View Full Version : Removing Camera Flashes
Rob Harlan June 2nd, 2010, 07:50 AM I saw a thread somewhere with a wedding clip showing the removal of stills camera-flashes.
The before/after shots looked quite impressive.
Cannot find the thread - anyone know which application/plugin is best used to remove camera flashes?
Some photographer flashes are acceptable in wedding videos, but others can cause rather unsightly brief whiteouts.
Don Bloom June 2nd, 2010, 08:37 AM NewBlueFX Video Essentials 1 has a 'Flash Remover' that works pretty well.
I don't know of any other plugin but I'd guess there are some.
Richard Wakefield June 2nd, 2010, 09:30 AM correct from Don Bloom there
it was Danny O'Neill (mintyslippers) that showed the superb before and after shots, and also NewBlueFX did a tutorial on it using some of my footage too - that plugin works amazingly well but i guess don't overdo it or it might seem unnatural...also, not sure how it copes with annoying (roller-shutter) flashes on SLR footage...
Danny O'Neill June 2nd, 2010, 09:48 AM We did a side by side comparison on our blog
And as if by magic | The flash disappeared Mintyslippers.com Wedding Blog (http://www.mintyslippers.com/blog/flash-removal.html)
Steven Davis June 2nd, 2010, 04:21 PM Baseball bat on the photogs flash?
I apologize for that comment. I'm with Don, try the New Blue
Philip Howells June 5th, 2010, 12:05 AM Because we use CCDs not CMOS, flashes aren't a technical problem for us but I suppose removal of all traces of the photographer has some appeal!
Before I invest (to use the term governments prefer now - I still think of it as spending) $100 on the NB product, could those who've used the NBfx let me know if there's any downside to the filter?
Presumably they do it by frame or even field doubling - is there any visible disruption?
Any blurring or loss of absolute sharpness?
Does it ever affect the sync either with the TC or the soundtrack?
Don Bloom June 5th, 2010, 04:55 AM Philip,
I can't say that I ever had a problem with the NewBlue Flash Remover doing anything to sync, audio or anything else. I can say that every once in a while if there are multiple flashes af high intensity the flash remover seems to miss one but it's not a big deal nor a major problem for me. If it removes 80% of the unsightly flahes than I'm fine with it. I don't bother with it fir receotion dancing but use it mainly in the post ceremony.
Philip Howells June 5th, 2010, 05:09 AM Don, thanks. I wonder if you were able to confirm that it works by frame or field doubling ie removal of the "flashed" frame and its substitution with an adjacent frame without the flash.
If it had a limit as to how many frames could be substituted in any given time period that might account for it "missing" some flashes.
The only alternative I can think of is that the software identifies the "un-flashed" colours from the previous/following frame and substitutes those colours in the "flashed" frame. That sounds much more complicated to achieve but would avoid the inherent problems of frame substitution.
Don Bloom June 5th, 2010, 09:35 AM Philip,
I'm one of those guys that don't care HOW it works just that it DOES work. Pretty much on most everything so I really don't know if it's frame or field. All I know is it helps out a lot. Honestly I don't expect perfection out of anything, maybe I should but I know when anything is touched by human hands it won't be perfect. Close maybe and that's what makes it work for me.
So anyway, no idea how, just that it does (mostly) but perhaps you could contact NewBlue and ask them. IMO their CS is 2nd to none.
Sorry I can't be more help.
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Dave Blackhurst June 5th, 2010, 12:50 PM I tested the demo version, and was pretty impressed (free to download and test). I did notice that it seemed like there was frame doubling going on - I picked up slight motion stutter when there was movement, for want of a better term. In the end I decided that the flashes weren't "that" annoying... part of the "ambiance" of the moment.
Danny O'Neill June 10th, 2010, 12:40 PM Sorry, meant to say. Yes, was newblue FX from their video essentials pack.
Sometimes we leave flashes in, but for the shoot in the example we had some wonderful moments where we wanted it to look like it was just the couple in a room on their own and having a camera flash go off ruined that.
Tom Hardwick June 11th, 2010, 10:39 AM It is indeed most impressive and if you stop your comparison movie on a flash frame (easily done with so many to choose from) there's no evidence that a flash was ever there. So it's done by frame blending the before and after flash frames is it? It's certainly not just a simple exposure reduction of that flashed frame.
Wonder how it looks with slo-mo shot footage, or footage slowed in post - do you know?
tom.
Danny O'Neill June 12th, 2010, 12:10 PM Dont really do slow mo so couldnt say ;)
You can download a free demo so give it a go.
Ryan ONeil June 12th, 2010, 10:15 PM Maybe an off-topic question, but when you use an effect like this in After effects or w/e, do you typically run it on the raw video, then do edits on the resulting video or just run it along with all the other effects?
Don Bloom June 13th, 2010, 06:56 AM I never run any effects on the RAW only on the edit. Just something I learned to do years ago. Why run something thru all the footage that is needed on all the footage.
Philip Howells June 13th, 2010, 05:48 PM It is indeed most impressive and if you stop your comparison movie on a flash frame (easily done with so many to choose from) there's no evidence that a flash was ever there. So it's done by frame blending the before and after flash frames is it? It's certainly not just a simple exposure reduction of that flashed frame.
Wonder how it looks with slo-mo shot footage, or footage slowed in post - do you know?
tom.
I don't understand exactly what Tom means by "frame blending"? The obvious and simple way to achieve the New Blue effect would be to substitute the offending frame with a copy of the one before or the one after, that's frame replacement or frame doubling and has the disadvantage that the result may appear as a stutter, as Dave confirmed. This is the basic process used by post-production slo mo.
The only other logical method would be to devise a way for the colours of each part of the "offending" frame to be captured from the previous/following frame - in much the same way as MPEG compression works. This method would maintain the movement continuity and avoid the stutter but would involve more processing and thus possibly take longer.
Thinking along the lines of MPEG compression, I suppose it is possible to conceive a method by which the programme would create a replacement frame based on the data and colours in the preceding and following frame (and which could be called "blending") but that sounds like even more work for the computer to do
The fact that New Blue's filter doesn't remove all the flashes suggests a simple frame doubling because correction of too many near-simultaneous flashes would result in too many frame doubles and thus a major stutter.
Although, as I've indicated previously, our cameras don't have rolling shutters, but I'd be interested in how effective this filter is with flashes recorded via and affected by rolling shutters.
Finally, since post-pro slo-mo'd material has frames doubled anyway, any risk of stuttering caused by further frame doubling to avoid camera flashes would be increased. I doubt if anyone in this field has a genuine slo-mo camera (ie recording at a faster than normal rate) but obviously any flash recorded in this way would affect proportionately more frames and thus risk proportionately more obvious stutters.
In any case it seems to me that Dave Blackhurst has it right when he says that flashes in this type of programme are part of the ambiance anyway so why risk degrading the material to make it look like something it wasn't?
Tom Hardwick June 14th, 2010, 01:19 AM Hi Philip, my Canopus Speed Control program doesn't do simple frame doubling, it really does appear to blend and smooth fields together. So of course it works best with interlaced footage. And I should say my NX5 does indeed have a genuine slo-mo facility (ie records at a faster than normal rate). I must fire off some electronic flash while it's shooting (MOS) slo-mo and see what the rolling shutter makes of that.
So much to do; so little time.
tom.
Greg Fiske November 23rd, 2010, 10:06 AM Been playing with this with 5d mark II footage. No problems with rolling shutter (one frame and flash fills half of the frame). When it doesn't work it doubles/stutters the footage. I tried to animate the effect to ignore the flash's it has problems with, but even at 0 the effect is still being used. Tonight I'm going to try to great a subclip and use the effect only on areas where it excels at. Having one flash go off in a clip compared to five is a lot less annoying.
Justin Ferar November 23rd, 2010, 02:34 PM Greg, are you saying the software does work with 5d footage (flash banding) or just some of the time?
Greg Fiske November 23rd, 2010, 03:19 PM It does work. Depends. Things like multiple flashes right after another trip it up, flash during out of focus to focus pulls, or fast pans. The way I do it, scrub to the frame with the flash showing, then try one of the three presets (you will see the frame going from half of the frame having a white streak, to it clearing up). Usually one of the presets will get rid of the flash, and the other two will cause some kind of ghosting on the footage (which you will either notice sitting on the current frame, or when you scrub the footage if it gets jerky). Worst case scenario non of the presets work, so in that case, which I'm going to try tonight, create a sub-clip without the flash removal effect and just leave that stubborn instance of the flash in. My success rate of wedding footage last night was about 75% of the time it works.
Justin Ferar November 23rd, 2010, 03:49 PM Thanks for the reply. I'll give it a try out : )
J.
Edward Troxel November 24th, 2010, 08:58 AM If you have some footage you'd like us to test with, feel free to start a help ticket and I can give you an upload location. We can then test with your footage and see if there's anything that can be done to improve results in those situations.
Chip Gallo January 5th, 2011, 08:14 AM Edward -- I use the VASST quad cam script in Vegas 10 Pro with ice skating video, 2 cameras. I have tried using the flash remover on camera tracks and it has no effect. I also tried it on the master track that quad cam creates and again no joy. It does make the video 1/4 size in the preview (with the cue marks) although the render comes out full size. Any tips on this situation?
[32 bit Vegas, OpenFX plug]
Edward Troxel January 5th, 2011, 02:08 PM I would apply the effect to the actual event that needs the flash removed after the Master track is created. Then you can apply it to only the specific events that need the effect. Then it should just be a matter of adjusting the settings necessary for that specific event.
Chip Gallo January 10th, 2011, 09:07 AM I tried applying the plug on select events in the master track and it didn't do anything. I'm thinking that the product install didn't work correctly so my next step will be to try it on an event in a test veg that doesn't have the multi cam and see if that works.
Chip Gallo January 13th, 2011, 10:14 AM I tried this on a single video event and it did not remove flashes. I will open a service request with the vendor to see what I may be doing wrong.
Tom Hardwick January 13th, 2011, 11:14 AM I think if it removed flash frames that would be overkill. At any given cake-cutting I can count 60 or 70 flashes on the timeline. Each camera person may only take a couple of photos, but many cameras give pre multi-flashes to set their camera's exposure and focus. Consequently my CMOS chipped timeline is a barrage of quarter, third and half exposed frames. Nasty. But it's a passing phase.
tom.
Chip Gallo January 13th, 2011, 01:10 PM My video is of ice skaters in a rink. No flash photography was allowed but for some reason there was a sole photog banging away with pre-flash and flash throughout the entire show. The sales literature doesn't say how they achieve flash removal but if it is by removing the entire frame then that could be a problem.
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