Only two months to respond :)
Thanks for the new photo. I am not a photographer, but had been working on an issue with a lens of mine, just got stuck talking in slr terms. Basically I just was trying to indicate a "film speed" (iso) that will get higher details and capture the contrast differences better. Most digicams will do this in portrait mode.
If you are curious as to why... Considering the deck isn't going anywhere, it is easy enough to slow down the camera shutter speed and use a lower (better) iso, which is done in portrait mode. Regular shooting modes set themselves up for movement to happen in the image (fast shutter) and cannot maximize the quality for a non moving object because the faster the shutter, the lower the light hitting the sensor. Portrait mode will make the image pop a bit more and allow the stains and the colors to show how they are doing. Only drawback is you have to hold your hand steady and it is best to make sure you are at a right angle from the object you are shooting, but thats easy on a deck.
Ugh now to decide, which to get for my deck (when it gets built this summer), defy since it is water based and seems to work or messmers since that also seems to work but it is oil based... I'm not a green freak or anything, but if there is no drawback the greener solution is better IMO.
Scot