Archived posting to the Leica Users Group, 2010/03/21

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Subject: [Leica] Any S2 experiences? Henning
From: philippe.amard at sfr.fr (philippe.amard)
Date: Sun, 21 Mar 2010 19:50:04 +0100
References: <C7CAB1DC.5FBFE%mark@rabinergroup.com> <4BA53D30.6090007@csdco.com> <B0286439-EE1E-4BC4-A2C7-33CBFF92F07A@sfr.fr> <4BA56386.6040107@csdco.com> <5CEA607A-7531-40A2-B7CE-03B2CB499485@sfr.fr> <p06230909c7cc1377582e@[192.168.1.5]>

Le 21 mars 10 ? 19:27, Henning Wulff a ?crit :

>
> At 11:08 AM +0100 3/21/10, philippe.amard wrote:
>> Le 21 mars 10 ? 01:08, John Nebel a ?crit :
>>
>>>
>>> Philippe,
>>>
>>> Rabs put it this way: "it's a medium format camera in a 35mm  
>>> package. Delight in its deceptiveness."
>>>
>>> S2 has an f/2.5 lens vs the M's f/1.4 (or f/1.0 or even f/.95) and  
>>> is slower due to the larger image circle.  The S2 sensor is  
>>> 45x30mm and the M's is 36x24mm.
>>>
>>> Maybe it is not correct, but I was thinking of a projector as an  
>>> analog, move it farther from the screen and the image is bigger,  
>>> but darker. Twice the diagonal size, 1/4 the brightness as the  
>>> lamp has to illuminate the equivalent of four of the original  
>>> images.  Makes me think of the Meno.
>>>
>>
>> 80/2,8 = 40/1,4 = 28.5714
>>
>> you get different aperture (f) values, but the amount of light is  
>> the same as the 'hole' is the same, or am I completely mistaken in  
>> the aperture calculation formula?
>>
>> http://fr.wikipedia.org/wiki/Ouverture_(photographie)
>>
>> I would bet that the absence of faster f value on a MF/LF sensitive  
>> media lenses results from other considerations such as angle and  
>> light fall out in the outer parts of the sheet/film/sensor.
>>
>>
>> At the other end of the size spectrum, if we take the Pana 4/3  
>> pancake you'd get 20/1.7 = 11.7647 a smaller hole, hence slower  
>> speeds? unless compensated by the electronics ? with less fall-out  
>> issues?
>> I really don't know.
>>
>>
>> Thanks
>> Philippe
>
>
> If the hole is the same size (physical aperture, not relative  
> aperture or f/ number) then the amount of light is the same, but the  
> sensor/film is larger, and that amount of light is spread over a  
> larger area so that's why the relative aperture is the one that  
> makes sense, and is what we use.

Well, I never made a difference in the reading of my Gossen Lunasix  
when I used to shoot the Mamiya C3 or another 24x36 manual camera ...
I must have always got something wrong then.

>
> Faster lenses on MF cameras don't exist because: on a 6x7 camera  
> (approximately twice the linear magnification of 35mm) an f/1.4  
> normal lens would weigh about 6x as much, and would probably cost  
> more by an even larger factor if it was approaching decent.

this makes perfect sense to me.

> Then there is the focussing and dof issue.

I also get this.

> Then there is the film flatness issue. So you would wind up with a  
> 3kg, $10 to 25k lens that you couldn't reliably focus and had  
> insufficient dof. Not a big seller.

OK

>
> Your comments about m4/3 I don't understand. However, fast lenses in  
> smaller formats have existed for a while,
I know this Henning - the thing was about the smaller diameter  
allowing light to get in - f 0.9 doesn't make sense if you don't know  
the focal length , hence the diameter and the amount of light that  
gets in I guess.
This was why I had doubts about the 4/3 , which have no faster lens  
than 1.4 for 50 or 2 at 200 ...

Puzzles me - I'll get back to my Instamatic as soon as I find film :-)

Thanks for the input Henning.
Bien cordialement de Metz
Philippe




> like the 13mm f/0.9 Switar for Bolex 8mm. It was a truly superb lens  
> and it was for sale 50 years ago. 8mm movie film never produced  
> crystal clarity, but that Switar was able to get the most out of it.
>
> -- 
>
>   *            Henning J. Wulff
>  /|\      Wulff Photography & Design
> /###\   mailto:henningw at archiphoto.com
> |[ ]|     http://www.archiphoto.com
>
> _______________________________________________
> Leica Users Group.
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>




In reply to: Message from mark at rabinergroup.com (Mark Rabiner) ([Leica] Any S2 experiences?)
Message from john.nebel at csdco.com (John Nebel) ([Leica] Any S2 experiences?)
Message from philippe.amard at sfr.fr (philippe.amard) ([Leica] Any S2 experiences?)
Message from john.nebel at csdco.com (John Nebel) ([Leica] Any S2 experiences?)
Message from philippe.amard at sfr.fr (philippe.amard) ([Leica] Any S2 experiences?)
Message from henningw at archiphoto.com (Henning Wulff) ([Leica] Any S2 experiences?)