Photo Stitching for DoF Effects

[draymorton]

Does anyone know how to use photo stitching to create either more or less DoF?

Ryan Brenizer wrote about it on his Amazon blog a while back, but I have to confess that I still have no idea what the hell he's talking about.

Any thoughts appreciated.

[drg]

I have not read the blog you are speaking of, but this technique is being used more frequently.

There is one straightforward way to do this to produce a photograph with a much greater than normal/typical depth of field.

Use HDR image processing techniques with each subsequent image that contributes to the composite having the focus shifted slightly. A little tricky as moving the camera while refocusing can be difficult to avoid.

Shifting the focus point further and further into the picture can increase beyond hyperfocal ranges the depth of field perceived. By using the optimum focus as a opposed to the infinity or magic point of hyperfocus, the image can be extremely clear and well defined from front to back, i.e. greater DOF. A moving subject of course is out of the question.

The HDR (High Dynamic Range) or XDR (Extreme Dynamic Range) resulting composite image can still be subject to all of the other issues associated with this type of photograph.

A series of layered images with masking can be used to either increase of decrease the depth of field to accentuate a central image by adding a blurred background, or even showing two objects that normally are not in the same focal plane as both being in focus by 'building up' the photograph. This was a technique that was done even with film.

There are some photostitching tools that look for the most clearly defined, highest contrast transition or sharpest edges to link images and in doing so effectively make the final product look better. By using a manual mode to specify the exact image set to be stitched or combined, a series of shallow depth of field or out of focus elements can be included to soften the image or create a photograph where the DOF is very restricted.

Unless a large panorama or very high pixel count photo is required, it is a lot of work to get a great result. Some cameras that build a panorama in the camera now, when set to the pano mode will use the highest possible Aperture available to produce an image that is easier to 'connect' with the appropriate adjacent image.

[draymorton]

drg - thanks for the detailed reply! I think this is starting to make sense.

Btw:

Here's the Brenizer article: http://www.amazon.com/gp/blog/post/PLNK1JWPN65CVOSZV

And some neat (but expensive) software I found: http://www.heliconsoft.com/heliconfocus.html

[mjs1973]

I have used the Helicon Focus software for this technique, and I was very happy with the results. I didn't think I would use it enough to justify the cost, so I didn't purchase it. I used the 30 day trial version and it was great. It didn't watermark my images like many trial versions of software do.

Here is a link to a thread that I posted a while back with some examples.

Helicon Focus, it's like HDR for DOF

This feature has now been built into Photoshop CS4 and was one of the biggest reasons I upgraded. Unfortunately, I haven't been able to get that feature to work. :s I keep getting a "not enough memory" error.

Like DRG said, you could do the same thing manually in Photoshop with layers and masks.

[SmartWombat]

OK, I was going to mention heliconfocus too.
But I don't consider $150 expensive for what it does, particularly the multiprocessor version.

[draymorton]

Thanks, guys.

mjs - The Helicon feature is built into CS4?!

Paul - I think the multiprocessor version is a bit more expensive than $150, no?

I'm a slow learner, but I think I'm finally beginning to understand what Brenizer is talking about. He shoots with a telephoto lens at close range for narrow dof and then stitches to recreate a wide-angle field-of-view, thereby decreasing the effective dof. (If this is common knowledge for any of you guys, it certainly wasn't for me!)

What I still don't quite get is a) how you shoot the additional frames that you'll be stitching in? Wouldn't you need to be careful about shooting at the exact same angle to retain proper perspective? And it must be a royal pain to keep focus on the subject in different parts of the frame while shooting other to-be-stitched sections of the scene.

And how one accomplishes any of this while shooting a living, breathing being - with strobes, no less! - is completely and utterly beyond me.

Anyway... lots to learn. Thanks again for the input!

[mjs1973]

Thanks, guys.

mjs - The Helicon feature is built into CS4?!

Yup. Here is a video showing how to use it.

http://vimeo.com/2133955

[draymorton]

That's killer!

[SmartWombat]

Paul - I think the multiprocessor version is a bit more expensive than $150, no?

A a plug-in it's only $75 which seems a good price to me.
Or unlimited licence for $150.

I wasn't looking at the standalone prices.

[vvprok]

mjs - The Helicon feature is built into CS4?!

Paul - I think the multiprocessor version is a bit more expensive than $150, no?

I tried CS4 and found that it is a bit sloooooooow… I even do not say that stacking there is not friendly. The main point of CS4 is low performance and also it confused me by throwing memory errors. :cryin:

Price? I do not see any license with $150 value…
http://d-studio.com.ua/products/heli.../purchase.html

[Medley]

Also, Helicon Focus has recently upgraded it's software, with much of that upgrade focusing on making it a more stable and memory efficient application. Just thought it woth mentioning.

- Joe U.