New Photos: HDR, Historical Overlay, and a Bunker Crawl

I recently went on a "bunker crawl" through San Francisco with my good friend Billy Coye.  We started with WWII-era fortifications but branched out to the Sutro Baths and a Nike missile site in the Marin headlands.  On this tour, I tried two new things I'd never done before: HDR, and historical overlay.  Yes, there will be pics.  :-)

High Dynamic Range photography (HDR) is a technique where you take multiple photos of the same thing at different exposures, and then blend them.  It works best for scenes with, well, a high dynamic range, ie. a high variation between light and dark.  For example, here are three photos I took of the Nike radar tracking system in the Marin Headlands:

The darker photo does a great job of showing off the beautiful cloud pattern, but the subjects in the foreground are blacked out.  The lighter photos do a great job of showing detail in the foreground, but you lose the clouds.  Combine the photos, and you get:

Historical overlay is taking a modern shot of something, and then superimposing an historical photo on top.  I was inspired by a beautiful series of photos from WWII.  There are lots of historical photos of San Francisco so I may try to make this a Thing.  But in the mean time, here's one:

The concept is rather simple: I went to the Sutro Baths, I quickly found an historical photo of the exterior online (on my smartphone), and then lined up my shot to match.  When I got it home, I photoshopped the historical photo on top of mine.  A little layer masking, blending, and some levels adjustment, and you have the final photo.  (Note: my photo is also HDR.)  I'm very pleased with the result and intend to do more.

Here's the rest of the Bunker Crawl:

I've been slowly going through the rest of my photo backlog and discovered other bracketed shots I'd taken.  "Bracketed" means I took the same shot at different exposures.  At the time I was trying to find the "best" exposure, but that's exactly how you make an HDR photo!  Here's a bracketed shot of the barracks at Fort Point:

And here's the HDR:

Gorilla at the San Diego zoo:

Here are a couple sunsets down on the San Francisco waterfront:

And finally, just in time for the holidays, the Hanukah candles.  Usually it's hard impossible to capture both the detail of the flame, and the candles themselves.  Unfortunately flames move a lot; out of dozens of shots, this was the only one that worked as HDR:

This was a fun experiment and I'm definitely doing more HDR and historical overlays.  I know there are a lot of interesting historical photos of San Francisco.  Any requests?