Well, I'm finally back from Greece and I have my head reasonably together.  Now I can turn my attention to the blog and this post takes the form of a work session with one of the pictures I brought back from Athens.  In the middle of the city is an ancient church, the Kapnikarea.  It's a small Byzantine church that sits right in the middle of the city and down from the main level by about two or three feet.  The result is that you're almost at the level of the roof before you descend the stairs to the church itself.  On the south side is a little porch with an apsidal ceiling which is covered with a beautiful mosaic of Mary ('theotokos') and the Christ Child.  I stood just to the south of that and, on a beautiful day in early October, took this ghastly shot.  What's wrong with it?  Let me count the ways.

What's wrong with it is that it's simultaneously underexposed and overexposed.  The overexposure shows up in the washed-out appearance and lowered contrast of the brick and ashlar facing; sure it's an old building but THAT colorless?  It looks like it needs a good dusting.  At the same time the mosaic of Virgin and Child is lost in the dark muck under the porch roof.  I thought, 'Aha!  HDR!'  Maybe there is a way to punch up the brightness of the mosaic and simultaneously push back the brightness of the building itself.

   In my Dynamic Photo HDR software I took a single image of this scene, a TIF and selected 'Eye-catching' and 'Full HDR process'. The first good news was the result of the primary HDR process.  In the preview I could see that every tessera in the mosaic was razor-sharp.  After the tone-mapping step was done I tried the various preliminary methods that Dynamic Photo provides.  'Eye-catching' with 'brightness' set to 20 seemed o.k.  The mosaic jumped out at you but the building was still washed out.  I couldn't find any setting that would make 'Ultra-Contrast' work (but then I never can).  'Halo-Matix' with Color Saturation set to 0.22 and Light Strength set to 0.75 seemed acceptable.  I couldn't find any settings for 'Smooth Compressor' that would work.  I finally settled on 'Human Eye with Color Saturation set to 0.62 and Light Strength set to 0.64.  This seemed to have an acceptable balance between a lightened and colorful mosaic along with a building that isn't totally washed out.   I'm not trying for the finished result here; just trying to get something that I can work on.  Here's the HDR result:

This is a huge improvement over the original. Now we have something, as I said, that I can work with. Before I didn't.  The building is close to what I want (it wasn't beautiful to start with).  I need to lighten up the mosaic.  I went into Photoshop and went into Quick Mask mode.  I placed a mask over the mosaic and exitted Quick Mask.  I then selected 'Select'->'Inverse' to actually select the mosaic.  I then used 'Image Adjust' -> 'Curves' to manipulate just this area which I made lighter and a little contrastier.  The result is this:

I still wasn't satisfied with the building even though the mosaic was coming along just fine.  I got back the mask I had drawn and inversed it to select the building.  Using Curves again I tightened up the contrast and adjusted the brightness.  Here's the final result (not sharpened):

At this point the image looks completely unrealistic but in this situation that's not a concern.  My goal on Squinchpix is photographs which show you what's there and I don't mind tweaking them.  You've got to admit: the mosaic looks a lot better.

Here it is sharpened:

...and here's the original so that you can compare them directly.

Till next time...