Archived posting to the Leica Users Group, 2008/06/17

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Subject: [Leica] How IR filters affect M8 B&W
From: kididdoc at cox.net (Steve Barbour)
Date: Tue Jun 17 16:49:55 2008
References: <469309.58596.qm@web82107.mail.mud.yahoo.com> <E4DFA006-E4FC-4729-BAA0-025079645639@mac.com> <p06230903c47db1231156@10.1.16.146> <EE0F12E5-DF94-4018-9C2F-86A43D69083E@mac.com> <p06230906c47dee4264d8@10.1.16.146> <58AB8BC9-D714-408F-9A00-9453FDE2AA50@mac.com> <3e7573d40806171604t60e23d8cicf0d618b8668614b@mail.gmail.com>

On Jun 17, 2008, at 4:04 PM, leo wesson wrote:

> I have to pipe in here with a comment about IR filters.  They solve  
> certain
> problems but I find that they degrade the image quality  
> significantly if
> there is a window or light source due to that good old problem,  
> flare, which
> isn't a problem with leica/cv glass if you aren't using filters.  I  
> also
> find them to be way too fragile for my liking, I'm noticing haze and
> scratches after only about 3 or 4 months.  I find myself not using  
> them at
> all these days and consequently not using my m8 if there is a  
> situation
> where I would get that unpleasant purple black nonsense.

that the way I handle the problem too Leo,

Steve



>
>
> leo
>
>
>
> On Tue, Jun 17, 2008 at 5:57 PM, Lottermoser George <imagist3@mac.com>
> wrote:
>
>> thanks for the clarifying metaphor.
>> when filters are used in front of the sensor/lens the buckets will  
>> hold
>> different data than unfiltered data.
>> got it makes sense.
>> quite the same as film.
>> if the data isn't there you can't put it there later.
>>
>> Fond regards,
>> George
>> george@imagist.com
>> www.imagist.com
>> http://www.imagist.com/blog
>> Picture A Week - www.imagist.com/paw_07
>>
>>
>>
>> On Jun 17, 2008, at 5:44 PM, Henning Wulff wrote:
>>
>> The basic point is that the spectral information is divided into  
>> three
>>> classes, R, G and B and collected in buckets. After that there are  
>>> only
>>> limited means of separating the photons (and translated charge  
>>> values) and
>>> their qualities into their smaller divisions, and that only by  
>>> comparing
>>> what's in one bucket to what's in the adjacent buckets. Software/ 
>>> firmware
>>> can do no more. Putting filters in front of the lens whether IR  
>>> cut or red
>>> makes the sorting of information by software a lot easier, as  
>>> certain
>>> variables get reduced in value.
>>>
>>>
>>
>> _______________________________________________
>> Leica Users Group.
>> See http://leica-users.org/mailman/listinfo/lug for more information
>>
>
>
>
> -- 
> Leo Wesson
> Photographer/Videographer
> 817.733.9157
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information


In reply to: Message from rgacpa at yahoo.com (Bob Adler) ([Leica] How IR filters affect M8 B&W)
Message from imagist3 at mac.com (Lottermoser George) ([Leica] How IR filters affect M8 B&W)
Message from imagist3 at mac.com (Lottermoser George) ([Leica] How IR filters affect M8 B&W)
Message from imagist3 at mac.com (Lottermoser George) ([Leica] How IR filters affect M8 B&W)
Message from leowesson at gmail.com (leo wesson) ([Leica] How IR filters affect M8 B&W)