What would cause this on photos?

Marcel

Marcel

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Marcel
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Forgive the seemingly noob question. Just been out to take a couple of quick photos for my son for his homework and came across a couple of anomalies.

All on the 7D and my Sigma 10-20

06.18_St_Georges_Church_Unsworth_-_Adobe_Bridge-20130618-200400.jpg


Look at how it's handled the extremes of contrast/exposure between the sky and the church. The sky was overcast, no direct sunlight, and the lens was clean at both ends and inside.
(Shot on aperture priority)
f/5.0 @ 14mm

06.18_St_Georges_Church_Unsworth_-_Adobe_Bridge-20130618-200545.jpg

Top half of another shot

06.18_St_Georges_Church_Unsworth_-_Adobe_Bridge-20130618-200632.jpg

And even worse. Definitely no direct sunlight.

06.18_St_Georges_Church_Unsworth_-_Adobe_Bridge-20130618-200735.jpg

I've experienced these in shots before, but only in very extreme circumstances and very localised (for example leaves against a sky shot etc).

Never on this scale.

I'm stumped.

BTW, these are all screenshots of the actual RAW previews from Adobe Bridge.
 
The second shot down has colour rainbow sort of effect, not a cheap or dirty filter by any chance?
 
My suggestion might be a lot more 'noob' than your question - but could it be a bit of lens flare on the highlights where the light breaks through the gaps in the trees/buildings in a sort of bokeh-stylee and could the rainbow effect be due to lens coatings (or even simply because of refraction)?

P.S. Could there have been any condensation/moisture on the lens
 
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swanseamale47 said:
The second shot down has colour rainbow sort of effect, not a cheap or dirty filter by any chance?
Click to expand...

that would be my guess too, either filter or front element is smeared/dirty and the less than perfect to begin with 10-20 is made much worse on the high contrast points. :shrug:
 
It's just over exposure from the sky, my suggestion is to take two shots, one for the sky and one for the building them blend them together or use a neutral density graduated filter.
 
Looks like a centre weighted average setting?
 
flare
 
What shutter speed was it giving you on Av for f/5.0?

My stab in the dark is: shady church with spot metering. Camera is giving you a relatively slow shutter speed. If we knew the shutter speed someone could take a rough guess as to whether it was in an appropriate range for even an overcast daytime sky.
It does look like a classic high dynamic range scene - wooded, walled off churchyard with imposing church vs daytime sky.
 
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i always use my 10-20 at f11 and a fast ish shutter speed ,has it got a filter on it can you go back to the same spot and take a few shots without the filter if it has 1 and use f11 -f22 as the sigma's seem to work better at around f11-f22 ok you will not get the same light as in the shot but it would let you see if it works any better for you
 
cosmicma said:
i'l go with the centre weighted / spot metering causing over exposure is what it looks like to me
Click to expand...

No it's not. That will cause the sky to be very bright and over exposed, sure, but I'm fairly certain the OP is on about the splodgy coloured flare.


It is flare. If you have a pointless UV or skylight filter on... remove it... preferably throw it in the bin.

If it's dirty, that will only make the problem worse too. Same with the lens itself. Dirt on the lens surface will increase flare when shooting into, or nearly into a very bright light source, or when very bright light is hitting the lens surface in general.


You are partially correct though, as having a sky that bright in shot will always increase the risk of flare dramatically. That's never good practice to shooot in these conditions without doing something about it.... but that flare there is really, really terrible. If there's no filter on that lens, and the lens is clean, then it's a really terrible lens IMO.
 
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It does look like really bad lens flare. As above, my first thought would be poor quality\dirty UV filter. Is it possible that your son breathed/blew on the front element to clean it and didn't allow it to dry fully before taking the shots?
 
I'd try to expose for the sky, then lift the shadows in LR, see what happens then
 
For all those who said filter, 'fraid not. Lens is as nekkid as the day it was opened.
The same goes for dirty. It's spotless.

I knew the sky would be overexposed, it's the bleed that I was worried about.
Could definitely be incorrect metering (I've forgotten what it's set to).

Here's a question though if the metering is incorrect.

A shot taken in Av with spot metering, ending up at, say, f/5.0 and 1/15th.....and a shot taken in full manual with the same settings.
The shots would be identical right? Therefore I'm unsure as to whether it's metering that's caused the bleed of light. Like I say I was exposing for the church, which is exposed OK to me.

This lens has been brilliant to me in the past, and has never exhibited anything of this nature. None of my lenses have. There are two separate behaviours shown here. The light bleed from the overexposed area, and the flare.

The flare I would normally put down to direct sunlight, or a dodgy filter, or a dirty lens.
BTW I'm not bothered about getting the shot, it was a simple snap for his homework that's all :)
 
Marcel said:
For all those who said filter, 'fraid not. Lens is as nekkid as the day it was opened.
The same goes for dirty. It's spotless.
Click to expand...

Then it's not a very good lens would be my first reaction.

Marcel said:
I knew the sky would be overexposed, it's the bleed that I was worried about.
Could definitely be incorrect metering (I've forgotten what it's set to).
Click to expand...

I can't see how it could be. The trees building etc are well exposed. It's just that the sky is so bright. It shouldn't be flaring like that though unless it was direct sunlight.. was it? It doesn't look like a sunny day... just bright overcast.



Marcel said:
A shot taken in Av with spot metering, ending up at, say, f/5.0 and 1/15th.....and a shot taken in full manual with the same settings.
The shots would be identical right?
Click to expand...

Correct.



Marcel said:
This lens has been brilliant to me in the past, and has never exhibited anything of this nature.
Click to expand...

Obviously you've just never used it in such extreme circumstances.


Marcel said:
None of my lenses have. There are two separate behaviours shown here. The light bleed from the overexposed area, and the flare.

The flare I would normally put down to direct sunlight, or a dodgy filter, or a dirty lens.
BTW I'm not bothered about getting the shot, it was a simple snap for his homework that's all :)
Click to expand...

I've shot in FAR worse conditions that that and never had that happen. It almost looks like there was condensation on the lens. Had he only just removed the lens cap proper to the shoot? If the lens was particularly cold when warm air hits it, it could have frosted over... and then evaporated very quickly.


BTW.. I feel weird saying this to a moderator.. but wouldn't this get a better response in the technical forum?
 
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If there's no filter in front of that lens, it's either mucky or there's an issue with coatings.

As David said, the only cause for that amount of flare is disruption to the light path into the sensor. There is no other explanation. it's flare, it's causes are simple.
 
The lens looks fine to the naked eye. I've used it in much worse conditions before.
I'll dig out some old archive shots from RAW, see what I can see :)

And yep, you're probably right pookey :)
 
Here's a quickie from 2009. No bleed.

Lightroom-20130619-151928.jpg

And another
Lightroom-20130619-152124.jpg


Harsh contrast, no bleed.
 
Then it has to be something temporary on the lens (condensation perhaps) or it has developed a fault of some kind.
 
I'll do some more shooting in a bit, see if it does it again :)
 
You guys! Stop delving so deep. The problem is with the exposure! You don't want the OP wondering about his gear, that can lead to all kinds of unnecessary expenditure :p
 
Oh dear lord, no more expenditure for me.....Spent way too much already.
But surely if it was just exposure, then the sky would be overexposed, and the building normal/underexposed. Why the bleed?
 
I have experienced blooming highlights like this before with my 7D. The sensor doesn't cope that well with highlights, especially when the sky you're shooting is grey/white. I personally stick to a smaller aperture when conditions are like that, set a faster shutter speed and alter my white balance accordingly. I have also messed about with Highlight Tone priority on occasion, which has helped in some cases!

[EDIT] Your images seem a bit blurry - perhaps camera shake? What shutter speed did you opt for? I imagine that had the surrounding foliage not been there, your shot may have been far more overexposed.
 
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Eddzz!! said:
You guys! Stop delving so deep. The problem is with the exposure!
Click to expand...

What do you base that upon? The OP has already posted other pics taken with the lens with subjects that have a far greater dynamic range without exhibiting the same results.


There is one caveat though... were the first shots taken wide open? There's no exif. If so, that will always make things a whole lot worse. If so then yes, it may well have something to do with exposure, but I'd not go as far as to say it definitely is until we know that.
 
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Pookeyhead said:
What do you base that upon? The OP has already posted other pics taken with the lens with subjects that have a far greater dynamic range without exhibiting the same results.


There is one caveat though... were the first shots taken wide open? There's no exif. If so, that will always make things a whole lot worse. If so then yes, it may well have something to do with exposure, but I'd not go as far as to say it definitely is until we know that.
Click to expand...

This is a good question, also are you sure the lens is stopping down correctly and isn't stuck at a wider aperture than you've set? Thinking aloud...I guess if that were the case then the image would be over-exposed as well. Hmm!
 
First, the 1st image is overexposed IMO. Metering brick red on the shadow side will cause this. Secondly, this is a wide aperture shot. Thirdly, you are shooting from "speckled" shadow under the tree.

So you have a combination of things going on. You have direct backlight with a wide aperture which will cause "blooming." You have the leaves scattering the light which will make it worse. And you also have "hot spots" hitting the lens which are creating multiple points of "lens flare" (3rd image) which is causing the color spots. Blooming can occur anytime you have a light source hitting the front element directly. Flare is worse when the light breaks over a hard edge (edge of building, leaves etc). It also looks like CA might be contributing. CA is worse with large apertures and backlit subjects; and it is common with WA lenses. But CA is typically much more clearly defined.

This is a weird confluence of circumstances...at first glance I would have said crappy filter. I wouldn't worry about it unless it occurs in more typical situations.
 
I'm with Pooks.
 
That's nice, are you having dinner together? :D
 
I think its got to be an exposure problem, the self portrait on your Avatar is also clearly underexposed.
 
That reminds me - completely forgot to take an over exposed SP for Terri...

Marcel's problem looks like flare to me too - or at least some sort of extreme highlight bleed. Condensation in lens or on sensor?
 
Why do people keep blaming exposure? The sky is blown because of the metering but the problem is the flare. The third image shows it most obviously on the left side. From the suggestions already put forward I think it's a problem with lens coating too if there's no obvious condensation etc seeing as the lens has been fine with the other examples posted.

Steve
 
Looks like fairly standard veil flare to me....did you have the hood on Sir?

Bob
 
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