That’s actually a big question and I’ll try not to be boring with too big an answer.
In the days of film, spots are caused either by fairly serious marks on the lens (front or rear if removable lens) or dust which has got into the camera and onto the film, or (less likely) dust during the development process. Film has an advantage here – dust on the film is wound out of the camera and only marks one shot. Dust on the film does not usually cause such big blobs on the image.
Most “lens spots” in the digital world are unfortunately caused by dust which gets onto the camera sensor. The unfortunate bit is that it often accumulates there forever, particularly more sticky stuff like pollen. It can cause marks such as seen in PedalGirls shot. This is why if you change lenses you should always hold your camera with the lens pointing downwards as this reduces dust falling into the camera. If out and about and breezy, then additionally shield your camera from the wind with your own body whilst you change your lens.
Sensor spots mostly show up at high F stops. If you want to see how dirty your sensor is, then point your camera upwards at a clear sky and take a shot at F22 or higher and prepare yourself for a shock!
During digital development, applications such as Lightroom, Photoshop etc have simple and quick tools to "clean" spots digitally - especially quick in low detail areas like skies where they show up most. One click in lightroom for example ...
Because I use Lightroom for my photo development, sometimes on a shoot I will take a shot of the sky as described, because I can then use Lightroom to “clean” that sky shot and copy the “cleaning settings” from that shot to clean all spots on the rest of the shoot.
Sensors can be physically cleaned, but don’t bother if you generally don’t notice it, and don’t do it yourself unless you have the right kit and really know what you are doing.
Hope that helps,
Alan.
PS – I’m no expert so if anyone wants to correct me or add to it then please do.
PPS - If you pay to have your sensor professionally cleaned then take a shot @ F22 or more and filling your frame with a very well lit peice of whte paper and do the same as soon as you get the camera back. I have had to query the effectiveness of one such professional clean and had it re-done.
Alan, is there a tutorial for doing this? Or a book you'd recommend on Lightroom?
Kate www.katetaylor.smugmug.com "You cannot depend on your eyes when your imagination is out of focus." Mark Twain
I have two books on Lightroom - The Adobe Photoshop Lightroom 3 Book for Digital Photographers by Scott Kelby, and Adobe Lightroom 3 - The missing FAQ by Victoria Bampton. Both of which I have found to be very good but would probably buy Scott Kelby if only one. Victoria's better covers broader issues such as maintenance, backup and practical advice on diverse things such as what to do when you upgrade or replace your machine – i.e. the missing FAQ’s as she puts it. Martin Evening’s books are also highly regarded.
Pointing out the obvious, the books are written for the specific version of Lightroom around at the time, and Lightroom 4 quite dramatically changed the way the development sliders work in the software rendering, so to some extent my versions of these books are now redundant! However, I hardly ever refer to them anymore.
Before buying a book, my advice would be to first look at the many sources of on-line material, some of which is exceedingly high quality and tends to stay more current, however you may need to browse several sites as many are aiming to sell you their training DVDs and don’t give everything away! For example …
A Google of “Lightroom” videos will show up many examples especially on YouTube.
Also if you need help on using Lightroom there is an Adobe online community forum which is populated by users (not Adobe staff) with a great deal of expertise. Like any online forum, some people can be a bit unfriendly and terse, but in the main most are very friendly and helpful. Victoria sometimes helps people online. http://forums.adobe.com/community/lightroom
Hope this helps,
Alan
PS - Many years ago, shooting RAW and buying Lightroom seriously improved my photography, but if you are buying it for the first time you need to understand its philosophy of what it does and does not do - it is not a replacement for Photoshop. It aims to do all the "development" and creative development that was once done in the darkroom - but does not contain scissors to be more creative. For that you need photoshop or an equivalent.
Comments
Anything with a time after will be ignored.
pp
Flickr
Great timing on your reminder.
Will try to do the next bit within 24hrs.
Flickr
www.katetaylor.smugmug.com
"You cannot depend on your eyes when your imagination is out of focus." Mark Twain
A specific training video on healing spots in Lightroom can be found here...
http://tv.adobe.com/watch/learn-lightroom-4/cleaning-up-blemishes/
I have two books on Lightroom - The Adobe Photoshop Lightroom 3 Book for Digital Photographers by Scott Kelby, and Adobe Lightroom 3 - The missing FAQ by Victoria Bampton. Both of which I have found to be very good but would probably buy Scott Kelby if only one. Victoria's better covers broader issues such as maintenance, backup and practical advice on diverse things such as what to do when you upgrade or replace your machine – i.e. the missing FAQ’s as she puts it. Martin Evening’s books are also highly regarded.
Pointing out the obvious, the books are written for the specific version of Lightroom around at the time, and Lightroom 4 quite dramatically changed the way the development sliders work in the software rendering, so to some extent my versions of these books are now redundant! However, I hardly ever refer to them anymore.
Before buying a book, my advice would be to first look at the many sources of on-line material, some of which is exceedingly high quality and tends to stay more current, however you may need to browse several sites as many are aiming to sell you their training DVDs and don’t give everything away! For example …
http://tv.adobe.com/show/learn-lightroom-4/
http://tv.adobe.com/show/getting-started-with-adobe-photoshop-lightroom-4/
http://blogs.adobe.com/jkost/lightroom-training-videos
http://www.slrlounge.com/category/post-production-tutorials/lightroom-tutorials
http://www.thedigitalphotographyconnection.com/LFDP.php
A Google of “Lightroom” videos will show up many examples especially on YouTube.
Also if you need help on using Lightroom there is an Adobe online community forum which is populated by users (not Adobe staff) with a great deal of expertise. Like any online forum, some people can be a bit unfriendly and terse, but in the main most are very friendly and helpful. Victoria sometimes helps people online. http://forums.adobe.com/community/lightroom
Hope this helps,
Alan
PS - Many years ago, shooting RAW and buying Lightroom seriously improved my photography, but if you are buying it for the first time you need to understand its philosophy of what it does and does not do - it is not a replacement for Photoshop. It aims to do all the "development" and creative development that was once done in the darkroom - but does not contain scissors to be more creative. For that you need photoshop or an equivalent.