# How to correct 'rolling shutter' distortion ?



## njwcat7 (May 29, 2017)

I went to Santa Pod yesterday to watch the drag racing and took a lot of photos on my Panasonic FZ1000.

Many of the ones taken where I was panning at high speed show distortion similar to the 'rolling shutter' effect often seen on action camera videos, presumably because of the way the sensor is scanned when capturing an image.

For the avoidance of doubt, these are still images shot in either raw or jpg, not video screengrabs 

Is there a way of correcting this in Lightroom ? Or, if not, is there another tool I could I try ? I've tried the perspective correction tools but unsurprisingly without success .

This photo isnt a 'keeper' but shows the effect quite well -




 

and a below is a wider shot showing less distortion (note the difference between the 'christmas tree' lights in the two photos)


 

and another - note the angle of the people in the background


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## Hal P Anderson (May 29, 2017)

You can't correct that in LR. It's caused by using an electronic shutter rather than a physical shutter.

Electronic shutters give a very high shutter speed in the sense that they don't allow much light to register for each pixel, but the time to scan the whole scene is relatively quite long, and if your subject is moving, you'll get distortion. Cameras usually use a mechanical shutter up to some threshold and use an electronic shutter above that. You probably ought to consult your owner's manual and use shutter speeds that are below that threshold.

To blur the background and keep the car in focus as you pan, you probably want to use a slower shutter speed, anyway.


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## Linwood Ferguson (May 29, 2017)

If you have Photoshop you can play a bit with the distortion tools there.  Filter - Sheer or maybe better a perspective crop will let you add or remove an overall slant distortion.  With perspective crop I'd start with it at 90 degrees, then move the opposite corner points equally (keeping the outside edges parallel) until the items in the photo which are truly vertical area lined with the grid, and see what you get when you apply.  It will crop a bit, of course, on the sides.  You'll want the grid to be a parallelogram like below (obviously I started with a non-slanted image; in your case the verticals and grid should be aligned).


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## Johan Elzenga (May 29, 2017)

The problem is that part of the image is distorted (things that moved) and part is not (things that were still relative to the camera). You can't correct both with a single perspection correction, neither in Lightroom nor in Photoshop. You will have to correct different parts differently, so work with layers. That is Photoshop territory.


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## njwcat7 (May 29, 2017)

Thanks everyone - I'll try to salvage what I can and remember to use the mechanical shutter next time - it was disabled because the camera was in silent mode, which is a bit ironic at a drag race meeting 

I think between you all you've given me an idea, which is to split the photos I want to keep into two layers, one with the car and one with the background, and then see if I can add a strong motion blur to the background layer to hide the rolling shutter


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