Thursday, September 15, 2011

Close Up Photography with Great DOF

Exploring objects closeup allows me to pursue my fondness for abstractness in trying to see the world around us in a new way. Shallow Depth of Field (DOF) is great for isolating specific parts in a scene and having the remainder fade softly into the background. But there are times, especially if the background is soft or non-existent like the photo below, where full sharpness seems to bring greater clarity (a bit of a pun) to the subject.  I have seen other photographers use the software Helicon Focus to take multiple images at different points of sharpness as you progress further back. The software determines which parts of the image is sharp and then combines your images with only those parts, like layer masks.

5 images combined with settings at f/9, 0.4 sec  @iso 200 with Tamron 90mm macro lens

On some of the images and even the version above, I found slight fringing (light lines) that followed the shape. This was really noticeable with black backgrounds as even a little colour shows up.

In the next image I used a little Photoshop processing to bring out some of the hidden colors in the black cloth as I wanted analogous color, here reddish blue, to support the magenta (blueish red) in the image.
11 images combined at f/8, 1/5 sec, iso 200 with Tamron 90mm macro lens.

In a close up below you can better see those ring lines.

The software does have 3 settings: Methods A &B; smoothing; and radius, which at this time I don't know their functions.  I think this will be a useful tool and therefore I should learn more about this program to better understand its limitations and how to use it correctly.

I believe those lines are caused when the software shrinks some of the further back images, as changing focus further back makes the images larger and software needs to align all parts so they overlap perfectly. This may leave residual edge not fully covered with its mask. Just a guess.

5 images combined at f/8, 1/5 sec @iso 200 with Tamron 90mm lens

This is one of my favourites as intense yellow and purples work well with little darkened and de-saturated green in the stems.

This was a home studio setup with window side-lighting using a tripod and set to time delay to ensure no shake. While I didn't notice any overexposed shots, the software told me the variance (sometimes 20-30%) in lightness for each run. This brightness variance was caused by slight changes, not really noticeable, as the intensity of the clouds changed.

There is a 30 day trial usage and I do suggest that you try this out.
In a future article I will perform an in depth review of this software and even try those full DOF landscape photographs.

Niels Henriksen


gandha key said...

I'd be very interested to know after reading Peter Watson's Capturing the Light why you use F8 rather than smaller apertures and IS0 200 rather than 100. Many thanks, I find your blog very useful.

nielsp said...

Thanks Gandha for your comments

The camera's base iso is 200 (Nikon 300) and all others are electronically controlled and I tend to use the base version unless I need to use others because of limiting light (too much or too little) factors.

F/8 tends to be the sweet spot in most lens for highest lpm (lines per millimetre) resolution.

When in macro mode the DOF can be very small and therefore I would need many more smaller increments in focusing steps to get clear focus on all elements in image.

If I decide to seriously peruse this mode then I will calculate the actual DOF for various f-stops and determine the best for each subject being focused.


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