Ladies and gentle beans,
I'm told the best technique for focus stacking is to move the camera, not the focusing ring. All well and good with macro, but you can't do that with a landscape photograph.
My problem is this: when changing focus for files to be focus stacked, I'm getting a lot of geometric distortion caused by changing the focusing point, more so at the top and bottom of the frame on a vertical comp. This makes it more difficult for CS5 to align and blend the files accurately. Sometimes it will and sometimes it won't.
Is there a common workaround for this, or do I have to buy a 30ft focusing rail?
I do focus stacking with an Arca Swiss monorail tethered to a laptop for macro work and then process the images in Zerene Stacker. I get beautiful results by moving the camera down the rail at about a mm a shot and will end up with a stack of 20+ images that will then be processed. I do not do this with landscape photography, but I had heard of Image Stacking using Multiple F-Stops and thought I would send this info along for you to read:
Barry - The reason to move the camera and not the focus ring is because it helps keep things aligned close to the lens as you would have with macro. It causes less of a perspective change than the zoom ring does. It still doesn't fix things entirely, but helps. So with landscape, even if you had a long enough macro rail, it would introduce much more perspective change at those lengths and be useless.
So with landscape, I wouldn't hesitate to use the focus ring. I'm assuming since you're having stacking problems, there are elements very close to the camera? So you have to use a lot of the focus range for the lens? If so, then yeah, alignment and distortion might be a problem from moving the focus ring a lot. The other possible problem is that your lens has enough distortion that it makes it difficult to stack.
Either way, you might need to take some more manual steps or try different software. It might be worth trying Zerene Stacker and Helicon Focus. They may do a better job, and I think both have options to help the software to align things - manually setting some points essentially.
I also use Helicon for this Barry and it does a lot better than CS. Sometimes there are slight problems, but nothing yet that I have not been able to fix.
Discussion
4 repliesI'm told the best technique for focus stacking is to move the camera, not the focusing ring. All well and good with macro, but you can't do that with a landscape photograph.
My problem is this: when changing focus for files to be focus stacked, I'm getting a lot of geometric distortion caused by changing the focusing point, more so at the top and bottom of the frame on a vertical comp. This makes it more difficult for CS5 to align and blend the files accurately. Sometimes it will and sometimes it won't.
Is there a common workaround for this, or do I have to buy a 30ft focusing rail?
http://www.cambridgeincolour.com/tutorials/image-stacking-fstop.htm
Good luck!
Darr
So with landscape, I wouldn't hesitate to use the focus ring. I'm assuming since you're having stacking problems, there are elements very close to the camera? So you have to use a lot of the focus range for the lens? If so, then yeah, alignment and distortion might be a problem from moving the focus ring a lot. The other possible problem is that your lens has enough distortion that it makes it difficult to stack.
Either way, you might need to take some more manual steps or try different software. It might be worth trying Zerene Stacker and Helicon Focus. They may do a better job, and I think both have options to help the software to align things - manually setting some points essentially.