How to create blue color gradient effect for tank photography?

[Shadow]

I was asking this before, how to create those blue color gradient effect for tank photography?

I read the instruction on "Creative Aquascape Union" web site, but don't really understand it sorry I'm newbie

This is what written:
Light blue background gradation from sky blue to dark blue
Light box white acrylic as diffuser, place on the wall; pull the top edge toward the backside of the tank. Now, the acrylic bottom part should remain touch the wall, the top edge touch the backside of the tank. The light source with blue filter place top down behind the acrylic. Since the main light source also top down. When check exposure reading base on the top part of the tank, the lower part acrylic will under exposure and as a result of a gradation blue background. Change the exposure combination will change the brightness of the background, however it will also affect the exposure of the plant, you may have to adjust the luminosity of two light source in order to find a desirable result.

Questions are:
1) White acrylic as diffuser? I though acryic is transparent how to use it as diffuser?
2) Light source with blue filter? is this normal PL /FL/T5 light or flash? where to get blue filter?

Does anyone try this before? Any tips?

[ranmasatome]

its a bit hard to understand as the english is so fragmented..but..
acrylic is not transparent... acrylic a type of plastic.. there is no limitation as to what colour acrylic can be. Its like saying styrofoam is white...but then...being white is not the limitation of colour on styrofoam as we all have seen black ones as well.

light source here i think refers to their flash...blue filter can make your own.

[Shadow]

Try it out and it does not work
1st problem: can't find the corect size, Art Fried sell it in specific sizes
2nd problem:acrilic must be wider than the tank, I bought exactly 2ft, 1824" clear
3rd problem: clear acrilic does not work and no stock for white acrylic
4th problem: one flash with blue filter is not enough to cover 2ft tank
5th problem: light box does help but then it can be fired by ST-E2 unless move further away

Give up until find other idea. Any suggestion?

This is what I'm trying to achive (Mod please delete the photo if I'm not allowed to use it):

[leeruisheng]

Was reading somewhere about using Photoshop to achieve the colour gradient you desire and then printing it out.

[Shadow]

hahaha...good idea but can't use that for ADA competition.

[leeruisheng]

Is it? Meaning ADA did specify only solid colours background?

But I meant printing out the background, place behind the tank and then do a photo shoot. And not photoshoped directly on the picture and submit.

[Shadow]

I mean you can't use photoshop. sorry miss understand

I was thinking of using water based paint. easier than printing large format.

[Jervis]

I believe the circular gradient blue in the pix is actually created by lighting. See the colour of the bottom glass... it shows blue light. Or it could be a combination of a backdrop + lighting effect.

You guys can try colour changing LEDs

[Shadow]

it is from light with blue color filter, see my first post. However it is hard to duplicate it without the construction diagram. I can only guess from the word they wrote on their web site.

[tcy81]

i feel its just using a blue background, then firing a flash near that point to create the bright spot.
maybe i am wrong

[CK Yeo]

From what I understand from the instructions:
i.e.
Place a WHITE acrylic board behind the tank. Tilt it such that the top edge is against the top edge of the tank and the bottom against the wall.
Light the bottom part of the acrylic with BLUE flash and light the top with normal white flash. Playing with the combination of both will get you the gradient.

You can buy "filter gels" and Omni bounce of different colours to cap over the flash unit to change the colour of the flash. I have not tried to find them before, but have a look at the usual mail order places for them.

You can try placing mirrors to fire a out-of-place flash.

ck

[trident]

I saw some colored diffuser at Orient. Not sure of the price.
The normal white diffuser cost $16.00.

[Shadow]

From what I understand from the instructions:
i.e.
Place a WHITE acrylic board behind the tank. Tilt it such that the top edge is against the top edge of the tank and the bottom against the wall.
Light the bottom part of the acrylic with BLUE flash and light the top with normal white flash. Playing with the combination of both will get you the gradient.

You can buy "filter gels" and Omni bounce of different colours to cap over the flash unit to change the colour of the flash. I have not tried to find them before, but have a look at the usual mail order places for them.

You can try placing mirrors to fire a out-of-place flash.

ck

Light the bottom part of the acrylic with BLUE flash and light the top with normal white flash? I miss this one out, but not possible to do with ST-E2, no line of sight. Putting mirror might cause unecessary reflection. Now I see the point of using cable.

[CK Yeo]

Can la. Your mirror no need to put in front of the tank. Can put above the tank, side etc such that the light from the flash won't bounce onto you, glass etc... I mean, the point of the mirror is so that ST-E2 don't have to be in the line of sight to your flash in the first place right? Try and see.

ck

Light the bottom part of the acrylic with BLUE flash and light the top with normal white flash? I miss this one out, but not possible to do with ST-E2, no line of sight. Putting mirror might cause unecessary reflection. Now I see the point of using cable.

[Shadow]

need to get mirror first

[Shadow]

Just bought the blue color flash diffuser, try it out on white wall and it does not seem to make the wall color turn blue. Do I need to set anything on the camera?

[ranmasatome]

Shadow... very simple.. dont think you even need a blue diffuser... just get those kind of blue celophane paper and wrap it around your flash.. place both flashes facing downwards.. blue flash shoot lower portion of white acrylic.. white normal flash shoot upper portion..

[CK Yeo]

erm... did you set the WB to auto? Change it to a fix value e.g. "outdoor"

ck

[Shadow]

yeah I set it to auto, will try to set it to fix setting.

Just wondering if I can make similar effect using blue light bulb

[Shadow]

After couple of days of trying and late night sleep, experimenting with the blue gradient idea, finaly manage to get it right. It is not as smooth or good as the one on CAU photo but will do for now

It is 2ft tank, not using flash only PL light, lots of them, total 55W+55W+72W basically cover the whole tank surface.

Few thing that I thing need some tweaking, I want to remove the shadow under the driftwood. Any suggestion leave it like that or fill flash?