# Trouble lighting a plexi background



## AdamZx3 (Aug 4, 2007)

I am trying to light up the setup below and I am having troubles keeping the plexiglass dark enough. Its a clear piece of plexi and a dark black sheet underneath, all is well untill I flash it. I can't find any solid black acrylic so I thought this would work.... I then thought about painting one side black, but i'd like to keep it clear to change colors if possible. Would some seamless black paper work better?


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## Peanuts (Aug 4, 2007)

Since all of the items here are dark in themselves, have you used a different background colour such as white or grey? (If that is an option)  In photoshop you can play around with levels or curves to make it a pure black, however you will loose detail in your subjects, especially the bottle. Also, try shooting straight down, especailly with teh ligh source, do you see the gradient of black, in the foreground is kind of 'greyish' and at the back it is closer to black?

One option is to buy a fleece (or better velvet) blanket or fabric specifically for this. I have attached a quick product shoot I did for a friend, though this is without the plexi glass using velvet.


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## AdamZx3 (Aug 5, 2007)

Thanks, I tried it on white and it didn't have the same effect, i will have to try the velvet for non reflective stuff though never thought of that.

Heres my best shot of trying to correct the background, and spiced it up a bit for a more dramatic look.


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## Peanuts (Aug 5, 2007)

Much improvement!


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## John_05 (Aug 5, 2007)

i tried the same type of shots,  and was told that its nearly impossible to get a good solid black backgrond with the reflections of the subject youre shooting using clear plexi and black fabric or paper underneath it.  

it was a long time ago,  and i dont remember the exact way it was said to me,  but it has to do with the thickness of the plexiglass and the distance from the paper or cloth underneath it.

ive found solid black acrylic,  and many other colors,  on Ebay.  3 sheets of black 12"x12" was about $23 including shipping.


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## AdamZx3 (Aug 5, 2007)

ah ebay....never thought about that!

I am having a really tough time with my monitor shifting brightness...if I just bob my head up and down it will change it to way to bright to way to dark...if I have it in the center of the screen and I lean back its just right, if I lean forward...too bright..grrrr

Its calibrated but this brightness shift is killing me, can you guys see the wrinkles in the 2nd pic? they should just disappear if its right and shouldn't see a shaddow blob around the hoppes bottle....guess I should spent the extra money on the apple cinema display :/

I'd love to hear what you guys see on your moniters and thanks for the tips and feedback


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## Hertz van Rental (Aug 5, 2007)

John_05 said:


> i tried the same type of shots,  and was told that its nearly impossible to get a good solid black backgrond with the reflections of the subject youre shooting using clear plexi and black fabric or paper underneath it.
> 
> it was a long time ago,  and i dont remember the exact way it was said to me,  but it has to do with the thickness of the plexiglass and the distance from the paper or cloth underneath it.



Black Perspex (UK name for plexiglass) only reflects off the top surface.
Clear reflects off both the top and the lower surface. The light bounces around inside (the basis of fibre optics) and causes a degree of flare on the fabric, reducing the contrast. That's why you don't get black.

If you can't get black plexi then try dropping the black backing about a foot below the plexiglass, lighting carefully and adjusting the angle that you are photographing from to minimise reflections.
It should work better.


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## John_05 (Aug 5, 2007)

AdamZx3 said:


> ah ebay....never thought about that!
> 
> I am having a really tough time with my monitor shifting brightness...if I just bob my head up and down it will change it to way to bright to way to dark...if I have it in the center of the screen and I lean back its just right, if I lean forward...too bright..grrrr
> 
> ...


 


Hertz van Rental said:


> Black Perspex (UK name for plexiglass) only reflects off the top surface.
> Clear reflects off both the top and the lower surface. The light bounces around inside (the basis of fibre optics) and causes a degree of flare on the fabric, reducing the contrast. That's why you don't get black.
> 
> If you can't get black plexi then try dropping the black backing about a foot below the plexiglass, lighting carefully and adjusting the angle that you are photographing from to minimise reflections.
> It should work better.


 
thats almost word for word how it was described to me.  thanks for clearing it up for me,  and for the tip.

im still stuck using an old monitor, and the only calibration i did with it is the calibration procedure in Paintshop Pro.

i see the wrinkles and shadow on the Hoppes bottle you mentioned in both shots. moving away from or changing viewing angles doesnt make a difference on my monitor. im using a 4-5 year old Emachines flat screen 17" CRT.


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## AdamZx3 (Aug 5, 2007)

Hertz: 
Thanks for the tip I never thought about that!

John:
Thanks for the feedback, Sometimes I wish I had my old crt again!

The lcd monitors are prone to this brightness falloff , high end monitors like LaCie and apple displays dont have near as much of an issue anymore, but are big bucks... $1800 for a 21" the apple 21" is around $1000....:meh: my Acer 22" was $380 and is great once calibrated for most stuff but if I have a solid gray wallpaper it looks like a gradient...solid colors and low key items seem to really throw it off.

Thanks guys!


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## fmw (Aug 6, 2007)

It's easier just to fix it in Photoshop.  In the levels adjustment, use the black eyedropper to pick the lightest area of the background.  That will throw the entire background to dead black.

I fooled around with your image and the problem you are having is that the background is not evenly lit.  You have a hot spot right in middle of the image just below the pistol - obviously a single hard light.  Use the black eyedropper right there to get a completely black background.


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## AdamZx3 (Aug 6, 2007)

Thanks Fred,

I will have to try and reshoot the image and try that, maybey I need to go higher above the table, I had it rather close (2ft or so) using an umbrella sofbox camera right and a reflector camera left.


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## Tom_Tom (Aug 10, 2007)

The shot is looking better in the second image , but still it's hard to define the details and the refection is a bit confusing especially around the trigger guard. Would it be possible to bring the light sources closer and light from above , say a big soft box on a boom right above the set up firing down?


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