more recent (and a Canon), things may be a little different. > I took a series of photos at ISO 200 & 800 without a motorized mount a few > nights ago the same as Arry !). > I used 30 s exposure, with a 20 mm f/2.8. > At iso 200, the stars are almost punctual and one can see meteors, the milky > way and andromeda. > All dimm, but visible. > At 800, the sky is less dark and the pollution due to the lights of the city > begins to be visible. > I am at 41,55° north, and the lens was pointed near the zenith, which > explains that the stars are > punctual. Gniiiiiiiii ! Big cut-and-forget-to-paste there under ! > In the case of Arry, I think he must live nearer and/or souther to the > equator (it's night at the same time > it was still daylight here, and corona borealis is at a place it were 2 or 3 > hours after where I live), which At least 10 lines missing, and... noone noticed this nonsense ? > explains that the stars are stretched though the focal is shorter (11 mm) and > though the lens points near > the north pole (located one field right I suppose). > Anyway, all this doesn't solve the dilemma, whether buying a motorized mount > or trying to have the best > from one's hardware with the means at hand. > > > > > Message du 26/08/15 19:49 > De : "Romano Giannetti" > A : darktable-users@lists.sourceforge.net > Copie à : > Objet : Re: [Darktable-users] milky way picture post processing > > > > On 26/08/15 18:12, Jean-Luc CECCOLI wrote: > > > > That said, for astophotography i'd rather (I indeed do) use the camera > > at its nominal sensitivity. > > > > Yours is 100 ISO, that's what you should use. 400 would be still good, > > but 1600 is far too high. > > > > Yes, then you would need to use a motorized mount... but that's > > another story. > > > > > > This is not so clear, really --- it will depend a lot on the camera and > its iso-variance. Look for example at > > http://photo.stackexchange.com/questions/12480/is-high-iso-useful-for-photography > > http://photo.stackexchange.com/questions/40188/longer-exposure-lower-iso-or-shorter-exposure-higher-iso-what-gives-better > > and anyway, without a motorized mount using low iso is practically > impossible --- unless you want star trails. > > Romano > > > > > > -- > Romano Giannetti > http://www.rgtti.com/ > > > ------------------------------------------------------------------------------ > _______________________________________________ > Darktable-users mailing list > Darktable-users@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/darktable-users > ------------------------------------------------------------------------------ _______________________________________________ Darktable-users mailing list Darktable-users@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/darktable-users
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