Therefore, at optical scan resolutions higher than that, I would expect multiscanning to cause blur from movement between samples, when viewed at the pixel level before downsampling. I suspect it is the mechanicals of the Epson that limit it to an effective maximum resolution of about 2000-2400 spi. The greater the resolution, the harder this is to do. The mechanicals have to be precise enough so that all samples are precisely aligned with each other. On consumer flatbeds such as an Epson, the CCD is squirming around between the samples, and you get blur just as you would if you thumped your camera between multiple exposures. The problem with multiscanning is mostly mechanical. Determining what is random color variation caused by noise and what is information requires a fine touch, of course. Noise removal software, on the other hand, looks for random color variations at the pixel level after the image is already scanned, and attempts to smooth those by averaging them with their neighbors by some algorithm or other. It should never affect the detail in the scan (but see below). By sampling it several times and taking an average, that noise is, to some extent, filtered out.īut I would only expect an improvement in highlight areas of negatives or shadow areas of transparencies, where the light reaching the sensor was dim enough to be close to the sensor's noise floor. When the scanned material is thick, the signal is close to the noise floor of the CCD, and so the noise, which is always random in nature, has a greater influence on the resulting pixel. The idea behind multiscanning is that it takes several samples of the same spot. Perhaps the noise the Epson generates is so consistent/non-random Vuescan can't determine what's noise and what's not. I did notice a difference with my Minolta and previous scanner. I think this will help allot of people that struggle with grain issues.I haven't noticed any difference with my Epson scanner. Also as this article points out the noise is mostly in the darker areas - so you can recomp back or relayer back the upper mids and highlites if you want - which further minimizes your filtering. The idea is to isolate areas of detail as a mask, and smooth areas as another mask. We used to use convolve matrixes - to isolate edges, but find edges, or sobel filtering and curves does the same. I found another psd article, which shows exactly what I do (in a different way that does the same steps and results ) in my compositing package to control the degraining. You can enhance with the below to retain the detail on the edges. Maybe it works for allot of stuff though? But not this one - even color saturation is getting greatly reduced around detailed areas. I tried what you wrote and on an image I'm loosing allot of edge detail. In my experience Dt will accept an image a little bit softer over having some grain. Not every image should be pristine, sterile or glassy. I think if the editors sees any grain - the image is refused - which is Dt's choice - but in allot of cases some film grain makes an image look much more realistic. However since I work with film, I know how much grain there is there I am surprised that DT kicks back photos or digitally created images that has less film grain than 35 mm shot imagery. There is no magic bullet for every image if you are picky as I am. Check each color channel too - as you might treat just a channel individually as others maybe fine. Those pink blocks you got to recolor away. Sometimes retinting the colors to eliminate the color artifacts ffrom jpegging. I tend to try different stuff for different areas of the image. I spend the most time on older jpeg shot images - and those take time. and also Digital Fusion's built in degrainer and I composite or blend back so i'm only degraining the areas i want. You still need light though.įor egregious grain, I have been using a psd/ after effects plugin called remove grain. Canon seems to be the best bet in my opinion for allowing you to push your iso without much sacrifice to noise. If you shoot everything in raw, and not go too high on the iso you will be happy there. You'll find through the tabs there is color and luma grain reduction - and this works exceptional without loss of detail. However I really like the canon raw photoshop importer. I have several tools for this and have used them with photography as well. I come from a visual effects background - where we are adding film grain to our images to look like film.īut we also degrain film footage that is exceptionally noise - or degrain so we can work on it and then regrain in the composite. Im going to try that LAb color technique and see what it does.
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