Bright halo / spot in pictures and videos

Thierry · Apr 21, 2015

Hi there !
I would like to know if some one have already met that kind of issues. I have a bright halo in some pictures and videos. It seems that it's related to where the sun is and the cam position. It's really annoying in videos. I have tested with both filters and can see the same problem. Should I try without them ?
What's odd is that it also seem to match the Inspire 1 shadow position on the ground. When it's close to the ground you can easily see it. I wonder if it's something reflecting from the quad structure laterally in the lens or ... ?
Any idea ? Thanks for your feedback

jon b · Apr 21, 2015

I've seen this as well. Assumed it's lens flare happening where I was shooting either midday or slightly toward the sun.

Looks like in your shots, you are side-on to the sun.

You can see that in this video at 40 second mark

Thierry · Apr 21, 2015

Thanks for you feeback Jon, I can see clearly the exact same issue in the grass at 40 sec. Happy to read that am not the only one ;-) It's weird and can't be a kind of lens flare in my opinion. It should be visible when you face the source of light... Am really wondering if it's come from a reflection on the body/landing gears coming right on the side of the lense.
It's a real problem lowering shot quality....Will continue my investigations, thanks for other suggestions !
PS nice video !

The Editor · Apr 21, 2015

It's not unique to the Inspire - I have seen the same phenomenon on GoPro's slung from quads and hexacopters.

It is THE sun causing it and it appears when the sun is behind the craft.

I'm not actually sure how or why though!?!?!

Thierry · Apr 21, 2015

Hey,thanks for the feedback,good to know!
Am really curious to learn how it's happening... Because... if the only solution to avoid the effect is flying in a cloudy weather,my shot will be less sexy ;-/ it's sooooo visible when you have a grass field or continuons color on the ground. Green seems to be the color that 'highlight' it the most by the way.

Thierry · Apr 21, 2015

I found that thread about the opposition effect very interesting...not really sure to understand yet but a good start to learn

thanks for feedbacks that guided me in a relevant Google search!
http://www.phantompilots.com/threads/bright-spot-in-pictures-video-defective-camera.4073/
Update: ok,got it,will have to live with that Oo
http://www.geospectra.net/kite/weather/opposit.htm

Daniel Mascheck · Apr 21, 2015

Just curious, but what kind of crops are in the photos? I plan on using the Inspire flying over fields in the Gulf Coast of Texas. Are these in Europe. Notice the controlled alley ways.

Thierry · Apr 22, 2015

Daniel Mascheck said:
Just curious, but what kind of crops are in the photos? I plan on using the Inspire flying over fields in the Gulf Coast of Texas. Are these in Europe. Notice the controlled alley ways.

Yes, that's in Europe, Switzerland. It's a corn field, the crops will be less visible in some weeks when the corn is higher ;-)

The Editor · Apr 22, 2015

Opposition effect - So now I know! Most noticeable on uniform fields of crops no less!

Makes sense, thank you

Daniel Mascheck · Apr 22, 2015

Curious to know your row spacing on the corn? Seems it is very narrow row. I plan on surveying corn with Central pivot irrigation in our area of the Gulf Coast of Texas,

Last time I was in Switzerland, I never ran across much corn. What area of Switzerland?

Thierry · Apr 22, 2015

Daniel Mascheck said:
Curious to know your row spacing on the corn? Seems it is very narrow row. I plan on surveying corn with Central pivot irrigation in our area of the Gulf Coast of Texas,

Last time I was in Switzerland, I never ran across much corn. What area of Switzerland?

Sorry am not a corn field specialist but I know that everything is smaller in Switzerland ;-)
That's exactly there, in the french part of Switzerland, near Lausanne. https://www.google.ch/maps/place/46...385,1008m/data=!3m2!1e3!4b1!4m2!3m1!1s0x0:0x0
You'll see that there is a lot of culture in this area.

jon b · Apr 22, 2015

BTW, I've seen sun shields made to fit right on the threaded end of the inspire camera for sale that supposedly eliminate this. Basically this is a kind of lens flare, the lens is getting hit by the sunlight. Even a glancing blow from an acute angle can cause this. Inspire, go pro, all the action cameras are wide angle and susceptible. Lots to keep in mind when you set-up a shot.

DaBone · Apr 22, 2015

How can you get a lensflare, when the sun is behind the camera ..?

m00se · Apr 23, 2015

this is very interesting, it may well explain some things I have seen in the past when doing photogrammetry at the time of day when the sun is at its Zenith. This is an annoying thing to say the least, as for many jobs you want to fly when the sun is at its zenith to avoid shadows in the job.

I wonder if there is a fix we can invent for this?

Thierry · Apr 23, 2015

Am not sure that a sun shield would help in that case...(but am interested to get a link on the product). It has nothing to do with a lens flare obviously. The only thing I can imagine to counter the opposition effect is...post production. A pain for videos... other ideas ?

DaBone · Apr 23, 2015

Thierry said:
Am not sure that a sun shield would help in that case...(but am interested to get a link on the product). It has nothing to do with a lens flare obviously. The only thing I can imagine to counter the opposition effect is...post production. A pain for videos... other ideas ?

http://www.ebay.com/itm/281654960747?ssPageName=STRK:MESOX:IT&_trksid=p3984.m1561.l2649

Thierry · Apr 23, 2015

DaBone said:
http://www.ebay.com/itm/281654960747?ssPageName=STRK:MESOX:IT&_trksid=p3984.m1561.l2649

Thanks !

jon b · Apr 23, 2015

DaBone said:
How can you get a lensflare, when the sun is behind the camera ..?

You can't, but that's not the case in the shots at the top of the thread or in my experience. Course with the sun directly behind you, you have to avoid placing a shadow of your craft in the shot.

It's got to be light bouncing around the lens elements from somewhere...

I'm going to do a little flying mid afternoon and put the camera at a few angles to the sun to see what happens. Get back to this thread soon

The Editor · Apr 24, 2015

Errrr.....guys, Don't waste your time trying to eliminate it (other than in post) because you won't.
It is not something that is unique to cameras, our eyes see it as well as it's just physics. It happens all the time but is only noticeable in certain situations - mostly on uniform crops due to the texture of the subject and acute angle of the crops causing reflected light to go off axis from our view point.
As light travels in straight lines (for the purposes of this phenomonen anyway) what we see in the world is made up of reflected light. (We Don't actually see any objects at all, only the light reflected from them)
In this scenario, when we view crops from above with the sun directly behind and at the same angle most of the light is reflected at angles off the crops which means what you see is very slightly darker. The bright spot is the light reflected in exactly the same plane as your viewpoint and angle and therefore very little of the light is lost in shadow/reflection. This then appears as a slightly brighter area from our viewpoint.