Digital BW, The Print

--- In DigitalBlackandWhiteThePrint@yahoogroups.com, "yaakovsinclair" <sinclair@...> wrote:
>
> I'm considering getting my Canon adapted by Lifepixel to be infrared
> sensitive.
> They remove the factory filter in front of the sensor which stops IR
> getting through.
>   This allows the full spectrum of to be read by the sensor.
>   My question is -  could I do the filtering in photoshop afterwards to
> achieve the effect of an opaque IR filter or would I need to use an
> opaque IR filter in the field. (This would make shooting much easier as
> I wouldn't have to use a tripod and shoot 'blind')
> This is probably not the best forum to ask this question, but it's
> certainly a black and white question -- ( even if the answer may not be
> b and w...)
> BTW -- is there another forum that would suit this question better?
> Many thanks to all in advance
> Yaakov Asher Sinclair
> Visit my website <http://seasonsofthemoon.com>
> 
Yaakov,

I have my Canon 20D converted to dedicated IR by LifePixel.  No complaints.  They also adjust the focus, since IR focuses differently than visible light.  

They offer 3 different filters in place of the normal IR blocking filter.  The "standard" filter, which I got, is similar to a Hoya R72 IR filter, and blocks most visible light, but allows a little visible color light to pass.  It is a good all around filter.  If you are interested in more colorful IR images, they have a filter that lets more IR pass, and for dedicated B&W, they have a heavier filter that blocks nearly all color, but gives more dramatic B&W results (darker skies and water, more contrast).  All three filters blocks most of the visible spectrum.  

Using an IR filter over the lens of a normal camera (film or digital) extens the exposure dramatically, since one is blocking IR and the other is blocking visible light, thus making exposures very long.  By removing the IR blocking filter that is standard on digital cameras, you end up with exposures that are much closer to normal.  No need to mount on a tripod for daylight exposures.  It is usually advisable to shoot in manual mode and use the histogram to make sure you expose more for the highlights, otherwise you end up with lots of noise.  

Photoshop and LightRoom can mimic IR to some extent, but in my experience, they cannot really replicate IR effects, since they are starting with normal wavelengths, not IR.  Natural greenery emits a lot of IR and blue skies and water tend to emit very little.  So, using the color controls in ACR or LR, you can approach this effect, but it isn't the same.  

I am happy with the LifePixel conversion and enjoy shooting IR.  It is a whole new adventure, and it takes some time to get used to what is a good subject, since it is different from what you see.  I find that setting a custom white balance on greenery is very helpful, since LR and ACR have a limited white balance adjustment.  Makes a big difference.  

I have some IR images in one of the galleries on my website at www.DinaGraphics.com/photos.php if you want to check them out.  

I thought I sent a similar message earlier, but for some reason, it didn't post.  If you get a duplicate or similar message, I apologize.  

Regards,,

Lou Dina