Hot Spots, Dead Pixels and Photography
When selling, printing or generally admiring your prize winning photograph you’ll want to make sure there are no dead pixels in the way.
Dead pixels or dust on the sensor show up on a photograph as a brightly coloured pixel, mine are usually pink. When viewing your photo at 100% in a photo manipulation program such as Photoshop, these blemishes will range from being very clear to very subtle.
Finding these hotspots is usually tricky and searching across a 4000 pixel wide image can take some time. So, this is what I do…
- Set your aperture to 8, slow your shutter speed down to around 5 seconds, leave the lens cap on and take a photograph.
- Open the image in Photoshop, you should see a large black photograph with no detail – obviously as you had the lens cap on.
- Increase the contrast of the photo until you start to see small, bright dots appearing across your image. There may be none, but on my 8 week old Canon 5D, I found 4 – so I imagine you’ll also find a few.
- Copy your hot spot image on top one of your award winning photographs. Now all you need to do is adjust the transparency of the hot spot image so that it acts like a map highlighting all the hot spots, hidden within the original.
Using this method you’ll eventually get used to where are your hotspots are in your image and will be able to edit them out when processing your images.
Remember to go through the above steps every now and then, you will pick up more and more dust spots along the way and you’ll need to know where they are.
If you want to get your sensor cleaned (and you’re not comfortable doing it yourself) I can recommend visiting Fixation.
