[Leica] 1.8 vs. 1.4!?!?

[mark at rabinergroup.com (Mark Rabiner)]

I was dying to find out what the real difference between f2 and f1.8 was.
http://imaginatorium.org/stuff/stops.htm

Its .304 stops.
Which to me is quite a bit smaller than .333... stops which  is s third
stop.

Three tenths of a stop is not three ninths of a stop is seems to me by far.

And when you click "whole stop's" it reads out that its a half stop diff.

So I'm not going to get all excited about a 1.8 lens over a Summicron.
I think its too close to worry about.





-- 
Mark R.
http://gallery.leica-users.org/v/lugalrabs/


> From: John McMaster <john at mcmaster.co.nz>
> Reply-To: Leica Users Group <lug at leica-users.org>
> Date: Thu, 3 Nov 2011 03:51:13 +0000
> To: Leica Users Group <lug at leica-users.org>
> Subject: Re: [Leica] 1.8 vs. 1.4!?!?
> 
> Usually not just speed differences, often a f1.8 is a superior performer 
> than
> an f1.4 - with Leica as an exception ;-) DoF, build quality and size/weight
> are other typical differences....
> 
> john
> 
> ________________________________________
> 
> 
> 2/3's as a decimal is 0.6666.
> 0.7251 - 0.6666  = 0.0585
> Cant figure out what fraction that would be.
> 
> Bottom line a 1.4 is for sure faster than a 1.8 not by an incremental 
> amount
> like I thought.
> 
> 
> 
> 
> --
> Mark R.
> 
> 
>> From: Quan Tran <quantran101 at gmail.com>
>> Reply-To: Leica Users Group <lug at leica-users.org>
>> Date: Wed, 2 Nov 2011 19:36:00 -0700
>> To: Leica Users Group <lug at leica-users.org>
>> Subject: Re: [Leica] 1.8 vs. 1.4!?!?
>> 
>> I found this: http://imaginatorium.org/stuff/stops.htm
>> 
>> When I select "precised", it show 0.7251 stops
>> When I select "third", it gave me 2/3 stops.
>> 
>> -Quan.
>> 
>> On Wed, Nov 2, 2011 at 3:32 PM, Mark Rabiner <mark at rabinergroup.com> 
>> wrote:
>> 
>>> I looked up f 1.8 vs. 1.4 thinking it was between a half and a quarter 
>>> of a
>>> stop and they are saying its 2/3rds!?!?! Anybody know that that's true?
>>> 
>>> Where is there a photo calculator that tells you these things?!?!?
>>> 
> 
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