A few hours of walking around in Aomori, Japan (map) revealed a city with more civic pride than just about any place I’ve been. Banners proclaim apple season, posters advertise that high speed train service (the shinkansen) will start in 2010, and there is fourteen story modern-architecture welcome center, officially called the Aomori Sightseeing Products Center (ASPAM).

ASPAM had an on-site bakery making pastries with those famous Aomori apples, bargain sales of smoked squid and scallops (delicious), and a live performance with traditional Japanese stringed instruments. There is an observation level on the twelfth floor offering panoramic views of the city and harbor.

The observation level is glassed in, so if any photos are to be taken, they will be taken through the glass. The outside of the glass is prone to dust. On a sea coast like Aomori the problem is compound by fine salt mist evaporating on the glass. The image I took of the city’s bridge and harbor looks grayed-out.

Bringing up the histogram of the levels in Photoshop Elements using Enhance > Lighting > Levels shows the problem.



There is no black in the photo. The darkest shade of gray is way above black. The cause of the problem is light scattering off the dust on the window. This is different manifestation of the problem of shooting towards a light source. With back lighting, the scattering is inside the camera lens. Here scattering is off the window dust.

The cure is to grab the arrow on the low end of the histogram and move it up to where the levels of the image start. This is shown with the yellow arrow and line I marked on the histogram (above). Also, the sky is too bright, losing detail. I touched that up using Enhance > Lighting > Shadows and Highlights. Lighten Shadows was set to zero and darken highlights increase until the clouds looked reasonable. The revised histogram, after both adjustments, shows the black level restored and the levels decreased on the bright end of the histogram.

The image is improved.



The dust on the window does little to deteriorate the sharpness of the image, it is only affecting the black levels. Consequently when the black level is restored, it can be a high quality image overall.

Reflections are another problem plaguing images taken through glass. The problem is greatest when the light on the camera side of the glass is brighter than the light on the scene being photographed. It is less of a problem for window to the outdoors than for a storefront window. The main cure is to get the camera close to the window so that only a small amount of reflection is in the field of view, and most of that is blocked by your shadow and shadow of the camera. This also avoids having the automatic focus latch on to the reflection. Be careful not to get so close that the lens might hit the glass if it extends to accomplish automatic focusing.

Wearing a dark shirt also helps minimize your reflection. I suppose that wearing a dark cape and spreading it before clicking the shutter would be a further aid, but I haven’t actually tried that.

If you’d like to see what is going on in Aomori right now, they have an excellent set of twenty-one webcams. One of the cams shows the ASPAM building. Another shows the harbor in the direction of the bridge. These are first class web cams that are, for reasons I cannot imagine, very difficult to find with a Google search.