Archived posting to the Leica Users Group, 2007/12/13

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Subject: [Leica] Consensus (? on LUG) on IR filters on M8
From: eduardoalbesi at ciudad.com.ar (Eduardo Albesi)
Date: Thu Dec 13 10:34:27 2007
References: <002e01c83d7b$d40617e0$6400a8c0@corp.nortel.com> <D914441A-FE78-4E55-90A0-747588E9F58C@ciudad.com.ar> <E568BC5C-AAAC-4052-8479-1B4649DE5842@pandora.be>

Hi Philippe,
funky indeed

sadly I have  built in IR-cut filters in my eyes...
LOL

makes you think of all the funky colors we're loosing outside our  
usual spectrum...

Ed

El 13/12/2007, a las 15:18, Philippe Orlent escribi?:

> Hi Ed,
> And there I was thinking: those are damn funky bags...
> Philippe
>
>
>
> Op 13-dec-07, om 15:38 heeft Eduardo Albesi het volgende geschreven:
>
>> Vick,
>>
>> There are noticeable color differences between using and not using  
>> the IR cut filters. The degree of how much noticeable this effect  
>> is depends on the particular lighting conditions of each scene.   
>> There are light sources that are more IR rich than others, as  
>> tungsten and halogen lamps. The sun is another high power IR  
>> emitter, but the high emissions in the rest of the visible  
>> spectrum tend to mask the IR artifacts of the M8.
>> Fluorescent light lacks typically IR emission in the M8 critical  
>> band, so there's no problem under them.
>>
>> The following samples are under halogen light, with and without  
>> filter, I think it cannot get worse than this:
>> http://gallery.leica-users.org/v/Fuchs/tech_001/IRNightmare1.jpg.html
>>
>> But it is effectively solved by the use of filters:
>> http://gallery.leica-users.org/v/Fuchs/tech_001/IRNightmare2.jpg.html
>>
>> Filter used is a B&W 486 UV/IR Cut filter. The lens is an Elmarit- 
>> M 28/2.8 asph.
>> Both files shot in DNG, converted to JPG in Adobe Camera Raw (PS  
>> CS3).
>>
>> There is another IR contamination effect that affects the M8: a  
>> soft focus 'glow' under certain circumstances. This latter effect  
>> is caused by the superposition of a focused visible-spectrum image  
>> and an out of focus IR image (remember that the IR plane of focus  
>> is slightly offset from the visible plane of focus, hence the  
>> different focusing IR mark on older lenses). This has been  
>> extensively exposed on other fora, especially the LUF.
>>
>> So, just color correcting the files does not solve the IR issue.  
>> But with high quality IR filters (B&W, Heliopan or Leica) you  
>> don't have any side effects, and the increased color and focus  
>> precision you get are worth their use. BTW, I have never noticed  
>> any image quality degradation using either brand.
>>
>> So, just mount them on every one of your lenses, forget about them  
>> and enjoy the camera, one of the very best out there.
>>
>> Ed
>>
>>
>>
>>
>> El 13/12/2007, a las 08:32, Vick Ko escribi?:
>>
>>> So, is there consensus on using IR filters on the M8, on lenses  
>>> without
>>> coding?
>>>
>>> I've searched the archives a bit, and get the perception:
>>> *   using the filter does degrade the image slightly
>>> *   it does work, but the magenta flaw happens only under pretty  
>>> severe
>>> conditions anyway
>>> *   for the majority of photo conditions, the filter isn't necessary
>>>
>>> I've been tempted with an M8, from a very reliable source and  
>>> very tempting
>>> conditions.
>>>
>>>
>>> ....Vick
>>>
>>> _______________________________________________
>>> Leica Users Group.
>>> See http://leica-users.org/mailman/listinfo/lug for more information
>>
>>
>>
>> _______________________________________________
>> Leica Users Group.
>> See http://leica-users.org/mailman/listinfo/lug for more information
>>
>
>
>
> _______________________________________________
> Leica Users Group.
> See http://leica-users.org/mailman/listinfo/lug for more information
>



In reply to: Message from vick.ko at sympatico.ca (Vick Ko) ([Leica] Consensus (? on LUG) on IR filters on M8)
Message from eduardoalbesi at ciudad.com.ar (Eduardo Albesi) ([Leica] Consensus (? on LUG) on IR filters on M8)
Message from philippe.orlent at pandora.be (Philippe Orlent) ([Leica] Consensus (? on LUG) on IR filters on M8)