Archived posting to the Leica Users Group, 2003/12/24
[Author Prev] [Author Next] [Thread Prev] [Thread Next] [Author Index] [Topic Index] [Home] [Search]we want to take pictures of something from our workplace at night What else? silly man - ----- Original Message ----- From: "B. D. Colen" <bdcolen@earthlink.net> To: <leica-users@mejac.palo-alto.ca.us> Sent: Wednesday, December 24, 2003 10:45 PM Subject: RE: [Leica] Fw: looking for line pairs with a stabiliser and a Leica and question > And, just out of curiosity, this has what to do with photography or any > real world use of Leica equipment? Just wondering. ;-) > > -----Original Message----- > From: owner-leica-users@mejac.palo-alto.ca.us > [mailto:owner-leica-users@mejac.palo-alto.ca.us] On Behalf Of animal > Sent: Wednesday, December 24, 2003 3:58 PM > To: leica-users@mejac.palo-alto.ca.us > Subject: [Leica] Fw: looking for line pairs with a stabiliser and a > Leica and question > > > Sorry for the earlier empty post. > Here goes. > A collegue and myself wanted to find out if we could get 80 line pairs > per millimeter using a Leica and a Kenyon gyro stabiliser. We could not > find those data in literature so last night, while also doing a test of > Laphroig versus Lagavullin, we decided to give it a try ourselves. > > We scribbled some lines on a piece of paper with a group of line pairs > one 1 cm per pair and the other 5 mm per pair. With a Noctilux 18 meters > away we calculated the image on the film to be 36 and 72 line pairs per > millimeter. We suspended the camera and running gyro from a bungee cord > and started. First exposure was at 1/250 second and f1.0 going in stops > to 1 second and f16.0. > > Then we tried the same sequence while handholding the camera and bracing > ourselves in a doorway. > > By then we became to doubt the ability of a 4000 dpi scanner to resolve > our results. While one would assume that 4000 dpi translates to 80 line > pairs per millimeter,some knowledgeable people we asked suggested that > 60lp/mm is about the best such a scanner can do. So we had to aim a > little lower and did the same test with an aasummicron90 mm and the > stabiliser starting at 1/60 and f2.0 . > > Although our test was hastily done it still yielded some suprises to us. > The biggest being that the stabiliser clearly is able to permit shots at > 1 second. Others were that the noctilux was still giving good results at > f 4.0 and 5.6 and stayed that way until f16.(we realise that the focus > shift of the lens could have been to our advantage at those apertures if > we started out with a focus error). Also suprising was that at f 8.0 and > smaller the summicron image is starting to fade. Lastly it shows that it > is hard to find the testcard when handholding the camera. On the page > the first column is the stabilised noctilux the second is the same > handheld(stopping at 1/8th) and the last is the summicron. The film used > was Kodak E100 GX . The question is to get rid of focusing errors .can > one set the lens accurately at infinity just by putting the index on > thatmarkingAnd if so at what distance would one have to put the target? > http://www.leica-gallery.net/apekop/folder-6004.html > best regards > simon jessurun > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html > > -- > To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html - -- To unsubscribe, see http://mejac.palo-alto.ca.us/leica-users/unsub.html