Raw files are what comes from the camera.
Does not matter what lens, filter, lighting, or even if fingers in front.
Peace, tOM Trottier 613 860 6633
2015 Feb 23 - Mon at 13:04 re:Re: [OM] Spotmeters …
Chuck Norcutt <olympus@xxxxxxxxxxxxxxxxx>wrote
>I don't consider a filtered image to be a raw file... at least not as
>the manufacturer intended it to be.
>
>Chuck Norcutt
>
>
>On 2/23/2015 11:34 AM, Ken Norton wrote:
>>> Yes it does. We proved that back in the B&W thread where the RAW
>>> photos came out exactly the same regardless of the Wratten filter that was
>>> used.
>>
>> Lens filters CAN and DO make a big difference if you are needing to do
>> correction to equalize the RGB sensels. This is very evident when you
>> do highlight or shadow recovery.
>>
>> Most camera sensors do not saturate equally. And even if they did, you
>> still have an issue with derived colors. In really, all colors are
>> derived colors, no matter what colors they are. Huh?
>>
>> Let's take a pure red. Photograph it. If you look at the actual data
>> stored in the raw file, you'll see the red sensels getting
>> measurements, but the green and blue sensels at or near zero. However,
>> once converted, the three sensels are combined and a fuzzy math
>> applied to the conversion and red is no longer red. The histogram you
>> are looking at is almost certainly not that of the red sensels, but of
>> the red channel of a combined RGB pixel.
>>
>> Still think I'm smoking dope? Well, do this. Put a Red #25 filter on
>> the lens of your digital camera and take some test pictures. Be VERY
>> careful to meter the scene before you put the filter on and take an
>> unfiltered shot. Lock the exposure down, shoot it with the filter.
>> Now, let the meter do its thing and shoot it again. Have fun doing
>> some +2/-2 brackets. Open the files up in your favorite raw converter
>> and start looking at your histograms. In fact, why don't you try doing
>> a monochrome conversion.
>>
>> That is what is happening with your lovely flowers.
>>
>> "Mommy? Why are those red tulips turning yellow?"
-- Absum! -- Quidquid latine dictum sit altum viditur.
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