…or the ‘fast track to carpal tunnel syndrome.’

On occasion a type of noise appears in some digital images that is nearly impossible to remove using an automated process - in fact using “normal” noise reduction actually makes this type of noise stand out even more. I can’t really reproduce it because I’m not really sure exactly what causes it to appear. However, I know it exists and that seems to be particularly bothersome during long exposures in warm weather and that it shows up mostly in the mid-tones and shadows.

I’m certain it can be fixed at exposure time by one or a combination of ETTR, Zero Noise, or HDR techniques, however none of those are particularly suited for long exposures with star trails which is the example I’m using here. Perhaps image averaging would work but I wasn’t familiar enough with it at the time of this exposure to use it.

In any case, here is the original image I’m working with:

While you can’t see the noise in the image at this size it is very obvious at a normal print size and would ruin the image if it was not removed.

Here is a 100% crop of the original in the lower area of the rocks - you can see the white speckly noise very clearly:

And here is the same 100% crop with the noise removed - quite a difference:

So the technique to remove this noise is one of those that starts with “Well, I’ll just try it on a small area first…” and then “That looks great, and it didn’t take that long!” followed by “Wow, this is taking forever, I can’t believe I’m still doing this…” and finally “I’ve come too far to stop now…”

But at least it’s really simple - zoom to 400% in your editor and use the clone tool or the healing brush to click on every single little speck. Sound tedious? Well, it is. And it also takes a really long time!

All is not lost however…the newest generation Canons - probably those that are using the Digic III processor and newer sensors - seem to have a much better handle on at least one type of noise that is difficult to remove during post processing. Post #4 in this thread compares ISO 1600 images of the 400D and the 450D and it’s obvious that the 450D has a much cleaner image including better control of the type of noise I’ve been complaining about.

Obviously this is not for everyone and certainly not for more than one or two images a year but when you need a solution it does really work.

Olympic Peninsula, WA

One of my favorite digital photography tutorial sites, Cambridge in Colour, has recently opened up a discussion forum for all things digital photography. There is already a lot of great information and I have no doubt that it will prove to be a great source of information in the future.

While you’re there be sure to check out the galleries of beautiful night photography by Sean McHugh from Cambridge University in England.

Dance - Toby Keller

The DARKNESSDARKNESS night photography show will be on display at the Boston Convention and Exhibition Center as part of the Solstice Art program between the end of this month through September 1, 2008. The opening reception is June 20. This is a great opportunity to see the work of some amazing night photographers!

Thanks again to Lance Keimig for putting this all together!