Tag Archives: correction

Creating Lens Profiles for Adobe Software

UPDATE:  It turns out, the upload process for the profile sends to an address that doesn’t work.  While I try to fix this, if you want the profiles to use, you can download them by clicking here.

Within Adobe processing software, there is lens correction functionality built in to the Lightroom Develop module (or Adobe Camera Raw in Photoshop) that compensates for distortion and vignetting in the lens the image was taken with.  Adobe has created a large number of lens profiles but they never created one for the Canon 500mm in its initial version.  Adobe also has an online tool for sharing profiles but this does not include one for this lens either.  The 600mm had a profile and it was supposedly close so I had been using that for a while.  Recently, though, I was shooting with the 1.4x teleconverter fitted and this introduced some new effects which required some manual tweaking to offset.

I still wasn’t happy with the result so I decided it was time to bite the bullet and create some profiles from scratch.  Adobe has a tool for creating a lens profile.  It involves printing out some grid targets which you then shoot a number of times to cover the whole of the frame.  It then calculates the profile.  I was shooting at both 500mm and 700mm so I needed a few targets.  To make a complete profile it is a good idea to shoot at a variety of focusing distances and with a range of apertures.  The tool comes with many targets.  Some I could print at home but some of the larger ones I got printed at FedEx and mounted on foam core to make them more rigid.  Then it was time to shoot a bunch of very boring shots.

The software is not the most intuitive I have ever worked with but it eventually was clear what I had to do.  (Why do some manual writers seem like they have never used the process they are writing about?)  I found out how to run the analysis for different charts and distances separately and append the data to the profile as I go.  I did need to quit the program periodically because it would run out of memory which seems like an odd bug these days.  After much processing and some dropped frames as a result of poor shooting on my part (even on the tripod I got some blur occasionally with very slow shutter speeds) it got a profile out.  The proof of the pudding is in the eating of course (that is what the actual phrase is for those of you that never get past the pudding part) so I tried the profile out on some recent shots.  It works!  I was rather delighted.  I may shoot a few more samples in good conditions to finish things off but this was a rather happy outcome.  Once I have tweaked the profiles sufficiently, I shall upload them to Adobe and anyone can use them.

Fisheye Correction in Lightroom

I have a pretty well defined routine for importing and processing my images in Adobe Lightroom. I have presets for importing images that put them in the right folders, apply copyright information and apply development presets. I can then edit from there as I go. One of the settings I have set as a default is the application of the lens correction settings. This setting deals with any natural vignette in the lens as well as some distortion. Occasionally this can be tricky if you have something close to the edge of a wide lens and it gets slightly chopped by the correction.

AU0E3419-2.jpg AU0E3419.jpgI discovered a more extreme version of this while processing some shots from the Lick Observatory. I had taken my 8-15mm fisheye zoom with me as I thought there might be some use for it in the telescope buildings. It turned out to be a good thing to have. When I first had the lens, Adobe had not created a profile for the lens so the shots came in uncorrected with the fisheye look I expected. More recently, Adobe have created a profile for this lens. It was added in one of the updates and, since I don’t use the lens all of the time, I hadn’t noticed.

AU0E3382-2.jpg AU0E3382.jpgWhen I was going through the shots, I noticed the wide shots had some strange distortion at the edges. I was perplexed by this and also wondered where the circular fisheye shots were because I was sure I had taken some. Only then did I realize that these were those shots and the corrections were being applied. Here are some examples of the before and after with the correction to give you a idea of what the transformation is. A pretty dramatic change. I might make use of this sometimes but I shall also have to remember switching this off when shots with this lens are involved.

Lightning Up the Mood

A little night shooting today and a confession about my role in what was going on. We moved to Chicago eight years ago. When we first got here, we were amazed by the storms we got. There seemed to be lots of them and they were really pretty spectacular. When looking out of the window we would see lightning all the time. Sometimes the storms went on for so long it was hard to believe that it was a storm and not someone planting an emergency vehicle outside the window – a neat trick at the height of our place!

Strangely, for the last few years, we have had very few storms. They seem to miss the city and go either north or south of us. Some people are getting a lot of them but not us. This was a bit disappointing to me because I love storms! They are so dramatic and very cool. They are, of course, rather destructive but watching them is exciting. This week we got a good storm. The sky was alive and it was a lot of fun. It was also rather late and I needed to go to bed. Consequently, I cheated.

My 17-40mm lens is not enough to cover the full view south of us so I went with the fish-eye zoom instead. I set the camera up on the tripod, added the intervalometer and basically set it on its way. The gap between the shutter closing and the trigger for the next shot was just long enough to allow the file to write out. Then I went to bed. The result is a LOT of pictures with almost all of them of no use. However, it did capture a couple of shots that I really like. I even tried using the new lens correction facility in Photoshop CS6. Our view is a little less impressive since the Trump Tower blocked a big chunk of the skyline but it still gives a nice look to the storm. Hope you like them too.