Dedicated B&W camera anyone?

[p_mui]

<p>Dan,<br>

<br /> I wonder what would happen if they removed JUST the AA filter and left the CFA alone. More than likely you would see an increase in sharpness when compared to the original picture. Yes, the color cast will still be there from the CFA, but this can always be processed out.</p>

[steve m smith]

<blockquote>

<p>I love film and I hope they never stop making it but processing it right ain't easy if you are a seriously committed film based photographer.</p>

 

</blockquote>

<p>It's not exactly difficult either. And many people did it without questioning it before they had another option.</p>

[dan_llewellyn]

<p>A standard conversion we do on many cameras is to remove the ICF/AA stack and replace with a new ICF. The ICF/AA is bonded together, so you can't just remove the ICF. You have to remove the ICF/AA and replace with a new ICF. This gets rid of the blur filter - or at least most of it. This is called our HR conversion (Hot Rod or High Resolution). The HR conversion increases sharpness and contrast by about 15-20% in most cases. Different cameras have different strengthes of blur filters. <br /> An interesting question is "why use a blur filter?" From a technical standpoint, you would need a minimum 50% blur filter because of the Nyquist Theorem which requires that you sample 2x digitally the maximum analog signal you are trying to record. In a RGBG CFA Bayer filter array, you might need an even higher blur filter for pure colors.<br /> Without a blur filter, you get moire patterns in certain conditions. In real life, this doesn't happen too much. Fashion photographers who photograph a lot of fabric have to be aware, but landscape photographers don't have much to worry about.<br /> All medium format cameras do not have a blur filter. My guess is that the pros know how to watch for moire, and they wouldn't put up with a blur filter in their camera. For consumer cameras, the manufacturers may be worried about somebody doing a test, posting or publishing it, and then everyone bad mouthing the camera.<br /> Interestingly, the manufactures are not willing to completely get rid of moire. It would cost too much resolution. Instead, they make a compromise to get rid of some of it to a point. The manufactures sometimes change their minds between models as well. One of my customers had a Nikon D70 and upgraded to a Nikon D200. He was upset that the sharpness was lower on the D200. I looked at the ICF/AA stack and noticed that the D200 had a much greater AA. I substituted the D70 ICF/AA and recalibrated the camera and sharpness increased. Then I made a custom ICF replacing the ICF/AA entirely. Sharpness was even much higher. <br /> You can see the results of our testing at <a rel="nofollow" href="http://www.maxmax.com/nikon_d200hr.htm" target="_blank">http://www.maxmax.com/nikon_d200hr.htm</a></p>

[yofoto_.]

<p>dan,<br>

since hot rodding a camera increases moire, will that also increase chromatic abberation?</p>

[dan_llewellyn]

<p>Yofoto,</p>

<p>An HR conversion won't affect chromatic aberration. Moire and chromatic aberration are two different things. Chromatic aberration is caused by focal plane differences between different light wavelengths (colors). Chromatic aberration is a lens issue. Moire is a sensor and camera software issue. Moire has to do with the digital sampling of an analog signal when you approach the limits of resolution for the digital sensor.</p>