Noctilux: how much light?

[Tinchohs]

Advertisement (gone after registration)

I've been wondering how much more light does the 0.95 lens allows in compared to the 1.4. Not easy to find what's the scale for anything less than f1. Thanks!

[ho_co]

Martin--

 

There was a long thread on the topic a while back where I demonstrated my lack of mathematical understanding and got well corrected!

 

The f/stop series works on a factor of √2.

 

I found that the easiest way to do it in a spreadsheet was use two series: Start one series at √2 and another at 1, and then double each sequence in turn.

 

To answer your question, there is no visible amount of difference in the amount of light passed at f/1.0 and at f/0.95.

 

In film days, 1/3 stop was taken as the smallest difference that can be seen; and 1/3 stop faster than f/1.0 would be f/0.88.

 

 

And one of the people who straightened me out will doubtless be along soon to put the icing on the cake!

[miscbill]

My math says about that's a difference of about 1.1 stops, which translates to about 2.2 times the light at f/0.95. Practically, that means that the f/0.95 will let you use half of the exposure time that would be required at f/1.4.

 

bill

[ho_co]

Ohmigosh! Sorry. I misread your post, Martin!

 

I thought you were asking the difference between the f/1.0 and the f/0.95: Basically, there's none to speak of there.

 

But what you asked was the difference between f/1.4 and f/0.95. My error.

 

Bill's answer is correct: An f/1.0 lens will let in one stop more light than an f/1.4, i.e twice as much in the same period of time.

 

 

Gee, from here on in, I'm not going to complain about people responding to a question other than the one asked.

[SJP]

<snip>Gee, from here on in, I'm not going to complain about people responding to a question other than the one asked.

What is the best way to cook fish & chips 2x faster?

 

[Tinchohs]

Thanks guys. Very much appreciate it. Now I have to get my head around the idea or saving for one of these lenses. We'll see!

[RobSkeoch]

Advertisement (gone after registration)

I'm not sure people buy the lens because of it's speed in low light, but because of the look of the images when shot wide open. Really in most cases the F1.4 will work great, it's just the look you get with the F.95 that is hard to beat.

I find it funny that people buy slow zooms and consider an F2.8 to be a really fast zoom for the dSLR, while rangefinder shooters get to use lenses many stops faster.

 

I don't own the noctilux myself. I think it's a great idea for those that like the look of the images.

[ho_co]

What is the best way to cook fish & chips 2x faster?

 

 

Stephen--

See? I knew you'd soon be along and even said so above!

... And one of the people who straightened me out will doubtless be along soon to put the icing on the cake!

[ho_co]

Martin--Rob's response is on the money.

 

I have the Summilux, but the extra stop of the Noctilux and its very special boke wide open represent a fantastic achievement from Leica.

 

You wouldn't go wrong with either, but the Noctilux is special. Two or three issues back, LFI offered a pretty good article on the Noctilux. And there are some good images here on the forum as well.

[Overgaard]

The f-stops are always halving and doubling of light.

 

I keep being annoyed about the lack of communication skills applied by the first camera engineers when cameras and lenses was designed. The aperture scale of f/2, 2.8, 3.4, 4.0, 5.6 makes absolutely no sense unless you know their thought behind it.

 

The f-stop aperture scale is an expression of the hole through (the word aperture comes from "to open") compared to the focal length. Hold on to your hats and glasses:

 

A 50mm lens which to most of us is a matter of viewing field, is actually 50mm because there is 50mm from the film plane to the focus axis inside the lens.

 

And the aperture f/2 then is focal length 50mm/2 = 25mm.

 

For a 90 mm lens f/2 the hole through would then be 45mm.

 

So the reason the aperture stops goes 1.4 - 2.0 - 2.8 and so on is that each step is halving or doubling the amount of light.

 

So the f/0.95 is 50mm/0.95 = a hole through of 52,6mm

 

Two lessons to be learned:

 

1) Forget about the engineer expressions f/2.8 and f/5.6 and just remember that each full click is halving and doubling of light intake. As each step in shutter speed (from 1/250 to 1/125 for example is also a halving or doubling of light intake, and ISO steps from say 100 ISO to 200 ISO is also a doubling or halving of light sensitivity, these are the parameters that goes together. You turn the lens aperture down from f/1.4 and can reduce ISO from 200 to 100 ISO. Same light intake, hence same correct exposure.

 

It'a all in place to make it possible to control the amount of light, though using the aperture should be used as a composition tool to increase or decrease the DOF so as to create "three dimensional composition" or simply by making the background sharp in for example shooting a group portrait with an f/1.4 lens (provided you want all faces to be sharp you have to go to f/4 or something).

 

2) Peter Karbe, who designed the Noctilux-M f/0.95 said in September 2010 to the LHSA audience in Solms that in designing the new Noctilux they wanted to surpass the precious ones; meaning same size and weight despite floating elements mechanism inside (!), and with better performance overall. Solms is not exactly a happening place in regards to night life, so the Leica people have to find their own ways of entertainment, such as developing impossible lenses. So how should they do that. Contrast, sharpness, micro detail ... and light! It's obvious that if you want to make the most light-strong lens better, it has to be more light-strong.

So that is the main reason the f/0.95 if not f/1.0. It's more difficult (a lot) to achieve those extra f/0.05, so it had to be done.

[giordano]

I keep being annoyed about the lack of communication skills applied by the first camera engineers when cameras and lenses was designed. The aperture scale of f/2, 2.8, 3.4, 4.0, 5.6 makes absolutely no sense unless you know their thought behind it.

 

I think you're forgetting two things. One, 19th-century camera engineers and lens designers didn't use f-numbers but a variety of aperture scales. Two, the f-number scale was universally adopted (between the 1890s and the 1920s) because unlike its predecessors it is dimensionless, doesn't involve any arbitrary constants, and works consistently for all focal lengths and stop sizes. In other words it makes a lot more sense than what went before.

[tobey bilek]

.95 meaningfully is 1 stop faster than 1.4.

 

.95 is inconsequential compared to 1.0.

 

I think you will find .95 is a better lens than the 1.0 both full open.

[smkoush]

Consider two lenses (lens A and lens of the same focal length, but two different apertures. Lens A has aperture alpha and lens B has aperture beta.

 

Then,

 

Amount of light through A

------------------------------------- = ( beta^2 / alpha^2 )

Amount of light through B

 

For this particular example, if lens A is 0.95, and lens B is 1.4, then lens A will allow 2.17 times more light, i.e., slightly more than 1 stop.

 

This is true for any aperture of any two lenses of the same focal length, i.e., a Noctilux used at f5.6 will collect half the amount of light than an Elmarit used at f4 as A/B = 4^2 / 5.6^2 = 0.51, i.e., a stop less.

 

 

Savvas

[Tinchohs]

I'm not sure people buy the lens because of it's speed in low light, but because of the look of the images when shot wide open. Really in most cases the F1.4 will work great, it's just the look you get with the F.95 that is hard to beat.

I find it funny that people buy slow zooms and consider an F2.8 to be a really fast zoom for the dSLR, while rangefinder shooters get to use lenses many stops faster.

 

I don't own the noctilux myself. I think it's a great idea for those that like the look of the images.

 

I follow... Perhaps I was not clear. I've been considering a 50mm lens, and I particularly like the way the older lens renders images at 1.0. I was unclear how much better 0.95 was compared to f1.0. It felt like it was not a full stop, but I was unsure if below one the scale was somewhat different.

 

Thanks SO much!

[luigi bertolotti]

I follow... Perhaps I was not clear. I've been considering a 50mm lens, and I particularly like the way the older lens renders images at 1.0. I was unclear how much better 0.95 was compared to f1.0. It felt like it was not a full stop, but I was unsure if below one the scale was somewhat different.

 

Thanks SO much!

 

It's all the same... reason for Zeiss once made a famous f 0,7 - 2 full stops over 1,4 (even if designing it as a f 0,63 ).. see another thread in "Barnack's bar" ("Kubrick and the f 0,95...")

[ho_co]

Now wait a minute, Martin!

 

That's the question I answered in response #2 above, before I realized you weren't asking it.

 

In terms of light-grasp, the difference between f/1.0 and f/0.95 is negligible.

 

The (standard, spherical design) f/1.0 lens was famous for its boke wide open. It had a bit of focus shift as you stopped it down.

 

The (new, aspherical design) f/0.95 has been designed

• to mimic that boke wide open;
  
• to reduce focus shift on stopping down; and
  
• to give better, 'snappier' performance when stopped down.
  

 

As I said above, see the LFI that has a comparison of all the Noctiluxes. The new one is a better performer in general, but that's not because of the minuscule difference in light-gathering.

 

 

The aperture series from one stop below f/1.0, in thirds of a stop, is:

f/0.70 | f/0.79 | f/0.88 | f/1.0 | f/1.1 | f/1.3 | f/1.4

 

The aperture series from one stop below f/1.0, in halves of a stop, is:

f/0.70 | f/0.83 | f/1.0 | f/1.2 | f/1.4

[luigi bertolotti]

That's perfect, Howard... I imagine the product planning meeting...

 

(lenses R&D manager) : "we have designed a f1 lens that is definitely better than the current Noctlilux ! Without that odd kind of glass we can't have anymore ! "

 

(production manager) : "hum... aspherical elements to machine... it will cost a lot..."

 

(marketing manager) : "no problem ! we will brand it as a f 0,95 ! who can say isn't so ? Maybe that hair splitters of the LUF ?"

[Michael Geschlecht]

Hello Everybody,

 

The difference between the ammount of light a lens of f 0.95 transmits as opposed to a lens of f 1.0 is 1/7th of a stop.

 

The basis for DIN choosing film speed increments which increase @ the rate of 3 units per stop was most people need a change of @ least 1/3d of a stop to see any visual difference when looking @ a developed negative.

 

Best Regards,

 

Michael

[click]

This thread is like saying a person can put instant coffee in the microwave and go back in time.

 

-click

[Advertisement]

Hallo,

Look here: Interesting Leica gear

[lars_bergquist]

The underlying rationale is that, long ago in another galaxy, Canon made a 50mm f:0.95 lens for their rangefinder cameras. I once characterised it as 'the world's most expensive ashtray'. Now even if Leica produced a better f:1 lens, some people would still say 'oh, but Canon made a 0.95 and that was the real feat – no matter how the pictures looked'. So the Gnomes of Solms decided to put a stop to that kind of talk. So now they have the bragging rights.

 

They could of course have designed a 1.4 lens with a state of correction like that of the Nocti, and nobody would have seen any difference in the imaging, but Leica would still ahve been accused of cheating. The photographic world is no more rational than the real one.

 

The old man from the Age of Reason