Helicon focus

[Carl_Constantine]

Ok, so I'm trying to combine my hopper images into a nice image using HF. I"ve probably done some drastic movements because the resulting image is not very pretty ;-)

So my question relates to both taking the images and processing them in HF. Becase you have to move the camera to change your DOF to get different parts of the subject into focus, how do you accomodate that in HF? For example, the series of 4 or 5 images I'm processing is from front to back of the hopper. So when the back is in focus, the front isn't, BUT the front of the hopper is now much closer to the lens, so there is an image shift that occurs.

How are you masters that use HF (and similar tools) handling this situation, or do you?

Does everyone understand the question?
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Carl B. Constantine
http://photo-op.ca/

[rjlittlefield]

Carl,

Yes, the situation that you describe does have to be handled.

The basic idea is that the scale (and if necessary, the offset and rotation) of various images gets adjusted so as to make a set with consistent geometry.

As a matter of practice, the software does this automatically by matching up sharply rendered detail in adjacent frames of the stack. The gory details of the process are slightly different from one software package to another.

In Helicon Focus, under View | Preferences | Autoadjustment, there are parameters that control how much adjustment HF is willing to make between frames. The defaults are 3% position, no rotation, and 5% scale. These values are suitable for carefully controlled stacks like produced by focusing slides and microscope stages. They are not suitable for handheld work -- you need to allow some rotation too.

It's also important that the images be processed strictly in either back-to-front or front-to-back order. If the software is asked to match up the foremost and backmost images, without going through all the intermediates, it is very likely to produce bad results. If the images were not shot in strict order, you may need to rename the files to get them processed that way.

One thing that none of the software can handle is significant change in the line of sight. If your camera moved significantly side-to-side between frames, then your only recourse will be manual editing in Photoshop. (This is Plonsky's method.)

Try again, enabling rotation, and see if you get better results.

--Rik

[Carl_Constantine]

Thanks for the tips Rik. I adjusted all the paramters to 10%, set my radius to 3 and my smoothing to 5. The resulting image turned out MUCH better, but still many artifacts due to the grass around him. Also, it looks like I should have more images than just 4 or 5 (probably 10 or so) to get a better shot.

Thanks again, you guys rock.
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Carl B. Constantine
http://photo-op.ca/

[rjlittlefield]

Carl,

I'm glad to hear that things are going better for you. For some other ideas about stacking "in the field", see this old posting about using an enlarging lens on a bellows, and this recent posting about stacking using the focus ring of a macro lens.

--Rik