Archived posting to the Leica Users Group, 1998/04/27[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]
>Message text written by Danny Gonzalez >I own both the Canon 50/1 and 85/1.2 lenses and am in NYC. If you're anywhere near, = >maybe we can test the lenses? If not, I'd be glad to go out to the roof and answer your = >questions. Just tell me what I need to do and with which film. Hi Danny, Thanks for the offer - putting the canon 50 and 85 lenses through there= paces, perhaps with the Leica 50 and 75 alongside, would be a clash of the titans which I would love to see and no doubt produce some very = interesting results. But I will probably not be in your vacinity for a while - wrong continen= t , I live just North of Inverness Scotland. If however you are interested in giving it a go - pushing your lenses to= the limits here' s a few pointers for fixed camera star photography: Use a exposure of 600/lens_focal_length any longer and the rotation of t= he earth starts to show up as star trails e.g. 50mm gives 12 seconds or 85 gives only 7 seconds = If its totally dark i.e. no moon or city lights - it's impossible to get too much exposure - If the lens is up to it - but as the exposure of a point source builds up beyond the minimum, what was once a single point starts to spread out. This is the problem the Noctilux handles so well, b= ut the Noct -Nikkor was hopeless at. = If you have it, the LFI article 'Lens and Image quality ' on pages 28,29 = of LFI 8/96 shows what happens very clearly. e.g. totally dark try - 50 f/1 @ f/1 for 12 s with Kodak TMZ pushed to 50,000 ASA This will even record the milky way bright and clear = But if the moons out or there is city skyglow using a film much faster than 1600 ASA for the same exposure and you will get pictures that look like they were taken during the day and only the brightest stars ( i.e. those in the classic constelations ) will show up. As for films: = I have found both Provia 1600 and Kodak EPH push very well to push +4 (= as long as you intend to print it - other wise push +3 ) = I only started trying color neg this year, but Kodak PJC at push +3 seems= to show more detail than TMZ at 50,000ASA - I think its because of the better red sensitivity. A more straight forward test : with the Noct-Nikkor, I found that with 1600ASA film at f/1.2 and say 20 seconds, distant street lights had a significant halo which reduced significantly with each stop the lens was closed. If things go well, I would not intend to seriously think about buying t= he Canon or any other lens until the winter and dark skies come around agai= n. I would not want to put you out of your way. If there is any thing I can do in return let me know. Thanks Donald.