Inverted reflection

T

Thorby

n3wb
Apr 28, 2016
22
9
I just got my DS-2CD2087G2-L from Amazon renewed, which ships from HIKVISION AUTHORIZED REFURB OUTLET.

I bought it just to look at my house decoration lights! LOL Yes, don't laugh, otherwise I'd only see the lights if I went somewhere and came home after dark!

ANYWAY - I got the camera installed, and I got this reflection:

inver.png

It happens on all settings (Normal, backlight, frontlight, lowlight, etc). I turned HLC on and off, I turned WDR on and off.

To view the lights properly (wicked motion blur) I had to crank exposure time up to 1/150 with WDR ON, and it looks ok, but I have the reflection on all exposures.

There's nothing near the camera that could throw that reflection.

Is there an adjustment or setting, or should I send it back as bad?

It looks like the camera came with firmware V5.7.12 build 230131.

Thanks for any help!
 
You probably have to play around with the angle of the camera if possible.

Bright LED lights like in your scenario are probably reflecting off the lens onto the protective glass and then back in and would likely get it from any camera at that ange and what you are looking at.
 
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wittaj said:
You probably have to play around with the angle of the camera if possible.

Bright LED lights like in your scenario are probably reflecting off the lens onto the protective glass and then back in and would likely get it from any camera at that ange and what you are looking at.
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Heh, well, that does suck. I had to build a box to mount under my mailbox - it's aimed up at the house and I don't see how I COULD change the angle. Darn. Any other angle and I won't be aimed at the house.
Am I screwed with this? Should I try a different TYPE of camera, like a dome, maybe?
 
A dome would be much worse.

If all you care about is seeing your house decoration lights, I would be inclined to say go with something with a smaller sensor.

The 4K on the 1/1.2" sensor is a great camera, but like anything, used in the wrong location or situation and it is crap.

That sensor lets in a lot of light and the f1.0 aperature probably allows it to get that reflection.

Does that camera have a iris setting? Maybe dial that way down. Or gain.
 
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I do not see a way to change the iris setting or gain, no.

Heh, I had no idea about the sensor size!

Got a camera recommendation for my purposes? I just want a nice clear look at my lights!
 
I spoke too soon! Changed it to "DAY" and found the gain slider. Cranked it down, it DID eliminate the reflection, but... I'll have to play with the other settings to get it so it looks nice again. I'll post a pic if/when I get it looking good. Thanks for the hint though!
 
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I THINK I can live with this... The reflection is actually not as bad in the actual video - can't really see it. I don't care for the "squared off" look the gain gives, and some of the color separation kind of runs together, but if this is my only option - I'll have to live with it!

1693101561729.png
 
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I've always wondered what a polarizing film sheet could do in such a situation. If you could rotate the sheet until the inverted image disappears the cam's iris would likely needed to be opened up a bit.

polarizing_sheet.jpg
 
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lens flare...just like pointing into, or nearly into the Sun.
 
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TonyR said:
I've always wondered what a polarizing film sheet could do in such a situation. If you could rotate the sheet until the inverted image disappears the cam's iris would likely needed to be opened up a bit.
Click to expand...

I tried that with a cam that I have at my pond to cut down reflection off of the water. Worked OK. First trick required is how to keep it on there. I happened to have a rubber cover for a dial-type tire gauge that kinda sorta fit the Dahua cam.
 
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Mike A. said:
I tried that with a cam that I have at my pond to cut down reflection off of the water. Worked OK. First trick required is how to keep it on there. I happened to have a rubber cover for a dial-type tire gauge that kinda sorta fit the Dahua cam.
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I was always entertained at how when wearing polarized sunglasses (the old Polaroid's of the 60's) you could be gazing down at fish in the lake and you could see them and then slowly tilt your head toward horizontal the fish you saw just under the water's surface would slowly be replaced with reflections of the clouds in the sky.

Yep, Edwin Land of Polaroid was a pretty smart cookie, IMO.

polarized-sunglasses.gif
 
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Mike A. said:
I tried that with a cam that I have at my pond to cut down reflection off of the water. Worked OK. First trick required is how to keep it on there. I happened to have a rubber cover for a dial-type tire gauge that kinda sorta fit the Dahua cam.
Click to expand...
Do you know what KIND you got? Apparently (who knew?) there are a whole BUNCH of different kinds!!
 
Thorby said:
Do you know what KIND you got? Apparently (who knew?) there are a whole BUNCH of different kinds!!
Click to expand...

Couldn't tell you. Just one of those things that I had laying around. I'm sure you probably can find something better if you're buying for that purpose.

Maybe look at these kind of things? I had some that I thought about using but none were big enough. Looks like they make some larger ones:
www.butlercreek.com

Blizzard Scope Cover | Scope Caps | Butler Creek

The Blizzard Scope Cover features a weather-resistant seal and silent open and close. Protect your scope with these scope covers. Discover Butler Creek today!
www.butlercreek.com www.butlercreek.com

Also looked at something like this thinking that I could find one to use with polarized camera filters that I have:
www.ebay.com

Marumi SL (slip-on) rubber lens hood | eBay

Find many great new & used options and get the best deals for Marumi SL (slip-on) rubber lens hood at the best online prices at eBay! Free shipping for many products!
www.ebay.com
 
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Also, one problem that you'll run into is that whatever will need to be relatively shallow or you'll see the dark circle around the image if you're using a wider focal length.
 
Mike A. said:
Also, one problem that you'll run into is that whatever will need to be relatively shallow or you'll see the dark circle around the image if you're using a wider focal length.
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Shallow - you mean very close to the camera lens itself?
 
This is a common issue with bright light sources, and as noted by someone else above, it is the same issue that causes lens flare in general photography. It is just unusual for there to be this many sources of lens flare in one scene.


Interesting fact: If you draw a line between each reflection and its source, the lines all cross through the center of the lens and are roughly equal length on each side of the lens center. This will still be true if you aim the camera differently, which is why you can't actually eliminate the reflections just by moving the camera, until you've moved the house fully out of view that is.

1693171858665.png


I suspect that, if a polarizing filter would help at all, it might have to be installed closer to the sensor. Behind the cover glass or maybe even behind the lens. It could depend on where exactly in the optical stack the light is becoming polarized (IF IT EVEN IS POLARIZED!). I'm sure an optics expert would know more, but that isn't me.
 
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