Tuesday, July 18, 2017

Warping can be fun

Modern lenses are incredible feats of engineering. Likewise, modern software is also incredible. Bring the two together with Magic Lantern and, well…you can get incredible images.

To illustrate what can be achieved, consider a standard EOSM 11-22mm lens, at 11mm. The minimum focus distance is 15cm, giving a near depth of field at 19 microns total blur (defocus and diffraction), at F/10 of about 13cm. But what if I wanted to focus closer, say right in front of the front of the lens, and (sic) get the background in focus.

I could use a tilt shift. But let’s say I don’t have one…I do really ;-)

One way is to combine focus stacking with a vertical pano; and because we can , throw in the need to cover a wider dynamic range than a single image can capture: so we’re use Magic Lantern Dual ISO as well!

Let's look at a single Dual-ISO image test (indoor) capture [ignore the artistry ;-)]

As we can see, the near field doesn't capture the full scene and is out of focus.

So lets take the first focus bracket set by pointing the lens down to capture all the scene from near to far, ie with five dual-ISO focus brackets.

Now repeat for the ‘normal’ image, once again capturing five dual-ISO focus brackets.

Ingest all ten images into Lightroom. Process the Dual-ISOs and export each five set bracket to Helicon Focus. Giving us two images ready for pano processing:

Do a round trip to AutoPano Giga to process the two perspectives, giving the following image, which is tack sharp from zero to infinity:

Bottom line: Extreme photography requires extreme processing. Yes, I could have captured a similar, in focus, image using my tilt-shift lens. But clearly there are alternatives and post processing can be fun ;-)

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