Olympus-OM
[Top] [All Lists]

Re: [OM] B&W filters on digital [was Non Bokeh 50mm F1.4 pictures]

Subject: Re: [OM] B&W filters on digital [was Non Bokeh 50mm F1.4 pictures]
From: Chuck Norcutt <chucknorcutt@xxxxxxxxxxxxxxxx>
Date: Sat, 05 Jun 2010 08:03:52 -0400
Increasing the cyans is interesting.  On your previous image turning off 
everything but the red in ACR made a mess of the sky.  But adding back 
some "blues" fixed it.

Chuck Norcutt


C.H.Ling wrote:
> I have slighly reduced the value of red and yellow to make them 100% and 
> below but the problem still exist. Tried playing with other values found 
> Cyans is the key, increase the Cyans helps a lot but this do not solve the 
> problem if the default CS4 red filter setting is simulating the effect of 
> red filter then changing anything will shift the effect.
> 
> C.H.Ling
> 
> ----- Original Message ----- 
> From: "Chuck Norcutt" <chucknorcutt@xxxxxxxxxxxxxxxx>
> 
> 
>> The first thing that gets my attention in the red filter is that there
>> are values of more than 100% while the B/W filter's values are all less
>> than 100%.  In particular, in the red filter the red and magenta are at
>> 120% and the yellow at 110%.  Does this mean that any red pixel is
>> multiplied by 1.2?  I don't know exactly what it means but if it does
>> mean multiply pixel values by 1.2 then any pixel of 213 or higher will
>> create a blown pixel.
>>
>> I note that the B/W filter with values all less than 100% produced a
>> good looking image without noise or pixelation.  Perhaps if the red
>> filter's values were divided by 1.2 you'd get proportional numbers
>> without causing blown highlights.
>>
>> That would give values of:
>>
>>> Reds 100%
>>> Yellows 92%
>>> Greens -8%
>>> Cyans -42%
>>> Blues 0%
>>> Magentas 100%
>> Chuck Norcutt
> 
-- 
_________________________________________________________________
Options: http://lists.thomasclausen.net/mailman/listinfo/olympus
Archives: http://lists.thomasclausen.net/mailman/private/olympus/
Themed Olympus Photo Exhibition: http://www.tope.nl/

<Prev in Thread] Current Thread [Next in Thread>
Sponsored by Tako
Impressum | Datenschutz