Lens Flare?

[jcon]

I have started to notice a blue "dot" on about half the New Years fireworks photos I took... I also noticed it in a family portrait taken outdoors a couple months ago. Here are 3 examples.... is this lens flare or something more serious?

[Wowzer]

Did you have a filter on your lens? If so, then that could be the culprit...yes it does look like lens flare to me.

[jcon]

No, I dont use filters... the odd thing though, its pretty much in the same spot on the photos, although, I didnt move the camera much...





*EDIT*

Here is another photo, Im starting to think this isnt lense flare. Can the moon cause lens flare in a situation like this? This time its a green dot, but in the same place....

[rawpaw18]

Jason,
Did you shoot your family portait outside? I would say that the moon could certainly cause flare,it is plenty bright enough, but if it is on a family portrait too????

[tcadwall]

I assume that you have ensured your lens is clean, and if so, have you had your sensor cleaned recently?

It does look like flare, but it might be a little peculiar that it occurs in the same place, regardless of where the light source is (framing). It almost seems like something (dust or scratch maybe) is causing some diffraction. This is just a guess.

[Gordoaus]

I have had the same problem with an FZ-30 and a D200 but much larger area and it was a fingerprint on the lens that wasn't cleaned off properly.
Looking at the lens square on I couldn't see anything wrong but once I got the light in the correct spot it was then that the problem appeared.
Drove me crazy for a while and only appeared when there was extra light coming into the front of the lens at a particular angle (approx 7 degrees).
I had to view the lens directly square on and have the light coming at it at approx that angle and then it was visible. Weird. (had eyes checked too :) )
Didn't get green on mine but it may be due to whatever colour it is getting hit with.

HTH

[Gordoaus]

of colour problem

[jcon]

Rich, yes it was on the family portrait aswell, which was taken outside. I dont remember it being that sunny out either.

tcad, I cleaned my sensor 2 days ago, and I always make sure my lenses are clean(no dust, ,spots).

[XaiLo]

Does it only occur with a particular lens?

[jcon]

I am pretty sure its happened with both my Sigmas. The one I used for the fireworks was the 18-50mm 2.8. I will have to do testing on the 50mm.

[tcadwall]

Is it just one lens?

Might want to try taking some shots indoors, of a light colored wall. See if you can make it happen when flare should not be an issue. If it seems to be one lens, start with that one, see if you can see anything if you can see the problem, try another lens. If you can't see anything, introduce a light from an angle that will directly hit lens front element - toying with the placement until you can reproduce the problem. Then try another lens, etc.

At least that might help you narrow down whether it is a lens issue or camera issue. I would suspect lens since it really seems that the light is diffracting. but I guess if it always is the same color, and the same exact spot regardless of lens used, then maybe there is something wrong with some "red" sensors on your ccd or something... Can't say that I have heard of this...

[jcon]

Ok, now.. I am starting to think lens flare,lol. Man this is frustrating me! Here are 2 shots I just took, first is with the 18-50mm 2.8 and the second is the Sigma 18-125mm. Both at 18mm, and when I started to zoom in even just a bit, it went away. Taken in my room, with 2 lightbulbs on ceiling. I know they arent the best looking pictures, but I just wanted to get some tests done and not worry about quality.

[tcadwall]

yup looks like flare. Just to confirm it even more, try taking the same shots from the opposite angle. IOW so that the lightbulbs are to the right of the lens. it should then of course flare into the left of the picture. All of your samples so far seem to have the light source to the left of center.

[jcon]

The 2 ceiling pictures are cropped and the flare was actually on the left/center of the photo. The fireworks were also cropped, but the flare was on the right/middle of most of the problem photos. There were a few that had it closer to the top of the middle. I held the AF-L button to keep focused locked for all the photos and didnt move the camera. So thats probably why its pretty much in the same spot.

As for your test, I panned the camera from right to left, and the flare shifted right along with the lens.

Case solved?:confused: :o

[tcadwall]

yup. Next question would be if you have a hood that you could use, and how much it would help (additional test I suppose). Or you can touch the photos in post, or you could say that it is for "artistic" effect... Assuming you don't want to shell out for new lenses.;)

[jcon]

LOL, I will be shelling out for new gear soon, I hope. My plan is the Nikon 17-55 2.8(I do hear that flare happens with lenses with a low wide end) and my next body will be a D2Xs. So I got some saving to do!

I do have hoods that come with the lenses, but silly me, I didnt think it would be needed since it was dark out:o

[tcadwall]

Honestly, to me it does seem weird that you would have such a flare issue with the fireworks. Thus the (tongue in cheek) new lens suggestion.

I only have noticed flare in a couple of my shots with my 18-200mm and those shots I expected flare... (ie. setting sun in top-right corner of frame)

And even more often I have taken shots where I expected flare, and didn't find any.

And the 18-200mm comes with a pretty large lens hood that I have never used.

[rawpaw18]

It was probably the moon that caused the flare, while you were using longer exposure to capture the fireworks the moonlight just got more intense.

[eduardofrances]

Flare is caused by poor optics, poor coatings or sometimes the element not being recessed enough to avoid the phenomenon, this said a hood could prove to be useful when the light (sun, moon, monolight, etc) comes from a side...



Also take in count that Sigma equivalent of the Nikkor 17-55mm f/2.8 and Nikkor 18-135mm are cheaper, you know the saying there isn't a free lunch in the world and this is applied also to lenses, the Sigma ones will have cheaper optics and not so good coatings and this will produce some phenomenons like flare, chromatic aberrations, etc, etc.. Another example is the sigma 70-200mm f/2.8 the main problem of this lens is flare, it is not as resistant to flare like the Nikkor 70-200mm f/2.8 VR or canon offering with the same specs, but Sigma is cheaper -and it will behave differently too...-

Other considerations are that the Zoom lenses have a more complicated lens formula (numbers of elements) than primes and longer focal length lenses will be more prone to this phenomenons. (like 7x or 10x zooms most people love) also Cheapo filters can cause flare and ghosting too... beware.

You can avoid flare by changing the way you do compositions, compose your scene and try to block the source of any flare inducting source. if you can place the flare inducting source behind you everything is good, if not use a hood at least.

[jcon]

Well, I went back looking for that family portrait I mentioned and couldnt find it but I found the exposure test shot I took right before the portrait and its got the blue dot on it, and its fairly large. As you can tell from the picture, it wasnt sunny out at all, I believe it was just before winter and looking back at the EXIF, I have NO IDEA why it was at F22:confused: Its hard for me to tell but it looks like its the shape of the blades(octogon) So I guess that makes it flare, but in that type of weather it shouldnt be there:confused:

This one was taken with the 50mm 1.8D. I am totally lost now, and havent gotten a reply from Nikon yet.

[rawpaw18]

Weird,
It seems like a very pronounced dot, most times when I have a flare that shows up, it is softer in appearance, the edges feather out more, and usually toward the green tones not blue. Curious to read what Nikon says.

[tcadwall]

Do you think that these are the same flare?

The last photo posted, makes me think that ITS cause might be the aperture setting. f22 is a pretty small aperture.

Good flare reading (http://www.luminous-landscape.com/columns/sm-03-01-12.shtml) from a luminous landscape article.

I would lean toward thinking that the flare source is not the same as the previous scenario.

[jcon]

Nikon thinks there might be something on the sensor and suggested I clean it or send it in for evaluation/repair. Since its under warranty, I am sending it in:(

Thanks for all the replies guys. Ill keep you posted on what happens.

[rawpaw18]

Camer seperation, that rots. I missed mine for the couple of weeks it gone for repair. Good luck.

[tcadwall]

That bites man, do they want you to send a lens with it?

What would stink even more is if you get it back and THEN find out it was lens flare!

[jcon]

Yea, it bites not having my camera, I feel like I lost a family member,lol.

The tech said its either a lens malfunction or something wrong with the sensor. Since its happened with all 3 lenses in my signature, it must be the camera. No I didnt send any lenses as I dont believe its a lens problem.

Thanks again for the comments! I will let you know what turns up!

OH and yea, my warranty expired on Jan. 3rd, but they said they would still honor it since its been a problem in the warranty period. *WHEW*

[jcon]

Well I should be getting my camera back late this week, or early next week. Early report I got was that they did a CCD clean, adjusted that AutoFocus mechanism and adjusted the iTTL Flash levels:eek:

Maybe now I know why my flash was underexposing, LOL. Hopefully the camera will be fine once I receive it!