[Leica] 1.8 vs. 1.4!?!? :-)

[tedgrant at shaw.ca (tedgrant at shaw.ca)]

Piers Hemy OFFERED:
Subject: Re: [Leica] 1.8 vs. 1.4!?!?


> Doesn't anyone read their Gossen exposure meter manual anymore?<<<<<

Hello Piers,
I don't recall reading it other than when the meter came out of the box. 
After I figured out how to take a meter reading it didn't seem necesary for 
anything, but press button needle shows f8.0 and be there! Once that was 
figured out that's all that was necessary. And threw it away!

But then I began using Leica's and never required any kind of meter after 
that! :-) And still don't. :-)

cheers,
Dr. ted :-)





> The Lunalux, Lunalite, Lunasix F, LunaPro F manuals all include the
> following explanatory text (along with other, much more useful material):
>
> "The [meter]  is calibrated in 1/3 f/stop increments with numerical
> indications at full stops. A table is included below with the actual
> numerical values of the 1/3 stop increments listed for levels from f/0.7 
> to
> f/128. Values not listed can be calculated from the formula that follows:
>
> New f/stop = (old f/stop) (square root (2) to the power (f/stop change))
>
> For example, if you wish to stop down 1/4 stop from f/4, take the square
> root which equals 1.414 and raise it to the power .25 which is the decimal
> equivalent of 1/4 stop."
>
> The table is in the appendix, and reads as follows:
>
> .7     2.8    11     45
> .8     3.2    13     51
> .9     3.5    14     57
> 1       4      16     64
> 1.1     4.5    18     72
> 1.3     5      20     81
> 1.4     5.6    22     90
> 1.6     6.3    25    101
> 1.8     7      29    113
> 2       8      32    128
> 2.2     9      36
> 2.5    10      40
>
> To make sense of that table, you will of course need to have a
> non-proportional font.
> Doesn't anyone read their emails in plain text anymore?
>
> Piers
>
> -----Original Message-----
> From: lug-bounces+piers.hemy=gmail.com at leica-users.org
> [mailto:lug-bounces+piers.hemy=gmail.com at leica-users.org] On Behalf Of
> George Lottermoser
> Sent: 03 November 2011 18:31
> To: Leica Users Group
> Subject: Re: [Leica] 1.8 vs. 1.4!?!?
>
>
> On Nov 2, 2011, at 5:32 PM, Mark Rabiner 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?!?!?
>
> I always thought the basic math for 1 f stop revolved around a factor of
> 1.4.
> 1.4 x 1.4 = 1.96
> 1.8 / 1.4 = 1.29
>
> so - yes - 2/3 would seem close enough for. what? I'm not sure.
>
> Regards,
> George Lottermoser
> george at imagist.com
> http://www.imagist.com
> http://www.imagist.com/blog
> http://www.linkedin.com/in/imagist
>
>
>
>
>
>
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>
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