jbouchard
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 Re: Snow Dunes (focus stacking experiment) | |
Great shots Scott, nice compositions all of them.
I don\'t mean to steal the thread but there seems to be some interest, so I\'d like to throw in a little about how I do focus stacking... the lazy man\'s way. I\'m a professional geek so the computer part of this is easy for me, it\'s the artsy part that I struggle with. I like this lazy man\'s approach because the effort to post process it is almost nil, which encourages me to shoot a bunch of shots, run them through the process and see what I get. If I don\'t like what I get, I can go back and try again. The shorter that feedback loop, the faster I learn.
I\'m using free software called \"hugin\" and \"enfuse\". Hugin handles alignment of the images, and enfuse handles the merging. I happen to be using it on my Linux laptop, but I\'m pretty sure it\'s available for Windows and Mac. I happen to be using funky commands at the command line, but I\'m pretty sure there are GUI-clicky apps which use hugin and enfuse in the background.
My lazy man\'s approach....
- ideally set camera to everything manual including turning off auto-iso and auto white balance. This keeps it consistent shot to shot. I seldom remember.
- set up on a tripod as appropriate to the scene. In the example below I\'m using a plain old 50/1.4 manual focus lens at f/5.6 to optimize sharpness while putting my background a bit out of focus.
- I shoot a handful of shots, like 5-10 depending on the depth. Just think of it this way... obviously to generate a crisp image in total, we need every piece of the puzzle sharp in at least one shot. For landscapes that might be 3 for macros it might be 40.
- the way I adjust focus is by simply rotating the focus ring between shots. You will get some focus breathing, but the software can deal with that. Don\'t frame too closely, leave a little extra around the sides, because the align and merge has a cropping effect. Some people use complex setups like rack and pinion slides, I don\'t.
- I take JPGs straight from the camera, because I\'m lazy and because it runs much faster on my computer. Convert RAW if you must, but make sure to do the same conversion for each shot.
- With Hugin there is a program called \"allign_image_stack\". I just run the command \"align_image_stack -v -m -a OUT *.JPG\" It generates a set of aligned TIF files called OUT0001.TIF, etc.
- Enfuse handles the merging. I run \"enfuse -v --exposure-weight=0 --saturation-weight=0 --contrast-weight=1 --hard-mask --contrast-edge-scale=0.5 --output=output.tif OUT*.tif\" It generates one file called \"output.tif\".
- On my 4 year old laptop each of those steps takes a couple of minutes. I\'m using 12mp normal JPG images from my D700, with half a dozen shots. If you have 36mp images x 40 shots it will probably churn all day.
Below is a shot from 7 images run the the above process, and no post processing beyond that point. I\'d take this result and apply a bit more color saturation etc, I just haven\'t gotten there yet. There is a bit of \"halo\"in places, particularly on that one leaf at 10 o\'clock. I\'m trying to figure out how to minimize that, but haven\'t figured that out yet.
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