I can tell you how I get my results, however I think most users are striving for a more photorealistic look. I like to have more "pop" in the image so I remove much of the middle grays to get more contrast between the image and background. First comes the photo. It has to be a good image with good quality. I look for an image with high contrasting elements in it. I also do a lot of screen printing and the rule applies to both when converting photos, " if you start with garbage you will end up with garbage" So good quality photo comes first. Second, your substrate need to be flat, perfectly flat. I only engrave about .035 max depth so any deviation will lose detail. I surface my substrate on the cnc, move the gantry, give it a quick sanding and start the engraving process. Third, size makes a difference. The larger the project the easier the detail will show up. Think of signing your entire name on a stamp with a fat marker then signing your name on the envelope with the same marker. Obviously the one on the envelope will be more legible and the one on the stamp will be a blob of ink. I use the bi-directional method when engraving and my project is about 13" tall and 11" wide.
The photo, I bring it into photoshop and convert it to grayscale (black and white) then I start working on the contrast. For instance, in the project with my 2 children I darkened some areas and lightened others. I darkened slightly around the left side of my son to give him contrast with the background or couch he was sitting on. I also darkened between the fingers. If you don't see the contrast in the generated image of photovcarve then you probably will not see it in your project. I have not used the contrast adjustment in the software itself but it may do the same thing that I do manually.
I hope this helps and I didn't steer you in the wrong direction. Again, this works for the type of results that I am looking for.
Here is one I donated to the SPCA. This was a cat they had that was special to them. I would not have chosen this photo due to all the grays but it worked out ok.
Last edited by mggraphix
on Mon Sep 23, 2013 2:07 pm, edited 1 time in total.