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What`s the latest and greatest dust removal technique?
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Author:  Ian [ Sat May 09, 2015 5:16 am ]
Post subject:  What`s the latest and greatest dust removal technique?

The old conundrum for time lapsers - dust spots. About my best clip recently risks being unuseable for this reason. :(
Have revisited various techniques today but all attempts at automation fall short when it comes to movement in the scene.

Is this still state of the art for dealing with this or has there since evolved something easier?:



Thanks

Author:  MikeA [ Sat May 09, 2015 11:24 am ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

http://www.visibledust.com/products3.php?pid=3 ;)

Author:  Ian [ Sat May 09, 2015 12:05 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

thanks for the link Mike. Do you use one of these?

Mind you I really meant software solutions once the spots are in your tl sequence.

Author:  pixelbot [ Sat May 09, 2015 2:32 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

i like to fix things in PreProduction - i.e. cleaning the sensor (regularly) and shooting below f8 to avoid spots to begin with.

timt

Author:  MikeA [ Sun May 10, 2015 1:04 am ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

Ian wrote:
thanks for the link Mike. Do you use one of these?

Mind you I really meant software solutions once the spots are in your tl sequence.


Hi, Ian, yes I do use one and I do realise you were after post production ;)
but Pixelbot put the problem into nicely into context
Quote:
i like to fix things in PreProduction - i.e. cleaning the sensor (regularly) and shooting below f8 to avoid spots to begin with.

timt

Author:  amongstmyselves [ Sun May 10, 2015 4:09 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

A technique I have used in the past works quite well and it is reasonably easy but it ain't no press a button and watch the magic happen.

You need to create a black and white mask of the spots. Use a frame of the spots from the footage, no need to recreate them though you will need to clean off all the other information. I then use this as a mask between the a brighter version of the footage and the normal exposure of the footage. It works very well because the spots are just dark parts of you footage. Give it a go on just one spot for starters.

Steve.

Author:  yayasite [ Mon May 11, 2015 4:57 am ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

amongstmyselves wrote:
A technique I have used in the past works quite well and it is reasonably easy but it ain't no press a button and watch the magic happen.

You need to create a black and white mask of the spots. Use a frame of the spots from the footage, no need to recreate them though you will need to clean off all the other information. I then use this as a mask between the a brighter version of the footage and the normal exposure of the footage. It works very well because the spots are just dark parts of you footage. Give it a go on just one spot for starters.

Steve.


Awesome tip Steve.

Yesterday, I worked on dust removal from a cloud timelapse during several hours trying to use different techniques :
- Remove dust point in Lightroom with the spot Removal tool and copy paste that setting on the other pictures (good if the spot is on a clear sky during all the sequence, very bad when the clouds are coming near the dust spot)
- Remove dust point in After Effects : duplicating the layer, put a small ellipse mask near the dust point, and moving that duplicated layer over the dust spot. (pretty the same result as removing it in Lightroom but you can easily animate the zone you want to duplicate and see the result in realtime. Results are not better that the above solution when the clouds are coming)
- With After Effets, create a britghter version of the sequence on another layer and put an ellipse mask on the dust point (works ok with the clouds on the dust point, but hard to configure the parameters of the ellipse mask to work well on clear sky)
- A mix of the 2 techniques above to have a good sequence but no perfect.

Conclusion : If I've read your post yesterday, I think it would have been a lot easier ;). So I'll try the "dust as a mask" technique which I think is a great idea.

Thanks Steve

Author:  amongstmyselves [ Mon May 11, 2015 3:25 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

Hope it works for you yayasite,

When I read about this technique myself it made sense from a purely physics point of view.

Steve.

Author:  Ian [ Tue May 12, 2015 3:42 am ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

Thanks for the replies.

Believe me I`m on board with the prevention is better than cure philosophy. But my little Dust-aid contraption has become not very effective. I`ll look into MikeA`s suggestion.

The offending clip was a day to night time lapse in the Alps using GBTimelapse aperture Ramping mode. Unless an nd filter is used, you`re down at f22 on a 6D (100 iso min) with bright foreground snow, even half an hour before sunset. I`ll be swapping to Mike`s nd filter route for the future, and ramp from f8 or so.

Steve, are there any youtube tutorials which help with your technique?

Thanks

Ian

Author:  amongstmyselves [ Tue May 12, 2015 3:30 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

Alas no video. I've seen other people do a similar technique by creating shapes but this technique is a little two fiddly. Here is one http://magictimelapse.blogspot.com.au/2 ... after.html

Here is a more detailed description of what I do which I found in my own records. The only caveat is that I use Sony Vegas but I am not using an fancy plugins. Hope this is some help.

The method described below removes spots by doing levels adjustments of the darkened or spotted area. This is mainly concerned with dust on your lens which is out of focus.

I've found the best of cleaning off lens spots is the following.

1) Identify the spots of the chosen frame - note that sometimes spots aren't first seen as they are in a dark region of the image so it's worth checking through a range of shots.
2) Using photoshop we need to isolate the spot(s) from the background. The best way of doing this is to use your levels or curves to make the spot as black as possible and it's surrounds as white as possible. Of course you can cleanup parts that you cannot isolate with levels with a brush. This will need to be repeated for as many spots as you have on your footage but you can always start off with just one and move onto the next step.
3) What you have created here is the mask. Using Vegas create 3 video tracks. Track 1 at the top of the list will be the utmost top layer. In this case this will be the levels adjusted version of the clip that will hide the spots but we haven't done the levels adjustment yet. The second video track will be the spot which is only a single frame and the third track will be the original video footage.
4) The second track with the spot is a mask so in Vegas you need to make this the child of the top layer. Also set a mask generator plugin for this track so the outcome is that the top layer will show through only where the spots are. This can be checked by muting the third track (original unchanged footage) which will either show a bunch of spots or the whole image with spots in it. If you have a whole image with holes in it then you need to hit the invert button.
5) So far you probably won't see any difference as you now need to change the top layers level around so as to hide the spots. Using a level plugin you can now start to manipulate the image to the point were you can no longer see the spot.

All going well you should now have a shot that no longer has spots. But lets make this clear it's always better to make sure you have a clean lens in the first place.

Author:  Ian [ Thu May 21, 2015 8:46 am ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

Link from MikeA:

http://www.visibledust.com/products3.php?pid=3

At $130 plus postage that needs to be nigh perfect, but it gets a lot of negative reviews. I wonder whether to jump straight to the wet cleaning system of Copper Hill.

Author:  FilippoRivetti [ Wed Oct 14, 2015 4:06 pm ]
Post subject:  Re: What`s the latest and greatest dust removal technique?

The technique I've been using works perfectly most of the time and it's quite simple.
In After Effect:
- duplicate layer with the affected footage
- mask out all the dust spots
- feather out the masks about 5-10 pixels
- apply dust & scratches effect with a radius of about 20 pixels (depending on size of dust spots).

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