Help - Ghost lights

**Peter Mallett** · 1 Jul 2019, 05:47 (Ref:3915273)

Hello you experts. I believe the phenomena in my photograph below is due to the digital sensor in my and anyone else's DSLR. What can be done to avoid these fairy light effects?

GORDON STREETER · 2 Jul 2019, 20:19 (Ref:3915545)

Quote:

Originally Posted by Peter Mallett

Hello you experts. I believe the phenomena in my photograph below is due to the digital sensor in my and anyone else's DSLR. What can be done to avoid these fairy light effects?

It may be impossible in some cases, however make Shure that the lens is spotlessly clean for a start. Are you using the correct lens hood for the focal length that you are using ? It might help using a UV or another type of coated filter. Failing that you'd best get on photoshop

**Aysedasi** · 2 Jul 2019, 20:29 (Ref:3915547)

I get them too Peter. Not always. I'd always thought it had something to do with shutter sync, but that may just be me mouthing about something I know absolutely nothing about.... Photoshop's clone stamp has generally come to my rescue for the most extreme cases, although sometimes they appear in tricky places to deal with.

**Peter Mallett** · 3 Jul 2019, 04:31 (Ref:3915597)

Gordon, Yes using the correct lens hoods and filters. Ayse, I try not to get too deep into Photoshop other than cropping and lighting. but I'll try the cloning tool.

**BertMk2** · 3 Jul 2019, 21:38 (Ref:3915755)

I've only seen them when I've got a filter on - I think it's the lights reflecting off the lens onto the filter then back onto the lens again.

JHamilton · 4 Jul 2019, 05:29 (Ref:3915806)

I don't get those Peter. Sometimes I get "halos" around the lights themselves but never that far to the side of the frame. I also only use a hood to protect the lens... I'm not convinced they do diddly squat.

I've never shot action with a filter, only stills at cars shows and the like. Could that be it?

**Woolley** · 4 Jul 2019, 12:44 (Ref:3915851)

Hood won't make a difference to that as lights are coming from the subject, not from the side so they'll always enter the lens. They look like internal reflections to me, either bouncing off a filter if you have one fitted or off the internal elements. the roughly circular pattern suggests the latter?

**Peter Mallett** · 4 Jul 2019, 13:05 (Ref:3915854)

Well possibly, they appear on some photos I took at night when the cars were passing by, not heading towards me so I think it's a function of the processor rather than the glass.

**Aysedasi** · 4 Jul 2019, 16:47 (Ref:3915881)

Filter sounds most likely to me. I realise now I didn't get any shots like that with my 100-400, which I used without a filter but I've certainly got them many times before with a skylight. Do you use a filter Peter?

andrewc · 4 Jul 2019, 21:50 (Ref:3915928)

I always use a lens hood.
I very rarely use filters, occasionally ND or CPL's but I don't buy into UV or Skylight filters are protection.

**Peter Mallett** · 5 Jul 2019, 04:26 (Ref:3915964)

I've always used a uv or skylight filter, still do.

grantp · 5 Jul 2019, 10:23 (Ref:3916006)

It's flare - the same sort of thing as one sometimes sees from the sun.

With very bright lights on cars and at certain angles the refraction of light through glass can create this effect. Filters can exacerbate the effect and the lens/filter coatings (or lack of them) can have some influence over how visible they are.

Quite a few things will influence how visible they are in the images.

https://www.cambridgeincolour.com/tu...lens-flare.htm

The article discusses sun based flare but you can get the same thing from direct point light sources where the source is offset from the centre line of the lens.

I'll see if I can find an article that specifically discusses that.

(Of course the is always Wikipedia to offer something!

https://en.wikipedia.org/wiki/Lens_f...lens_flare.jpg )

I only have one lens with a filter on it (bought used and the filter was fitted so I left it on). I have not noticed any problems with flare but as it's a the Canon 24-105 L zoom I may not be using it in many situations where the flare would be very evident.

**Peter Mallett** · 5 Jul 2019, 11:08 (Ref:3916009)

Seems then, that I need to remove the filters. As said I do have lens hoods fitted. Will give it a go at the Silverstone Classic.

grantp · 5 Jul 2019, 13:54 (Ref:3916024)

Quote:

Originally Posted by Peter Mallett

Seems then, that I need to remove the filters. As said I do have lens hoods fitted. Will give it a go at the Silverstone Classic.

Peter,

You'll probably only really notice it at certain angles and bright light positions when it's relatively dark.

But yes, removing the filter(s) could help though possibly not entirely eliminate.

What aperture were you using for that shot? There might be some compensation to be had there but the trade off between f-stop, shutter speed and ISO setting is not always easy especially in high movement situations.

In general most lenses for a couple of decades or more have had very good coatings - especially externally - so that the use of filters is not that much help in terms of protection (though a hood can be) the original UV/Skylight filtration adjustments were intended for film whereas now they are dealt with either by filters on the sensor and in camera software or, additionally, by computer software.

Part of the reason fot at is that the digital cameras will do their own thing for things like White Balance which was one of the primary uses of filters back in film days.

If one shoots RAW images, rather than in camera jpg, even the White Balance is not relevant since it can be completely changed by the 'development'/editing process.

For action shots some of the more serious correction filters can prove problematic for some of the camera settings (unless shooting manual mode). In particular for actions shots where a filter may have a significant affect on the amount of light available to the focus system and therefore affect the speed at which it operates.

I once tried an experiment with a 1 series Canon camera, a very fast (f2.8) 70-200mm zoom lens and a Polarising filter on an extremely sunny day at Brands Hatch. Pretty much head on with the sun behind me on the straight heading into Hawthorn's Bend

Whatever I tried, with the filter in place the focus system never did better that catch the very rear of a car. It just could not follow focus quickly enough because of the extra 2 stops of light loss due to the filter despite the very bright light.

**Peter Mallett** · 5 Jul 2019, 14:13 (Ref:3916025)

Here's the data.

**Peter Mallett** · 6 Jul 2019, 12:54 (Ref:3916141)

I used the clone stamp to remove those lights. Not a perfect solution but hey ho.

grantp · 6 Jul 2019, 14:07 (Ref:3916148)

Quote:

Originally Posted by Peter Mallett

I used the clone stamp to remove those lights. Not a perfect solution but hey ho.

That's as good as it gets really. Healing tools might be a marginal improvement but it looks like the slightly simpler and more commonly used clone approach should work for this one.

Peter, it's difficult to tell form the resolution of the image posted but I think you have multiple ghosts there, the others being less obvious.

Usually with these things they can be seen around the centre point of the lens position of the image as taken. (Any crops may make it look a little different positionally.)

As you took that almost head on and with the car more or less in the centre of the frame I would expect there to be some ghosts (probably very feint) around the front of the car, in this shot pretty much in the same place as the lights but with a slight offset.

The more obvious ones you have cloned from the upper left side look more likely to have come from filter(s) or some secondary reflective source.

That said light - and different sources of light - can do odd things as can lens designs. So I am just speculating on that one.