Interesting method and certainly grain aliasing needs to be accounted for. I accept that you are seeing an improvement with this method. I wonder though how much benefit is gained when downsampling particularly when downsampling by large amounts. My concern would be the fact that we have no control over the pixels to be discarded therefore perhaps it would be better to gradually downsize in 10-20% steps and choosing an algorithm that adds no sharpening to the image until the last step to final size (I read this somewhere but cannot remember the source).
I have not done any film scanning for a long time and have not tried this or another technique that I have seen recommended. This one came from the Vuescan bible.
Set the scan resolution to the maximum optical resolution e.g. 6400 and set the scale to 50% (3200). It was stated that the effect could not be replicated in an editing application after but has to be done during scanning. I will probably give this method a try next time I scan a film and hope it is not a voodoo move
There are so many different options to compare. I haven't yet downloaded the Vuescan software for the V700. Maybe I should give it a try. When the Minolta Dimage 5400 II was no longer supported by the manufacturer regarding updated drivers for the new 64 bit operating systems, I found that Vuescan did include a driver that worked. I now find that Nikon do not provide drivers for my Coolscan 8000ED that allow me to use the scanner with Windows 7, but Silverfast does.
The reason I bought the V700, despite still having a couple of functioning, dedicated film scanners, was the potential for speeding up the scanning process. The 35mm film holder for the V700 can hold up to 24 frames. What this means in effect is, I can spend just a few seconds making individual adjustments for each frame, say 15 or 20 minutes in total, then batch scan all 24 negatives, leaving me free to do other things whilst the scanner's doing its job.
As a rough estimate, if it takes 20-30 minutes to make the adjustments in the scanner's software for each individual frame, including the insertion and removal of the 4 strips of negatives in the film holder, and if it takes an hour to batch scan all 24 negatives, I should be able to scan about 168 negatives during a 10 hour period, but the amount of work required from me during that 10 hour period might be as little as 3 hours. That's the appeal.
However, so far it hasn't quite worked out like that because I've spent so much time trying out the different scanning software and the different options in Silverfast. I was particularly interested in Silverfast's RAW HDR and ME (multiple exposure) scan method which claims to capture all the detail one's scanner is capable of delivering, whilst also preserving the negative aspect of the negatives.
This seemed a great idea because one doesn't have to spend time making individual adjustments for each frame in the scanner software, and one can process the images later as time permits.
Having downloaded the trial version of Silverfast HDR, which is specifically designed for converting the RAW negatives to positives and making the sorts of adjustments one might have made previously if one hadn't scanned in RAW HDR mode, I find that the entire process is unfortunately more time-consuming and that it's much more difficult to get a satisfactory color balance through that route, even when including further processing in Photoshop.
I've now reverted to using the Epson Scan software bundled with the scanner. I find it quicker and simpler than Silverfast, and any deficiencies in the color and contrast of the scanned result are usually fixed instantly with a single click on Auto Color or Auto Tone in Photoshop.
If anyone's interested, my method at this stage is to first click on Color Restoration, which dramatically changes the appearance of the image but also appears to blow out the highlights and block the shadows. I then bring up the histogram, which is similar to the 'levels' histogram in Photoshop, which allows me to unblock the shadows and reduce the highlights, causing the image to look flatter and less contrasty, but never mind because there are other controls in the Epson Scan software that are similar to the Color balance tool and Brightness/Contrast tool in Photoshop, as well as a general Saturation slider.
By playing around with these sliders for just a few seconds, moving Blue towards Yellow and/or Red towards Cyan etc, and increasing saturation and brightness, I find I can get the image in the ballpark so that often (not always) a single click on Auto Color in Photoshop results in a satisfactory outcome, or gets me 90% of the way there.
For some reason, I find it easier and quicker to unblock the deepest shadows using Epson Scan.