luigi bertolotti Posted May 22, 2009 Share #61 Posted May 22, 2009 Advertisement (gone after registration) About the stops: if I counted correct, the stops between 1.0 and 1.4 go as follows:1/3 stop: 1.1547... 1/2 stop: 1.2247... 2/3 stop: 1.29099... .... Sorry...my computation (but I CAN be wrong... I never went in depth about the rigorous definition of the term "stop") gives me, between 1.0 and 1.4 : "0" stop: 1,0 (Light crosses area = 1) 1/3 stop: 1,0954.... (Light crosses area = 0,83333) 1/2 stop: 1,1547.... (Light crosses area = 0,75) 2/3 stop: 1,2247.... (Light crosses area = 0,6666) 3/3=1 stop : 1,414...(Light crosses area = 0,5) Authority needed... Link to post Share on other sites More sharing options...
Advertisement Posted May 22, 2009 Posted May 22, 2009 Hi luigi bertolotti, Take a look here New Nokton 50mm f/1.1 coming from Cosina. I'm sure you'll find what you were looking for!
masjah Posted May 22, 2009 Share #62 Posted May 22, 2009 Sorry...my computation (but I CAN be wrong... I never went in depth about the rigorous definition of the term "stop") gives me, between 1.0 and 1.4 : "0" stop: 1,0 (Light crosses area = 1) 1/3 stop: 1,0954.... (Light crosses area = 0,83333) 1/2 stop: 1,1547.... (Light crosses area = 0,75) 2/3 stop: 1,2247.... (Light crosses area = 0,6666) 3/3=1 stop : 1,414...(Light crosses area = 0,5) Authority needed... OK here's a thrid set of numbers! 0 stop 2**0 = 1 1/3 stop 2**(1/6) = 1.1225 1/2 stop 2**(1/4) = 1.1892 2/3 stop 2**(2/6) = 1.2599 3/3 stop 2**(1/2) = 1.4142 (give or take a bit of truncation error in the last decimal place). These multiply correctly, so that , for example, 1/3 of a stop followed by 2/3 of a stop would give 1.1225x1.2599 = 1.4142, that is, one stop. Link to post Share on other sites More sharing options...
wlaidlaw Posted May 22, 2009 Share #63 Posted May 22, 2009 I agree with John's calculations. The formula is root 2 to the power of n, where n is the f stop multiplication factor, starting with a f number base of 1.0000. Wilson Link to post Share on other sites More sharing options...
Finnkare Posted May 22, 2009 Share #64 Posted May 22, 2009 This is getting interesting ! My numbers came from these equations: π * R^2 = (4/3) * π * r^2 R = r * 2√3 ≈ 1,1547 r π * R^2 = (3/2) * π * r^2 R = r * √(3/2) ≈ 1,2247 r π * R^2 = (5/3) * π * r^2 R = r * √(5/3) ≈ 1,29099 r where R is the bigger radius, r the smaller radius. I don't know how correct this is, but it seems to work with the powers of 2, which in turn give the familiar series 1,4 - 2 - 2,8 ---... Link to post Share on other sites More sharing options...
biglouis Posted May 22, 2009 Share #65 Posted May 22, 2009 This is getting interesting ! My numbers came from these equations: π * R^2 = (4/3) * π * r^2 R = r * 2√3 ≈ 1,1547 r π * R^2 = (3/2) * π * r^2 R = r * √(3/2) ≈ 1,2247 r π * R^2 = (5/3) * π * r^2 R = r * √(5/3) ≈ 1,29099 r where R is the bigger radius, r the smaller radius. I don't know how correct this is, but it seems to work with the powers of 2, which in turn give the familiar series 1,4 - 2 - 2,8 ---... Completely irrelevant but the mathematicians in this thread really should take a look at this: http://www.wolframalpha.com LouisB Link to post Share on other sites More sharing options...
wlaidlaw Posted May 22, 2009 Share #66 Posted May 22, 2009 Completely irrelevant but the mathematicians in this thread really should take a look at this: Wolfram|Alpha LouisB A couple of us boring farts used it yesterday when watching the Grand Prix practice at Monaco. We wanted to know the apparent change in RPM due to doppler shift, as an F1 car goes NEYAOUUUUUU...... past you at 18000 RPM and 190 MPH. The answer is the RPM coming towards you sounds like 21,600 and going away from you like 14,400. Possibly the most useless piece of information in the world ;-}} Wilson Link to post Share on other sites More sharing options...
luigi bertolotti Posted May 22, 2009 Share #67 Posted May 22, 2009 Advertisement (gone after registration) A couple of us boring farts used it yesterday when watching the Grand Prix practice at Monaco. We wanted to know the apparent change in RPM due to doppler shift, as an F1 car goes NEYAOUUUUUU...... past you at 18000 RPM and 190 MPH. The answer is the RPM coming towards you sounds like 21,600 and going away from you like 14,400. Possibly the most useless piece of information in the world ;-}} Wilson Wilson... don't ridiculize the Doppler Effect... after all, our Universe's dimension has been computed with such formulas... and this is NOT useless to plan travels... Link to post Share on other sites More sharing options...
kenneth Posted May 22, 2009 Share #68 Posted May 22, 2009 What a load of rubbish. Fast lenses have three very real uses: 1) Use in low lighting when you don't want to use high ISO and a flash is unsuitable 2) When you want from the aesthetic point of view, to have a very shallow depth of focus 3) Linked to the above, fast lenses tend to have a particular signature, unique to each lens. This can be used to great effect. Some of my best photos with the M8 were taken when I had a Noctilux and it was being used wide open. Sadly due to an old hand injury plus arthitis, it was just too uncomfortable to use but I still regret letting it go. As and when I can afford it, I will almost certainly get a new Noctilux, which due to the different dimensions, fits my hand much better. Wilson I rest my case Link to post Share on other sites More sharing options...
andybarton Posted May 22, 2009 Share #69 Posted May 22, 2009 Kenneth I'd have thought that Wilson's 3 arguments were pretty strong. Can you expand further on why you "Rest your case", given his response? Link to post Share on other sites More sharing options...
Maarten van Druten Posted May 22, 2009 Share #70 Posted May 22, 2009 I also ordered a copy of the 50 F1.1 lens, I'm sure it wil be my fave lens in te future. Now I'm using the 35 F1.2 lens the most, I like it's soft, painting like image and of course it's handling (I like it big ;-) The 50 F1.1 has "only" 10 aperture blades, while the 35 F1.2 has 12.... We have wait to see what the brokeh will look like..... Link to post Share on other sites More sharing options...
alexanderruas Posted May 22, 2009 Share #71 Posted May 22, 2009 I also ordered a copy of the 50 F1.1 lens, I'm sure it wil be my fave lens in te future.Now I'm using the 35 F1.2 lens the most, I like it's soft, painting like image and of course it's handling (I like it big ;-) The 50 F1.1 has "only" 10 aperture blades, while the 35 F1.2 has 12.... We have wait to see what the brokeh will look like..... how does the nr of blades usually affect the look? Link to post Share on other sites More sharing options...
veraikon Posted May 22, 2009 Share #72 Posted May 22, 2009 how does the nr of blades usually affect the look? it influences the bokeh . Link to post Share on other sites More sharing options...
Maarten van Druten Posted May 22, 2009 Share #73 Posted May 22, 2009 more blades gives a more perfect aperture circle resulting in "better" (softer) "bokeh" But it also depends on the shape of the blades "Curved" ones may give a more perfect circle than "straight" ones Does anybody know how many aperture blades the Leica F0.95 Noctilux has? (it's not listed in the technical PDF on their website) Link to post Share on other sites More sharing options...
wlaidlaw Posted May 22, 2009 Share #74 Posted May 22, 2009 how does the nr of blades usually affect the look? Because the edge of the aperture blade acts as a line on a diffraction grating or one edge of a Schlieren slit and the light diffracts round the edge. It is probably of more relevance for flare ghosted images. If say you have a 6 blade diaphragm, the ghosted images will be hexagons. It is usually said that the more diaphragm blades you have, the smoother your bokeh will be but there are many other factors. The worst bokeh I had on a modern lens was on the Zeiss 35mm Planar G, which had a 12 blade diaphragm but personal taste enters into the equation as well. Picture below showing basic Schlieren apparatus Wilson Welcome, dear visitor! As registered member you'd see an image here… Simply register for free here – We are always happy to welcome new members! Link to post Share on other sites Simply register for free here – We are always happy to welcome new members! ' data-webShareUrl='https://www.l-camera-forum.com/topic/85386-new-nokton-50mm-f11-coming-from-cosina/?do=findComment&comment=907827'>More sharing options...
captain Posted May 22, 2009 Share #75 Posted May 22, 2009 "....... and when you get a bad one, it is very very bad." So too must you remember I have heard just as many horror stories of Leica lenses being lemons out of the box. When Voigtlander does it its poor quality control, when Leica does it its just the handbuilt nature of their products but easily rectified LOL. (I love it when I hear that on a 5 grand lens :-) You have definitely had a bad run buy the sounds of it, im sure someone out there has had dud Rolexs or other premium products and swear off them. In your situation after 3 I probably wouldn't stick with a brand either. My first 40mm f1.4 has a stiff focusing problem and the front began to loosen, it was a common problem with the first batch but to Cosina's credit they redesigned the lens and by the second batch the problem had been solved. In a similar situation I doubt Leica would have responded so quickly and pretended there was never a systemic fault at all. You still are reasonably prepared to give this lens a try (4th time lucky hopefully) but why dont you first meet up with another forum member for the day who eventually gets one and are happy with it and have a try that way and see if you like it? I see alot of people already dissing the image quality of the shots from the lens but remember that Tom shot them all handheld. He wanted to test the lens as he would in the field as a handheld lowlight shooter. The few users and testers have all suggested it is superior in optical quality to the f1.0 Noctilux but people seem to be already saying it cant come close to this lens. In reality though most Voigtlander offerings are better than the previous generation of Leica lenses, this one is no different with the new .95 being king of the hill. The old ones have been fetching ridiculous prices lately. This lens should offer a viable alternative with no optical compromise to the older Noctilux on what after all is a decades older design. Link to post Share on other sites More sharing options...
Guest darkstar2004 Posted May 22, 2009 Share #76 Posted May 22, 2009 This is getting interesting ! My numbers came from these equations: π * R^2 = (4/3) * π * r^2 R = r * 2√3 ≈ 1,1547 r π * R^2 = (3/2) * π * r^2 R = r * √(3/2) ≈ 1,2247 r π * R^2 = (5/3) * π * r^2 R = r * √(5/3) ≈ 1,29099 r where R is the bigger radius, r the smaller radius. I don't know how correct this is, but it seems to work with the powers of 2, which in turn give the familiar series 1,4 - 2 - 2,8 ---... Some people say we Leica junkies are camera nerds. I just don't see where they get that from... Link to post Share on other sites More sharing options...
Guest darkstar2004 Posted May 22, 2009 Share #77 Posted May 22, 2009 Here's a bit of what Tom Abrahamsson has to say about the Nokton 50/1.1: I like it for several reasons. A - It is affordable, B - it is a modern lens with 35 years of evolution since the Noctilux when it come to glass composition and coatings, C - It is compact enough that it can substitute for a regular 50 with the added speed when needed. <snip> Sharpness at f1.1 is quite remarkable - very low flare, very little if any distorsion and, yes , it is a damned good lens and at a price that is palatable too. You can find a nice evaluation/essay from Tom about this lens here Voigtlander 50/1.1 Nokton Link to post Share on other sites More sharing options...
Finnkare Posted May 22, 2009 Share #78 Posted May 22, 2009 Some people say we Leica junkies are camera nerds. I just don't see where they get that from... Beats me . Link to post Share on other sites More sharing options...
kenneth Posted May 22, 2009 Share #79 Posted May 22, 2009 Kenneth I'd have thought that Wilson's 3 arguments were pretty strong. Can you expand further on why you "Rest your case", given his response? Work it out Andy- see his avatar Link to post Share on other sites More sharing options...
andybarton Posted May 22, 2009 Share #80 Posted May 22, 2009 Work it out Andy- see his avatar No You'll have to spell it out to me. Wilson's avatar is of him in a helmet in a car Link to post Share on other sites More sharing options...
Recommended Posts
Archived
This topic is now archived and is closed to further replies.